You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@cayenne.apache.org by Anthony Brew <an...@swrve.com> on 2011/09/01 19:04:28 UTC
Data base externally modified
Hi,
I have a two processes one which writes to a several database tables (a
ruby on rails application) and a java application that reads the state these
data base tables using Cayenne and writes to other tables.
When the ruby modifies the underlying data-base I am seeing that Cayenne is
not automatically picking up that the underlying data is now inconsistant
and not reloading. Is there some way I can config Cayenne to aggressive
check some tables for updates while ignoring others?
Thanks a Million
Anthony Brew
Re: Data base externally modified
Posted by Anthony Brew <an...@swrve.com>.
Hi Andrus,
That has worked nicely, thanks a mill for all your help
On Fri, Sep 2, 2011 at 7:02 PM, Andrus Adamchik <an...@objectstyle.org>wrote:
> Another way to refresh an object, including the content of its
> relationships (but not the contents of the related objects) is this:
>
> context.invalidateObjects(Collections.singleton(myObject));
>
> This may be more in line of what you are trying to do.
>
> Andrus
>
> On Sep 2, 2011, at 1:59 PM, Andrus Adamchik wrote:
>
> > In general a Cayenne user may be dealing with an object graph that can
> potentially start at 1 entity and then span the entire DB (prefetches can be
> multi-step). So Cayenne can't guess for you which relationships need to be
> refreshed, without potentially incurring a gigantic query.
> >
> > So it is still your responsibility as a user to tell it how much or how
> little to prefetch. And you can do something dynamic. E.g. if you decide
> that all the relationships you care about are only 1 level deep, you can
> find an ObjEntity and iterate through all relationships to add prefetches:
> >
> > SelectQuery q =
> > ObjEntity entity =
> context.getEntityResolver().lookupObjEntity(MyClass.class);
> > for(Relationship r : entity.getRelationships) {
> > q.addPrefetch(r.getName());
> > }
> >
> > Andrus
> >
> >
> > On Sep 2, 2011, at 1:51 PM, Anthony Brew wrote:
> >
> >> Hi Andrus,
> >> Yeah thats the most viable solution I have found so far,
> but
> >> tbh but from a code point of view here I think its a risky option as it
> >> could introduce bugs, it not all changing properties are added to the
> >> prefetch.
> >>
> >> query.addPrefetch(Item.SUB_ITEMS_PROPERTY);
> >>
> >> Would be nice to have a way when the NO_CACHE item is specified to make
> sure
> >> linked objects are pulled fresh also.
> >>
> >> Thanks a million for all your help.
> >> Anthony
> >>
> >> On Fri, Sep 2, 2011 at 6:04 PM, Andrus Adamchik <andrus@objectstyle.org
> >wrote:
> >>
> >>> To refresh a relationship, you may use a prefetch on the query:
> >>>
> >>>
> >>>
> >>>
> >>> Andrus
> >>>
> >>>
> >>> On Sep 2, 2011, at 12:51 PM, Joseph Senecal wrote:
> >>>
> >>>> I think the generated code for the getter() should always return the
> >>> existing list because that is the whole point of an ORM, to manage an
> object
> >>> graph in memory.
> >>>>
> >>>> But it should be easy to override that getter() method in the
> generated
> >>> subclass to always do an uncached query.
> >>>>
> >>>> Joe
> >>>>
> >>>> On Sep 2, 2011, at 9:45 AM, Mike Kienenberger wrote:
> >>>>
> >>>>> There may be a better way, but one obvious way this could be done is
> to
> >>>>> change the code generation so that the getter() executes a select
> query
> >>>>> rather than returning an existing list.
> >>>>>
> >>>>> On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <
> anthony.brew@swrve.com
> >>>> wrote:
> >>>>>
> >>>>>> Hi,
> >>>>>> Just an update, and I think I forgot to include something important
> >>>>>> Its a one to many relationship that I am seeing cached, (ie I fetch
> >>> "Item"
> >>>>>> and the many to one "Item.getSubItems()" are being fetched from the
> >>> cache)
> >>>>>>
> >>>>>> My code now looks a bit like:
> >>>>>>
> >>>>>> Expression e1 = Expression.fromString("id = $id");
> >>>>>> Map params = new HashMap();
> >>>>>> params.put("id", item.getId());
> >>>>>>
> >>>>>> SelectQuery query = new SelectQuery(Item.class,
> >>>>>> e1.expWithParameters(params));
> >>>>>> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
> >>>>>>
> >>>>>> List items = context.performQuery(query);
> >>>>>> if(items.size() != 1){
> >>>>>> throw new RuntimeException("");
> >>>>>> }
> >>>>>> freshitem = (Item) items.get(0);
> >>>>>>
> >>>>>> subitems = freshitem.getSubItems()
> >>>>>>
> >>>>>> Where subitems are stale.
> >>>>>>
> >>>>>> I am sure I am making this more complicated than needs be. As I
> >>> mentioned
> >>>>>> before I would like to turn on some flag to essentially always read
> >>> from DB
> >>>>>> when I do items.getSubItems() if possible, or when I reload the Item
> >>> when
> >>>>>> its getter methods are called to make it always read from the DB the
> >>> first
> >>>>>> time when QueryCacheStrategy.NO_CACHE is specified...
> >>>>>>
> >>>>>> Thanks a Million,
> >>>>>> Anthony
> >>>>>>
> >>>>>>
> >>>>>> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <
> mkienenb@gmail.com
> >>>>>>> wrote:
> >>>>>>
> >>>>>>> You may want to review these two threads from the end of July:
> >>>>>>>
> >>>>>>> OSCache is gone
> >>>>>>> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
> >>>>>>>
> >>>>>>> EhCache integration preview
> >>>>>>> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
> >>>>>>>
> >>>>>>>
> >>>>>>> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <
> anthony.brew@swrve.com
> >>>>>>>> wrote:
> >>>>>>>
> >>>>>>>> Hi Andrus,
> >>>>>>>> I was just about to get back to you on, I accidentally
> >>>>>>>> started two threads when I joined the mailing list.
> >>>>>>>>
> >>>>>>>> Essentially we have a ruby on rails project that creates config on
> >>> the
> >>>>>>>> front
> >>>>>>>> end, this is the part that is changing externally. Then internally
> we
> >>>>>>> read
> >>>>>>>> these config and do a bunch of processing and write the results to
> a
> >>>>>>>> separate set of tables. The tables are in turn read by the R on R
> app
> >>>>>> but
> >>>>>>>> never written to
> >>>>>>>>
> >>>>>>>> so
> >>>>>>>> Tables Set A | Set B
> >>>>>>>>
> >>>>>>
> >>>
> ------------------------------------------------------------------------
> >>>>>>>> Rails read and write | read only
> >>>>>>>> Java read only | read and write
> >>>>>>>>
> >>>>>>>> The issues I am facing are with set A changing in the app.
> >>>>>>>>
> >>>>>>>> I have tried forcing the Item to reload by doing this, (I cut code
> >>> from
> >>>>>>>> Cayennes: DataObjectUtils.objectForPK(threadDataContext,
> >>>>>> Item.class,
> >>>>>>>> dirtyItem.getId());)
> >>>>>>>>
> >>>>>>>> private Item getItemWithNoCayenneCache(Item newGame, DataContext
> >>>>>>>> threadDataContext) {
> >>>>>>>> ObjectId gameIdentifier = buildId(threadDataContext,
> Game.class,
> >>>>>>>> newGame.getId());
> >>>>>>>>
> >>>>>>>> return (Item) DataObjectUtils.objectForQuery(threadDataContext,
> >>>>>>> new
> >>>>>>>> ObjectIdQuery(
> >>>>>>>> gameIdentifier,
> >>>>>>>> false,
> >>>>>>>> ObjectIdQuery.CACHE_REFRESH));
> >>>>>>>> }
> >>>>>>>> }
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> stepping into *DataObjectUtils.objectForQuery stepping into the
> >>> Cayenne
> >>>>>>>> code
> >>>>>>>> I eventually get to DataContext.java*
> >>>>>>>> *
> >>>>>>>> *
> >>>>>>>> where I see the following method called
> >>>>>>>>
> >>>>>>>> *
> >>>>>>>> @Override
> >>>>>>>> @SuppressWarnings("unchecked")
> >>>>>>>> public List performQuery(Query query) {
> >>>>>>>> query = nonNullDelegate().willPerformQuery(this, query);
> >>>>>>>> if (query == null) {
> >>>>>>>> return new ArrayList<Object>(1);
> >>>>>>>> }
> >>>>>>>>
> >>>>>>>> List result = onQuery(this, query).firstList();
> >>>>>>>> return result != null ? result : new ArrayList<Object>(1);
> >>>>>>>> }
> >>>>>>>> *
> >>>>>>>>
> >>>>>>>> however i see that the delgate in *
> >>>>>>>> nonNullDelegate() is null and so I get back
> NoopDelegate.noopDelegate
> >>>>>>> which
> >>>>>>>> I assume is the route of my woes.
> >>>>>>>> *
> >>>>>>>> *
> >>>>>>>>
> >>>>>>>> *
> >>>>>>>> Im interested in trying the OSCache solution you proposed in my
> other
> >>>>>>>> thread, but I am a little wary the code is stale as my maven
> >>>>>> dependancies
> >>>>>>>> fail (I am actually pretty new to maven so this might be my bad).
> >>>>>>>> OSCache appears to be quite old since the OpenSymphony project
> died,
> >>>>>>> maybe
> >>>>>>>> my maven config is off, are there still active contributors?
> >>>>>>>>
> >>>>>>>> In my pom I have specified
> >>>>>>>> <dependency>
> >>>>>>>> <groupId>opensymphony</groupId>
> >>>>>>>> <artifactId>oscache</artifactId>
> >>>>>>>> <version>2.4</version>
> >>>>>>>> </dependency>
> >>>>>>>>
> >>>>>>>> however the dependancies on
> >>>>>>>>
> >>>>>>>> - javax.jms:jms:1.1
> >>>>>>>>
> >>>>>>>> Thanks a Million
> >>>>>>>> Anthony
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
> >>>>>> andrus@objectstyle.org
> >>>>>>>>> wrote:
> >>>>>>>>
> >>>>>>>>> Could you please explain your data access patterns?
> >>>>>>>>>
> >>>>>>>>> E.g. if you fetch some objects and store them in an instance
> >>> variable
> >>>>>>> in
> >>>>>>>>> your application, they are not going to get refreshed
> automatically.
> >>>>>> To
> >>>>>>>>> refresh objects you need to either invalidate them explicitly via
> >>>>>>>>> context.invalidateObjects() or run a query. All the cache
> settings
> >>>>>> are
> >>>>>>>>> essentially about optimizing query execution (refresh data, but
> only
> >>>>>> as
> >>>>>>>>> often as needed).
> >>>>>>>>>
> >>>>>>>>> Andrus
> >>>>>>>>>
> >>>>>>>>> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
> >>>>>>>>>
> >>>>>>>>>> Hi Gary,
> >>>>>>>>>> Yeah thats what I am seeing in the code, but I cant for
> >>>>>>> the
> >>>>>>>>> life
> >>>>>>>>>> of me see how to turn off the caching completely in the
> modeller, I
> >>>>>>>>> actually
> >>>>>>>>>> think it wont hit our performance very badly to have no caching.
> >>>>>>>>>>
> >>>>>>>>>> The cache setting I see are the in the DataDomain Configuration
> >>>>>>>>>>
> >>>>>>>>>> Which has an option for a Query Cache Factory with a choice of
> two
> >>>>>>>>> classes.
