jakarta-jcs-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Tim Stibbs <stripybad...@gmail.com>
Subject Re: Guaranteed persistence
Date Wed, 04 Aug 2010 10:45:49 GMT
Thanks Simon,

That's one of the options I had tried - for some reason it seems to result
in nothing being written to the cache at all. Is there another option that I
need to use in conjunction with MaxPurgatorySize?

On 4 August 2010 11:23, Simon Horton <Simon.Horton@uk.mizuho-sc.com> wrote:

> Hi Tim,
>
> Try setting your MaxPurgatorySize to 0 so there is no asynchronous
> caching of data written to the disk cache, it will reduce your
> performance but means your data goes straight to disk.
>
> jcs.auxiliary.DC.attributes.MaxPurgatorySize=0
>
> Purgatory
> Writing to the disk cache is asynchronous and made efficient by using a
> memory staging area called purgatory. Retrievals check purgatory then
> disk for an item. When items are sent to purgatory they are
> simultaneously queued to be put to disk. If an item is retrieved from
> purgatory it will no longer be written to disk, since the cache hub will
> move it back to memory. Using purgatory insures that there is no wait
> for disk writes, unecessary disk writes are avoided for borderline
> items, and the items are always available
>
>
>
> -----Original Message-----
> From: Tim Stibbs [mailto:stripybadger@gmail.com]
> Sent: 04 August 2010 08:25
> To: JCS Users List
> Subject: Re: Guaranteed persistence
>
> I am using CompositeCacheManager.getUnconfiguredInstance(); and
> configuring
> it programatically with the following properties:
>
> jcs.default=DC
> jcs.default.cacheattributes=org.apache.jcs.engine.CompositeCacheAttribut
> es
> jcs.default.cacheattributes.MaxObjects=0
> jcs.default.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory
> .lru.LRUMemoryCache
> jcs.auxiliary.DC=org.apache.jcs.auxiliary.disk.indexed.IndexedDiskCacheF
> actory
> jcs.auxiliary.DC.attributes=org.apache.jcs.auxiliary.disk.indexed.Indexe
> dDiskCacheAttributes
> jcs.auxiliary.DC.attributes.DiskPath=C:\path\etc
> jcs.auxiliary.DC.attributes.MaxKeySize=1000
> jcs.auxiliary.DC.attributes.OptimizeAtRemoveCount=1000
>
> My main aims are:
> - guaranteed persistence - once I've added it to the cache, even if the
> application crashes, the key value pair will still be available when the
> app
> starts up again
> - a non-infinite cache - I want the number of items in the cache to not
> exceed order of 1000 to conserve disk space, though the exact number is
> not
> important.
>
> Do these sound like something that is possible with JCS? I've looked
> through
> all the documentation and can't find anything along these lines.
>
> Thanks,
>
> Tim.
>
> On 3 August 2010 20:17, Jorge Medina <cerebrotecnologico@gmail.com>
> wrote:
>
> > Look at :
> > http://jakarta.apache.org/jcs/RegionProperties.html
> > and
> > http://jakarta.apache.org/jcs/IndexedDiskCacheProperties.html
> >
> > What are the properties of your disk cache ?
> >
> >
> > On Mon, Aug 2, 2010 at 4:51 AM, Tim Stibbs <stripybadger@gmail.com>
> wrote:
> > > Hi,
> > >
> > > I am looking into using JCS as a disk-based key-value store, and it
> seems
> > to
> > > work fine. However if the jvm is terminated, the .key file may not
> get
> > > written to, and although the .data file has my data in, when I
> restart
> > the
> > > application it cannot access anything in the cache (presumably due
> to the
> > > .key file being empty).
> > >
> > > So, is there anyway to force the cache to immediately persist to
> disk?
> > > Having MaxObjects=0 on the memory cache seems to help, but still
> doesn't
> > > cause the .key file to be written.
> > >
> > > I also though I might be able to use ICacheEventLogger to see when
> data
> > has
> > > actually been written to the disk store, but the logging stuff
> doesn't
> > seem
> > > to be in the released version, although it is in the documentation?
> > >
> > > Does anyone know if it is even possible to do what I am trying to
> do, or
> > > have any suggestions?
> > >
> > > Thanks.
> > >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: jcs-users-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: jcs-users-help@jakarta.apache.org
> >
> >
>
> This message and any files transmitted with it are confidential and
> intended solely for the use of the individual or entity to whom they are
> addressed. If you have received this message in error please delete it and
> any files transmitted with it, after notifying postmaster@uk.mizuho-sc.com
> Any opinions expressed in this message may be those of the author and not
> necessarily those of the company. The company accepts no responsibility for
> the accuracy or completeness of any information contained herein. This
> message is not intended to create legal relations between the company and
> the recipient.
> Recipients should please note that messages sent via the Internet may be
> intercepted and that caution should therefore be exercised before
> dispatching to the company any confidential or sensitive information.
> Mizuho International plc Bracken House, One Friday Street, London EC4M 9JA.
> TEL. 020 72361090. Wholly owned subsidiary of Mizuho Securities Co., Ltd.
> Member of Mizuho Financial Group. Authorised and regulated by the Financial
> Services Authority. Member of the London Stock Exchange.
>
> Registered in England No. 1203696. Registered office as above.
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: jcs-users-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: jcs-users-help@jakarta.apache.org
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message