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Posted to user@cayenne.apache.org by Markus Reich <ma...@markusreich.at> on 2013/05/15 15:28:29 UTC
Change data by an external process (non cayenne)
Hi,
is there really no better way than described here:
http://markmail.org/message/plnaj4zj4gxrt6hk
regards
Meex
Re: Change data by an external process (non cayenne)
Posted by Mike Kienenberger <mk...@gmail.com>.
If you're planning to do this for a web app, you should make sure it
happens before your regular web app is handed the request. In older
versions of BasicServletConfiguration worked, but I don't think that
class still exists. One way that should work in any version is to
put it in a servlet filter than runs before your web app's servlet. I
don't think you''d want to call this code more than once per request.
On Fri, May 24, 2013 at 4:15 AM, Markus Reich
<ma...@markusreich.at> wrote:
> Hi,
>
> I can't find the BasicServletConfiguration class, should I override
> the BaseContext.getThreadObjectContext() method, for checking external
> changes in db?
>
> Meex
>
>
> 2013/5/16 Mike Kienenberger <mk...@gmail.com>
>
>> Something to keep in mind for web apps is that you probably do not
>> want to have a data refresh at some arbitrary point during a request,
>> only at the beginning of a request. It's generally better to have
>> your data be a second or two out of date than to have the value of an
>> object or object's relationships change mid-stream while you are
>> working with it.
>>
>> I've been using the LAST_EXTERNAL_UPDATE method for several years now,
>> and I haven't had any regrets. I've considered changing it over to
>> jms or a similar notification framework, but there weren't any
>> compelling reasons to do so. This way there's no dependencies in the
>> external processes (most of which are not maintained or written by
>> me), and it's also easy to manually execute a database update and
>> insure that the change will become visible to the active web sessions
>> immediately. On the other hand, external changes to our database are
>> rare. Normally only a couple times a day.
>>
>>
>> On Thu, May 16, 2013 at 1:34 PM, Andrus Adamchik <an...@objectstyle.org>
>> wrote:
>> > Actually if cross-context events are in effect (which is the default),
>> invalidating an object from a given ObjectContext will automatically
>> invalidate it across peers.
>> >
>> > I would still approach it via query cache and cache groups though. All
>> that is needed is that all contexts access those objects via a query
>> instead of storing a direct reference.
>> >
>> > Andrus
>> >
>> > On May 16, 2013, at 12:14 PM, Markus Reich <ma...@markusreich.at>
>> wrote:
>> >
>> >> :-) sorry, I try it more detailed
>> >>
>> >> I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by
>> other
>> >> processes. A refresh is not enough to show the changed data, so my idea
>> is
>> >> to make a servlet, which invalidates certain DataObjects (mostly it's
>> just
>> >> one) of all thread binded contexts.
>> >> So when the user refreshes the UI and the data gets selected again, the
>> >> changed values are shown.
>> >> So it would be enough to make object hollow.
>> >>
>> >> Markus
>> >>
>> >>
>> >> 2013/5/16 Andrus Adamchik <an...@objectstyle.org>
>> >>
>> >>> The question is too generic, so the answer is "yes" :) Could you
>> describe
>> >>> the scenario in a bit more detail?
>> >>>
>> >>> Also does your interface needs to know when an object is invalidated
>> right
>> >>> at that moment or is it enough to make the object "hollow" so that it
>> is
>> >>> refetched lazily on next access?
>> >>>
>> >>> Andrus
>> >>>
>> >>> On May 16, 2013, at 7:52 AM, Markus Reich <markus.reich@markusreich.at
>> >
>> >>> wrote:
>> >>>> would it be possible to work with a servlet to invalidate certain
>> >>> objects?
>> >>>>
>> >>>> Is there a way to get all ObjectStores of all Threads or is the only
>> >>>> solution to set the DataContext as attribute in the session?
>> >>>>
>> >>>>
>> >>>> 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
>> >>>>
>> >>>>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to
>> cache
>> >>> the
>> >>>>> results, and then define expiration time for a given set of cache
>> groups
>> >>>>> for whatever cache provider is in use (EhCache most likely, so this
>> >>> will go
>> >>>>> into ehcache.xml).