> >>>>>>>>>> - org.apache.cayenne.cache.MapQueryCacheFactory
> >>>>>>>>>> - org.apache.cayenne.cache.OSQueryCacheFactory
> >>>>>>>>>>
> >>>>>>>>>> I selected the MapQueryCache and trie to set the size of the
> object
> >>>>>>>> cache
> >>>>>>>>> to
> >>>>>>>>>> 1 (couldn't set this to zero) as the application barfed saying
> >>>>>> caches
> >>>>>>>> had
> >>>>>>>>> to
> >>>>>>>>>> be greater than size zero.
> >>>>>>>>>>
> >>>>>>>>>> in my cayenne.xml I see the line
> >>>>>>>>>>
> >>>>>>>>>> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
> >>>>>>>>>>
> >>>>>>>>>> was added, perhaps there is some manual setting I can add to
> this
> >>>>>>> file
> >>>>>>>> to
> >>>>>>>>>> turn caching off?
> >>>>>>>>>>
> >>>>>>>>>> All the Best,
> >>>>>>>>>> Anthony
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <
> garyjarrel@gmail.com
> >>>>>>>
> >>>>>>>>> wrote:
> >>>>>>>>>>
> >>>>>>>>>>> I'd say that would be cache related, as Cayenne is caching the
> >>>>>> data
> >>>>>>>>>>> from the database, switch the cache of in the Modeler perhaps
> and
> >>>>>>> that
> >>>>>>>>>>> should fix your problem.
> >>>>>>>>>>>
> >>>>>>>>>>> G
> >>>>>>>>>>>
> >>>>>>>>>>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
> >>>>>>> anthony.brew@swrve.com>
> >>>>>>>>>>> wrote:
> >>>>>>>>>>>> Hi,
> >>>>>>>>>>>> I have a two processes one which writes to a several database
> >>>>>>>> tables
> >>>>>>>>>>> (a
> >>>>>>>>>>>> ruby on rails application) and a java application that reads
> the
> >>>>>>>> state
> >>>>>>>>>>> these
> >>>>>>>>>>>> data base tables using Cayenne and writes to other tables.
> >>>>>>>>>>>>
> >>>>>>>>>>>> When the ruby modifies the underlying data-base I am seeing
> that
> >>>>>>>>> Cayenne
> >>>>>>>>>>> is
> >>>>>>>>>>>> not automatically picking up that the underlying data is now
> >>>>>>>>> inconsistant
> >>>>>>>>>>>> and not reloading. Is there some way I can config Cayenne to
> >>>>>>>> aggressive
> >>>>>>>>>>>> check some tables for updates while ignoring others?
> >>>>>>>>>>>>
> >>>>>>>>>>>> Thanks a Million
> >>>>>>>>>>>> Anthony Brew
> >>>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>
> >>>>>>>
> >>>>>>
> >>>>
> >>>>
> >>>
> >>>
> >
> >
>
>
Re: Data base externally modified
Posted by Andrus Adamchik <an...@objectstyle.org>.
Another way to refresh an object, including the content of its relationships (but not the contents of the related objects) is this:
context.invalidateObjects(Collections.singleton(myObject));
This may be more in line of what you are trying to do.
Andrus
On Sep 2, 2011, at 1:59 PM, Andrus Adamchik wrote:
> In general a Cayenne user may be dealing with an object graph that can potentially start at 1 entity and then span the entire DB (prefetches can be multi-step). So Cayenne can't guess for you which relationships need to be refreshed, without potentially incurring a gigantic query.
>
> So it is still your responsibility as a user to tell it how much or how little to prefetch. And you can do something dynamic. E.g. if you decide that all the relationships you care about are only 1 level deep, you can find an ObjEntity and iterate through all relationships to add prefetches:
>
> SelectQuery q =
> ObjEntity entity = context.getEntityResolver().lookupObjEntity(MyClass.class);
> for(Relationship r : entity.getRelationships) {
> q.addPrefetch(r.getName());
> }
>
> Andrus
>
>
> On Sep 2, 2011, at 1:51 PM, Anthony Brew wrote:
>
>> Hi Andrus,
>> Yeah thats the most viable solution I have found so far, but
>> tbh but from a code point of view here I think its a risky option as it
>> could introduce bugs, it not all changing properties are added to the
>> prefetch.
>>
>> query.addPrefetch(Item.SUB_ITEMS_PROPERTY);
>>
>> Would be nice to have a way when the NO_CACHE item is specified to make sure
>> linked objects are pulled fresh also.
>>
>> Thanks a million for all your help.
>> Anthony
>>
>> On Fri, Sep 2, 2011 at 6:04 PM, Andrus Adamchik <an...@objectstyle.org>wrote:
>>
>>> To refresh a relationship, you may use a prefetch on the query:
>>>
>>>
>>>
>>>
>>> Andrus
>>>
>>>
>>> On Sep 2, 2011, at 12:51 PM, Joseph Senecal wrote:
>>>
>>>> I think the generated code for the getter() should always return the
>>> existing list because that is the whole point of an ORM, to manage an object
>>> graph in memory.
>>>>
>>>> But it should be easy to override that getter() method in the generated
>>> subclass to always do an uncached query.
>>>>
>>>> Joe
>>>>
>>>> On Sep 2, 2011, at 9:45 AM, Mike Kienenberger wrote:
>>>>
>>>>> There may be a better way, but one obvious way this could be done is to
>>>>> change the code generation so that the getter() executes a select query
>>>>> rather than returning an existing list.
>>>>>
>>>>> On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <anthony.brew@swrve.com
>>>> wrote:
>>>>>
>>>>>> Hi,
>>>>>> Just an update, and I think I forgot to include something important
>>>>>> Its a one to many relationship that I am seeing cached, (ie I fetch
>>> "Item"
>>>>>> and the many to one "Item.getSubItems()" are being fetched from the
>>> cache)
>>>>>>
>>>>>> My code now looks a bit like:
>>>>>>
>>>>>> Expression e1 = Expression.fromString("id = $id");
>>>>>> Map params = new HashMap();
>>>>>> params.put("id", item.getId());
>>>>>>
>>>>>> SelectQuery query = new SelectQuery(Item.class,
>>>>>> e1.expWithParameters(params));
>>>>>> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
>>>>>>
>>>>>> List items = context.performQuery(query);
>>>>>> if(items.size() != 1){
>>>>>> throw new RuntimeException("");
>>>>>> }
>>>>>> freshitem = (Item) items.get(0);
>>>>>>
>>>>>> subitems = freshitem.getSubItems()
>>>>>>
>>>>>> Where subitems are stale.
>>>>>>
>>>>>> I am sure I am making this more complicated than needs be. As I
>>> mentioned
>>>>>> before I would like to turn on some flag to essentially always read
>>> from DB
>>>>>> when I do items.getSubItems() if possible, or when I reload the Item
>>> when
>>>>>> its getter methods are called to make it always read from the DB the
>>> first
>>>>>> time when QueryCacheStrategy.NO_CACHE is specified...
>>>>>>
>>>>>> Thanks a Million,
>>>>>> Anthony
>>>>>>
>>>>>>
>>>>>> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mkienenb@gmail.com
>>>>>>> wrote:
>>>>>>
>>>>>>> You may want to review these two threads from the end of July:
>>>>>>>
>>>>>>> OSCache is gone
>>>>>>> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
>>>>>>>
>>>>>>> EhCache integration preview
>>>>>>> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.brew@swrve.com
>>>>>>>> wrote:
>>>>>>>
>>>>>>>> Hi Andrus,
>>>>>>>> I was just about to get back to you on, I accidentally
>>>>>>>> started two threads when I joined the mailing list.
>>>>>>>>
>>>>>>>> Essentially we have a ruby on rails project that creates config on
>>> the
>>>>>>>> front
>>>>>>>> end, this is the part that is changing externally. Then internally we
>>>>>>> read
>>>>>>>> these config and do a bunch of processing and write the results to a
>>>>>>>> separate set of tables. The tables are in turn read by the R on R app
>>>>>> but
>>>>>>>> never written to
>>>>>>>>
>>>>>>>> so
>>>>>>>> Tables Set A | Set B
>>>>>>>>
>>>>>>
>>> ------------------------------------------------------------------------
>>>>>>>> Rails read and write | read only
>>>>>>>> Java read only | read and write
>>>>>>>>
>>>>>>>> The issues I am facing are with set A changing in the app.
>>>>>>>>
>>>>>>>> I have tried forcing the Item to reload by doing this, (I cut code
>>> from
>>>>>>>> Cayennes: DataObjectUtils.objectForPK(threadDataContext,
>>>>>> Item.class,
>>>>>>>> dirtyItem.getId());)
>>>>>>>>
>>>>>>>> private Item getItemWithNoCayenneCache(Item newGame, DataContext
>>>>>>>> threadDataContext) {
>>>>>>>> ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
>>>>>>>> newGame.getId());
>>>>>>>>
>>>>>>>> return (Item) DataObjectUtils.objectForQuery(threadDataContext,
>>>>>>> new
>>>>>>>> ObjectIdQuery(
>>>>>>>> gameIdentifier,
>>>>>>>> false,
>>>>>>>> ObjectIdQuery.CACHE_REFRESH));
>>>>>>>> }
>>>>>>>> }
>>>>>>>>
>>>>>>>>
>>>>>>>> stepping into *DataObjectUtils.objectForQuery stepping into the
>>> Cayenne
>>>>>>>> code
>>>>>>>> I eventually get to DataContext.java*
>>>>>>>> *
>>>>>>>> *
>>>>>>>> where I see the following method called
>>>>>>>>
>>>>>>>> *
>>>>>>>> @Override
>>>>>>>> @SuppressWarnings("unchecked")
>>>>>>>> public List performQuery(Query query) {
>>>>>>>> query = nonNullDelegate().willPerformQuery(this, query);
>>>>>>>> if (query == null) {
>>>>>>>> return new ArrayList<Object>(1);
>>>>>>>> }
>>>>>>>>
>>>>>>>> List result = onQuery(this, query).firstList();
>>>>>>>> return result != null ? result : new ArrayList<Object>(1);
>>>>>>>> }
>>>>>>>> *
>>>>>>>>
>>>>>>>> however i see that the delgate in *
>>>>>>>> nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
>>>>>>> which
>>>>>>>> I assume is the route of my woes.
>>>>>>>> *
>>>>>>>> *
>>>>>>>>
>>>>>>>> *
>>>>>>>> Im interested in trying the OSCache solution you proposed in my other
>>>>>>>> thread, but I am a little wary the code is stale as my maven
>>>>>> dependancies
>>>>>>>> fail (I am actually pretty new to maven so this might be my bad).
>>>>>>>> OSCache appears to be quite old since the OpenSymphony project died,
>>>>>>> maybe
>>>>>>>> my maven config is off, are there still active contributors?
>>>>>>>>
>>>>>>>> In my pom I have specified
>>>>>>>> <dependency>
>>>>>>>> <groupId>opensymphony</groupId>
>>>>>>>> <artifactId>oscache</artifactId>
>>>>>>>> <version>2.4</version>
>>>>>>>> </dependency>
>>>>>>>>
>>>>>>>> however the dependancies on
>>>>>>>>
>>>>>>>> - javax.jms:jms:1.1
>>>>>>>>
>>>>>>>> Thanks a Million
>>>>>>>> Anthony
>>>>>>>>
>>>>>>>>
>>>>>>>> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
>>>>>> andrus@objectstyle.org
>>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> Could you please explain your data access patterns?
>>>>>>>>>
>>>>>>>>> E.g. if you fetch some objects and store them in an instance
>>> variable
>>>>>>> in
>>>>>>>>> your application, they are not going to get refreshed automatically.
