-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 CBy,
On 3/8/2010 7:03 AM, CBy wrote: > My web service wraps a command-line application that is rather resource > demanding. To manage the maximum number of instances that can run > concurrently, it uses a (custom) thread pool. Are you on Java 1.5+? (If not, you should be). If you are, you can use one of the fine implementations of executors in java.util.concurrent, such as ThreadPoolExecutor. > Now that I have to > develop similar services, I would like to share the pool instead. I was > thinking of switching to Tomcat's Executor - > http://tomcat.apache.org/tomcat-6.0-doc/config/executor.html - but > cannot find any examples on how to use it. I don't believe user code has any access to Tomcat's thread pool(s). Why not run your own thread pool(s) for this particular requirement? > If I uncomment the corresponding lines in server.xml, can I then use the > default tomcatThreadPool by just instantiating > org.apache.catalina.core.StandardThreadExecutor? Almost certainly not. You'd have to create your own StandardThreadExecutor, configure it, and then use it. The same is true if you were to use the Java API-provided one, except you wouldn't tie yourself to Tomcat in that case. > Do I have to call start() and stop() on StandardThreadExecutor or is > this handled by Tomcat? If you used StandardThreadExecutor, Tomcat wouldn't be managing it: you would. > Is it possible to block on the execute() method of StandardThreadExecutor? > > Can you only have one Executor per Connector? > > My current thread pool uses java.util.concurrent.ExecutorService, which > allows to submit (execute) a Callable (instead of Runnable) task. This > is very convenient for returning the exit code of the command line > application to my Java code. It seems to me that this isn't possible > with StandardThreadExecutor or any other executor that implement the > |org.apache.catalina.Executor| interface? > > Would it be appropriate to not use Tomcat's Executor and share my custom > thread pool among all services by using Tomcat's common/shared class > loader? I think that would be better. On the other hand, you could create a service that runs these things on your behalf, and then connect to that. Then, you only have one thread pool in use, here. I think that will be less fragile than trying to share a thread pool across web applications. This also allows you to do thing like re-locate webapps that use the pool without having to figure out what to do next: you just connect to the same service you always did. It also makes it possible for you to load-balance such a service if necessary without figuring out how to change the clients of the service. Hope that helps, - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkuVF2QACgkQ9CaO5/Lv0PArSgCgwkGmosZtlnDJUWAGyJpeEX7L QUsAoJZVO27SQITXqGQ/a193yY90650c =wdN3 -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
