[mod_cluster-issues] [JBoss JIRA] (MODCLUSTER-372) Number of registered contexts negatively affects mod_cluster performance
Michal Babacek (JIRA)
issues at jboss.org
Mon Feb 24 07:43:47 EST 2014
[ https://issues.jboss.org/browse/MODCLUSTER-372?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12947320#comment-12947320 ]
Michal Babacek commented on MODCLUSTER-372:
-------------------------------------------
I've revisited the mod_jk/mod_cluster performance benchmarks, this time with multiple contexts (mod_cluster's weak spot). There were 5 workers, 61 deployed contexts each. The *{{sessions}}* label represents the number of active clients, keeping sessions and sending 1 request per second each.
||natives||sessions||mean response time, {{ms}}||throughput, {{samples/s}}||CPU load, {{%}}||
|m_c 1.2.6.Final|2000|1182|901.4|85|
|m_c 1.2.x HEAD:1d1512f|2000|1221|906.8|85|
|m_c 1.3.1 HEAD:88040c3|2000|1572|781.6|34|
|mod_jk/1.2.37|2000|651|1237.9|9|
||natives||sessions||mean response time, {{ms}}||throughput, {{samples/s}}||CPU load, {{%}}||
|m_c 1.2.6.Final|1700|899|895.4|85|
|m_c 1.2.x HEAD:1d1512f|1700|853|924.4|85|
|m_c 1.3.1 HEAD:88040c3|1700|259|1345.9|53|
|mod_jk/1.2.37|1700|16|1672.9|10|
Given the additional logic mod_cluster computes on the balancer, I believe it is actually not a fair comparison though. One should be comparing apples to apples which, in this case, does not hold, so the mod_jk data should be considered only as a reference.
> Number of registered contexts negatively affects mod_cluster performance
> ------------------------------------------------------------------------
>
> Key: MODCLUSTER-372
> URL: https://issues.jboss.org/browse/MODCLUSTER-372
> Project: mod_cluster
> Issue Type: Bug
> Affects Versions: 1.2.4.Final, 1.2.6.Final
> Environment: RHEL6, other platforms are to be confirmed.
> Reporter: Michal Babacek
> Assignee: Jean-Frederic Clere
> Labels: mod_cluster, performace
> Fix For: 1.3.0.Final, 1.2.8.Final
>
> Attachments: 4-workers-1-context-balancer-cpu.png, 4-workers-61-context-accessing-1-balancer-cpu.png, 9-workers-1-context-balancer-cpu.png, 9-workers-31-context-accessing-1-balancer-cpu.png, 9-workers-31-context-round-robin-balancer-cpu.png, callgrind.zip, httpd.conf
>
>
> There is a performance concern regarding CPU usage on the Apache HTTP Server with mod_cluster set up as a load balancer. Perf tests revealed that the major variable affecting the CPU usage is the overall number of registered contexts. It's noteworthy that these contexts actually don't need to be accessed at all, it's enough that they are present.
> The first test [9 workers, 31 contexts, round robin|https://issues.jboss.org/browse/MODCLUSTER-372#9workers,31contexts,roundrobin] depicts a behavior where all contexts are being accessed in a round robin fashion. Note the CPU usage. If we compare it to the [9 workers, 1 context|https://issues.jboss.org/browse/MODCLUSTER-372#9workers,1context] test, it becomes apparent that there is something wrong with the CPU usage. As it is clear from the [9 workers, 31 contexts, access 1|https://issues.jboss.org/browse/MODCLUSTER-372#9workers,31contexts,accessingonlyoneofthem] test, accessing only one of these contexts doesn't help much.
> The last two tests, [4 workers, 61 contexts, accessing 1|https://issues.jboss.org/browse/MODCLUSTER-372#4workers,61contexts,accessingonlyoneofthem] and [4 workers, 1 context|https://issues.jboss.org/browse/MODCLUSTER-372#4workers,1context] confirm the results, environment differs only in number of nodes and number of contexts.
> [^httpd.conf] attached, stay tuned for some profiler outputs...
> h3. 9 workers, 31 contexts, round robin
> !9-workers-31-context-round-robin-balancer-cpu.png|thumbnail!