>>>>>> To
>>>>>>>>> refresh objects you need to either invalidate them explicitly via
>>>>>>>>> context.invalidateObjects() or run a query. All the cache settings
>>>>>> are
>>>>>>>>> essentially about optimizing query execution (refresh data, but only
>>>>>> as
>>>>>>>>> often as needed).
>>>>>>>>>
>>>>>>>>> Andrus
>>>>>>>>>
>>>>>>>>> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
>>>>>>>>>
>>>>>>>>>> Hi Gary,
>>>>>>>>>> Yeah thats what I am seeing in the code, but I cant for
>>>>>>> the
>>>>>>>>> life
>>>>>>>>>> of me see how to turn off the caching completely in the modeller, I
>>>>>>>>> actually
>>>>>>>>>> think it wont hit our performance very badly to have no caching.
>>>>>>>>>>
>>>>>>>>>> The cache setting I see are the in the DataDomain Configuration
>>>>>>>>>>
>>>>>>>>>> Which has an option for a Query Cache Factory with a choice of two
>>>>>>>>> classes.
>>>>>>>>>> - org.apache.cayenne.cache.MapQueryCacheFactory
>>>>>>>>>> - org.apache.cayenne.cache.OSQueryCacheFactory
>>>>>>>>>>
>>>>>>>>>> I selected the MapQueryCache and trie to set the size of the object
>>>>>>>> cache
>>>>>>>>> to
>>>>>>>>>> 1 (couldn't set this to zero) as the application barfed saying
>>>>>> caches
>>>>>>>> had
>>>>>>>>> to
>>>>>>>>>> be greater than size zero.
>>>>>>>>>>
>>>>>>>>>> in my cayenne.xml I see the line
>>>>>>>>>>
>>>>>>>>>> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
>>>>>>>>>>
>>>>>>>>>> was added, perhaps there is some manual setting I can add to this
>>>>>>> file
>>>>>>>> to
>>>>>>>>>> turn caching off?
>>>>>>>>>>
>>>>>>>>>> All the Best,
>>>>>>>>>> Anthony
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <garyjarrel@gmail.com
>>>>>>>
>>>>>>>>> wrote:
>>>>>>>>>>
>>>>>>>>>>> I'd say that would be cache related, as Cayenne is caching the
>>>>>> data
>>>>>>>>>>> from the database, switch the cache of in the Modeler perhaps and
>>>>>>> that
>>>>>>>>>>> should fix your problem.
>>>>>>>>>>>
>>>>>>>>>>> G
>>>>>>>>>>>
>>>>>>>>>>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
>>>>>>> anthony.brew@swrve.com>
>>>>>>>>>>> wrote:
>>>>>>>>>>>> Hi,
>>>>>>>>>>>> I have a two processes one which writes to a several database
>>>>>>>> tables
>>>>>>>>>>> (a
>>>>>>>>>>>> ruby on rails application) and a java application that reads the
>>>>>>>> state
>>>>>>>>>>> these
>>>>>>>>>>>> data base tables using Cayenne and writes to other tables.
>>>>>>>>>>>>
>>>>>>>>>>>> When the ruby modifies the underlying data-base I am seeing that
>>>>>>>>> Cayenne
>>>>>>>>>>> is
>>>>>>>>>>>> not automatically picking up that the underlying data is now
>>>>>>>>> inconsistant
>>>>>>>>>>>> and not reloading. Is there some way I can config Cayenne to
>>>>>>>> aggressive
>>>>>>>>>>>> check some tables for updates while ignoring others?
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks a Million
>>>>>>>>>>>> Anthony Brew
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>
>>>>
>>>
>>>
>
>
Re: Data base externally modified
Posted by Andrus Adamchik <an...@objectstyle.org>.
In general a Cayenne user may be dealing with an object graph that can potentially start at 1 entity and then span the entire DB (prefetches can be multi-step). So Cayenne can't guess for you which relationships need to be refreshed, without potentially incurring a gigantic query.
So it is still your responsibility as a user to tell it how much or how little to prefetch. And you can do something dynamic. E.g. if you decide that all the relationships you care about are only 1 level deep, you can find an ObjEntity and iterate through all relationships to add prefetches:
SelectQuery q =
ObjEntity entity = context.getEntityResolver().lookupObjEntity(MyClass.class);
for(Relationship r : entity.getRelationships) {
q.addPrefetch(r.getName());
}
Andrus
On Sep 2, 2011, at 1:51 PM, Anthony Brew wrote:
> Hi Andrus,
> Yeah thats the most viable solution I have found so far, but
> tbh but from a code point of view here I think its a risky option as it
> could introduce bugs, it not all changing properties are added to the
> prefetch.
>
> query.addPrefetch(Item.SUB_ITEMS_PROPERTY);
>
> Would be nice to have a way when the NO_CACHE item is specified to make sure
> linked objects are pulled fresh also.
>
> Thanks a million for all your help.
> Anthony
>
> On Fri, Sep 2, 2011 at 6:04 PM, Andrus Adamchik <an...@objectstyle.org>wrote:
>
>> To refresh a relationship, you may use a prefetch on the query:
>>
>>
>>
>>
>> Andrus
>>
>>
>> On Sep 2, 2011, at 12:51 PM, Joseph Senecal wrote:
>>
>>> I think the generated code for the getter() should always return the
>> existing list because that is the whole point of an ORM, to manage an object
>> graph in memory.
>>>
>>> But it should be easy to override that getter() method in the generated
>> subclass to always do an uncached query.
>>>
>>> Joe
>>>
>>> On Sep 2, 2011, at 9:45 AM, Mike Kienenberger wrote:
>>>
>>>> There may be a better way, but one obvious way this could be done is to
>>>> change the code generation so that the getter() executes a select query
>>>> rather than returning an existing list.
>>>>
>>>> On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <anthony.brew@swrve.com
>>> wrote:
>>>>
>>>>> Hi,
>>>>> Just an update, and I think I forgot to include something important
>>>>> Its a one to many relationship that I am seeing cached, (ie I fetch
>> "Item"
>>>>> and the many to one "Item.getSubItems()" are being fetched from the
>> cache)
>>>>>
>>>>> My code now looks a bit like:
>>>>>
>>>>> Expression e1 = Expression.fromString("id = $id");
>>>>> Map params = new HashMap();
>>>>> params.put("id", item.getId());
>>>>>
>>>>> SelectQuery query = new SelectQuery(Item.class,
>>>>> e1.expWithParameters(params));
>>>>> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
>>>>>
>>>>> List items = context.performQuery(query);
>>>>> if(items.size() != 1){
>>>>> throw new RuntimeException("");
>>>>> }
>>>>> freshitem = (Item) items.get(0);
>>>>>
>>>>> subitems = freshitem.getSubItems()
>>>>>
>>>>> Where subitems are stale.
>>>>>
>>>>> I am sure I am making this more complicated than needs be. As I
>> mentioned
>>>>> before I would like to turn on some flag to essentially always read
>> from DB
>>>>> when I do items.getSubItems() if possible, or when I reload the Item
>> when
>>>>> its getter methods are called to make it always read from the DB the
>> first
>>>>> time when QueryCacheStrategy.NO_CACHE is specified...
>>>>>
>>>>> Thanks a Million,
>>>>> Anthony
>>>>>
>>>>>
>>>>> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mkienenb@gmail.com
>>>>>> wrote:
>>>>>
>>>>>> You may want to review these two threads from the end of July:
>>>>>>
>>>>>> OSCache is gone
>>>>>> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
>>>>>>
>>>>>> EhCache integration preview
>>>>>> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
>>>>>>
>>>>>>
>>>>>> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.brew@swrve.com
>>>>>>> wrote:
>>>>>>
>>>>>>> Hi Andrus,
>>>>>>> I was just about to get back to you on, I accidentally
>>>>>>> started two threads when I joined the mailing list.
>>>>>>>
>>>>>>> Essentially we have a ruby on rails project that creates config on
>> the
>>>>>>> front
>>>>>>> end, this is the part that is changing externally. Then internally we
>>>>>> read
>>>>>>> these config and do a bunch of processing and write the results to a
>>>>>>> separate set of tables. The tables are in turn read by the R on R app
>>>>> but
>>>>>>> never written to
>>>>>>>
>>>>>>> so
>>>>>>> Tables Set A | Set B
>>>>>>>
>>>>>
>> ------------------------------------------------------------------------
>>>>>>> Rails read and write | read only
>>>>>>> Java read only | read and write
>>>>>>>
>>>>>>> The issues I am facing are with set A changing in the app.
>>>>>>>
>>>>>>> I have tried forcing the Item to reload by doing this, (I cut code
>> from
>>>>>>> Cayennes: DataObjectUtils.objectForPK(threadDataContext,
>>>>> Item.class,
>>>>>>> dirtyItem.getId());)
>>>>>>>
>>>>>>> private Item getItemWithNoCayenneCache(Item newGame, DataContext
>>>>>>> threadDataContext) {
>>>>>>> ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
>>>>>>> newGame.getId());
>>>>>>>
>>>>>>> return (Item) DataObjectUtils.objectForQuery(threadDataContext,
>>>>>> new
>>>>>>> ObjectIdQuery(
>>>>>>> gameIdentifier,
>>>>>>> false,
>>>>>>> ObjectIdQuery.CACHE_REFRESH));
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>>
>>>>>>> stepping into *DataObjectUtils.objectForQuery stepping into the
>> Cayenne
>>>>>>> code
>>>>>>> I eventually get to DataContext.java*
>>>>>>> *
>>>>>>> *
>>>>>>> where I see the following method called
>>>>>>>
>>>>>>> *
>>>>>>> @Override
>>>>>>> @SuppressWarnings("unchecked")
>>>>>>> public List performQuery(Query query) {
>>>>>>> query = nonNullDelegate().willPerformQuery(this, query);
>>>>>>> if (query == null) {
>>>>>>> return new ArrayList<Object>(1);
>>>>>>> }
>>>>>>>
>>>>>>> List result = onQuery(this, query).firstList();
>>>>>>> return result != null ? result : new ArrayList<Object>(1);
>>>>>>> }
>>>>>>> *
>>>>>>>
>>>>>>> however i see that the delgate in *
>>>>>>> nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
>>>>>> which
>>>>>>> I assume is the route of my woes.
>>>>>>> *
>>>>>>> *
>>>>>>>
>>>>>>> *
>>>>>>> Im interested in trying the OSCache solution you proposed in my other
>>>>>>> thread, but I am a little wary the code is stale as my maven
>>>>> dependancies
>>>>>>> fail (I am actually pretty new to maven so this might be my bad).
>>>>>>> OSCache appears to be quite old since the OpenSymphony project died,
>>>>>> maybe
>>>>>>> my maven config is off, are there still active contributors?
>>>>>>>
>>>>>>> In my pom I have specified
>>>>>>> <dependency>
>>>>>>> <groupId>opensymphony</groupId>
>>>>>>> <artifactId>oscache</artifactId>
>>>>>>> <version>2.4</version>
>>>>>>> </dependency>
>>>>>>>
>>>>>>> however the dependancies on
>>>>>>>
>>>>>>> - javax.jms:jms:1.1
>>>>>>>
>>>>>>> Thanks a Million
>>>>>>> Anthony
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
>>>>> andrus@objectstyle.org
>>>>>>>> wrote:
>>>>>>>
>>>>>>>> Could you please explain your data access patterns?
>>>>>>>>
>>>>>>>> E.g. if you fetch some objects and store them in an instance
>> variable
>>>>>> in
>>>>>>>> your application, they are not going to get refreshed automatically.