>> >>>>>
>> >>>>> If you want real-time refresh, EhCache might be configured to listen
>> to
>> >>>>> cache group refresh events via JMS. Your external process would send
>> >>> such
>> >>>>> events via ActiveMQ (that supports a bunch of command-line friendly
>> >>>>> protocols, not just JMS) whenever the data is changed.
>> >>>>>
>> >>>>> Andrus
>> >>>>>
>> >>>>>
>> >>>>> On May 15, 2013, at 4:28 PM, Markus Reich <
>> markus.reich@markusreich.at>
>> >>>>> wrote:
>> >>>>>
>> >>>>>> Hi,
>> >>>>>>
>> >>>>>> is there really no better way than described here:
>> >>>>>> http://markmail.org/message/plnaj4zj4gxrt6hk
>> >>>>>>
>> >>>>>> regards
>> >>>>>> Meex
>> >>>>>
>> >>>>>
>> >>>>
>> >>>>
>> >>>> --
>> >>>> *Markus Reich*
>> >>>> Moosbach 28/2
>> >>>> 6392 St. Jakob i.H.
>> >>>> www.markusreich.at / www.meeximum.at
>> >>>> markus.reich@markusreich.at
>> >>>
>> >>>
>> >>
>> >>
>> >> --
>> >> *Markus Reich*
>> >> Moosbach 28/2
>> >> 6392 St. Jakob i.H.
>> >> www.markusreich.at / www.meeximum.at
>> >> markus.reich@markusreich.at
>> >
>>
>
>
>
> --
> *Markus Reich*
> Moosbach 28/2
> 6392 St. Jakob i.H.
> www.markusreich.at / www.meeximum.at
> markus.reich@markusreich.at
Re: Change data by an external process (non cayenne)
Posted by Markus Reich <ma...@markusreich.at>.
Hi,
I can't find the BasicServletConfiguration class, should I override
the BaseContext.getThreadObjectContext() method, for checking external
changes in db?
Meex
2013/5/16 Mike Kienenberger <mk...@gmail.com>
> Something to keep in mind for web apps is that you probably do not
> want to have a data refresh at some arbitrary point during a request,
> only at the beginning of a request. It's generally better to have
> your data be a second or two out of date than to have the value of an
> object or object's relationships change mid-stream while you are
> working with it.
>
> I've been using the LAST_EXTERNAL_UPDATE method for several years now,
> and I haven't had any regrets. I've considered changing it over to
> jms or a similar notification framework, but there weren't any
> compelling reasons to do so. This way there's no dependencies in the
> external processes (most of which are not maintained or written by
> me), and it's also easy to manually execute a database update and
> insure that the change will become visible to the active web sessions
> immediately. On the other hand, external changes to our database are
> rare. Normally only a couple times a day.
>
>
> On Thu, May 16, 2013 at 1:34 PM, Andrus Adamchik <an...@objectstyle.org>
> wrote:
> > Actually if cross-context events are in effect (which is the default),
> invalidating an object from a given ObjectContext will automatically
> invalidate it across peers.
> >
> > I would still approach it via query cache and cache groups though. All
> that is needed is that all contexts access those objects via a query
> instead of storing a direct reference.
> >
> > Andrus
> >
> > On May 16, 2013, at 12:14 PM, Markus Reich <ma...@markusreich.at>
> wrote:
> >
> >> :-) sorry, I try it more detailed
> >>
> >> I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by
> other
> >> processes. A refresh is not enough to show the changed data, so my idea
> is
> >> to make a servlet, which invalidates certain DataObjects (mostly it's
> just
> >> one) of all thread binded contexts.
> >> So when the user refreshes the UI and the data gets selected again, the
> >> changed values are shown.
> >> So it would be enough to make object hollow.
> >>
> >> Markus
> >>
> >>
> >> 2013/5/16 Andrus Adamchik <an...@objectstyle.org>
> >>
> >>> The question is too generic, so the answer is "yes" :) Could you
> describe
> >>> the scenario in a bit more detail?
> >>>
> >>> Also does your interface needs to know when an object is invalidated
> right
> >>> at that moment or is it enough to make the object "hollow" so that it
> is
> >>> refetched lazily on next access?
> >>>
> >>> Andrus
> >>>
> >>> On May 16, 2013, at 7:52 AM, Markus Reich <markus.reich@markusreich.at
> >
> >>> wrote:
> >>>> would it be possible to work with a servlet to invalidate certain
> >>> objects?
