[Wrapper-user] NT Service Issues

[Adam E. <ada...@dy...>]

Hi all,

We are trialling using the Java Service Wrapper for our product and so =
far are very impressed. We do however have two major issues that appear =
to manifest themselves mostly under Windows 2003 Server.

To explain our issues, I'll first give some background on what our =
application does. Our application consists of 5 java processes, plus one =
we call the ServiceManager. The ServiceManager upon startup starts each =
of the other 5 processes by calling Runtime.getRuntime().exec(). It then =
continually checks that they are alive, and if not restarts them. It =
also has a Runtime.getRuntime().addShutdownHook() to ensure that its =
child processes are shutdown when it is shutdown.

We are using the Java Service Wrapper (3.1.1) to wrap our ServiceManager =
by simply specifying our classname in the conf file. Our problems are as =
follows:

1. When certain users log off from the server (via Remote Desktop), =
although the logs specify that the logged off signal is ignored, the =
child processes (ran via Runtime.getRuntime().exec() are killed).

e.g.
INFO   | wrapper  | 2005/02/14 15:22:14 | User logged out.  Ignored.
INFO   | jvm 1    | 2005/02/14 15:22:14 | 15:22:14,421 INFO  =
[ServiceRunner] Starting service scheduler
INFO   | jvm 1    | 2005/02/14 15:22:15 | 15:22:14,968 INFO  =
[ServiceRunner] Starting service authenticator
INFO   | jvm 1    | 2005/02/14 15:22:15 | 15:22:14,984 INFO  =
[ServiceRunner] Starting service freetext
INFO   | jvm 1    | 2005/02/14 15:22:15 | 15:22:15,015 INFO  =
[ServiceRunner] Starting service conversion

The ServiceRunner INFO messages are from our ServiceManager which is =
still running, but detecting the other service have shutdown so is =
restarting them.

This is a problem as we are a web app, and users logged into our system =
will be kicked out as their sessions are tied to these running apps.

Is there any way of preventing "child" processes of the wrapped service =
from also being killed?


2. Every now and then, presumably when the server is under load, the JVM =
is terminated. This presents two problems, firstly that it is happening, =
and secondly that it doesn't call our shutdown hook, so the child =
processes aren't killed, but then when it is restarted by the service =
wrapper, the child processes are all started for a second time, leading =
to catastropic consequences to our application!

INFO   | jvm 1    | 2005/02/16 09:44:07 | 09:44:07,659 INFO  =
[ServiceRunner] Starting service conversion
ERROR  | wrapper  | 2005/02/17 08:13:29 | JVM appears hung: Timed out =
waiting for signal from JVM.
ERROR  | wrapper  | 2005/02/17 08:13:29 | JVM did not exit on request, =
terminated
STATUS | wrapper  | 2005/02/17 08:13:34 | Launching a JVM...
INFO   | jvm 2    | 2005/02/17 08:13:35 | Wrapper (Version 3.1.1) =
http://wrapper.tanukisoftware.org
INFO   | jvm 2    | 2005/02/17 08:13:35 |=20
INFO   | jvm 2    | 2005/02/17 08:13:35 | 08:13:35,375 INFO  =
[RpcHandler] RPC: invoking start
INFO   | jvm 2    | 2005/02/17 08:13:35 | 08:13:35,375 INFO  =
[ServiceHandler] Reading configuration file
INFO   | jvm 2    | 2005/02/17 08:13:35 | 08:13:35,406 INFO  =
[ServiceRunner] Starting service resourcecentre
INFO   | jvm 2    | 2005/02/17 08:13:37 | 08:13:37,250 INFO  =
[ServiceRunner] Starting service resourcecentre
INFO   | jvm 2    | 2005/02/17 08:13:39 | 08:13:39,000 INFO  =
[ServiceRunner] Starting service resourcecentre
INFO   | jvm 2    | 2005/02/17 08:13:40 | 08:13:40,406 INFO  =
[ServiceRunner] Starting service freetext
INFO   | jvm 2    | 2005/02/17 08:13:40 | 08:13:40,734 INFO  =
[ServiceRunner] Starting service resourcecentre
INFO   | jvm 2    | 2005/02/17 08:13:42 | 08:13:42,578 INFO  =
[ServiceRunner] Starting service resourcecentre

Is there any way to prevent the JVM appearing as hung when it isn't =
really?




Look forward to hearing back from anyone!

Cheers, Adam

Adam Eijdenberg
DYTECH SOLUTIONS Pty. Ltd.
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Level 2, 25 Argyle Street
GPO Box 642
Hobart TAS 7000
Ph:   +61 3 6235 2222
Fax:  +61 3 6235 2299
ada...@dy...
www.dytech.com.au
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