Hi Emmanuel, Yes exactly! Thanks a lot, i should have searched the Jira first.
I tried the patch and i confirm a 50% boost in performance (in terms of CPU %). Regards, Alex On Wed, Oct 9, 2013 at 4:15 PM, Emmanuel Lécharny <elecha...@gmail.com>wrote: > Hi Alex, > > it's quite likely connected to this JIRA : > > > https://issues.apache.org/jira/browse/DIRMINA-948?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13790224#comment-13790224 > > right ? > > > > Le 10/9/13 3:14 PM, Alexandros Touloupis a écrit : > > Hi all, > > > > I am currently stress testing my application that uses MINA. In my stress > > test I am quite satisfied with the TPS handled by the application, but > > still i think there is room for improvement. > > I am using mina 2.0.7 and i monitored during the stress test using the > > VisualVM. CPU sampler shows huge amount spend in the > > DefaultWriteRequestQueue.size method. > > > > > org.apache.mina.core.session.DefaultIoSessionDataStructureFactory$DefaultWriteRequestQueue.size() > > 70.299576 2138327 ms (70.3%) 2138327 ms > > > > From the thread dump I could see that most threads were spending most of > > the time in the following stack trace: > > > > java.lang.Thread.State: RUNNABLE > > at > > > java.util.concurrent.ConcurrentLinkedQueue.size(ConcurrentLinkedQueue.java:449) > > at > > > org.apache.mina.core.session.DefaultIoSessionDataStructureFactory$DefaultWriteRequestQueue.size(DefaultIoSessionDataStructureFactory.java:232) > > at > > > org.apache.mina.core.session.AbstractIoSession$CloseAwareWriteQueue.size(AbstractIoSession.java:1388) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain$HeadFilter.filterWrite(DefaultIoFilterChain.java:600) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.callPreviousFilterWrite(DefaultIoFilterChain.java:482) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1400(DefaultIoFilterChain.java:47) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.filterWrite(DefaultIoFilterChain.java:775) > > at > > > org.apache.mina.core.filterchain.IoFilterAdapter.filterWrite(IoFilterAdapter.java:123) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.callPreviousFilterWrite(DefaultIoFilterChain.java:482) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1400(DefaultIoFilterChain.java:47) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.filterWrite(DefaultIoFilterChain.java:775) > > at > > > org.apache.mina.filter.codec.ProtocolCodecFilter.filterWrite(ProtocolCodecFilter.java:331) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.callPreviousFilterWrite(DefaultIoFilterChain.java:482) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1400(DefaultIoFilterChain.java:47) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.filterWrite(DefaultIoFilterChain.java:775) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.filterWrite(DefaultIoFilterChain.java:705) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.callPreviousFilterWrite(DefaultIoFilterChain.java:482) > > at > > > org.apache.mina.core.filterchain.DefaultIoFilterChain.fireFilterWrite(DefaultIoFilterChain.java:475) > > at > > > org.apache.mina.core.session.AbstractIoSession.write(AbstractIoSession.java:494) > > at > > > org.apache.mina.core.session.AbstractIoSession.write(AbstractIoSession.java:439) > > > > > > As it is states in the javadoc > > > http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentLinkedQueue.html > > ConcurrentLinkedQueue#size() > > method is *NOT* a constant-time operation. > > Actually it seems quite costly as it tries to determine the first element > > in a for(;;) loop ( > > > http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/util/AbstractCollection.java#AbstractCollection.size%28%29 > > ). Since the stress test adds in the queue constantly i think that there, > > the problems begins. > > > > I found a commit related to the following code in DefaultIoChain ( > > > http://mail-archives.apache.org/mod_mbox/mina-commits/201209.mbox/%3c20120928145021.1d32c2388...@eris.apache.org%3E > > ) > > > > - s.getWriteRequestQueue().offer(s, writeRequest); > > + WriteRequestQueue writeRequestQueue = > s.getWriteRequestQueue(); > > + > > if (!s.isWriteSuspended()) { > > - s.getProcessor().flush(s); > > + if (writeRequestQueue.size() == 0) { > > + // We can write directly the message > > + s.getProcessor().write(s, writeRequest); > > + } else { > > + s.getWriteRequestQueue().offer(s, writeRequest); > > + s.getProcessor().flush(s); > > + } > > + } else { > > + s.getWriteRequestQueue().offer(s, writeRequest); > > } > > } > > > > > > Is this improvement really necessary? The "if > > (writeRequestQueue.size() == 0)" statement seems to be causing huge > > load for me. > > > > > > Thank you in advance! > > > > Best regards, > > > > Alex > > > > > -- > Regards, > Cordialement, > Emmanuel Lécharny > www.iktek.com > >