> >>>>
> >>>> Is there a way to get all ObjectStores of all Threads or is the only
> >>>> solution to set the DataContext as attribute in the session?
> >>>>
> >>>>
> >>>> 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
> >>>>
> >>>>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to
> cache
> >>> the
> >>>>> results, and then define expiration time for a given set of cache
> groups
> >>>>> for whatever cache provider is in use (EhCache most likely, so this
> >>> will go
> >>>>> into ehcache.xml).
> >>>>>
> >>>>> If you want real-time refresh, EhCache might be configured to listen
> to
> >>>>> cache group refresh events via JMS. Your external process would send
> >>> such
> >>>>> events via ActiveMQ (that supports a bunch of command-line friendly
> >>>>> protocols, not just JMS) whenever the data is changed.
> >>>>>
> >>>>> Andrus
> >>>>>
> >>>>>
> >>>>> On May 15, 2013, at 4:28 PM, Markus Reich <
> markus.reich@markusreich.at>
> >>>>> wrote:
> >>>>>
> >>>>>> Hi,
> >>>>>>
> >>>>>> is there really no better way than described here:
> >>>>>> http://markmail.org/message/plnaj4zj4gxrt6hk
> >>>>>>
> >>>>>> regards
> >>>>>> Meex
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>> --
> >>>> *Markus Reich*
> >>>> Moosbach 28/2
> >>>> 6392 St. Jakob i.H.
> >>>> www.markusreich.at / www.meeximum.at
> >>>> markus.reich@markusreich.at
> >>>
> >>>
> >>
> >>
> >> --
> >> *Markus Reich*
> >> Moosbach 28/2
> >> 6392 St. Jakob i.H.
> >> www.markusreich.at / www.meeximum.at
> >> markus.reich@markusreich.at
> >
>
--
*Markus Reich*
Moosbach 28/2
6392 St. Jakob i.H.
www.markusreich.at / www.meeximum.at
markus.reich@markusreich.at
Re: Change data by an external process (non cayenne)
Posted by Mike Kienenberger <mk...@gmail.com>.
Yeah, I still have internal change events under my Cayenne 1.1 web app
project sending notifications to other sessions, and it's probably
causes most, if not all, of the few remaining weird errors I see.
At some point, I am going to totally disable it, leaving contexts
completely isolated.
On Thu, May 16, 2013 at 2:20 PM, Andrus Adamchik <an...@objectstyle.org> wrote:
> On May 16, 2013, at 8:49 PM, Mike Kienenberger <mk...@gmail.com> wrote:
>
>> Something to keep in mind for web apps is that you probably do not
>> want to have a data refresh at some arbitrary point during a request,
>> only at the beginning of a request. It's generally better to have
>> your data be a second or two out of date than to have the value of an
>> object or object's relationships change mid-stream while you are
>> working with it.
>
> Yeah, the more I've been dealing with this over the years, the more I think our cross-context syncing features are for single user GUI apps. They should be disabled in the web apps. They don't scale (pinging all unrelated contexts in the app with random garbage), they interrupt whatever the context is currently doing, etc.
>
> This is why I am such a fan of cache groups that are simply marked as expired. No objects are touched by an event. Events are small (essentially the event is a cache group name, no matter how many objects are affected) and hence almost infinitely scaleable.
>
> Andrus
>
>
> On May 16, 2013, at 8:49 PM, Mike Kienenberger <mk...@gmail.com> wrote:
>
>> Something to keep in mind for web apps is that you probably do not
>> want to have a data refresh at some arbitrary point during a request,
>> only at the beginning of a request. It's generally better to have
>> your data be a second or two out of date than to have the value of an
>> object or object's relationships change mid-stream while you are
>> working with it.
>>
>> I've been using the LAST_EXTERNAL_UPDATE method for several years now,
>> and I haven't had any regrets. I've considered changing it over to
>> jms or a similar notification framework, but there weren't any
>> compelling reasons to do so. This way there's no dependencies in the
>> external processes (most of which are not maintained or written by
>> me), and it's also easy to manually execute a database update and
>> insure that the change will become visible to the active web sessions
>> immediately. On the other hand, external changes to our database are
>> rare. Normally only a couple times a day.
