StuckThead on Process.waitfor

Question

Version Weblogic 9.2.1
OS: Solaris 10
We are encountering StuckThread when we are execing out to a process from within a MessageDrivenBean. The error seems to occur after high volume of JMS messages to the queue (around 3000 in a hour time frame). The stack trace of the Stuck Thread indicates the Process.waitFor is the reason for the stuck thread.
The type of processes that we are execing out too are:
- UNIX command "file" to determine file type
- McAfee virus scanning
It then appears that the JMS server restarts but the messages pending on the JMS queue are lost. We are using non-persistant queues and are required for other reasons. Using persistant queues is not an option.
Any information on how to resolve is greatly appreciated.
Below is the snippet of code.
public int execProcess(String args[])
     int lProcRetVal = -1;
     if (args.length < 1)
     myLogger.error("No Command to Be executed");
     return lProcRetVal;
     try
     Runtime rt = Runtime.getRuntime();
     Process proc = rt.exec(args);
     // Gets an inputstream to read error messages from
     // if there are any error message,
     StreamGobbler errorGobbler =
new StreamGobbler(proc.getErrorStream(), "ERROR");
     // Gets an inputstream to read stdout messages from
     // the process if there is any output.
     StreamGobbler outputGobbler =
new StreamGobbler(proc.getInputStream(), "OUTPUT");
     // NOTE: To passes data to the process use the
     // processes method proc.getOutputStream
     // Which returns an Output Stream to write to.
     // kick them off
     errorGobbler.start();
     outputGobbler.start();
     // IF the process succeeded then returns 0 any error???
     lProcRetVal = proc.waitFor();
     } catch (IOException ioe)
               SevereSystemException se = new SevereSystemException(
                         ErrorCodes.PROCESS_EXEC_PROCESS,
                         ErrorCodes.PROCESS_EXEC_ERROR, ioe);
               throw se;
     catch (InterruptedException ie) {
               WarningSystemException wse = new WarningSystemException(
                         ErrorCodes.PROCESS_EXEC_PROCESS,
                         ErrorCodes.PROCESS_EXEC_ERROR, ie);
               wse.createLog();
     return lProcRetVal;
}

Answer 1

You probably need to consume the output of your script before waiting. The script has filled its output buffer and is waiting for your app to empty it. The app is waiting for the script to finish. This article discusses this and other problems using exec():
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
HTH
Graeme