>>>>> To
>>>>>>>> refresh objects you need to either invalidate them explicitly via
>>>>>>>> context.invalidateObjects() or run a query. All the cache settings
>>>>> are
>>>>>>>> essentially about optimizing query execution (refresh data, but only
>>>>> as
>>>>>>>> often as needed).
>>>>>>>>
>>>>>>>> Andrus
>>>>>>>>
>>>>>>>> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
>>>>>>>>
>>>>>>>>> Hi Gary,
>>>>>>>>> Yeah thats what I am seeing in the code, but I cant for
>>>>>> the
>>>>>>>> life
>>>>>>>>> of me see how to turn off the caching completely in the modeller, I
>>>>>>>> actually
>>>>>>>>> think it wont hit our performance very badly to have no caching.
>>>>>>>>>
>>>>>>>>> The cache setting I see are the in the DataDomain Configuration
>>>>>>>>>
>>>>>>>>> Which has an option for a Query Cache Factory with a choice of two
>>>>>>>> classes.
>>>>>>>>> - org.apache.cayenne.cache.MapQueryCacheFactory
>>>>>>>>> - org.apache.cayenne.cache.OSQueryCacheFactory
>>>>>>>>>
>>>>>>>>> I selected the MapQueryCache and trie to set the size of the object
>>>>>>> cache
>>>>>>>> to
>>>>>>>>> 1 (couldn't set this to zero) as the application barfed saying
>>>>> caches
>>>>>>> had
>>>>>>>> to
>>>>>>>>> be greater than size zero.
>>>>>>>>>
>>>>>>>>> in my cayenne.xml I see the line
>>>>>>>>>
>>>>>>>>> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
>>>>>>>>>
>>>>>>>>> was added, perhaps there is some manual setting I can add to this
>>>>>> file
>>>>>>> to
>>>>>>>>> turn caching off?
>>>>>>>>>
>>>>>>>>> All the Best,
>>>>>>>>> Anthony
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <garyjarrel@gmail.com
>>>>>>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>> I'd say that would be cache related, as Cayenne is caching the
>>>>> data
>>>>>>>>>> from the database, switch the cache of in the Modeler perhaps and
>>>>>> that
>>>>>>>>>> should fix your problem.
>>>>>>>>>>
>>>>>>>>>> G
>>>>>>>>>>
>>>>>>>>>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
>>>>>> anthony.brew@swrve.com>
>>>>>>>>>> wrote:
>>>>>>>>>>> Hi,
>>>>>>>>>>> I have a two processes one which writes to a several database
>>>>>>> tables
>>>>>>>>>> (a
>>>>>>>>>>> ruby on rails application) and a java application that reads the
>>>>>>> state
>>>>>>>>>> these
>>>>>>>>>>> data base tables using Cayenne and writes to other tables.
>>>>>>>>>>>
>>>>>>>>>>> When the ruby modifies the underlying data-base I am seeing that
>>>>>>>> Cayenne
>>>>>>>>>> is
>>>>>>>>>>> not automatically picking up that the underlying data is now
>>>>>>>> inconsistant
>>>>>>>>>>> and not reloading. Is there some way I can config Cayenne to
>>>>>>> aggressive
>>>>>>>>>>> check some tables for updates while ignoring others?
>>>>>>>>>>>
>>>>>>>>>>> Thanks a Million
>>>>>>>>>>> Anthony Brew
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>
>>>
>>
>>
Re: Data base externally modified
Posted by Anthony Brew <an...@swrve.com>.
Hi Andrus,
Yeah thats the most viable solution I have found so far, but
tbh but from a code point of view here I think its a risky option as it
could introduce bugs, it not all changing properties are added to the
prefetch.
query.addPrefetch(Item.SUB_ITEMS_PROPERTY);
Would be nice to have a way when the NO_CACHE item is specified to make sure
linked objects are pulled fresh also.
Thanks a million for all your help.
Anthony
On Fri, Sep 2, 2011 at 6:04 PM, Andrus Adamchik <an...@objectstyle.org>wrote:
> To refresh a relationship, you may use a prefetch on the query:
>
>
>
>
> Andrus
>
>
> On Sep 2, 2011, at 12:51 PM, Joseph Senecal wrote:
>
> > I think the generated code for the getter() should always return the
> existing list because that is the whole point of an ORM, to manage an object
> graph in memory.
> >
> > But it should be easy to override that getter() method in the generated
> subclass to always do an uncached query.
> >
> > Joe
> >
> > On Sep 2, 2011, at 9:45 AM, Mike Kienenberger wrote:
> >
> >> There may be a better way, but one obvious way this could be done is to
> >> change the code generation so that the getter() executes a select query
> >> rather than returning an existing list.
> >>
> >> On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <anthony.brew@swrve.com
> >wrote:
> >>
> >>> Hi,
> >>> Just an update, and I think I forgot to include something important
> >>> Its a one to many relationship that I am seeing cached, (ie I fetch
> "Item"
> >>> and the many to one "Item.getSubItems()" are being fetched from the
> cache)
> >>>
> >>> My code now looks a bit like:
> >>>
> >>> Expression e1 = Expression.fromString("id = $id");
> >>> Map params = new HashMap();
> >>> params.put("id", item.getId());
> >>>
> >>> SelectQuery query = new SelectQuery(Item.class,
> >>> e1.expWithParameters(params));
> >>> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
> >>>
> >>> List items = context.performQuery(query);
> >>> if(items.size() != 1){
> >>> throw new RuntimeException("");
> >>> }
> >>> freshitem = (Item) items.get(0);
> >>>
> >>> subitems = freshitem.getSubItems()
> >>>
> >>> Where subitems are stale.
> >>>
> >>> I am sure I am making this more complicated than needs be. As I
> mentioned
> >>> before I would like to turn on some flag to essentially always read
> from DB
> >>> when I do items.getSubItems() if possible, or when I reload the Item
> when
> >>> its getter methods are called to make it always read from the DB the
> first
> >>> time when QueryCacheStrategy.NO_CACHE is specified...
> >>>
> >>> Thanks a Million,
> >>> Anthony
> >>>
> >>>
> >>> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mkienenb@gmail.com
> >>>> wrote:
> >>>
> >>>> You may want to review these two threads from the end of July:
> >>>>
> >>>> OSCache is gone
> >>>> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
> >>>>
> >>>> EhCache integration preview
> >>>> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
> >>>>
> >>>>
> >>>> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.brew@swrve.com
> >>>>> wrote:
> >>>>
> >>>>> Hi Andrus,
> >>>>> I was just about to get back to you on, I accidentally
> >>>>> started two threads when I joined the mailing list.
> >>>>>
> >>>>> Essentially we have a ruby on rails project that creates config on
> the
> >>>>> front
> >>>>> end, this is the part that is changing externally. Then internally we
> >>>> read
> >>>>> these config and do a bunch of processing and write the results to a
> >>>>> separate set of tables. The tables are in turn read by the R on R app
> >>> but
> >>>>> never written to
> >>>>>
> >>>>> so
> >>>>> Tables Set A | Set B
> >>>>>
> >>>
> ------------------------------------------------------------------------
> >>>>> Rails read and write | read only
> >>>>> Java read only | read and write
> >>>>>
> >>>>> The issues I am facing are with set A changing in the app.
> >>>>>
> >>>>> I have tried forcing the Item to reload by doing this, (I cut code
> from
> >>>>> Cayennes: DataObjectUtils.objectForPK(threadDataContext,
> >>> Item.class,
> >>>>> dirtyItem.getId());)
> >>>>>
> >>>>> private Item getItemWithNoCayenneCache(Item newGame, DataContext
> >>>>> threadDataContext) {
> >>>>> ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
> >>>>> newGame.getId());
> >>>>>
> >>>>> return (Item) DataObjectUtils.objectForQuery(threadDataContext,
> >>>> new
> >>>>> ObjectIdQuery(
> >>>>> gameIdentifier,
> >>>>> false,
> >>>>> ObjectIdQuery.CACHE_REFRESH));
> >>>>> }
> >>>>> }
> >>>>>
> >>>>>
> >>>>> stepping into *DataObjectUtils.objectForQuery stepping into the
> Cayenne
> >>>>> code
> >>>>> I eventually get to DataContext.java*
> >>>>> *
> >>>>> *
> >>>>> where I see the following method called
> >>>>>
> >>>>> *
> >>>>> @Override
> >>>>> @SuppressWarnings("unchecked")
> >>>>> public List performQuery(Query query) {
> >>>>> query = nonNullDelegate().willPerformQuery(this, query);
> >>>>> if (query == null) {
> >>>>> return new ArrayList<Object>(1);
> >>>>> }
> >>>>>
> >>>>> List result = onQuery(this, query).firstList();
> >>>>> return result != null ? result : new ArrayList<Object>(1);
> >>>>> }
> >>>>> *
> >>>>>
> >>>>> however i see that the delgate in *
> >>>>> nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
> >>>> which
> >>>>> I assume is the route of my woes.
> >>>>> *
> >>>>> *
> >>>>>
> >>>>> *
> >>>>> Im interested in trying the OSCache solution you proposed in my other
> >>>>> thread, but I am a little wary the code is stale as my maven
> >>> dependancies
> >>>>> fail (I am actually pretty new to maven so this might be my bad).
> >>>>> OSCache appears to be quite old since the OpenSymphony project died,
> >>>> maybe
> >>>>> my maven config is off, are there still active contributors?
> >>>>>
> >>>>> In my pom I have specified
> >>>>> <dependency>
> >>>>> <groupId>opensymphony</groupId>
> >>>>> <artifactId>oscache</artifactId>
> >>>>> <version>2.4</version>
> >>>>> </dependency>
> >>>>>
> >>>>> however the dependancies on
> >>>>>
> >>>>> - javax.jms:jms:1.1
> >>>>>
> >>>>> Thanks a Million
> >>>>> Anthony
> >>>>>
> >>>>>
> >>>>> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
> >>> andrus@objectstyle.org
> >>>>>> wrote:
> >>>>>
> >>>>>> Could you please explain your data access patterns?
> >>>>>>
> >>>>>> E.g. if you fetch some objects and store them in an instance
> variable
> >>>> in
> >>>>>> your application, they are not going to get refreshed automatically.
> >>> To
> >>>>>> refresh objects you need to either invalidate them explicitly via
> >>>>>> context.invalidateObjects() or run a query. All the cache settings
> >>> are
> >>>>>> essentially about optimizing query execution (refresh data, but only
> >>> as
> >>>>>> often as needed).
> >>>>>>
> >>>>>> Andrus
> >>>>>>
> >>>>>> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
> >>>>>>
> >>>>>>> Hi Gary,
> >>>>>>> Yeah thats what I am seeing in the code, but I cant for
> >>>> the
> >>>>>> life
> >>>>>>> of me see how to turn off the caching completely in the modeller, I
> >>>>>> actually
> >>>>>>> think it wont hit our performance very badly to have no caching.
> >>>>>>>
> >>>>>>> The cache setting I see are the in the DataDomain Configuration
> >>>>>>>
> >>>>>>> Which has an option for a Query Cache Factory with a choice of two
> >>>>>> classes.
> >>>>>>> - org.apache.cayenne.cache.MapQueryCacheFactory
> >>>>>>> - org.apache.cayenne.cache.OSQueryCacheFactory
> >>>>>>>
> >>>>>>> I selected the MapQueryCache and trie to set the size of the object
> >>>>> cache
> >>>>>> to
> >>>>>>> 1 (couldn't set this to zero) as the application barfed saying
> >>> caches
> >>>>> had
> >>>>>> to
> >>>>>>> be greater than size zero.