>>
>>
>> On Thu, May 16, 2013 at 1:34 PM, Andrus Adamchik <an...@objectstyle.org> wrote:
>>> Actually if cross-context events are in effect (which is the default), invalidating an object from a given ObjectContext will automatically invalidate it across peers.
>>>
>>> I would still approach it via query cache and cache groups though. All that is needed is that all contexts access those objects via a query instead of storing a direct reference.
>>>
>>> Andrus
>>>
>>> On May 16, 2013, at 12:14 PM, Markus Reich <ma...@markusreich.at> wrote:
>>>
>>>> :-) sorry, I try it more detailed
>>>>
>>>> I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by other
>>>> processes. A refresh is not enough to show the changed data, so my idea is
>>>> to make a servlet, which invalidates certain DataObjects (mostly it's just
>>>> one) of all thread binded contexts.
>>>> So when the user refreshes the UI and the data gets selected again, the
>>>> changed values are shown.
>>>> So it would be enough to make object hollow.
>>>>
>>>> Markus
>>>>
>>>>
>>>> 2013/5/16 Andrus Adamchik <an...@objectstyle.org>
>>>>
>>>>> The question is too generic, so the answer is "yes" :) Could you describe
>>>>> the scenario in a bit more detail?
>>>>>
>>>>> Also does your interface needs to know when an object is invalidated right
>>>>> at that moment or is it enough to make the object "hollow" so that it is
>>>>> refetched lazily on next access?
>>>>>
>>>>> Andrus
>>>>>
>>>>> On May 16, 2013, at 7:52 AM, Markus Reich <ma...@markusreich.at>
>>>>> wrote:
>>>>>> would it be possible to work with a servlet to invalidate certain
>>>>> objects?
>>>>>>
>>>>>> Is there a way to get all ObjectStores of all Threads or is the only
>>>>>> solution to set the DataContext as attribute in the session?
>>>>>>
>>>>>>
>>>>>> 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
>>>>>>
>>>>>>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache
>>>>> the
>>>>>>> results, and then define expiration time for a given set of cache groups
>>>>>>> for whatever cache provider is in use (EhCache most likely, so this
>>>>> will go
>>>>>>> into ehcache.xml).
>>>>>>>
>>>>>>> If you want real-time refresh, EhCache might be configured to listen to
>>>>>>> cache group refresh events via JMS. Your external process would send
>>>>> such
>>>>>>> events via ActiveMQ (that supports a bunch of command-line friendly
>>>>>>> protocols, not just JMS) whenever the data is changed.
>>>>>>>
>>>>>>> Andrus
>>>>>>>
>>>>>>>
>>>>>>> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> is there really no better way than described here:
>>>>>>>> http://markmail.org/message/plnaj4zj4gxrt6hk
>>>>>>>>
>>>>>>>> regards
>>>>>>>> Meex
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> *Markus Reich*
>>>>>> Moosbach 28/2
>>>>>> 6392 St. Jakob i.H.
>>>>>> www.markusreich.at / www.meeximum.at
>>>>>> markus.reich@markusreich.at
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> *Markus Reich*
>>>> Moosbach 28/2
>>>> 6392 St. Jakob i.H.
>>>> www.markusreich.at / www.meeximum.at
>>>> markus.reich@markusreich.at
>>>
>>
>
Re: Change data by an external process (non cayenne)
Posted by Andrus Adamchik <an...@objectstyle.org>.
On May 16, 2013, at 8:49 PM, Mike Kienenberger <mk...@gmail.com> wrote:
> Something to keep in mind for web apps is that you probably do not
> want to have a data refresh at some arbitrary point during a request,
> only at the beginning of a request. It's generally better to have
> your data be a second or two out of date than to have the value of an
> object or object's relationships change mid-stream while you are
> working with it.
Yeah, the more I've been dealing with this over the years, the more I think our cross-context syncing features are for single user GUI apps. They should be disabled in the web apps. They don't scale (pinging all unrelated contexts in the app with random garbage), they interrupt whatever the context is currently doing, etc.
This is why I am such a fan of cache groups that are simply marked as expired. No objects are touched by an event. Events are small (essentially the event is a cache group name, no matter how many objects are affected) and hence almost infinitely scaleable.
