jakarta-jcs-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Simon Horton" <Simon.Hor...@uk.mizuho-sc.com>
Subject RE: Guaranteed persistence
Date Wed, 04 Aug 2010 10:23:15 GMT
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. 


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
it programatically with the following properties:


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
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

Do these sound like something that is possible with JCS? I've looked
all the documentation and can't find anything along these lines.



On 3 August 2010 20:17, Jorge Medina <cerebrotecnologico@gmail.com>

> 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>
> > Hi,
> >
> > I am looking into using JCS as a disk-based key-value store, and it
> to
> > work fine. However if the jvm is terminated, the .key file may not
> > written to, and although the .data file has my data in, when I
> 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
> > Having MaxObjects=0 on the memory cache seems to help, but still
> > cause the .key file to be written.
> >
> > I also though I might be able to use ICacheEventLogger to see when
> has
> > actually been written to the disk store, but the logging stuff
> 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

View raw message