> >>>>>>>
> >>>>>>> in my cayenne.xml I see the line
> >>>>>>>
> >>>>>>> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
> >>>>>>>
> >>>>>>> was added, perhaps there is some manual setting I can add to this
> >>>> file
> >>>>> to
> >>>>>>> turn caching off?
> >>>>>>>
> >>>>>>> All the Best,
> >>>>>>> Anthony
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <garyjarrel@gmail.com
> >>>>
> >>>>>> wrote:
> >>>>>>>
> >>>>>>>> I'd say that would be cache related, as Cayenne is caching the
> >>> data
> >>>>>>>> from the database, switch the cache of in the Modeler perhaps and
> >>>> that
> >>>>>>>> should fix your problem.
> >>>>>>>>
> >>>>>>>> G
> >>>>>>>>
> >>>>>>>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
> >>>> anthony.brew@swrve.com>
> >>>>>>>> wrote:
> >>>>>>>>> Hi,
> >>>>>>>>> I have a two processes one which writes to a several database
> >>>>> tables
> >>>>>>>> (a
> >>>>>>>>> ruby on rails application) and a java application that reads the
> >>>>> state
> >>>>>>>> these
> >>>>>>>>> data base tables using Cayenne and writes to other tables.
> >>>>>>>>>
> >>>>>>>>> When the ruby modifies the underlying data-base I am seeing that
> >>>>>> Cayenne
> >>>>>>>> is
> >>>>>>>>> not automatically picking up that the underlying data is now
> >>>>>> inconsistant
> >>>>>>>>> and not reloading. Is there some way I can config Cayenne to
> >>>>> aggressive
> >>>>>>>>> check some tables for updates while ignoring others?
> >>>>>>>>>
> >>>>>>>>> Thanks a Million
> >>>>>>>>> Anthony Brew
> >>>>>>>>>
> >>>>>>>>
> >>>>>>
> >>>>>>
> >>>>>
> >>>>
> >>>
> >
> >
>
>
Re: Data base externally modified
Posted by Andrus Adamchik <an...@objectstyle.org>.
To refresh a relationship, you may use a prefetch on the query:
query.addPrefetch(Item.SUB_ITEMS_PROPERTY);
Andrus
On Sep 2, 2011, at 12:51 PM, Joseph Senecal wrote:
> I think the generated code for the getter() should always return the existing list because that is the whole point of an ORM, to manage an object graph in memory.
>
> But it should be easy to override that getter() method in the generated subclass to always do an uncached query.
>
> Joe
>
> On Sep 2, 2011, at 9:45 AM, Mike Kienenberger wrote:
>
>> There may be a better way, but one obvious way this could be done is to
>> change the code generation so that the getter() executes a select query
>> rather than returning an existing list.
>>
>> On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <an...@swrve.com>wrote:
>>
>>> Hi,
>>> Just an update, and I think I forgot to include something important
>>> Its a one to many relationship that I am seeing cached, (ie I fetch "Item"
>>> and the many to one "Item.getSubItems()" are being fetched from the cache)
>>>
>>> My code now looks a bit like:
>>>
>>> Expression e1 = Expression.fromString("id = $id");
>>> Map params = new HashMap();
>>> params.put("id", item.getId());
>>>
>>> SelectQuery query = new SelectQuery(Item.class,
>>> e1.expWithParameters(params));
>>> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
>>>
>>> List items = context.performQuery(query);
>>> if(items.size() != 1){
>>> throw new RuntimeException("");
>>> }
>>> freshitem = (Item) items.get(0);
>>>
>>> subitems = freshitem.getSubItems()
>>>
>>> Where subitems are stale.
>>>
>>> I am sure I am making this more complicated than needs be. As I mentioned
>>> before I would like to turn on some flag to essentially always read from DB
>>> when I do items.getSubItems() if possible, or when I reload the Item when
>>> its getter methods are called to make it always read from the DB the first
>>> time when QueryCacheStrategy.NO_CACHE is specified...
>>>
>>> Thanks a Million,
>>> Anthony
>>>
>>>
>>> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mkienenb@gmail.com
>>>> wrote:
>>>
>>>> You may want to review these two threads from the end of July:
>>>>
>>>> OSCache is gone
>>>> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
>>>>
>>>> EhCache integration preview
>>>> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
>>>>
>>>>
>>>> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.brew@swrve.com
>>>>> wrote:
>>>>
>>>>> Hi Andrus,
>>>>> I was just about to get back to you on, I accidentally
>>>>> started two threads when I joined the mailing list.
>>>>>
>>>>> Essentially we have a ruby on rails project that creates config on the
>>>>> front
>>>>> end, this is the part that is changing externally. Then internally we
>>>> read
>>>>> these config and do a bunch of processing and write the results to a
>>>>> separate set of tables. The tables are in turn read by the R on R app
>>> but
>>>>> never written to
>>>>>
>>>>> so
>>>>> Tables Set A | Set B
>>>>>
>>> ------------------------------------------------------------------------
>>>>> Rails read and write | read only
>>>>> Java read only | read and write
>>>>>
>>>>> The issues I am facing are with set A changing in the app.
>>>>>
>>>>> I have tried forcing the Item to reload by doing this, (I cut code from
>>>>> Cayennes: DataObjectUtils.objectForPK(threadDataContext,
>>> Item.class,
>>>>> dirtyItem.getId());)
>>>>>
>>>>> private Item getItemWithNoCayenneCache(Item newGame, DataContext
>>>>> threadDataContext) {
>>>>> ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
>>>>> newGame.getId());
>>>>>
>>>>> return (Item) DataObjectUtils.objectForQuery(threadDataContext,
>>>> new
>>>>> ObjectIdQuery(
>>>>> gameIdentifier,
>>>>> false,
>>>>> ObjectIdQuery.CACHE_REFRESH));
>>>>> }
>>>>> }
>>>>>
>>>>>
>>>>> stepping into *DataObjectUtils.objectForQuery stepping into the Cayenne
>>>>> code
>>>>> I eventually get to DataContext.java*
>>>>> *
>>>>> *
>>>>> where I see the following method called
>>>>>
>>>>> *
>>>>> @Override
>>>>> @SuppressWarnings("unchecked")
>>>>> public List performQuery(Query query) {
>>>>> query = nonNullDelegate().willPerformQuery(this, query);
>>>>> if (query == null) {
>>>>> return new ArrayList<Object>(1);
>>>>> }
>>>>>
>>>>> List result = onQuery(this, query).firstList();
>>>>> return result != null ? result : new ArrayList<Object>(1);
>>>>> }
>>>>> *
>>>>>
>>>>> however i see that the delgate in *
>>>>> nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
>>>> which
>>>>> I assume is the route of my woes.
>>>>> *
>>>>> *
>>>>>
>>>>> *
>>>>> Im interested in trying the OSCache solution you proposed in my other
>>>>> thread, but I am a little wary the code is stale as my maven
>>> dependancies
>>>>> fail (I am actually pretty new to maven so this might be my bad).
>>>>> OSCache appears to be quite old since the OpenSymphony project died,
>>>> maybe
>>>>> my maven config is off, are there still active contributors?
>>>>>
>>>>> In my pom I have specified
>>>>> <dependency>
>>>>> <groupId>opensymphony</groupId>
>>>>> <artifactId>oscache</artifactId>
>>>>> <version>2.4</version>
>>>>> </dependency>
>>>>>
>>>>> however the dependancies on
>>>>>
>>>>> - javax.jms:jms:1.1
>>>>>
>>>>> Thanks a Million
>>>>> Anthony
>>>>>
>>>>>
>>>>> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
>>> andrus@objectstyle.org
>>>>>> wrote:
>>>>>
>>>>>> Could you please explain your data access patterns?
>>>>>>
>>>>>> E.g. if you fetch some objects and store them in an instance variable
>>>> in
>>>>>> your application, they are not going to get refreshed automatically.
>>> To
>>>>>> refresh objects you need to either invalidate them explicitly via
>>>>>> context.invalidateObjects() or run a query. All the cache settings
>>> are
>>>>>> essentially about optimizing query execution (refresh data, but only
>>> as
>>>>>> often as needed).
>>>>>>
>>>>>> Andrus
>>>>>>
>>>>>> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
>>>>>>
>>>>>>> Hi Gary,
>>>>>>> Yeah thats what I am seeing in the code, but I cant for
>>>> the
>>>>>> life
>>>>>>> of me see how to turn off the caching completely in the modeller, I
>>>>>> actually
>>>>>>> think it wont hit our performance very badly to have no caching.
>>>>>>>
>>>>>>> The cache setting I see are the in the DataDomain Configuration
>>>>>>>
>>>>>>> Which has an option for a Query Cache Factory with a choice of two
>>>>>> classes.
>>>>>>> - org.apache.cayenne.cache.MapQueryCacheFactory
>>>>>>> - org.apache.cayenne.cache.OSQueryCacheFactory
>>>>>>>
>>>>>>> I selected the MapQueryCache and trie to set the size of the object
>>>>> cache
>>>>>> to
>>>>>>> 1 (couldn't set this to zero) as the application barfed saying
>>> caches
>>>>> had
>>>>>> to
>>>>>>> be greater than size zero.
>>>>>>>
>>>>>>> in my cayenne.xml I see the line
>>>>>>>
>>>>>>> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
>>>>>>>
>>>>>>> was added, perhaps there is some manual setting I can add to this
>>>> file
>>>>> to
>>>>>>> turn caching off?
>>>>>>>
>>>>>>> All the Best,
>>>>>>> Anthony
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <garyjarrel@gmail.com
>>>>
>>>>>> wrote:
>>>>>>>
>>>>>>>> I'd say that would be cache related, as Cayenne is caching the
>>> data
>>>>>>>> from the database, switch the cache of in the Modeler perhaps and
>>>> that
>>>>>>>> should fix your problem.
>>>>>>>>
>>>>>>>> G
>>>>>>>>
>>>>>>>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
>>>> anthony.brew@swrve.com>
>>>>>>>> wrote:
>>>>>>>>> Hi,
>>>>>>>>> I have a two processes one which writes to a several database
>>>>> tables
>>>>>>>> (a
>>>>>>>>> ruby on rails application) and a java application that reads the
>>>>> state
>>>>>>>> these
>>>>>>>>> data base tables using Cayenne and writes to other tables.
>>>>>>>>>
>>>>>>>>> When the ruby modifies the underlying data-base I am seeing that
>>>>>> Cayenne
>>>>>>>> is
>>>>>>>>> not automatically picking up that the underlying data is now
>>>>>> inconsistant
>>>>>>>>> and not reloading. Is there some way I can config Cayenne to
>>>>> aggressive
>>>>>>>>> check some tables for updates while ignoring others?
>>>>>>>>>
>>>>>>>>> Thanks a Million
>>>>>>>>> Anthony Brew
>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>
>
Re: Data base externally modified
Posted by Joseph Senecal <se...@apple.com>.
I think the generated code for the getter() should always return the existing list because that is the whole point of an ORM, to manage an object graph in memory.
But it should be easy to override that getter() method in the generated subclass to always do an uncached query.
Joe
On Sep 2, 2011, at 9:45 AM, Mike Kienenberger wrote:
> There may be a better way, but one obvious way this could be done is to
> change the code generation so that the getter() executes a select query
> rather than returning an existing list.
