JVM system time runs faster than HP UNIX OS system time

Posted by winston on Server Fault See other posts from Server Fault or by winston
Published on 2012-12-12T04:05:47Z Indexed on 2012/12/12 5:06 UTC
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Filed under:

time

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timesync

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weblogic

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jvm

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hp-ux

Hello I have the following output from a simple debug jsp:

Weblogic Startup Since: Friday, October 19, 2012, 08:36:12 AM
Database Current Time: Wednesday, December 12, 2012, 11:43:44 AM
Weblogic JVM Current Time: Wednesday, December 12, 2012, 11:45:38 AM

Line 1 was a recorded variable during WebLogic webapp startup.
Line 2 was output from database query select sysdate from dual;
Line 3 was output from java code new Date()

I have checked from shell date command that line 2 output conforms with OS time. The output of line 3 was mysterious. I don't know how it comes from Java VM.

On another machine with same setting, the same jsp output like this:

Weblogic Startup Since: Tuesday, December 11, 2012, 02:29:06 PM
Database Current Time: Wednesday, December 12, 2012, 11:51:48 AM
Weblogic JVM Current Time: Wednesday, December 12, 2012, 11:51:50 AM

Another machine:

Weblogic Startup Since: Monday, December 10, 2012, 05:00:34 PM
Database Current Time: Wednesday, December 12, 2012, 11:52:03 AM
Weblogic JVM Current Time: Wednesday, December 12, 2012, 11:52:07 AM

Findings: the pattern shows that the longer Weblogic startup, the larger the discrepancy of OS time with JVM time.

Anybody could help on HP JVM?

On HP UNIX, NTP was done daily.

Anyway here comes the server versions:

HP-UX machinex B.11.31 U ia64 2426956366 unlimited-user license

java version "1.6.0.04"
Java(TM) SE Runtime Environment (build 1.6.0.04-jinteg_28_apr_2009_04_46-b00)
Java HotSpot(TM) Server VM (build 11.3-b02-jre1.6.0.04-rc2, mixed mode)

WebLogic Server Version: 10.3.2.0

Java properties

java.runtime.name=Java(TM) SE Runtime Environment
java.runtime.version=1.6.0.04-jinteg_28_apr_2009_04_46-b00
java.vendor=Hewlett-Packard Co.
java.vendor.url=http\://www.hp.com/go/Java
java.version=1.6.0.04
java.vm.name=Java HotSpot(TM) 64-Bit Server VM
java.vm.info=mixed mode
java.vm.specification.vendor=Sun Microsystems Inc.
java.vm.vendor="Hewlett-Packard Company"
sun.arch.data.model=64
sun.cpu.endian=big
sun.cpu.isalist=ia64r0
sun.io.unicode.encoding=UnicodeBig
sun.java.launcher=SUN_STANDARD
sun.jnu.encoding=8859_1
sun.management.compiler=HotSpot 64-Bit Server Compiler
sun.os.patch.level=unknown
os.name=HP-UX
os.version=B.11.31

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