Re: [infinispan-dev] Concurrent hashmaps parameters

Using NonBlockingHashMap from highscalelib could be another option. On Tue, Sep 15, 2009 at 5:59 PM, Bela Ban <bban(a)redhat.com&gt; 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(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/infinispan-dev >