Good afternoon. I have a really incomprehensible problem with the Java virtual machine on my CentOS 6 (64-bit) server. This is a server with a quad-core processor (with a hyper-thread), 16 GB of RAM and 2 TB of hard disk space (on software RAID1). I decided that I am asking myself here because, according to frequently asked questions, questions about the "usual tools" used by developers are relevant. Hope someone can shed some light on the problem.
I run part of the Java software on the server, 24 hours a day. Earlier today (detected a few hours after midnight on the server locale, which is noteworthy because this is the first day of the month), I received messages from users connecting to this software, as clients suddenly became unusable. The JVM never interrupted or restarted. The last time it was restarted only a few days ago, and since then it worked fine (using about 5% or less CPU, which is normal).
This time, when I checked this process, it essentially collected all the time of the processor, which it could fight with other applications running on the server (as reported from above), or more than 100% (as reported by ps). I tried to stop and restart the application, but as soon as it starts, the processor load will immediately begin to rise again to 100%. Memory usage is normal. I experimented with different JVM flags, but to no avail. I tried to download the latest software and make a new installation, but that didn't help either. Finally, I tried downloading another, completely different piece of Java software, but when I ran it on the server, it had the same problem.
When I downloaded the software and ran it on my computer, the processor load was normal. Therefore, I assume that it is wrong on the server, but I can not imagine what it could be. The JVM server is updated from the standard repository package (without configuration).
From java -version:
java version "1.6.0_24"
OpenJDK Runtime Environment (IcedTea6 1.11.3) (rhel-1.48.1.11.3.el6_2-x86_64)
OpenJDK 64-Bit Server VM (build 20.0-b12, mixed mode)
From uname -a:
2.6.32-131.21.1.el6.x86_64
From centos-release / redhat-release / system release:
CentOS release 6.2 (Final)
Free reports on free RAM at 14.5 GB. df reports a 1.4 TB free disk in the / home section (where the software and all their files were located).
Any ideas? Please ask if you need more data and feel free to offer me procedures for verification / verification. When searching for the problem, I found several cases where people had problems with JVMs stealing the entire processor on CentOS, but none of them seemed to match my problem.