NPE during Tomcat shutdown: HSQLDB thread

Good day.

I’'m new to running Wildfire as a Tomcat servlet.

I have the following few lines in my catalina.out file appearing following a Tomcat shutdown

May 15, 2006 2:43:37 AM org.apache.coyote.http11.Http11AprProtocol destroy

INFO: Stopping Coyote HTTP/1.1 on http-8080

May 15, 2006 2:43:37 AM org.apache.coyote.http11.Http11BaseProtocol destroy

INFO: Stopping Coyote HTTP/1.1 on http-8443

Exception in thread “HSQLDB Timer @1f4cbee” java.lang.NullPointerException

at org.hsqldb.lib.HsqlTimer.nextTask(Unknown Source)

at org.hsqldb.lib.HsqlTimer$ Source)


My question is: is the version of HSQLDB bundled with Wildfire compiled with debug=“on”?

Thank you.

The problem with this error is that some thread is not shutting down cleanly, which is preventing Tomcat from shutting down. I have to do a ‘‘kill’’ on the Tomcat java process to affect a shutdown.

What version of HSQLDB is wildfire.war using?


I’'m using Windows, Tomcat 5.5, Java 1.5 and did never see this problem.


Thank you for the reply.

I must be doing something systematically incorrect, as I obtain the same result under OS X (Java 1.5, Apache Tomcat 5.5.17).

Here is how I configure the servlet, which is hacky, but the best I could piece together looking at forum posts and Unix-like “trace/strace” output:

$ export CATALINA_HOME=/u/p/tomcat

$ export CATALINA_OPTS=-DwildfireHome=/u/p/tomcat/wildfire

$ mkdir -p $CATALINA_HOME/wildfire/conf $CATALINA_HOME/resources/security

$ cp $dist/target/conf/wildfire.xml $CATALINA_HOME/wildfire/conf/

$ cp $dist/target/resources/security/*store $CATALINA_HOME/wildfire/resources/security/

where $dist is the the toplevel directory of the source distribution for Wildfire itself.


$ sh $CATALINA_HOME/bin/

followed a minute or two later by

$ sh $CATALINA_HOME/bin/

My reading of these instructions!default.jspa?categoryID=22&externalI D=431

leads me to conclude that the configuration I show above should produce a workable server.

Things that make you go “Hmm”.


Am facing the same problem. Have you been able to resolve this issue?



It looks like this is an HSQLDB bug. The release notes includes:

“Fixed bug where Server.shutdown() threw spurious NPE.”

That seems to match this issue description pretty well. Wildfire uses at the moment. I’'ve filed JM-827 to do the upgrade.



Hi Matt,

so you want to offer once again a .war file for Tomcat?


No. If people are smart enough to build the WAR themselves and really like using it, that’‘s fine with us. It causes a lot more trouble than it’'s worth in order to support it officially though.