>
> On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <an...@swrve.com>wrote:
>
>> Hi,
>> Just an update, and I think I forgot to include something important
>> Its a one to many relationship that I am seeing cached, (ie I fetch "Item"
>> and the many to one "Item.getSubItems()" are being fetched from the cache)
>>
>> My code now looks a bit like:
>>
>> Expression e1 = Expression.fromString("id = $id");
>> Map params = new HashMap();
>> params.put("id", item.getId());
>>
>> SelectQuery query = new SelectQuery(Item.class,
>> e1.expWithParameters(params));
>> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
>>
>> List items = context.performQuery(query);
>> if(items.size() != 1){
>> throw new RuntimeException("");
>> }
>> freshitem = (Item) items.get(0);
>>
>> subitems = freshitem.getSubItems()
>>
>> Where subitems are stale.
>>
>> I am sure I am making this more complicated than needs be. As I mentioned
>> before I would like to turn on some flag to essentially always read from DB
>> when I do items.getSubItems() if possible, or when I reload the Item when
>> its getter methods are called to make it always read from the DB the first
>> time when QueryCacheStrategy.NO_CACHE is specified...
>>
>> Thanks a Million,
>> Anthony
>>
>>
>> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mkienenb@gmail.com
>>> wrote:
>>
>>> You may want to review these two threads from the end of July:
>>>
>>> OSCache is gone
>>> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
>>>
>>> EhCache integration preview
>>> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
>>>
>>>
>>> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.brew@swrve.com
>>>> wrote:
>>>
>>>> Hi Andrus,
>>>> I was just about to get back to you on, I accidentally
>>>> started two threads when I joined the mailing list.
>>>>
>>>> Essentially we have a ruby on rails project that creates config on the
>>>> front
>>>> end, this is the part that is changing externally. Then internally we
>>> read
>>>> these config and do a bunch of processing and write the results to a
>>>> separate set of tables. The tables are in turn read by the R on R app
>> but
>>>> never written to
>>>>
>>>> so
>>>> Tables Set A | Set B
>>>>
>> ------------------------------------------------------------------------
>>>> Rails read and write | read only
>>>> Java read only | read and write
>>>>
>>>> The issues I am facing are with set A changing in the app.
>>>>
>>>> I have tried forcing the Item to reload by doing this, (I cut code from
>>>> Cayennes: DataObjectUtils.objectForPK(threadDataContext,
>> Item.class,
>>>> dirtyItem.getId());)
>>>>
>>>> private Item getItemWithNoCayenneCache(Item newGame, DataContext
>>>> threadDataContext) {
>>>> ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
>>>> newGame.getId());
>>>>
>>>> return (Item) DataObjectUtils.objectForQuery(threadDataContext,
>>> new
>>>> ObjectIdQuery(
>>>> gameIdentifier,
>>>> false,
>>>> ObjectIdQuery.CACHE_REFRESH));
>>>> }
>>>> }
>>>>
>>>>
>>>> stepping into *DataObjectUtils.objectForQuery stepping into the Cayenne
>>>> code
>>>> I eventually get to DataContext.java*
>>>> *
>>>> *
>>>> where I see the following method called
>>>>
>>>> *
>>>> @Override
>>>> @SuppressWarnings("unchecked")
>>>> public List performQuery(Query query) {
>>>> query = nonNullDelegate().willPerformQuery(this, query);
>>>> if (query == null) {
>>>> return new ArrayList<Object>(1);
>>>> }
>>>>
>>>> List result = onQuery(this, query).firstList();
>>>> return result != null ? result : new ArrayList<Object>(1);
>>>> }
>>>> *
>>>>
>>>> however i see that the delgate in *
>>>> nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
>>> which
>>>> I assume is the route of my woes.
>>>> *
>>>> *
>>>>
>>>> *
>>>> Im interested in trying the OSCache solution you proposed in my other
>>>> thread, but I am a little wary the code is stale as my maven
>> dependancies
>>>> fail (I am actually pretty new to maven so this might be my bad).
>>>> OSCache appears to be quite old since the OpenSymphony project died,
>>> maybe
>>>> my maven config is off, are there still active contributors?
>>>>
>>>> In my pom I have specified
>>>> <dependency>
>>>> <groupId>opensymphony</groupId>
>>>> <artifactId>oscache</artifactId>
>>>> <version>2.4</version>
>>>> </dependency>
>>>>
>>>> however the dependancies on
>>>>
>>>> - javax.jms:jms:1.1
>>>>
>>>> Thanks a Million
>>>> Anthony
>>>>
>>>>
>>>> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
>> andrus@objectstyle.org
>>>>> wrote:
>>>>
>>>>> Could you please explain your data access patterns?
>>>>>
>>>>> E.g. if you fetch some objects and store them in an instance variable
>>> in
>>>>> your application, they are not going to get refreshed automatically.
>> To
>>>>> refresh objects you need to either invalidate them explicitly via
>>>>> context.invalidateObjects() or run a query. All the cache settings
>> are
>>>>> essentially about optimizing query execution (refresh data, but only
>> as
>>>>> often as needed).
>>>>>
>>>>> Andrus
>>>>>
>>>>> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
>>>>>
>>>>>> Hi Gary,
>>>>>> Yeah thats what I am seeing in the code, but I cant for
>>> the
>>>>> life
>>>>>> of me see how to turn off the caching completely in the modeller, I
>>>>> actually
>>>>>> think it wont hit our performance very badly to have no caching.
>>>>>>
>>>>>> The cache setting I see are the in the DataDomain Configuration
>>>>>>
>>>>>> Which has an option for a Query Cache Factory with a choice of two
>>>>> classes.
>>>>>> - org.apache.cayenne.cache.MapQueryCacheFactory
>>>>>> - org.apache.cayenne.cache.OSQueryCacheFactory
>>>>>>
>>>>>> I selected the MapQueryCache and trie to set the size of the object
>>>> cache
>>>>> to
>>>>>> 1 (couldn't set this to zero) as the application barfed saying
>> caches
>>>> had
>>>>> to
>>>>>> be greater than size zero.
>>>>>>
>>>>>> in my cayenne.xml I see the line
>>>>>>
>>>>>> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
>>>>>>
>>>>>> was added, perhaps there is some manual setting I can add to this
>>> file
>>>> to
>>>>>> turn caching off?
>>>>>>
>>>>>> All the Best,
>>>>>> Anthony
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <garyjarrel@gmail.com
>>>
>>>>> wrote:
>>>>>>
>>>>>>> I'd say that would be cache related, as Cayenne is caching the
>> data
>>>>>>> from the database, switch the cache of in the Modeler perhaps and
>>> that
>>>>>>> should fix your problem.
>>>>>>>
>>>>>>> G
>>>>>>>
>>>>>>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
>>> anthony.brew@swrve.com>
>>>>>>> wrote:
>>>>>>>> Hi,
>>>>>>>> I have a two processes one which writes to a several database
>>>> tables
>>>>>>> (a
>>>>>>>> ruby on rails application) and a java application that reads the
>>>> state
>>>>>>> these
>>>>>>>> data base tables using Cayenne and writes to other tables.
>>>>>>>>
>>>>>>>> When the ruby modifies the underlying data-base I am seeing that
>>>>> Cayenne
>>>>>>> is
>>>>>>>> not automatically picking up that the underlying data is now
>>>>> inconsistant
>>>>>>>> and not reloading. Is there some way I can config Cayenne to
>>>> aggressive
>>>>>>>> check some tables for updates while ignoring others?
>>>>>>>>
>>>>>>>> Thanks a Million
>>>>>>>> Anthony Brew
>>>>>>>>
>>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
Re: Data base externally modified
Posted by Mike Kienenberger <mk...@gmail.com>.
There may be a better way, but one obvious way this could be done is to
change the code generation so that the getter() executes a select query
rather than returning an existing list.
On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <an...@swrve.com>wrote:
> Hi,
> Just an update, and I think I forgot to include something important
> Its a one to many relationship that I am seeing cached, (ie I fetch "Item"
> and the many to one "Item.getSubItems()" are being fetched from the cache)
>
> My code now looks a bit like:
>
> Expression e1 = Expression.fromString("id = $id");
> Map params = new HashMap();
> params.put("id", item.getId());
>
> SelectQuery query = new SelectQuery(Item.class,
> e1.expWithParameters(params));
> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
>
> List items = context.performQuery(query);
> if(items.size() != 1){
> throw new RuntimeException("");
> }
> freshitem = (Item) items.get(0);
>
> subitems = freshitem.getSubItems()
>
> Where subitems are stale.
>
> I am sure I am making this more complicated than needs be. As I mentioned
> before I would like to turn on some flag to essentially always read from DB
> when I do items.getSubItems() if possible, or when I reload the Item when
> its getter methods are called to make it always read from the DB the first
> time when QueryCacheStrategy.NO_CACHE is specified...
>
> Thanks a Million,
> Anthony
>
>
> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mkienenb@gmail.com
> >wrote:
>
> > You may want to review these two threads from the end of July:
> >
> > OSCache is gone
> > http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
> >
> > EhCache integration preview
> > http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
> >
> >
> > On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.brew@swrve.com
> > >wrote:
> >
> > > Hi Andrus,
> > > I was just about to get back to you on, I accidentally
> > > started two threads when I joined the mailing list.
> > >
> > > Essentially we have a ruby on rails project that creates config on the
> > > front
> > > end, this is the part that is changing externally. Then internally we
> > read
> > > these config and do a bunch of processing and write the results to a
> > > separate set of tables. The tables are in turn read by the R on R app
> but
> > > never written to
> > >
> > > so
> > > Tables Set A | Set B
> > >
> ------------------------------------------------------------------------
> > > Rails read and write | read only
> > > Java read only | read and write
> > >
> > > The issues I am facing are with set A changing in the app.
> > >
> > > I have tried forcing the Item to reload by doing this, (I cut code from
> > > Cayennes: DataObjectUtils.objectForPK(threadDataContext,
> Item.class,
> > > dirtyItem.getId());)
> > >
> > > private Item getItemWithNoCayenneCache(Item newGame, DataContext
> > > threadDataContext) {
> > > ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
> > > newGame.getId());
> > >
> > > return (Item) DataObjectUtils.objectForQuery(threadDataContext,
> > new
> > > ObjectIdQuery(
> > > gameIdentifier,
> > > false,
> > > ObjectIdQuery.CACHE_REFRESH));
> > > }
> > > }
> > >
> > >
> > > stepping into *DataObjectUtils.objectForQuery stepping into the Cayenne
> > > code
> > > I eventually get to DataContext.java*
> > > *
> > > *
> > > where I see the following method called
> > >
> > > *
> > > @Override
> > > @SuppressWarnings("unchecked")
> > > public List performQuery(Query query) {
> > > query = nonNullDelegate().willPerformQuery(this, query);
> > > if (query == null) {
> > > return new ArrayList<Object>(1);
> > > }
> > >
> > > List result = onQuery(this, query).firstList();
> > > return result != null ? result : new ArrayList<Object>(1);
> > > }
> > > *
> > >
> > > however i see that the delgate in *
> > > nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
> > which
> > > I assume is the route of my woes.
> > > *
> > > *
> > >
> > > *
> > > Im interested in trying the OSCache solution you proposed in my other
> > > thread, but I am a little wary the code is stale as my maven
> dependancies
> > > fail (I am actually pretty new to maven so this might be my bad).
> > > OSCache appears to be quite old since the OpenSymphony project died,
> > maybe
> > > my maven config is off, are there still active contributors?
> > >
> > > In my pom I have specified
> > > <dependency>
> > > <groupId>opensymphony</groupId>
> > > <artifactId>oscache</artifactId>
> > > <version>2.4</version>
> > > </dependency>
> > >
> > > however the dependancies on
> > >
> > > - javax.jms:jms:1.1
> > >
> > > Thanks a Million
> > > Anthony
> > >
> > >
> > > On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
> andrus@objectstyle.org
> > > >wrote:
> > >
> > > > Could you please explain your data access patterns?
