[infinispan-dev] Concurrent hashmaps parameters

[Adrian Cole]

If necessary, MapMaker can help you create a CCHM with parameters relevant
for your deployment schema.

http://google-collections.googlecode.com/svn/trunk/javadoc/com/google/common/collect/MapMaker.html

-A

On Tue, Sep 15, 2009 at 9:59 AM, Christian Vest Hansen <karmazilla at gmail.com
> wrote:

> Using NonBlockingHashMap from highscalelib could be another option.
>
> On Tue, Sep 15, 2009 at 5:59 PM, Bela Ban <bban at redhat.com> wrote:
> > FYI,
> >
> > This might be important for you guys as well (if you haven't done so):
> > I'll add code to configure ConcurrentHashMaps based on system
> > properties, e.g. capacity, load factory etc.
> >
> > This will be important for large clusters. E.g. when we have 1000 nodes
> > in the cluster, most hashmaps in JGroups will contain 1000 entries, and
> > if we only have 16 buckets (the default IIRC), there would be a lot of
> > contention.
> >
> >
> > https://jira.jboss.org/jira/browse/JGRP-1049
> >
> > ConcurrentHashMap
> > -----------------
> >
> > CCHMs have a default initial capacity (16), load factor (0.75) and
> > concurrency level (16). These are OK for most
> > scenarios, but we have to investigate whether these values are
> > sufficient for 1000 node clusters.
> >
> > When for example 1000 threads from different senders access the same
> > CCHM, we need to make sure we don't have high
> > contention, ie. by spreading a 1000 senders over 16 buckets.
> >
> > Investigate whether we should add CCHM initial sizes, load factors and
> > concurrency levels as properties.
> >
> > With ergonomics [1], we could for example set bucket sizes for CCHMs
> > dynamically, e.g. based on cluster size.
> >
> >
> >
> > [1] https://jira.jboss.org/jira/browse/JGRP-1037
> >
> > --
> > Bela Ban
> > Lead JGroups / Clustering Team
> > JBoss
> >
> > _______________________________________________
> > infinispan-dev mailing list
> > infinispan-dev at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/infinispan-dev
> >
>
>
>
> --
> Venlig hilsen / Kind regards,
> Christian Vest Hansen.
> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/infinispan-dev/attachments/20090915/7b11063f/attachment-0002.html