[jboss-user] High CPU due to threads looping in OutputBuffer.realWriteChars

[Nie Fei]

Hi all,

We're seeing JBoss consumes high CPU and the thread dumps and CPU data
indicates that the high consuming threads are always in some point of the
OutputBuffer.realWriteChars method and its underlying char to byte
conversions and buffer flushes, for example

"ajp-127.0.0.1-8009-1" daemon prio=10 tid=0x00002aabd4fb2000 nid=0x7a6
runnable [0x00002b24a1517000]
java.lang.Thread.State: RUNNABLE
at sun.nio.cs.ISO_8859_1$Encoder.encodeArrayLoop(ISO_8859_1.java:148)
at sun.nio.cs.ISO_8859_1$Encoder.encodeLoop(ISO_8859_1.java:187)
at java.nio.charset.CharsetEncoder.encode(CharsetEncoder.java:544)
at org.apache.tomcat.util.buf.C2BConverter.convert(C2BConverter.java:91)
at org.apache.catalina.connector.OutputBuffer.realWriteChars(OutputBuffer.java:465)
at org.apache.tomcat.util.buf.CharChunk.flushBuffer(CharChunk.java:440)
at org.apache.tomcat.util.buf.CharChunk.append(CharChunk.java:295)
at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:499)
at org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:143)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:119)
at org.apache.jasper.runtime.JspWriterImpl.write(JspWriterImpl.java:326)


Does anybody know how to fix it?

In fact, there is an article which describes the same situation I have. But
I have no enough privileges to read the full content.

Can you help me ?

https://access.redhat.com/solutions/129963

thanks,
br,
/nf