Bug 810155

I'll try to obtain improved JProfiler snapshots (based on sampling for this)

Workaround: for size2 installations use JGroups config with UNICAST if it performs better.

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Hot rod client stress tests of cluster of size 2 perform better with ER4 JGroups config (UNICAST) vs ER6 (UNICAST2+RSVP)

Changed target release to 6.0.0.GA.

Ondra, pls update the status once you run ER10 with ER4 jgroups config for 2 node cluster.

[1] is a throughput chart of a client stress test with Hotrod, dist, cluster size2 and jgroups subsystem config used in ER4. It can handle 25% more clients then when we use our common config although the max throughput is approximately the same.

[1] https://hudson.qa.jboss.com/hudson/view/EDG6/view/EDG-REPORTS-PERF/job/edg-60-perf-client-stress-test-hotrod/279/artifact/report/throughput.png

Ondra, we would need to run this again with ER11. If this is still the case then your observation needs to be documented in tuning guide.

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@@ -1 +1 @@
-Hot rod client stress tests of cluster of size 2 perform better with ER4 JGroups config (UNICAST) vs ER6 (UNICAST2+RSVP)+Hot rod client stress tests with a two node cluster results in better performance with the ER4 JGroups configuration (using UNICAST) than the ER6 JGroups configuration (using UNICAST2 and RSVP).

For ER11 the conclusion is that for cluster size 2 the performance is better with jgroups configuration used with ER4 while it doesn't improve size 4 perf.

Prabhat's very valid point about external parties not knowing what we refer to by ERX:

"ER releases are internal and customers wont understand what we mean by these. I suggest this to convey "Out of box configuration is not optimal for a 2-node cluster." Ideally this should mention code snippet with right configuration or point to some URL which  has the configuration."

Flagging Michal as he provided the original information for this bug.

Created attachment 590427 [details]
JGroups UNICAST UDP config snippet

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@@ -1 +1 @@
-Hot rod client stress tests with a two node cluster results in better performance with the ER4 JGroups configuration (using UNICAST) than the ER6 JGroups configuration (using UNICAST2 and RSVP).+Out-of-the-box JGroups configuration (using UNICAST2 and RSVP) might not lead to optimal performance in 2-node cluster scenario. We've found that 2-node clusters perform better with UNICAST and without RSVP. See attached JGroups subsystem configuration snippet "JGroups UNICAST UDP config snippet".

    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -1 +1 @@
-Out-of-the-box JGroups configuration (using UNICAST2 and RSVP) might not lead to optimal performance in 2-node cluster scenario. We've found that 2-node clusters perform better with UNICAST and without RSVP. See attached JGroups subsystem configuration snippet "JGroups UNICAST UDP config snippet".+The default JBoss Data Grid JGroups configuration (using UNICAST2 and RSVP) does not lead to optimal performance in a two node cluster scenario. Two node clusters show improved performance with UNICAST and without RSVP.

In hyperion size2 tests the performance difference isn't that significant
http://www.qa.jboss.com/~mlinhard/hyperion/run190-client-stress-02-CR2-unicast-no-rsvp/compare/merged-throughput.png

The two runs differ only in configuration of JGroups stack in the two protocols (UNICAST vs UNICAST2+RSVP), every other setting I've synced.
http://www.qa.jboss.com/~mlinhard/hyperion/run190-client-stress-02-CR2-unicast-no-rsvp/compare/configs/standalone_unicast.xml
http://www.qa.jboss.com/~mlinhard/hyperion/run190-client-stress-02-CR2-unicast-no-rsvp/compare/configs/standalone_unicast2+rsvp.xml

Perf difference (UNICAST vs UNICAST2+RSVP)
max number of clients: 26000 vs 23500 (10.6 %)
max throughput: 132609.20 vs 129351.05 (2.5 %)

The JDG 6.0.1 ER1 server distribution now contains a sample configuration file ($JDG_HOME/docs/examples/configs/standalone-two-nodes.xml) with so far the most optimal configuration for 2-node cluster. I'm closing this for now as verified but in the future we should find out if there's not even a better configuration in terms of performance.