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Posted to jcs-users@jakarta.apache.org by Eddie Liu <ei...@gmail.com> on 2006/04/24 23:40:12 UTC
Disk Cache and MemoryShrinker
I might not understand enough, but when I enabled MemoryShrinker, in the log
when it says:
[4/24/06 17:17:16:688 EDT] 00000036 CacheEventQue I Cache event queue
created: CacheEventQueue [listenerId=-842985658, cacheName=enforce2ListDS]
[4/24/06 17:17:26:703 EDT] 00000041 CacheEventQue I QProcessor exiting for
CacheEventQueue [listenerId=-842985658, cacheName=enforce2ListDS]
>From my observation, that was when it wrote to disk cache? Right after I
saw that, I made another request for the same cached data, but this time it
returned null on the jcs.get(id) call.
Why it didn't load it from disk? I timed it and made sure I made the new
request after it wrote to disk but BEFORE it exceed the maxLifeSeconds. But
it behaved as if it has already expired. Is there anything else I need to
do to get the data from disk-cache?
Thanks alot!
Eddie
Configuration as follow:
-----------------------------------------------------------------------------
jcs.region.listDS=DC
jcs.region.listDS.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes
jcs.region.listDS.cacheattributes.MaxObjects=1200
jcs.region.listDS.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache
jcs.region.listDS.elementattributes.IsEternal=false
jcs.region.listDS.elementattributes.MaxLifeSeconds=30
jcs.region.listDS.elementattributes.IdleTime=1800
jcs.region.listDS.elementattributes.IsSpool=true
jcs.region.listDS.elementattributes.IsRemote=true
jcs.region.listDS.elementattributes.IsLateral=true
jcs.region.listDS.cacheattributes.UseMemoryShrinker=true
jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
jcs.region.listDS.cacheattributes.ShrinkerIntervalSeconds=5
jcs.region.listDS.cacheattributes.MaxSpoolPerRun=500
-----------------------------------------------------------------------------
Re: Disk Cache and MemoryShrinker
Posted by Alistair Forbes <fo...@googlemail.com>.
Least recently used. A MRU (Most recently used) does exist, but I doubt that
this is what you want.
Al
On 4/26/06, Eddie Liu <ei...@gmail.com> wrote:
>
> Thanks for the explanation! I now have a much clearer picture of how JCS
> works.
>
> One thing I want to make sure I understand correctly: When I am using LRU
> memory cache, the *last* recently used item will be spooled to disk when
> an
> item is put into memory? Or the *least* recently used item will be
> spooled
> to disk?
>
> Thanks.
>
> Eddie
>
>
> On 4/24/06, Aaron Smuts <as...@yahoo.com> wrote:
> >
> > The memory shrinker does 2 things.
> >
> > (1) It removes items that have exceeded their max
> > life. That is, it removes them altogether. It
> > doesn't put them on disk; it simply gets rid of them.
> > If you don't run the memory shrinker these items can
> > hang around in memory, but they will not be returned
> > by the jcs.get call. Each time you get an item from
> > the cache, JCS checks to see if it has expired. If it
> > has expired, it will not be returned.
> >
> > (2) The memory shrinker moves items from memory to
> > disk if the items have exceeded their max memory time.
> > In you cache.ccf file this is set on the line that
> > looks like this:
> > jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
> > You have it set to a mere 5 seconds. This is why the
> > items are being put to disk so quickly. Remember that
> > items are also put to disk when the max memory size.
> > If you are using the LRU memory cache, which is the
> > defualt, the lest recently used item will be spooled
> > to disk when an item is put into memory. Items are
> > put into memory in three ways: (a) An item goes into
> > memory if you call put( key, value ). (b) Items are
> > put into memory if they are retrieved from disk. (c)
> > If an item is put into the cache from a lateral or
> > remote auxiliary, it will be added to memory.
> >
> > I hope this helps.
> >
> > Cheers,
> >
> > Aaron
> >
> > --- Eddie Liu <ei...@gmail.com> wrote:
> >
> > > I might not understand enough, but when I enabled
> > > MemoryShrinker, in the log
> > > when it says:
> > >
> > > [4/24/06 17:17:16:688 EDT] 00000036 CacheEventQue I
> > > Cache event queue
> > > created: CacheEventQueue [listenerId=-842985658,
> > > cacheName=enforce2ListDS]
> > > [4/24/06 17:17:26:703 EDT] 00000041 CacheEventQue I
> > > QProcessor exiting for
> > > CacheEventQueue [listenerId=-842985658,
> > > cacheName=enforce2ListDS]
> > >
> > > From my observation, that was when it wrote to disk
> > > cache? Right after I
> > > saw that, I made another request for the same cached
> > > data, but this time it
> > > returned null on the jcs.get(id) call.