> ||Nodes||Sessions||Ses.Active||Samples||samples/s||mean resp. ms||max resp. ms||conn. errors||valid samples||%||
> |9|150|150|8843|147.4|15|60|0|8843|100%|
> |9|250|250|14422|240.3|37|215|0|14422|100%|
> |9|350|350|17551|292.5|196|443|0|17551|100%|
> |9|450|450|21303|355.0|269|603|0|21303|100%|
> |9|550|550|24818|413.6|325|686|0|24818|100%|
> |9|650|650|26804|446.7|469|800|0|26804|100%|
> |9|750|750|29930|498.8|507|985|0|29930|100%|
> |9|850|850|30665|511.0|665|1185|0|30665|100%|
> |9|950|950|34421|573.6|647|1316|0|34421|100%|
> |9|1050|1050|35067|584.4|800|1487|0|35067|100%|
> |9|1150|1150|36024|600.4|925|1612|0|36024|100%|
> |9|1250|1250|36635|610.5|1030|1815|0|36635|100%|
> |9|1350|1350|38395|639.9|1096|1942|0|38395|100%|
> |9|1450|1450|39713|661.8|1170|2466|0|39713|100%|
> |9|1550|1550|39455|657.5|1392|2340|0|39455|100%|
> |9|1650|1650|39849|664.1|1465|4240|0|39849|100%|
> |9|1750|1750|42435|707.2|1454|6511|0|42435|100%|
> |9|1850|1850|44714|745.2|1498|4866|0|44714|100%|
> |9|1950|1911|46072|767.8|1554|43016|0|46072|100%|
> |9|2050|1911|44496|741.5|1617|4953|39|44457|99%|
> |9|2150|1911|43715|728.5|1632|5348|125|43590|99%|
> |9|2250|1911|41112|685.1|1764|9800|155|40957|99%|
> h3. 9 workers, 31 contexts, accessing only one of them
> !9-workers-31-context-accessing-1-balancer-cpu.png|thumbnail!
> ||Nodes||Sessions||Ses.Active||Samples||samples/s||mean resp. ms||max resp. ms||conn. errors||valid samples||%||
> |9|150|150|8954|149.2|4|42|0|8954|100%|
> |9|250|250|14897|248.3|7|33|0|14897|100%|
> |9|350|350|20784|346.4|8|68|0|20784|100%|
> |9|450|450|26748|445.8|8|69|0|26748|100%|
> |9|550|550|32553|542.5|11|92|0|32553|100%|
> |9|650|650|38558|642.6|10|60|0|38558|100%|
> |9|750|750|43571|726.1|29|329|0|43571|100%|
> |9|850|850|46133|768.8|99|494|0|46133|100%|
> |9|950|950|50854|847.5|120|501|0|50854|100%|
> |9|1050|1050|54451|907.4|154|584|0|54451|100%|
> |9|1150|1150|59961|999.3|138|674|0|59961|100%|
> |9|1250|1250|62567|1,042.6|198|675|0|62567|100%|
> |9|1350|1350|61939|1,032.2|301|799|0|61939|100%|
> |9|1450|1450|67920|1,131.9|276|844|0|67920|100%|
> |9|1550|1550|73151|1,219.1|261|861|0|73151|100%|
> |9|1650|1650|73937|1,232.2|332|955|0|73937|100%|
> |9|1750|1750|73516|1,225.2|423|1046|0|73516|100%|
> |9|1850|1850|72556|1,209.1|515|1264|0|72556|100%|
> |9|1950|1911|78613|1,310.1|454|50273|0|78613|100%|
> |9|2050|1911|80141|1,335.6|431|1225|39|80102|99%|
> |9|2150|1911|76979|1,282.9|490|1338|127|76852|99%|
> |9|2250|1911|78048|1,300.7|464|1305|136|77912|99%|
> h3. 9 workers, 1 context
> !9-workers-1-context-balancer-cpu.png|thumbnail!