Andrus
On May 16, 2013, at 8:49 PM, Mike Kienenberger <mk...@gmail.com> wrote:
> Something to keep in mind for web apps is that you probably do not
> want to have a data refresh at some arbitrary point during a request,
> only at the beginning of a request. It's generally better to have
> your data be a second or two out of date than to have the value of an
> object or object's relationships change mid-stream while you are
> working with it.
>
> I've been using the LAST_EXTERNAL_UPDATE method for several years now,
> and I haven't had any regrets. I've considered changing it over to
> jms or a similar notification framework, but there weren't any
> compelling reasons to do so. This way there's no dependencies in the
> external processes (most of which are not maintained or written by
> me), and it's also easy to manually execute a database update and
> insure that the change will become visible to the active web sessions
> immediately. On the other hand, external changes to our database are
> rare. Normally only a couple times a day.
>
>
> On Thu, May 16, 2013 at 1:34 PM, Andrus Adamchik <an...@objectstyle.org> wrote:
>> Actually if cross-context events are in effect (which is the default), invalidating an object from a given ObjectContext will automatically invalidate it across peers.
>>
>> I would still approach it via query cache and cache groups though. All that is needed is that all contexts access those objects via a query instead of storing a direct reference.
>>
>> Andrus
>>
>> On May 16, 2013, at 12:14 PM, Markus Reich <ma...@markusreich.at> wrote:
>>
>>> :-) sorry, I try it more detailed
>>>
>>> I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by other
>>> processes. A refresh is not enough to show the changed data, so my idea is
>>> to make a servlet, which invalidates certain DataObjects (mostly it's just
>>> one) of all thread binded contexts.
>>> So when the user refreshes the UI and the data gets selected again, the
>>> changed values are shown.
>>> So it would be enough to make object hollow.
>>>
>>> Markus
>>>
>>>
>>> 2013/5/16 Andrus Adamchik <an...@objectstyle.org>
>>>
>>>> The question is too generic, so the answer is "yes" :) Could you describe
>>>> the scenario in a bit more detail?
>>>>
>>>> Also does your interface needs to know when an object is invalidated right
>>>> at that moment or is it enough to make the object "hollow" so that it is
>>>> refetched lazily on next access?
>>>>
>>>> Andrus
>>>>
>>>> On May 16, 2013, at 7:52 AM, Markus Reich <ma...@markusreich.at>
>>>> wrote:
>>>>> would it be possible to work with a servlet to invalidate certain
>>>> objects?
>>>>>
>>>>> Is there a way to get all ObjectStores of all Threads or is the only
>>>>> solution to set the DataContext as attribute in the session?
>>>>>
>>>>>
>>>>> 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
>>>>>
>>>>>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache
>>>> the
>>>>>> results, and then define expiration time for a given set of cache groups
>>>>>> for whatever cache provider is in use (EhCache most likely, so this
>>>> will go
>>>>>> into ehcache.xml).
>>>>>>
>>>>>> If you want real-time refresh, EhCache might be configured to listen to
>>>>>> cache group refresh events via JMS. Your external process would send
>>>> such
>>>>>> events via ActiveMQ (that supports a bunch of command-line friendly
>>>>>> protocols, not just JMS) whenever the data is changed.
>>>>>>
>>>>>> Andrus
>>>>>>
>>>>>>
>>>>>> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
>>>>>> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> is there really no better way than described here:
>>>>>>> http://markmail.org/message/plnaj4zj4gxrt6hk
>>>>>>>
>>>>>>> regards
>>>>>>> Meex
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> *Markus Reich*
>>>>> Moosbach 28/2
>>>>> 6392 St. Jakob i.H.
>>>>> www.markusreich.at / www.meeximum.at
>>>>> markus.reich@markusreich.at
>>>>
>>>>
>>>
>>>
>>> --
>>> *Markus Reich*
>>> Moosbach 28/2
>>> 6392 St. Jakob i.H.
>>> www.markusreich.at / www.meeximum.at
>>> markus.reich@markusreich.at
>>
>
Re: Change data by an external process (non cayenne)
Posted by Mike Kienenberger <mk...@gmail.com>.
Something to keep in mind for web apps is that you probably do not
want to have a data refresh at some arbitrary point during a request,
only at the beginning of a request. It's generally better to have
your data be a second or two out of date than to have the value of an
object or object's relationships change mid-stream while you are
working with it.