> > >
> > > Why it didn't load it from disk? I timed it and
> > > made sure I made the new
> > > request after it wrote to disk but BEFORE it exceed
> > > the maxLifeSeconds. But
> > > it behaved as if it has already expired. Is there
> > > anything else I need to
> > > do to get the data from disk-cache?
> > >
> > > Thanks alot!
> > >
> > > Eddie
> > >
> > > Configuration as follow:
> > >
> >
> >
> -----------------------------------------------------------------------------
> > > jcs.region.listDS=DC
> > >
> >
> >
> jcs.region.listDS.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes
> > > jcs.region.listDS.cacheattributes.MaxObjects=1200
> > >
> >
> >
> jcs.region.listDS.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache
> > > jcs.region.listDS.elementattributes.IsEternal=false
> > >
> > jcs.region.listDS.elementattributes.MaxLifeSeconds=30
> > > jcs.region.listDS.elementattributes.IdleTime=1800
> > > jcs.region.listDS.elementattributes.IsSpool=true
> > > jcs.region.listDS.elementattributes.IsRemote=true
> > > jcs.region.listDS.elementattributes.IsLateral=true
> > >
> > jcs.region.listDS.cacheattributes.UseMemoryShrinker=true
> > >
> > jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
> > >
> > jcs.region.listDS.cacheattributes.ShrinkerIntervalSeconds=5
> > > jcs.region.listDS.cacheattributes.MaxSpoolPerRun=500
> > >
> >
> >
> -----------------------------------------------------------------------------
> > >
> >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: jcs-users-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: jcs-users-help@jakarta.apache.org
> >
> >
>
>
Re: Disk Cache and MemoryShrinker
Posted by Aaron Smuts <as...@yahoo.com>.
Least. See this page for more information.
http://jakarta.apache.org/jcs/index.html
--- Eddie Liu <ei...@gmail.com> wrote:
> Thanks for the explanation! I now have a much
> clearer picture of how JCS
> works.
>
> One thing I want to make sure I understand
> correctly: When I am using LRU
> memory cache, the *last* recently used item will be
> spooled to disk when an
> item is put into memory? Or the *least* recently
> used item will be spooled
> to disk?
>
> Thanks.
>
> Eddie
>
>
> On 4/24/06, Aaron Smuts <as...@yahoo.com> wrote:
> >
> > The memory shrinker does 2 things.
> >
> > (1) It removes items that have exceeded their max
> > life. That is, it removes them altogether. It
> > doesn't put them on disk; it simply gets rid of
> them.
> > If you don't run the memory shrinker these items
> can
> > hang around in memory, but they will not be
> returned
> > by the jcs.get call. Each time you get an item
> from
> > the cache, JCS checks to see if it has expired.
> If it
> > has expired, it will not be returned.
> >
> > (2) The memory shrinker moves items from memory to
> > disk if the items have exceeded their max memory
> time.
> > In you cache.ccf file this is set on the line that
> > looks like this:
> >
>
jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
> > You have it set to a mere 5 seconds. This is why
> the
> > items are being put to disk so quickly. Remember
> that
> > items are also put to disk when the max memory
> size.
> > If you are using the LRU memory cache, which is
> the
> > defualt, the lest recently used item will be
> spooled
> > to disk when an item is put into memory. Items
> are
> > put into memory in three ways: (a) An item goes
> into
> > memory if you call put( key, value ). (b) Items
> are
> > put into memory if they are retrieved from disk.
> (c)
> > If an item is put into the cache from a lateral or
> > remote auxiliary, it will be added to memory.
> >
> > I hope this helps.
> >
> > Cheers,
> >
> > Aaron
> >
> > --- Eddie Liu <ei...@gmail.com> wrote:
> >
> > > I might not understand enough, but when I
> enabled
> > > MemoryShrinker, in the log
> > > when it says:
> > >
> > > [4/24/06 17:17:16:688 EDT] 00000036
> CacheEventQue I
> > > Cache event queue
> > > created: CacheEventQueue [listenerId=-842985658,
> > > cacheName=enforce2ListDS]
> > > [4/24/06 17:17:26:703 EDT] 00000041
> CacheEventQue I
> > > QProcessor exiting for
> > > CacheEventQueue [listenerId=-842985658,
> > > cacheName=enforce2ListDS]
> > >
> > > From my observation, that was when it wrote to
> disk
> > > cache? Right after I
> > > saw that, I made another request for the same
> cached
> > > data, but this time it
> > > returned null on the jcs.get(id) call.