> > > >
> > > > E.g. if you fetch some objects and store them in an instance variable
> > in
> > > > your application, they are not going to get refreshed automatically.
> To
> > > > refresh objects you need to either invalidate them explicitly via
> > > > context.invalidateObjects() or run a query. All the cache settings
> are
> > > > essentially about optimizing query execution (refresh data, but only
> as
> > > > often as needed).
> > > >
> > > > Andrus
> > > >
> > > > On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
> > > >
> > > > > Hi Gary,
> > > > > Yeah thats what I am seeing in the code, but I cant for
> > the
> > > > life
> > > > > of me see how to turn off the caching completely in the modeller, I
> > > > actually
> > > > > think it wont hit our performance very badly to have no caching.
> > > > >
> > > > > The cache setting I see are the in the DataDomain Configuration
> > > > >
> > > > > Which has an option for a Query Cache Factory with a choice of two
> > > > classes.
> > > > > - org.apache.cayenne.cache.MapQueryCacheFactory
> > > > > - org.apache.cayenne.cache.OSQueryCacheFactory
> > > > >
> > > > > I selected the MapQueryCache and trie to set the size of the object
> > > cache
> > > > to
> > > > > 1 (couldn't set this to zero) as the application barfed saying
> caches
> > > had
> > > > to
> > > > > be greater than size zero.
> > > > >
> > > > > in my cayenne.xml I see the line
> > > > >
> > > > > <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
> > > > >
> > > > > was added, perhaps there is some manual setting I can add to this
> > file
> > > to
> > > > > turn caching off?
> > > > >
> > > > > All the Best,
> > > > > Anthony
> > > > >
> > > > >
> > > > >
> > > > > On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <garyjarrel@gmail.com
> >
> > > > wrote:
> > > > >
> > > > >> I'd say that would be cache related, as Cayenne is caching the
> data
> > > > >> from the database, switch the cache of in the Modeler perhaps and
> > that
> > > > >> should fix your problem.
> > > > >>
> > > > >> G
> > > > >>
> > > > >> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
> > anthony.brew@swrve.com>
> > > > >> wrote:
> > > > >>> Hi,
> > > > >>> I have a two processes one which writes to a several database
> > > tables
> > > > >> (a
> > > > >>> ruby on rails application) and a java application that reads the
> > > state
> > > > >> these
> > > > >>> data base tables using Cayenne and writes to other tables.
> > > > >>>
> > > > >>> When the ruby modifies the underlying data-base I am seeing that
> > > > Cayenne
> > > > >> is
> > > > >>> not automatically picking up that the underlying data is now
> > > > inconsistant
> > > > >>> and not reloading. Is there some way I can config Cayenne to
> > > aggressive
> > > > >>> check some tables for updates while ignoring others?
> > > > >>>
> > > > >>> Thanks a Million
> > > > >>> Anthony Brew
> > > > >>>
> > > > >>
> > > >
> > > >
> > >
> >
>
Re: Data base externally modified
Posted by Anthony Brew <an...@swrve.com>.
Hi,
Just an update, and I think I forgot to include something important
Its a one to many relationship that I am seeing cached, (ie I fetch "Item"
and the many to one "Item.getSubItems()" are being fetched from the cache)
My code now looks a bit like:
Expression e1 = Expression.fromString("id = $id");
Map params = new HashMap();
params.put("id", item.getId());
SelectQuery query = new SelectQuery(Item.class,
e1.expWithParameters(params));
query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
List items = context.performQuery(query);
if(items.size() != 1){
throw new RuntimeException("");
}
freshitem = (Item) items.get(0);
subitems = freshitem.getSubItems()
Where subitems are stale.
I am sure I am making this more complicated than needs be. As I mentioned
before I would like to turn on some flag to essentially always read from DB
when I do items.getSubItems() if possible, or when I reload the Item when
its getter methods are called to make it always read from the DB the first
time when QueryCacheStrategy.NO_CACHE is specified...
Thanks a Million,
Anthony
On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mk...@gmail.com>wrote:
> You may want to review these two threads from the end of July:
>
> OSCache is gone
> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
>
> EhCache integration preview
> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
>
>
> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.brew@swrve.com
> >wrote:
>
> > Hi Andrus,
> > I was just about to get back to you on, I accidentally
> > started two threads when I joined the mailing list.
> >
> > Essentially we have a ruby on rails project that creates config on the
> > front
> > end, this is the part that is changing externally. Then internally we
> read
> > these config and do a bunch of processing and write the results to a
> > separate set of tables. The tables are in turn read by the R on R app but
> > never written to
> >
> > so
> > Tables Set A | Set B
> > ------------------------------------------------------------------------
> > Rails read and write | read only
> > Java read only | read and write
> >
> > The issues I am facing are with set A changing in the app.
> >
> > I have tried forcing the Item to reload by doing this, (I cut code from
> > Cayennes: DataObjectUtils.objectForPK(threadDataContext, Item.class,
> > dirtyItem.getId());)
> >
> > private Item getItemWithNoCayenneCache(Item newGame, DataContext
> > threadDataContext) {
> > ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
> > newGame.getId());
> >
> > return (Item) DataObjectUtils.objectForQuery(threadDataContext,
> new
> > ObjectIdQuery(
> > gameIdentifier,
> > false,
> > ObjectIdQuery.CACHE_REFRESH));
> > }
> > }
> >
> >
> > stepping into *DataObjectUtils.objectForQuery stepping into the Cayenne
> > code
> > I eventually get to DataContext.java*
> > *
> > *
> > where I see the following method called
> >
> > *
> > @Override
> > @SuppressWarnings("unchecked")
> > public List performQuery(Query query) {
> > query = nonNullDelegate().willPerformQuery(this, query);
> > if (query == null) {
> > return new ArrayList<Object>(1);
> > }
> >
> > List result = onQuery(this, query).firstList();
> > return result != null ? result : new ArrayList<Object>(1);
> > }
> > *
> >
> > however i see that the delgate in *
> > nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
> which
> > I assume is the route of my woes.
> > *
> > *
> >
> > *
> > Im interested in trying the OSCache solution you proposed in my other
> > thread, but I am a little wary the code is stale as my maven dependancies
> > fail (I am actually pretty new to maven so this might be my bad).
> > OSCache appears to be quite old since the OpenSymphony project died,
> maybe
> > my maven config is off, are there still active contributors?
> >
> > In my pom I have specified
> > <dependency>
> > <groupId>opensymphony</groupId>
> > <artifactId>oscache</artifactId>
> > <version>2.4</version>
> > </dependency>
> >
> > however the dependancies on
> >
> > - javax.jms:jms:1.1
> >
> > Thanks a Million
> > Anthony
> >
> >
> > On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <andrus@objectstyle.org
> > >wrote:
> >
> > > Could you please explain your data access patterns?
> > >
> > > E.g. if you fetch some objects and store them in an instance variable
> in
> > > your application, they are not going to get refreshed automatically. To
> > > refresh objects you need to either invalidate them explicitly via
> > > context.invalidateObjects() or run a query. All the cache settings are
> > > essentially about optimizing query execution (refresh data, but only as
> > > often as needed).
> > >
> > > Andrus
> > >
> > > On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
> > >
> > > > Hi Gary,
> > > > Yeah thats what I am seeing in the code, but I cant for
> the
> > > life
> > > > of me see how to turn off the caching completely in the modeller, I
> > > actually
> > > > think it wont hit our performance very badly to have no caching.
> > > >
> > > > The cache setting I see are the in the DataDomain Configuration
> > > >
> > > > Which has an option for a Query Cache Factory with a choice of two
> > > classes.
> > > > - org.apache.cayenne.cache.MapQueryCacheFactory
> > > > - org.apache.cayenne.cache.OSQueryCacheFactory
> > > >
> > > > I selected the MapQueryCache and trie to set the size of the object
> > cache
> > > to
> > > > 1 (couldn't set this to zero) as the application barfed saying caches
> > had
> > > to
> > > > be greater than size zero.
> > > >
> > > > in my cayenne.xml I see the line
> > > >
> > > > <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
> > > >
> > > > was added, perhaps there is some manual setting I can add to this
> file
> > to
> > > > turn caching off?
> > > >
> > > > All the Best,
> > > > Anthony
> > > >
> > > >
> > > >
> > > > On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <ga...@gmail.com>
> > > wrote:
> > > >
> > > >> I'd say that would be cache related, as Cayenne is caching the data
> > > >> from the database, switch the cache of in the Modeler perhaps and
> that
> > > >> should fix your problem.
> > > >>
> > > >> G
> > > >>
> > > >> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
> anthony.brew@swrve.com>
> > > >> wrote:
> > > >>> Hi,
> > > >>> I have a two processes one which writes to a several database
> > tables
> > > >> (a
> > > >>> ruby on rails application) and a java application that reads the
> > state
> > > >> these
> > > >>> data base tables using Cayenne and writes to other tables.
> > > >>>
> > > >>> When the ruby modifies the underlying data-base I am seeing that
> > > Cayenne
> > > >> is
> > > >>> not automatically picking up that the underlying data is now
> > > inconsistant
> > > >>> and not reloading. Is there some way I can config Cayenne to
> > aggressive
> > > >>> check some tables for updates while ignoring others?
> > > >>>
> > > >>> Thanks a Million
> > > >>> Anthony Brew
> > > >>>
> > > >>
> > >
> > >
> >
>
Re: Data base externally modified
Posted by Mike Kienenberger <mk...@gmail.com>.
You may want to review these two threads from the end of July:
OSCache is gone
http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
EhCache integration preview
http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <an...@swrve.com>wrote:
> Hi Andrus,
> I was just about to get back to you on, I accidentally
> started two threads when I joined the mailing list.
>
> Essentially we have a ruby on rails project that creates config on the
> front
> end, this is the part that is changing externally. Then internally we read
> these config and do a bunch of processing and write the results to a
> separate set of tables. The tables are in turn read by the R on R app but
> never written to
>
> so
> Tables Set A | Set B
> ------------------------------------------------------------------------
> Rails read and write | read only
> Java read only | read and write
>
> The issues I am facing are with set A changing in the app.
>
> I have tried forcing the Item to reload by doing this, (I cut code from
> Cayennes: DataObjectUtils.objectForPK(threadDataContext, Item.class,
> dirtyItem.getId());)
>
> private Item getItemWithNoCayenneCache(Item newGame, DataContext
> threadDataContext) {
> ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
> newGame.getId());
>
> return (Item) DataObjectUtils.objectForQuery(threadDataContext, new
> ObjectIdQuery(
> gameIdentifier,
> false,
> ObjectIdQuery.CACHE_REFRESH));
> }
> }
>
>
> stepping into *DataObjectUtils.objectForQuery stepping into the Cayenne
> code
> I eventually get to DataContext.java*
> *
> *
> where I see the following method called
>
> *
> @Override
> @SuppressWarnings("unchecked")
> public List performQuery(Query query) {
> query = nonNullDelegate().willPerformQuery(this, query);
> if (query == null) {
> return new ArrayList<Object>(1);
> }
>
> List result = onQuery(this, query).firstList();
> return result != null ? result : new ArrayList<Object>(1);
> }
> *
>
> however i see that the delgate in *
> nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate which
> I assume is the route of my woes.
> *
> *
>
> *
> Im interested in trying the OSCache solution you proposed in my other
> thread, but I am a little wary the code is stale as my maven dependancies
> fail (I am actually pretty new to maven so this might be my bad).