I've been using the LAST_EXTERNAL_UPDATE method for several years now,
and I haven't had any regrets. I've considered changing it over to
jms or a similar notification framework, but there weren't any
compelling reasons to do so. This way there's no dependencies in the
external processes (most of which are not maintained or written by
me), and it's also easy to manually execute a database update and
insure that the change will become visible to the active web sessions
immediately. On the other hand, external changes to our database are
rare. Normally only a couple times a day.
On Thu, May 16, 2013 at 1:34 PM, Andrus Adamchik <an...@objectstyle.org> wrote:
> Actually if cross-context events are in effect (which is the default), invalidating an object from a given ObjectContext will automatically invalidate it across peers.
>
> I would still approach it via query cache and cache groups though. All that is needed is that all contexts access those objects via a query instead of storing a direct reference.
>
> Andrus
>
> On May 16, 2013, at 12:14 PM, Markus Reich <ma...@markusreich.at> wrote:
>
>> :-) sorry, I try it more detailed
>>
>> I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by other
>> processes. A refresh is not enough to show the changed data, so my idea is
>> to make a servlet, which invalidates certain DataObjects (mostly it's just
>> one) of all thread binded contexts.
>> So when the user refreshes the UI and the data gets selected again, the
>> changed values are shown.
>> So it would be enough to make object hollow.
>>
>> Markus
>>
>>
>> 2013/5/16 Andrus Adamchik <an...@objectstyle.org>
>>
>>> The question is too generic, so the answer is "yes" :) Could you describe
>>> the scenario in a bit more detail?
>>>
>>> Also does your interface needs to know when an object is invalidated right
>>> at that moment or is it enough to make the object "hollow" so that it is
>>> refetched lazily on next access?
>>>
>>> Andrus
>>>
>>> On May 16, 2013, at 7:52 AM, Markus Reich <ma...@markusreich.at>
>>> wrote:
>>>> would it be possible to work with a servlet to invalidate certain
>>> objects?
>>>>
>>>> Is there a way to get all ObjectStores of all Threads or is the only
>>>> solution to set the DataContext as attribute in the session?
>>>>
>>>>
>>>> 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
>>>>
>>>>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache
>>> the
>>>>> results, and then define expiration time for a given set of cache groups
>>>>> for whatever cache provider is in use (EhCache most likely, so this
>>> will go
>>>>> into ehcache.xml).
>>>>>
>>>>> If you want real-time refresh, EhCache might be configured to listen to
>>>>> cache group refresh events via JMS. Your external process would send
>>> such
>>>>> events via ActiveMQ (that supports a bunch of command-line friendly
>>>>> protocols, not just JMS) whenever the data is changed.
>>>>>
>>>>> Andrus
>>>>>
>>>>>
>>>>> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
>>>>> wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> is there really no better way than described here:
>>>>>> http://markmail.org/message/plnaj4zj4gxrt6hk
>>>>>>
>>>>>> regards
>>>>>> Meex
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> *Markus Reich*
>>>> Moosbach 28/2
>>>> 6392 St. Jakob i.H.
>>>> www.markusreich.at / www.meeximum.at
>>>> markus.reich@markusreich.at
>>>
>>>
>>
>>
>> --
>> *Markus Reich*
>> Moosbach 28/2
>> 6392 St. Jakob i.H.
>> www.markusreich.at / www.meeximum.at
>> markus.reich@markusreich.at
>
Re: Change data by an external process (non cayenne)
Posted by Andrus Adamchik <an...@objectstyle.org>.
Actually if cross-context events are in effect (which is the default), invalidating an object from a given ObjectContext will automatically invalidate it across peers.
I would still approach it via query cache and cache groups though. All that is needed is that all contexts access those objects via a query instead of storing a direct reference.
Andrus
On May 16, 2013, at 12:14 PM, Markus Reich <ma...@markusreich.at> wrote:
> :-) sorry, I try it more detailed
>
> I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by other
> processes. A refresh is not enough to show the changed data, so my idea is
> to make a servlet, which invalidates certain DataObjects (mostly it's just
> one) of all thread binded contexts.
> So when the user refreshes the UI and the data gets selected again, the
> changed values are shown.
> So it would be enough to make object hollow.
>
> Markus
>
>
> 2013/5/16 Andrus Adamchik <an...@objectstyle.org>
>
>> The question is too generic, so the answer is "yes" :) Could you describe
>> the scenario in a bit more detail?