> > >
> > > Why it didn't load it from disk? I timed it and
> > > made sure I made the new
> > > request after it wrote to disk but BEFORE it
> exceed
> > > the maxLifeSeconds. But
> > > it behaved as if it has already expired. Is
> there
> > > anything else I need to
> > > do to get the data from disk-cache?
> > >
> > > Thanks alot!
> > >
> > > Eddie
> > >
> > > Configuration as follow:
> > >
> >
> >
>
-----------------------------------------------------------------------------
> > > jcs.region.listDS=DC
> > >
> >
> >
>
jcs.region.listDS.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes
> > >
> jcs.region.listDS.cacheattributes.MaxObjects=1200
> > >
> >
> >
>
jcs.region.listDS.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache
> > >
> jcs.region.listDS.elementattributes.IsEternal=false
> > >
> >
>
jcs.region.listDS.elementattributes.MaxLifeSeconds=30
> > >
> jcs.region.listDS.elementattributes.IdleTime=1800
> > > jcs.region.listDS.elementattributes.IsSpool=true
> > >
> jcs.region.listDS.elementattributes.IsRemote=true
> > >
> jcs.region.listDS.elementattributes.IsLateral=true
> > >
> >
>
jcs.region.listDS.cacheattributes.UseMemoryShrinker=true
> > >
> >
>
jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
> > >
> >
>
jcs.region.listDS.cacheattributes.ShrinkerIntervalSeconds=5
> > >
> jcs.region.listDS.cacheattributes.MaxSpoolPerRun=500
> > >
> >
> >
>
-----------------------------------------------------------------------------
> > >
> >
> >
> >
>
---------------------------------------------------------------------
> > To unsubscribe, e-mail:
> jcs-users-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail:
> jcs-users-help@jakarta.apache.org
> >
> >
>
---------------------------------------------------------------------
To unsubscribe, e-mail: jcs-users-unsubscribe@jakarta.apache.org
For additional commands, e-mail: jcs-users-help@jakarta.apache.org
Re: Disk Cache and MemoryShrinker
Posted by Eddie Liu <ei...@gmail.com>.
Thanks for the explanation! I now have a much clearer picture of how JCS
works.
One thing I want to make sure I understand correctly: When I am using LRU
memory cache, the *last* recently used item will be spooled to disk when an
item is put into memory? Or the *least* recently used item will be spooled
to disk?
Thanks.
Eddie
On 4/24/06, Aaron Smuts <as...@yahoo.com> wrote:
>
> The memory shrinker does 2 things.
>
> (1) It removes items that have exceeded their max
> life. That is, it removes them altogether. It
> doesn't put them on disk; it simply gets rid of them.
> If you don't run the memory shrinker these items can
> hang around in memory, but they will not be returned
> by the jcs.get call. Each time you get an item from
> the cache, JCS checks to see if it has expired. If it
> has expired, it will not be returned.
>
> (2) The memory shrinker moves items from memory to
> disk if the items have exceeded their max memory time.
> In you cache.ccf file this is set on the line that
> looks like this:
> jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
> You have it set to a mere 5 seconds. This is why the
> items are being put to disk so quickly. Remember that
> items are also put to disk when the max memory size.
> If you are using the LRU memory cache, which is the
> defualt, the lest recently used item will be spooled
> to disk when an item is put into memory. Items are
> put into memory in three ways: (a) An item goes into
> memory if you call put( key, value ). (b) Items are
> put into memory if they are retrieved from disk. (c)
> If an item is put into the cache from a lateral or
> remote auxiliary, it will be added to memory.
>
> I hope this helps.
>
> Cheers,
>
> Aaron
>
> --- Eddie Liu <ei...@gmail.com> wrote:
>
> > I might not understand enough, but when I enabled
> > MemoryShrinker, in the log
> > when it says:
> >
> > [4/24/06 17:17:16:688 EDT] 00000036 CacheEventQue I
> > Cache event queue
> > created: CacheEventQueue [listenerId=-842985658,
> > cacheName=enforce2ListDS]
> > [4/24/06 17:17:26:703 EDT] 00000041 CacheEventQue I
> > QProcessor exiting for
> > CacheEventQueue [listenerId=-842985658,
> > cacheName=enforce2ListDS]
> >
> > From my observation, that was when it wrote to disk
> > cache? Right after I
> > saw that, I made another request for the same cached
> > data, but this time it
> > returned null on the jcs.get(id) call.
> >
> > Why it didn't load it from disk? I timed it and
> > made sure I made the new
> > request after it wrote to disk but BEFORE it exceed
> > the maxLifeSeconds. But
> > it behaved as if it has already expired. Is there
> > anything else I need to
> > do to get the data from disk-cache?
