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I have set up a Tomcat server using Server 2008 and IIS 7.
How can I tell if the JAVA_OPTS environment variable is actually being used?

I've heard before that the I have to edit the service.bat file in order to make the JAVA_OPTS environment variable be used, but how can I tell if it's successful?

I haven't been able to find out if there is a way to view this in the logs or something else more quantitative. The only way I could think of to try to test it is to edit the variable and try to tell if there is a difference in performance. I set the JAVA_OPTS to be the following:

-server -Xmx1k -Xms1k-Xmn1k -Xss128k -XX:+UseParallelGC -XX:ParallelGCThreads=20 -XX:PermSize=1k -XX:MaxPermSize=1k

Also, I found documentation saying to change the following line in service.bat from:

"%EXECUTABLE%" //US//%SERVICE_NAME% ++JvmOptions "-Djava.io.tmpdir=%CATALINA_BASE%\temp;-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager;-Djava.util.logging.config.file=%CATALINA_BASE%\conf\logging.properties" --JvmMs 128 --JvmMx 256

to:

"%EXECUTABLE%" //US//%SERVICE_NAME% ++JvmOptions "-Djava.io.tmpdir=%CATALINA_BASE%\temp;-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager;-Djava.util.logging.config.file=%CATALINA_BASE%\conf\logging.properties" %JAVA_OPTS%

I got no errors when I ran the command 

service install ServiceName

So far everything seems to be running as fast as it always is before I reinstalled the service with the changed memory settings, making me think that the JAVA_OPTS isn't affecting anything.

Sorry if this is a broad sort of question, but I haven't found a good lead to go off of yet as to what is actually happening in the back end. Can somebody shed some light on this?

OrangeGrover
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    Instead of futzing with .bat files you should be using the Tomcat7w.exe utility to modify the service settings. – user207421 Jul 26 '12 at 07:03

2 Answers2

7

Alright, I found the information I was looking for so I'm going to accept my answer because I'm giving more details, but +1 to David Levesque for the leads.

I found out that the memory settings I was trying to set were not being used. In order to change the memory settings I used the tomcat7w in the \bin folder.

Run the following command:

tomcat7w //ES//<ServiceName>

Then the following should pop up:

Java Service Manager

Click the Java tab that is underlined and add the arguments in the highlighted areas.

In order to check this, I used the jinfo executable (in the \bin folder). Jinfo prints Java configuration information for a given Java process. Run this command using the following syntax:

jinfo -flags PID-of-Tomcat-executable

The following little script saved me some time from having to find out Tomcat's PID every time, so I figured I may as well post it here:

@echo off
for /f "tokens=1,2 delims= " %%i in ('=tasklist ^| findstr "tomcat"') do (
    echo Tomcat Executable = %%i
    echo Tomcat Process ID = %%j
    set tomcat_pid=%%j
)
echo %tomcat_pid%
%JAVA_HOME%\bin\jinfo -flags %tomcat_pid%
OrangeGrover
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5

You can use the jinfo utility that comes with the JDK to query the VM flags and system properties at runtime.

David Levesque
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  • Okay, this does seem to be what I'm looking for, however I can't get it to work. I ran the following command in my batch file: %JAVA_HOME%\bin\jinfo -flag ParallelGCThreads %tomcat_pid% and I get the following message returned: Not enough storage is available to process this command – OrangeGrover Jul 31 '12 at 21:12
  • This error is most often seen when running Tomcat as a Windows service . Tools like jinfo can't reach the service because of security restrictions. One option is to run Tomcat from the command line. If you want to keep it running as a service, there are ways to do it, but they involve a bit a work. For example: http://stackoverflow.com/questions/906620/jstack-and-not-enough-storage-is-available-to-process-this-command – David Levesque Aug 01 '12 at 01:05
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    You need to run this command as the same user running the java process, so if you have this error: `DebuggerException`, try e.g. `sudo -u tomcat jinfo 2976` – Jose Alban Sep 02 '15 at 14:06