>>
>> Also does your interface needs to know when an object is invalidated right
>> at that moment or is it enough to make the object "hollow" so that it is
>> refetched lazily on next access?
>>
>> Andrus
>>
>> On May 16, 2013, at 7:52 AM, Markus Reich <ma...@markusreich.at>
>> wrote:
>>> would it be possible to work with a servlet to invalidate certain
>> objects?
>>>
>>> Is there a way to get all ObjectStores of all Threads or is the only
>>> solution to set the DataContext as attribute in the session?
>>>
>>>
>>> 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
>>>
>>>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache
>> the
>>>> results, and then define expiration time for a given set of cache groups
>>>> for whatever cache provider is in use (EhCache most likely, so this
>> will go
>>>> into ehcache.xml).
>>>>
>>>> If you want real-time refresh, EhCache might be configured to listen to
>>>> cache group refresh events via JMS. Your external process would send
>> such
>>>> events via ActiveMQ (that supports a bunch of command-line friendly
>>>> protocols, not just JMS) whenever the data is changed.
>>>>
>>>> Andrus
>>>>
>>>>
>>>> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
>>>> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> is there really no better way than described here:
>>>>> http://markmail.org/message/plnaj4zj4gxrt6hk
>>>>>
>>>>> regards
>>>>> Meex
>>>>
>>>>
>>>
>>>
>>> --
>>> *Markus Reich*
>>> Moosbach 28/2
>>> 6392 St. Jakob i.H.
>>> www.markusreich.at / www.meeximum.at
>>> markus.reich@markusreich.at
>>
>>
>
>
> --
> *Markus Reich*
> Moosbach 28/2
> 6392 St. Jakob i.H.
> www.markusreich.at / www.meeximum.at
> markus.reich@markusreich.at
Re: Change data by an external process (non cayenne)
Posted by Markus Reich <ma...@markusreich.at>.
:-) sorry, I try it more detailed
I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by other
processes. A refresh is not enough to show the changed data, so my idea is
to make a servlet, which invalidates certain DataObjects (mostly it's just
one) of all thread binded contexts.
So when the user refreshes the UI and the data gets selected again, the
changed values are shown.
So it would be enough to make object hollow.
Markus
2013/5/16 Andrus Adamchik <an...@objectstyle.org>
> The question is too generic, so the answer is "yes" :) Could you describe
> the scenario in a bit more detail?
>
> Also does your interface needs to know when an object is invalidated right
> at that moment or is it enough to make the object "hollow" so that it is
> refetched lazily on next access?
>
> Andrus
>
> On May 16, 2013, at 7:52 AM, Markus Reich <ma...@markusreich.at>
> wrote:
> > would it be possible to work with a servlet to invalidate certain
> objects?
> >
> > Is there a way to get all ObjectStores of all Threads or is the only
> > solution to set the DataContext as attribute in the session?
> >
> >
> > 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
> >
> >> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache
> the
> >> results, and then define expiration time for a given set of cache groups
> >> for whatever cache provider is in use (EhCache most likely, so this
> will go
> >> into ehcache.xml).
> >>
> >> If you want real-time refresh, EhCache might be configured to listen to
> >> cache group refresh events via JMS. Your external process would send
> such
> >> events via ActiveMQ (that supports a bunch of command-line friendly
> >> protocols, not just JMS) whenever the data is changed.
> >>
> >> Andrus
> >>
> >>
> >> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
> >> wrote:
> >>
> >>> Hi,
> >>>
> >>> is there really no better way than described here:
> >>> http://markmail.org/message/plnaj4zj4gxrt6hk
> >>>
> >>> regards
> >>> Meex
> >>
> >>
> >
> >
> > --
> > *Markus Reich*
> > Moosbach 28/2
> > 6392 St. Jakob i.H.
> > www.markusreich.at / www.meeximum.at
> > markus.reich@markusreich.at
>
>
--
*Markus Reich*
Moosbach 28/2
6392 St. Jakob i.H.
www.markusreich.at / www.meeximum.at
markus.reich@markusreich.at
Re: Change data by an external process (non cayenne)
Posted by Andrus Adamchik <an...@objectstyle.org>.
The question is too generic, so the answer is "yes" :) Could you describe the scenario in a bit more detail?
