有没有办法在同一服务器上运行两个JVM？

Question

I'm having some issues with the JVM; I have a Web page and an application with no GUI(UDP server), and both uses the same database, the application(UDP server) it's working ok but if the web application get out of memory the whole JVM stop; so I was thinking to put the UDP server in a different JVM.

I'm getting the following messages

May 21, 2013 5:24:05 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/track] created a ThreadLocal with key of type [org.opengts.util.ThreadLocalMap$1] (value [org.opengts.util.ThreadLocalMap$1@277085a4]) and a value of type [java.util.Hashtable] (value [{jdbc:mysql://localhost:3306/gts?characterEncoding=UTF-8&useUnicode=true&characterSetResults=utf8=org.opengts.dbtools.DBConnection@22236dae}]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.

and when I restart the web page

May 21, 2013 5:24:20 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2695 ms
Exception in thread "http-bio-8080-Acceptor-0" java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:657)
at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:943)
at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1336)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:176)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:156)
at org.apache.tomcat.util.net.JIoEndpoint.processSocket(JIoEndpoint.java:510)
at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:229)
at java.lang.Thread.run(Thread.java:679)
Exception in thread "http-bio-8080-exec-8" java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:657)
at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:943)
at java.util.concurrent.ThreadPoolExecutor.processWorkerExit(ThreadPoolExecutor.java:992)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:679)

NEW INFO

I tried the ulimit command getting the following results.

ulimit
unlimited
ulimit -Hn
163840
ulimit -n
163840
ulimit -u
1024

Now I'm wondering what's the meaning of those numbers? They are the amount of process or memory in MBytes?

Answer 1

您必须在不同的端口上运行Web服务器，所以这不是JVM问题-它是catalina的配置

Answer 2

The "java.lang.OutOfMemoryError: unable to create new native thread" error isn't really an out of memory error at all -- the JVM is unable to create a new thread due to an OS limitation.

What OS are you using? On linux, you can increase this by doing:

ulimit -u <new limit>

Answer 3

Before creating new JVM I would examine Thread creation first.

I had the same problem with number of Threads limitation until I added

executor.shutdown(); 

for ExecutorService within the finally block