> >
> > Thanks alot!
> >
> > Eddie
> >
> > Configuration as follow:
> >
>
> -----------------------------------------------------------------------------
> > jcs.region.listDS=DC
> >
>
> jcs.region.listDS.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes
> > jcs.region.listDS.cacheattributes.MaxObjects=1200
> >
>
> jcs.region.listDS.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache
> > jcs.region.listDS.elementattributes.IsEternal=false
> >
> jcs.region.listDS.elementattributes.MaxLifeSeconds=30
> > jcs.region.listDS.elementattributes.IdleTime=1800
> > jcs.region.listDS.elementattributes.IsSpool=true
> > jcs.region.listDS.elementattributes.IsRemote=true
> > jcs.region.listDS.elementattributes.IsLateral=true
> >
> jcs.region.listDS.cacheattributes.UseMemoryShrinker=true
> >
> jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
> >
> jcs.region.listDS.cacheattributes.ShrinkerIntervalSeconds=5
> > jcs.region.listDS.cacheattributes.MaxSpoolPerRun=500
> >
>
> -----------------------------------------------------------------------------
> >
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: jcs-users-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: jcs-users-help@jakarta.apache.org
>
>
Re: Disk Cache and MemoryShrinker
Posted by Aaron Smuts <as...@yahoo.com>.
The memory shrinker does 2 things.
(1) It removes items that have exceeded their max
life. That is, it removes them altogether. It
doesn't put them on disk; it simply gets rid of them.
If you don't run the memory shrinker these items can
hang around in memory, but they will not be returned
by the jcs.get call. Each time you get an item from
the cache, JCS checks to see if it has expired. If it
has expired, it will not be returned.
(2) The memory shrinker moves items from memory to
disk if the items have exceeded their max memory time.
In you cache.ccf file this is set on the line that
looks like this:
jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
You have it set to a mere 5 seconds. This is why the
items are being put to disk so quickly. Remember that
items are also put to disk when the max memory size.
If you are using the LRU memory cache, which is the
defualt, the lest recently used item will be spooled
to disk when an item is put into memory. Items are
put into memory in three ways: (a) An item goes into
memory if you call put( key, value ). (b) Items are
put into memory if they are retrieved from disk. (c)
If an item is put into the cache from a lateral or
remote auxiliary, it will be added to memory.
I hope this helps.
Cheers,
Aaron
--- Eddie Liu <ei...@gmail.com> wrote:
> I might not understand enough, but when I enabled
> MemoryShrinker, in the log
> when it says:
>
> [4/24/06 17:17:16:688 EDT] 00000036 CacheEventQue I
> Cache event queue
> created: CacheEventQueue [listenerId=-842985658,
> cacheName=enforce2ListDS]
> [4/24/06 17:17:26:703 EDT] 00000041 CacheEventQue I
> QProcessor exiting for
> CacheEventQueue [listenerId=-842985658,
> cacheName=enforce2ListDS]
>
> From my observation, that was when it wrote to disk
> cache? Right after I
> saw that, I made another request for the same cached
> data, but this time it
> returned null on the jcs.get(id) call.
>
> Why it didn't load it from disk? I timed it and
> made sure I made the new
> request after it wrote to disk but BEFORE it exceed
> the maxLifeSeconds. But
> it behaved as if it has already expired. Is there
> anything else I need to
> do to get the data from disk-cache?
>
> Thanks alot!
>
> Eddie
>
> Configuration as follow:
>
-----------------------------------------------------------------------------
> jcs.region.listDS=DC
>
jcs.region.listDS.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes
> jcs.region.listDS.cacheattributes.MaxObjects=1200
>
jcs.region.listDS.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache
> jcs.region.listDS.elementattributes.IsEternal=false
>
jcs.region.listDS.elementattributes.MaxLifeSeconds=30
> jcs.region.listDS.elementattributes.IdleTime=1800
> jcs.region.listDS.elementattributes.IsSpool=true
> jcs.region.listDS.elementattributes.IsRemote=true
> jcs.region.listDS.elementattributes.IsLateral=true
>
jcs.region.listDS.cacheattributes.UseMemoryShrinker=true
>
jcs.region.listDS.cacheattributes.MaxMemoryIdleTimeSeconds=5
>
jcs.region.listDS.cacheattributes.ShrinkerIntervalSeconds=5
> jcs.region.listDS.cacheattributes.MaxSpoolPerRun=500
>
-----------------------------------------------------------------------------
>
---------------------------------------------------------------------
To unsubscribe, e-mail: jcs-users-unsubscribe@jakarta.apache.org
For additional commands, e-mail: jcs-users-help@jakarta.apache.org