Also does your interface needs to know when an object is invalidated right at that moment or is it enough to make the object "hollow" so that it is refetched lazily on next access?
Andrus
On May 16, 2013, at 7:52 AM, Markus Reich <ma...@markusreich.at> wrote:
> would it be possible to work with a servlet to invalidate certain objects?
>
> Is there a way to get all ObjectStores of all Threads or is the only
> solution to set the DataContext as attribute in the session?
>
>
> 2013/5/15 Andrus Adamchik <an...@objectstyle.org>
>
>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache the
>> results, and then define expiration time for a given set of cache groups
>> for whatever cache provider is in use (EhCache most likely, so this will go
>> into ehcache.xml).
>>
>> If you want real-time refresh, EhCache might be configured to listen to
>> cache group refresh events via JMS. Your external process would send such
>> events via ActiveMQ (that supports a bunch of command-line friendly
>> protocols, not just JMS) whenever the data is changed.
>>
>> Andrus
>>
>>
>> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
>> wrote:
>>
>>> Hi,
>>>
>>> is there really no better way than described here:
>>> http://markmail.org/message/plnaj4zj4gxrt6hk
>>>
>>> regards
>>> Meex
>>
>>
>
>
> --
> *Markus Reich*
> Moosbach 28/2
> 6392 St. Jakob i.H.
> www.markusreich.at / www.meeximum.at
> markus.reich@markusreich.at
Re: Change data by an external process (non cayenne)
Posted by Markus Reich <ma...@markusreich.at>.
would it be possible to work with a servlet to invalidate certain objects?
Is there a way to get all ObjectStores of all Threads or is the only
solution to set the DataContext as attribute in the session?
2013/5/15 Andrus Adamchik <an...@objectstyle.org>
> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache the
> results, and then define expiration time for a given set of cache groups
> for whatever cache provider is in use (EhCache most likely, so this will go
> into ehcache.xml).
>
> If you want real-time refresh, EhCache might be configured to listen to
> cache group refresh events via JMS. Your external process would send such
> events via ActiveMQ (that supports a bunch of command-line friendly
> protocols, not just JMS) whenever the data is changed.
>
> Andrus
>
>
> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
> wrote:
>
> > Hi,
> >
> > is there really no better way than described here:
> > http://markmail.org/message/plnaj4zj4gxrt6hk
> >
> > regards
> > Meex
>
>
--
*Markus Reich*
Moosbach 28/2
6392 St. Jakob i.H.
www.markusreich.at / www.meeximum.at
markus.reich@markusreich.at
Re: Change data by an external process (non cayenne)
Posted by Markus Reich <ma...@markusreich.at>.
thank for the hint with the cache groups
2013/5/15 Andrus Adamchik <an...@objectstyle.org>
> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache the
> results, and then define expiration time for a given set of cache groups
> for whatever cache provider is in use (EhCache most likely, so this will go
> into ehcache.xml).
>
> If you want real-time refresh, EhCache might be configured to listen to
> cache group refresh events via JMS. Your external process would send such
> events via ActiveMQ (that supports a bunch of command-line friendly
> protocols, not just JMS) whenever the data is changed.
>
> Andrus
>
>
> On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at>
> wrote:
>
> > Hi,
> >
> > is there really no better way than described here:
> > http://markmail.org/message/plnaj4zj4gxrt6hk
> >
> > regards
> > Meex
>
>
--
*Markus Reich*
Moosbach 28/2
6392 St. Jakob i.H.
www.markusreich.at / www.meeximum.at
markus.reich@markusreich.at
Re: Change data by an external process (non cayenne)
Posted by Andrus Adamchik <an...@objectstyle.org>.
I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to cache the results, and then define expiration time for a given set of cache groups for whatever cache provider is in use (EhCache most likely, so this will go into ehcache.xml).
If you want real-time refresh, EhCache might be configured to listen to cache group refresh events via JMS. Your external process would send such events via ActiveMQ (that supports a bunch of command-line friendly protocols, not just JMS) whenever the data is changed.
Andrus
On May 15, 2013, at 4:28 PM, Markus Reich <ma...@markusreich.at> wrote:
> Hi,
>
> is there really no better way than described here:
> http://markmail.org/message/plnaj4zj4gxrt6hk
>
> regards
> Meex