| We have several heavily loaded instances of Jenkins. The most biggest of them builds around 30 000 jobs per day (two others - around 6000). After upgrade to Jenkins 2.107.3 on the most heavily loaded instance we see a hight CPU sys time consumption.  After some investigation we have found that the processes, who consume CPU sys time most of all, are hanging on "futext" system call:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
74.31 13168.872885 68562 192072 38348 futex
19.97 3539.132374 5998529 590 440 restart_syscall
1.98 351.174121 24197 14513 18 recvfrom
1.75 310.265366 865 358527 1466 write
1.05 185.451445 59325 3126 poll
0.18 31.986477 1823 17547 1006 read
0.15 26.976110 33100 815 accept
0.11 19.407311 982 19760 2760 stat
In strace output for such processes we can see something like that:
futex(0x7fc42800ba54, FUTEX_WAIT_BITSET_PRIVATE, 1, {5161981, 228340395}, ffffffff) = -1 ETIMEDOUT (Connection timed out)
futex(0x7fc42800ba28, FUTEX_WAKE_PRIVATE, 1) = 0
futex(0x7fc42800ba54, FUTEX_WAIT_BITSET_PRIVATE, 1, {5161981, 278655215}, ffffffff) = -1 ETIMEDOUT (Connection timed out)
futex(0x7fc42800ba28, FUTEX_WAKE_PRIVATE, 1) = 0
futex(0x7fc42800ba54, FUTEX_WAIT_BITSET_PRIVATE, 1, {5161981, 328848067}, ffffffff) = -1 ETIMEDOUT (Connection timed out)
futex(0x7fc42800ba28, FUTEX_WAKE_PRIVATE, 1) = 0
futex(0x7fc42800ba54, FUTEX_WAIT_BITSET_PRIVATE, 1, {5161981, 379185329}, ffffffff) = -1 ETIMEDOUT (Connection timed out)
corresponding Java-process:
"MVStore background writer nio:/u01/jenkins/jenkins_home/jenkins-jobs/jenkins-jobs.mv.db" #96324 daemon prio=5 os_prio=0 tid=0x00007fc3500a4000 nid=0x6048 in Object.wait() [0x
java.lang.Thread.State: TIMED_WAITING (on object monitor)
<------>at java.lang.Object.wait(Native Method)
<------>at org.h2.mvstore.MVStore$BackgroundWriterThread.run(MVStore.java:2715)
<------>- locked <0x00000001d78dfc88> (a java.lang.Object)
Locked ownable synchronizers:
<------>- None
Environment: RHEL 7.5 with the latest updates (except of kernel). DRBD+ext4. OpenStack KVM. 32 CPU 64 GB RAM.
JENKINS_JAVA_OPTIONS="-Djava.awt.headless=true -Dgroovy.use.classvalue=true -Xms32g -Xmx32g -XX:MaxGCPauseMillis=200 -XX:ParallelGCThreads=20 -XX:ConcGCThreads=5 -XX:InitiatingHeapOccupancyPercent=75 -XX:MaxMetaspaceSize=3024m -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/u01/jenkins -XX:+UnlockDiagnosticVMOptions -Djenkins.model.Jenkins.logStartupPerformance=true -Dhudson.plugins.git.GitStatus.allowNotifyCommitParameters=true -Dhudson.model.ParametersAction.keepUndefinedParameters=true -Dhudson.model.DirectoryBrowserSupport.CSP=\"default-src 'self'; img-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; child-src 'self'; frame-src 'self';\" -Djenkins.model.DirectoryBrowserSupport.CSP=\"default-src 'self'; img-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; child-src 'self'; frame-src 'self';\" -Dorg.apache.commons.jelly.tags.fmt.timeZone=\"Europe/Moscow\" -Dhudson.model.User.SECURITY_243_FULL_DEFENSE=false -Dcom.cloudbees.workflow.rest.external.ChangeSetExt.resolveCommitAuthors=false -server -XX:+UseG1GC -XX:+ExplicitGCInvokesConcurrent -XX:+ParallelRefProcEnabled -XX:+UseStringDeduplication -Xloggc:${JENKINS_HOME}/gc_logs/gc-%t.log -XX:NumberOfGCLogFiles=5 -XX:+UseGCLogFileRotation -XX:GCLogFileSize=20m -XX:+PrintGC -XX:+PrintGCDateStamps -XX:+PrintGCDetails -XX:+PrintTenuringDistribution -XX:+PrintAdaptiveSizePolicy -Dcom.sun.management.jmxremote.port=3333 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.io.tmpdir=/u01/jenkins/tmp -Dhudson.remoting.ClassFilter=org.jenkinsci.lib.xtrigger.AbstractTrigger"
root@jenkins-master-002:~$ uname -a
Linux jenkins-master-002.vm.mos.cloud.sbrf.ru 3.10.0-514.el7.x86_64 #1 SMP Wed Oct 19 11:24:13 EDT 2016 x86_64 x86_64 x86_64 GNU/Linux
root@jenkins-master-002:~$ java -version
java version "1.8.0_151"
Java(TM) SE Runtime Environment (build 1.8.0_151-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.151-b12, mixed mode)
More diagnostic information in the attachments (we have created screenshots and ThreadDumps not at the same time, but at a time when we have seen the problem). |