> OSCache appears to be quite old since the OpenSymphony project died, maybe
> my maven config is off, are there still active contributors?
>
> In my pom I have specified
> <dependency>
> <groupId>opensymphony</groupId>
> <artifactId>oscache</artifactId>
> <version>2.4</version>
> </dependency>
>
> however the dependancies on
>
> - javax.jms:jms:1.1
>
> Thanks a Million
> Anthony
>
>
> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <andrus@objectstyle.org
> >wrote:
>
> > Could you please explain your data access patterns?
> >
> > E.g. if you fetch some objects and store them in an instance variable in
> > your application, they are not going to get refreshed automatically. To
> > refresh objects you need to either invalidate them explicitly via
> > context.invalidateObjects() or run a query. All the cache settings are
> > essentially about optimizing query execution (refresh data, but only as
> > often as needed).
> >
> > Andrus
> >
> > On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
> >
> > > Hi Gary,
> > > Yeah thats what I am seeing in the code, but I cant for the
> > life
> > > of me see how to turn off the caching completely in the modeller, I
> > actually
> > > think it wont hit our performance very badly to have no caching.
> > >
> > > The cache setting I see are the in the DataDomain Configuration
> > >
> > > Which has an option for a Query Cache Factory with a choice of two
> > classes.
> > > - org.apache.cayenne.cache.MapQueryCacheFactory
> > > - org.apache.cayenne.cache.OSQueryCacheFactory
> > >
> > > I selected the MapQueryCache and trie to set the size of the object
> cache
> > to
> > > 1 (couldn't set this to zero) as the application barfed saying caches
> had
> > to
> > > be greater than size zero.
> > >
> > > in my cayenne.xml I see the line
> > >
> > > <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
> > >
> > > was added, perhaps there is some manual setting I can add to this file
> to
> > > turn caching off?
> > >
> > > All the Best,
> > > Anthony
> > >
> > >
> > >
> > > On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <ga...@gmail.com>
> > wrote:
> > >
> > >> I'd say that would be cache related, as Cayenne is caching the data
> > >> from the database, switch the cache of in the Modeler perhaps and that
> > >> should fix your problem.
> > >>
> > >> G
> > >>
> > >> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <an...@swrve.com>
> > >> wrote:
> > >>> Hi,
> > >>> I have a two processes one which writes to a several database
> tables
> > >> (a
> > >>> ruby on rails application) and a java application that reads the
> state
> > >> these
> > >>> data base tables using Cayenne and writes to other tables.
> > >>>
> > >>> When the ruby modifies the underlying data-base I am seeing that
> > Cayenne
> > >> is
> > >>> not automatically picking up that the underlying data is now
> > inconsistant
> > >>> and not reloading. Is there some way I can config Cayenne to
> aggressive
> > >>> check some tables for updates while ignoring others?
> > >>>
> > >>> Thanks a Million
> > >>> Anthony Brew
> > >>>
> > >>
> >
> >
>
Re: Data base externally modified
Posted by Anthony Brew <an...@swrve.com>.
Hi Andrus,
I was just about to get back to you on, I accidentally
started two threads when I joined the mailing list.
Essentially we have a ruby on rails project that creates config on the front
end, this is the part that is changing externally. Then internally we read
these config and do a bunch of processing and write the results to a
separate set of tables. The tables are in turn read by the R on R app but
never written to
so
Tables Set A | Set B
------------------------------------------------------------------------
Rails read and write | read only
Java read only | read and write
The issues I am facing are with set A changing in the app.
I have tried forcing the Item to reload by doing this, (I cut code from
Cayennes: DataObjectUtils.objectForPK(threadDataContext, Item.class,
dirtyItem.getId());)
private Item getItemWithNoCayenneCache(Item newGame, DataContext
threadDataContext) {
ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
newGame.getId());
return (Item) DataObjectUtils.objectForQuery(threadDataContext, new
ObjectIdQuery(
gameIdentifier,
false,
ObjectIdQuery.CACHE_REFRESH));
}
}
stepping into *DataObjectUtils.objectForQuery stepping into the Cayenne code
I eventually get to DataContext.java*
*
*
where I see the following method called
*
@Override
@SuppressWarnings("unchecked")
public List performQuery(Query query) {
query = nonNullDelegate().willPerformQuery(this, query);
if (query == null) {
return new ArrayList<Object>(1);
}
List result = onQuery(this, query).firstList();
return result != null ? result : new ArrayList<Object>(1);
}
*
however i see that the delgate in *
nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate which
I assume is the route of my woes.
*
*
*
Im interested in trying the OSCache solution you proposed in my other
thread, but I am a little wary the code is stale as my maven dependancies
fail (I am actually pretty new to maven so this might be my bad).
OSCache appears to be quite old since the OpenSymphony project died, maybe
my maven config is off, are there still active contributors?
In my pom I have specified
<dependency>
<groupId>opensymphony</groupId>
<artifactId>oscache</artifactId>
<version>2.4</version>
</dependency>
however the dependancies on
- javax.jms:jms:1.1
Thanks a Million
Anthony
On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <an...@objectstyle.org>wrote:
> Could you please explain your data access patterns?
>
> E.g. if you fetch some objects and store them in an instance variable in
> your application, they are not going to get refreshed automatically. To
> refresh objects you need to either invalidate them explicitly via
> context.invalidateObjects() or run a query. All the cache settings are
> essentially about optimizing query execution (refresh data, but only as
> often as needed).
>
> Andrus
>
> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
>
> > Hi Gary,
> > Yeah thats what I am seeing in the code, but I cant for the
> life
> > of me see how to turn off the caching completely in the modeller, I
> actually
> > think it wont hit our performance very badly to have no caching.
> >
> > The cache setting I see are the in the DataDomain Configuration
> >
> > Which has an option for a Query Cache Factory with a choice of two
> classes.
> > - org.apache.cayenne.cache.MapQueryCacheFactory
> > - org.apache.cayenne.cache.OSQueryCacheFactory
> >
> > I selected the MapQueryCache and trie to set the size of the object cache
> to
> > 1 (couldn't set this to zero) as the application barfed saying caches had
> to
> > be greater than size zero.
> >
> > in my cayenne.xml I see the line
> >
> > <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
> >
> > was added, perhaps there is some manual setting I can add to this file to
> > turn caching off?
> >
> > All the Best,
> > Anthony
> >
> >
> >
> > On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <ga...@gmail.com>
> wrote:
> >
> >> I'd say that would be cache related, as Cayenne is caching the data
> >> from the database, switch the cache of in the Modeler perhaps and that
> >> should fix your problem.
> >>
> >> G
> >>
> >> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <an...@swrve.com>
> >> wrote:
> >>> Hi,
> >>> I have a two processes one which writes to a several database tables
> >> (a
> >>> ruby on rails application) and a java application that reads the state
> >> these
> >>> data base tables using Cayenne and writes to other tables.
> >>>
> >>> When the ruby modifies the underlying data-base I am seeing that
> Cayenne
> >> is
> >>> not automatically picking up that the underlying data is now
> inconsistant
> >>> and not reloading. Is there some way I can config Cayenne to aggressive
> >>> check some tables for updates while ignoring others?
> >>>
> >>> Thanks a Million
> >>> Anthony Brew
> >>>
> >>
>
>
Re: Data base externally modified
Posted by Andrus Adamchik <an...@objectstyle.org>.
Could you please explain your data access patterns?
E.g. if you fetch some objects and store them in an instance variable in your application, they are not going to get refreshed automatically. To refresh objects you need to either invalidate them explicitly via context.invalidateObjects() or run a query. All the cache settings are essentially about optimizing query execution (refresh data, but only as often as needed).
Andrus
On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
> Hi Gary,
> Yeah thats what I am seeing in the code, but I cant for the life
> of me see how to turn off the caching completely in the modeller, I actually
> think it wont hit our performance very badly to have no caching.
>
> The cache setting I see are the in the DataDomain Configuration
>
> Which has an option for a Query Cache Factory with a choice of two classes.
> - org.apache.cayenne.cache.MapQueryCacheFactory
> - org.apache.cayenne.cache.OSQueryCacheFactory
>
> I selected the MapQueryCache and trie to set the size of the object cache to
> 1 (couldn't set this to zero) as the application barfed saying caches had to
> be greater than size zero.
>
> in my cayenne.xml I see the line
>
> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
>
> was added, perhaps there is some manual setting I can add to this file to
> turn caching off?
>
> All the Best,
> Anthony
>
>
>
> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <ga...@gmail.com> wrote:
>
>> I'd say that would be cache related, as Cayenne is caching the data
>> from the database, switch the cache of in the Modeler perhaps and that
>> should fix your problem.
>>
>> G
>>
>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <an...@swrve.com>
>> wrote:
>>> Hi,
>>> I have a two processes one which writes to a several database tables
>> (a
>>> ruby on rails application) and a java application that reads the state
>> these
>>> data base tables using Cayenne and writes to other tables.
>>>
>>> When the ruby modifies the underlying data-base I am seeing that Cayenne
>> is
>>> not automatically picking up that the underlying data is now inconsistant
>>> and not reloading. Is there some way I can config Cayenne to aggressive
>>> check some tables for updates while ignoring others?
>>>
>>> Thanks a Million
>>> Anthony Brew
>>>
>>
Re: Data base externally modified
Posted by Anthony Brew <an...@swrve.com>.
Hi Gary,
Yeah thats what I am seeing in the code, but I cant for the life
of me see how to turn off the caching completely in the modeller, I actually
think it wont hit our performance very badly to have no caching.
The cache setting I see are the in the DataDomain Configuration
Which has an option for a Query Cache Factory with a choice of two classes.
- org.apache.cayenne.cache.MapQueryCacheFactory
- org.apache.cayenne.cache.OSQueryCacheFactory
I selected the MapQueryCache and trie to set the size of the object cache to
1 (couldn't set this to zero) as the application barfed saying caches had to
be greater than size zero.
in my cayenne.xml I see the line
<property name="cayenne.DataRowStore.snapshot.size" value="1"/>
was added, perhaps there is some manual setting I can add to this file to
turn caching off?
All the Best,
Anthony
On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <ga...@gmail.com> wrote:
> I'd say that would be cache related, as Cayenne is caching the data
> from the database, switch the cache of in the Modeler perhaps and that
> should fix your problem.
>
> G
>
> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <an...@swrve.com>
> wrote:
> > Hi,
> > I have a two processes one which writes to a several database tables
> (a
> > ruby on rails application) and a java application that reads the state
> these
> > data base tables using Cayenne and writes to other tables.
> >
> > When the ruby modifies the underlying data-base I am seeing that Cayenne
> is
> > not automatically picking up that the underlying data is now inconsistant
> > and not reloading. Is there some way I can config Cayenne to aggressive
> > check some tables for updates while ignoring others?
> >
> > Thanks a Million
> > Anthony Brew
> >
>
Re: Data base externally modified
Posted by Gary Jarrel <ga...@gmail.com>.
I'd say that would be cache related, as Cayenne is caching the data
from the database, switch the cache of in the Modeler perhaps and that
should fix your problem.
G
On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <an...@swrve.com> wrote:
> Hi,
> I have a two processes one which writes to a several database tables (a
> ruby on rails application) and a java application that reads the state these
> data base tables using Cayenne and writes to other tables.
>
> When the ruby modifies the underlying data-base I am seeing that Cayenne is
> not automatically picking up that the underlying data is now inconsistant
> and not reloading. Is there some way I can config Cayenne to aggressive
> check some tables for updates while ignoring others?
>
> Thanks a Million
> Anthony Brew
>