I couldn't find the explanation of this in other threads, I've tried to
search the archive.
I have a high load average on a server and the reason for that is kernel
function futex_wait invoked by java thread.
By doing jstack, I see a lot of BLOCKED threads like these:
Thread 1725: (state = BLOCKED)
- sun.misc.Unsafe.park(boolean, long) @bci=0 (Compiled frame; information
may be imprecise)
- java.util.concurrent.locks.LockSupport.parkNanos(java.lang.Object, long)
@bci=20, line=215 (Compiled frame)
-
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(long)
@bci=78, line=2078 (Compiled frame)
- java.util.concurrent.LinkedBlockingQueue.poll(long,
java.util.concurrent.TimeUnit) @bci=62, line=467 (Compiled frame)
- org.apache.tomcat.util.threads.TaskQueue.poll(long,
java.util.concurrent.TimeUnit) @bci=3, line=85 (Compiled frame)
- org.apache.tomcat.util.threads.TaskQueue.poll(long,
java.util.concurrent.TimeUnit) @bci=3, line=31 (Compiled frame)
- java.util.concurrent.ThreadPoolExecutor.getTask() @bci=134, line=1066
(Compiled frame)
-
java.util.concurrent.ThreadPoolExecutor.runWorker(java.util.concurrent.ThreadPoolExecutor$Worker)
@bci=26, line=1127 (Compiled frame)
- java.util.concurrent.ThreadPoolExecutor$Worker.run() @bci=5, line=617
(Compiled frame)
- org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run() @bci=4,
line=61 (Compiled frame)
- java.lang.Thread.run() @bci=11, line=745 (Compiled frame)
What does this
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run() actually
does when BLOCKED?
Should I perhaps lower some tomcat config values or just forget about
measuring system resources if the server works? My tomcat is configured as
follows:
my Tomcat is configured as follows:
<Connector port="8181"
protocol="org.apache.coyote.http11.Http11AprProtocol"
SSLCertificateFile="/etc/letsencrypt/live/numbeo.com/cert.pem"
SSLCertificateKeyFile="/etc/letsencrypt/live/
numbeo.com/privkey.pem"
SSLCertificateChainFile="/etc/letsencrypt/live/
numbeo.com/chain.pem"
SSLVerifyClient="optional" SSLProtocol="TLSv1+TLSv1.1+TLSv1.2"
connectionTimeout="20000" acceptCount="30000"
acceptorThreadCount="2"
compression="on" maxConnections="50000" maxThreads="500"
compressableMimeType="text/html,text/xml,text/plain,text/css,text/javascript,application/javascript,image/svg+xml,image/svg,image/png,image/jpeg"
useSendfile="false"
maxHttpHeaderSize="16392" SSLEnabled="true"
enableLookups="false"
scheme="https" secure="true" clientAuth="false"
useBodyEncodingForURI="true"
URIEncoding="UTF-8"
/>
