Re: Trying to use Loom virtual threads with Tomcat
Il 03/05/2022 08:31, Cay Horstmann ha scritto: Il 03/05/2022 07:25, Rémy Maucherat ha scritto: On Tue, May 3, 2022 at 6:24 AM Cay Horstmann wrote: Hi, I am trying to experiment with Loom (https://openjdk.java.net/jeps/425) virtual threads in Tomcat 10. There is a nice extension point in server.xml where I can provide an Executor and use it in the default Connector. It works like a charm--all my requests run on a virtual thread, and AFAIK, nothing else does. There is just one issue. It takes forever for Tomcat to execute the virtual threads. I made a timestamp for each invocation of public void execute(Runnable command) called from org.apache.tomcat.util.net.AbstractEndpoint.processSocket When I fire 1000 simultaneous requests, I can see that method being invoked 1000 times, but it takes a while to work through the requests. The last invocation occurs two minutes (!) from the sending of the requests. When using the org.apache.catalina.core.StandardThreadExecutor, that many requests are handled in 3 seconds. Is there something that I am overlooking? I had hoped that execute would be called near-instantly 1000 times, and then the Loom virtual threads could show their mettle and execute concurrently. I wanted to experiment with Loom, but most likely the current Tomcat NIO(2) connector is not nice for that. I was thinking that resurrecting the java.io code (actually: writing a new java.io connector) could be a slightly better plan, but to be honest I don't expect very good results. I wasn't planning to do it immediately since Loom is so experimental right now. I figured this out in the end. When using Nio2, changing the executor in server.xml doesn't seem useful. That executor is then used in the inner workings of the selector mechanism. That is probably not what anyone wants to do. But with Nio, plugging in Loom for running the servlet methods is very reasonable. There is only one issue. Loom cannot (yet) handle "synchronized". Changing the synchronized block in org/apache/tomcat/util/net/SocketProcessorBase.run() to a ReentrantLock makes the Loom threads fly, with impressive performance. Cheers, Cay -- Cay S. Horstmann | http://horstmann.com | mailto:c...@horstmann.com - To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
Re: Trying to use Loom virtual threads with Tomcat
Il 03/05/2022 07:25, Rémy Maucherat ha scritto: On Tue, May 3, 2022 at 6:24 AM Cay Horstmann wrote: Hi, I am trying to experiment with Loom (https://openjdk.java.net/jeps/425) virtual threads in Tomcat 10. There is a nice extension point in server.xml where I can provide an Executor and use it in the default Connector. It works like a charm--all my requests run on a virtual thread, and AFAIK, nothing else does. There is just one issue. It takes forever for Tomcat to execute the virtual threads. I made a timestamp for each invocation of public void execute(Runnable command) called from org.apache.tomcat.util.net.AbstractEndpoint.processSocket When I fire 1000 simultaneous requests, I can see that method being invoked 1000 times, but it takes a while to work through the requests. The last invocation occurs two minutes (!) from the sending of the requests. When using the org.apache.catalina.core.StandardThreadExecutor, that many requests are handled in 3 seconds. Is there something that I am overlooking? I had hoped that execute would be called near-instantly 1000 times, and then the Loom virtual threads could show their mettle and execute concurrently. I wanted to experiment with Loom, but most likely the current Tomcat NIO(2) connector is not nice for that. I was thinking that resurrecting the java.io code (actually: writing a new java.io connector) could be a slightly better plan, but to be honest I don't expect very good results. I wasn't planning to do it immediately since Loom is so experimental right now. Thanks for your fast response. I am wondering what issue you see with that connector. I am not changing the threading for the NIO part. Only when a socket is connected, a Loom thread is created. I tried reading through the code of NioEndpoint/AbstractEndpoint (which I find on the call stack of the call to execute in my executor). I can't find anything that throttles the acceptance. I don't think that there would necessarily be a huge win with Loom, but I am baffled why it is doing so much worse. Cheers, Cay -- Cay S. Horstmann | http://horstmann.com | mailto:c...@horstmann.com - To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
Trying to use Loom virtual threads with Tomcat
Hi, I am trying to experiment with Loom (https://openjdk.java.net/jeps/425) virtual threads in Tomcat 10. There is a nice extension point in server.xml where I can provide an Executor and use it in the default Connector. It works like a charm--all my requests run on a virtual thread, and AFAIK, nothing else does. There is just one issue. It takes forever for Tomcat to execute the virtual threads. I made a timestamp for each invocation of public void execute(Runnable command) called from org.apache.tomcat.util.net.AbstractEndpoint.processSocket When I fire 1000 simultaneous requests, I can see that method being invoked 1000 times, but it takes a while to work through the requests. The last invocation occurs two minutes (!) from the sending of the requests. When using the org.apache.catalina.core.StandardThreadExecutor, that many requests are handled in 3 seconds. Is there something that I am overlooking? I had hoped that execute would be called near-instantly 1000 times, and then the Loom virtual threads could show their mettle and execute concurrently. Thanks, Cay -- Cay S. Horstmann | http://horstmann.com | mailto:c...@horstmann.com - To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