> ||Nodes||Sessions||Ses.Active||Samples||samples/s||mean resp. ms||max resp. ms||conn. errors||valid samples||%||
> |9|150|150|8965|149.4|2|12|0|8965|100%|
> |9|250|250|14965|249.4|2|22|0|14965|100%|
> |9|350|350|20950|349.1|2|23|0|20950|100%|
> |9|450|450|26941|449.0|2|26|0|26941|100%|
> |9|550|550|32937|548.9|1|26|0|32937|100%|
> |9|650|650|38900|648.3|1|19|0|38900|100%|
> |9|750|750|44918|748.6|1|11|0|44918|100%|
> |9|850|850|50902|848.3|2|22|0|50902|100%|
> |9|950|950|56878|947.9|1|14|0|56878|100%|
> |9|1050|1050|62874|1,047.8|2|12|0|62874|100%|
> |9|1150|1150|68845|1,147.3|2|99|0|68845|100%|
> |9|1250|1250|74851|1,247.4|2|103|0|74851|100%|
> |9|1350|1350|80826|1,347.0|2|100|0|80826|100%|
> |9|1450|1450|86806|1,446.7|2|19|0|86806|100%|
> |9|1550|1550|92817|1,546.8|2|52|0|92817|100%|
> |9|1650|1650|98774|1,646.1|2|18|0|98774|100%|
> |9|1750|1750|104755|1,745.8|2|18|0|104755|100%|
> |9|1850|1850|110734|1,845.4|2|20|0|110734|100%|
> |9|1950|1910|113419|1,890.2|9|41855|0|113419|100%|
> |9|2050|1911|114437|1,907.1|2|77962|39|114397|99%|
> |9|2150|1911|114481|1,907.9|2|15|128|114353|99%|
> |9|2250|1911|114545|1,908.9|2|24|144|114401|99%|
> h3. 4 workers, 61 contexts, accessing only one of them
> !4-workers-61-context-accessing-1-balancer-cpu.png|thumbnail!
> ||Nodes||Sessions||Ses.Active||Samples||samples/s||mean resp. ms||max resp. ms||conn. errors||valid samples||%||
> |4|500|500|29796|496.6|6|52|0|29796|100%|
> |4|650|650|38706|645.0|7|149|0|38706|100%|
> |4|800|800|47585|793.0|8|129|0|47585|100%|
> |4|950|950|54467|907.7|43|377|0|54467|100%|
> |4|1100|1100|62500|1,041.6|54|396|0|62500|100%|
> |4|1250|1250|69446|1,157.3|81|512|0|69446|100%|
> |4|1400|1400|76217|1,270.2|97|517|0|76217|100%|
> |4|1550|1550|80216|1,336.8|152|810|0|80216|100%|
> |4|1700|1700|80797|1,346.5|271|864|0|80797|100%|
> |4|1850|1850|94172|1,569.3|182|822|0|94172|100%|
> |4|2000|1916|91014|1,516.8|253|48650|0|91014|100%|
> |4|2150|1916|95852|1,597.4|205|848|83|95769|99%|
> h3. 4 workers, 1 context
> !4-workers-1-context-balancer-cpu.png|thumbnail!
> ||Nodes||Sessions||Ses.Active||Samples||samples/s||mean resp. ms||max resp. ms||conn. errors||valid samples||%||
> |4|500|500|29922|498.7|2|39|0|29922|100%|
> |4|650|650|38923|648.7|1|39|0|38923|100%|
> |4|800|800|47916|798.5|1|17|0|47916|100%|
> |4|950|950|56896|948.2|1|17|0|56896|100%|
> |4|1100|1100|65889|1,098.1|1|115|0|65889|100%|
> |4|1250|1250|74874|1,247.8|1|101|0|74874|100%|
> |4|1400|1400|83818|1,396.8|1|17|0|83818|100%|
> |4|1550|1550|92830|1,547.0|1|17|0|92830|100%|
> |4|1700|1700|101805|1,696.6|1|11|0|101805|100%|
> |4|1850|1850|110785|1,846.3|1|11|0|110785|100%|
> |4|2000|1916|113747|1,895.6|10|53108|0|113747|100%|
> |4|2150|1916|114825|1,913.6|1|24|83|114742|99%|
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
More information about the mod_cluster-issues
mailing list