topic Re: What's the difference between binaries "java" and "java_q3p"? in Operating System - HP-UX

What's the difference between binaries "java" and "java_q3p"?

Ralph Grothe — Tue, 03 Nov 2009 09:49:54 GMT

Hello,

again I had a script failing because of seemingly wrong assumptions about a program's appearance in the process table.

Though this should have been a known issue to me,
since I already had posted this thread
( http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1201739 )
almost two years ago (unfortunately without the hoped for solution then),
it just has haunted me back.

The silly and bewildering mystery to me is its two guises it shows up as.

See what I mean?

# UNIX95= ps -C java -o pid,ppid,comm,args
PID PPID COMMAND COMMAND

# UNIX95= ps -C java_q3p -o pid,ppid,comm,args
PID PPID COMMAND COMMAND
12952 12951 java /opt/java1.5/bin/PA_RISC2.0/java -Xms512m -Xmx2048m -XX:NewSize

# UNIX95= ps -p 12952 -o comm,args
COMMAND COMMAND
java /opt/java1.5/bin/PA_RISC2.0/java -Xms512m -Xmx2048m -XX:NewSize

# UNIX95= ps -p 12952 -o comm
COMMAND
java

# UNIX95= ps -p 12952
PID TTY TIME CMD
12952 ? 03:05:15 java

# ps -p 12952
PID TTY TIME COMMAND
12952 ? 185:16 java_q3p

In the Java15JDK package where this belongs to
there are two differently named (and obviously different) binaries of same size.

# swlist -l file Java15JDK|grep java_q3p
Java15JDK.Jdk15.JDK15-PA20: /opt/java1.5/bin/PA_RISC2.0/java_q3p
Java15JDK.Jre15.JRE15-PA20: /opt/java1.5/jre/bin/PA_RISC2.0/java_q3p

# ll -i /opt/java1.5/bin/PA_RISC2.0/java{,_q3p}
8546 -r-xr-xr-x 1 bin bin 126648 Oct 17 2006 /opt/java1.5/bin/PA_RISC2.0/java
8547 -r-xr-xr-x 1 bin bin 126648 Oct 17 2006 /opt/java1.5/bin/PA_RISC2.0/java_q3p

# diff /opt/java1.5/bin/PA_RISC2.0/java{,_q3p}
Binary files /opt/java1.5/bin/PA_RISC2.0/java and /opt/java1.5/bin/PA_RISC2.0/java_q3p differ

I am really curious what the meaning is of this duplicity?

Regards
Ralph

Re: What's the difference between binaries "java" and "java_q3p"?

Dennis Handly — Tue, 03 Nov 2009 10:21:39 GMT

>I am really curious what the meaning is of this duplicity?

If you tell java you need a larger heap, it invokes the chatr +q3p version of java, for 1 Gb more.

Re: What's the difference between binaries "java" and "java_q3p"?

Ralph Grothe — Tue, 03 Nov 2009 11:42:26 GMT

Thank you for the explanation Dennis.

Since we asked for a heap size between 512-2048 MB (i.e. args -Xms512m -Xmx2048m to JVM) it has started the java_q3p binary.

Now I know how and when to distinguish.

Btw, just for me as a memory hook, does q3 refer to "quadrant 3" in terms of imaginative memory mapping?

Re: What's the difference between binaries "java" and "java_q3p"?

Don Morris_1 — Tue, 03 Nov 2009 11:52:41 GMT

Yes, this has a direct analogy to the char_pa(1) q3p / q4p sections and signifies Java running with the 3rd Quadrant private.

Re: What's the difference between binaries "java" and "java_q3p"?

Don Morris_1 — Tue, 03 Nov 2009 11:53:22 GMT

Argh... typo -- that should have been "chatr_pa(1)", of course. Sorry.

Re: What's the difference between binaries "java" and "java_q3p"?

Ralph Grothe — Tue, 03 Nov 2009 12:05:55 GMT

So guys, I now changed my script so that it would hopefully catch the JVM's PID, no matter in what memory quadrant it has been placed,
by using

e.g.

jvm_pid=$(NIX95= ps -C java,java_q3p,java_q4p -o pid=)

So while this would fail

$ UNIX95= ps -C java
PID TTY TIME CMD

this seems to work

$ UNIX95= ps -C java,java_q3p,java_q4p -o pid=
3527

$ ps -fp 3527
UID PID PPID C STIME TTY TIME COMMAND
www 3527 1 0 Oct 26 ? 8:58 /opt/java1.5/bin/PA_RISC2.0/java -Xms512m -Xmx2048m -XX:NewSize

Of course, you now may now argue that if I had several JVMs in possibly several quadrants running, it would still break.

But that's ok since there ought to be running only one JVM per node.

Re: What's the difference between binaries "java" and "java_q3p"?

Dennis Handly — Tue, 03 Nov 2009 23:30:37 GMT

>that's ok since there ought to be running only one JVM per node.

You can have one JVM for each java application.

Re: What's the difference between binaries "java" and "java_q3p"?

Ralph Grothe — Wed, 04 Nov 2009 09:12:01 GMT

> You can have one JVM for each java application.

I know, but these are dedicated cluster nodes with each of them running exactly one Tomcat instance (which itself isn't a cluster shared resource as part of an MC/SG package).