Re: Virtual Threads
On 07/09/2023 15:41, Christopher Schultz wrote: On 9/6/23 16:29, Mark Thomas wrote: There isn't much point using an executor with virtual threads. Okay then perche https://tomcat.apache.org/tomcat-11.0-doc/config/executor.html#Virtual_Thread_Implementation ? That is the internal executor we use to provide virtual threads to the connector. The same code exists in all current versions. Not sure why it was documented. It may have been while we were exploring what was possible. I'd lean towards removing that section from the Tomcat 11 docs. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Virtual Thread Configuration In Tomcat 11
William, On 9/7/23 08:04, William Crowell wrote: When I set -Djdk.tracePinnedThreads=short, then I see this: … Thread[#41,ForkJoinPool-1-worker-4,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.isValid(ConnectionImpl.java:2516) <== monitors:1 Thread[#39,ForkJoinPool-1-worker-2,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.isValid(ConnectionImpl.java:2516) <== monitors:1 Thread[#41,ForkJoinPool-1-worker-4,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:2005) <== monitors:1 Thread[#43,ForkJoinPool-1-worker-5,5,CarrierThreads] com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:893) <== monitors:1 com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1061) <== monitors:1 com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1009) <== monitors:1 Thread[#43,ForkJoinPool-1-worker-5,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.commit(ConnectionImpl.java:791) <== monitors:1 Thread[#43,ForkJoinPool-1-worker-5,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:2005) <== monitors:1 … I started digging into the MySQL client code: https://github.com/mysql/mysql-connector-j/blob/8.0.33/src/main/user-impl/java/com/mysql/cj/jdbc/ConnectionImpl.java This class is littered with synchronized blocks, so now this makes sense to me why virtual threads would take longer than a regular OS thread. This is precisely the kind of thing I was expecting to see. If your "application code" (which includes everything your application does, including calling into libraries) contains lots of "synchronized" blocks, then I think this is the situation you will often find yourself in. I would expect that if you were to increase the size of the virtual thread pool things would start to get better, but in order to truly use virtual threads effectively, you have to track-down and eliminate many uses of synchronized blocks and methods in both your application and the libraries you use. I wouldn't expect virtual threads to become a very widely-deployed performance-optimization technique in the immediate future. I expect that, eventually, lots of code will be re-written to be more virtual-thread-friendly. -chris - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
solved: java.lang.ClassNotFoundException for listener class
I was wong, the deployed context under eclipse and under tomcat autonomous instance were not identical at all. Form some reason when eclipse deploys the web application copy the class files under WEB-INF/services/ under WEB-INF/classes, so the tomcat class loading finds classes were expected -- Hello all. I have developed a web application using Eclipse as an IDE and test environment and it runs as expected. Then I have built a war file and deployed it under another Tomcat instance. In both case tomcat version is 8.5 Under this last instance the application can't start and in the log files I find: 07-Sep-2023 07:48:18.173 SEVERE [http-nio-8080-exec-129] org.apache.catalina.core.StandardContext.listenerStart Error configuring application listener of class [it.archimede.met.obliterazione.zse.servlet.CreaConnessione] java.lang.ClassNotFoundException: it.archimede.met.obliterazione.zse.servlet.CreaConnessione at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1358) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1180) at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:545) at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:526) at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:150) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4613) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5155) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:743) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:705) at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:614) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:486) at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1634) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:607) at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:286) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1562) at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:990) at org.apache.catalina.manager.HTMLManagerServlet.deployInternal(HTMLManagerServlet.java:320) at org.apache.catalina.manager.HTMLManagerServlet.doPost(HTMLManagerServlet.java:209) at javax.servlet.http.HttpServlet.service(HttpServlet.java:652) at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.filters.CsrfPreventionFilter.doFilter(CsrfPreventionFilter.java:211) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:109) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:668) at org.apache.catalina.valves.RequestFilterValve.process(RequestFilterValve.java:348) at
Re: Virtual Threads
Mark, On 9/6/23 16:29, Mark Thomas wrote: On 06/09/2023 21:24, Christopher Schultz wrote: On 9/6/23 03:29, Mark Thomas wrote: On 05/09/2023 22:02, Christopher Schultz wrote: Thanks for the correction. I just did a quick docs[1] search for "virtual" in Tomcat 10.x for example and I didn't see useVirtualThreads, so I assumed it wasn't in there. Maybe we need some documentation back-ports? Odd. It is there as an attribute on the Connector. And in 9.0.x and 8.5.x too. https://tomcat.apache.org/tomcat-10.0-doc/config/executor.html I don't find the word "virtual" anywhere on that page. It is a Connector attribute, not an Executor attribute. There isn't much point using an executor with virtual threads. Okay then perche https://tomcat.apache.org/tomcat-11.0-doc/config/executor.html#Virtual_Thread_Implementation ? -chris - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Virtual Thread Configuration In Tomcat 11
When I set -Djdk.tracePinnedThreads=short, then I see this: … Thread[#41,ForkJoinPool-1-worker-4,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.isValid(ConnectionImpl.java:2516) <== monitors:1 Thread[#39,ForkJoinPool-1-worker-2,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.isValid(ConnectionImpl.java:2516) <== monitors:1 Thread[#41,ForkJoinPool-1-worker-4,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:2005) <== monitors:1 Thread[#43,ForkJoinPool-1-worker-5,5,CarrierThreads] com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:893) <== monitors:1 com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1061) <== monitors:1 com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1009) <== monitors:1 Thread[#43,ForkJoinPool-1-worker-5,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.commit(ConnectionImpl.java:791) <== monitors:1 Thread[#43,ForkJoinPool-1-worker-5,5,CarrierThreads] com.mysql.cj.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:2005) <== monitors:1 … I started digging into the MySQL client code: https://github.com/mysql/mysql-connector-j/blob/8.0.33/src/main/user-impl/java/com/mysql/cj/jdbc/ConnectionImpl.java This class is littered with synchronized blocks, so now this makes sense to me why virtual threads would take longer than a regular OS thread. Regards, William Crowell This e-mail may contain information that is privileged or confidential. If you are not the intended recipient, please delete the e-mail and any attachments and notify us immediately.
Re: Virtual Thread Configuration In Tomcat 11
Chris, I did set -Djdk.tracePinnedThreads=full and found there were a few pinned threads: Thread[#43,ForkJoinPool-1-worker-4,5,CarrierThreads] java.base/java.lang.VirtualThread$VThreadContinuation.onPinned(VirtualThread.java:185) java.base/jdk.internal.vm.Continuation.onPinned0(Continuation.java:393) java.base/java.lang.VirtualThread.parkNanos(VirtualThread.java:631) java.base/java.lang.System$2.parkVirtualThread(System.java:2648) java.base/jdk.internal.misc.VirtualThreads.park(VirtualThreads.java:67) java.base/java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:408) … com.mysql.cj.protocol.FullReadInputStream.readFully(FullReadInputStream.java:64) com.mysql.cj.protocol.a.SimplePacketReader.readHeaderLocal(SimplePacketReader.java:81) … com.mysql.cj.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:2005) <== monitors:1 com.zaxxer.hikari.pool.ProxyConnection.setAutoCommit(ProxyConnection.java:401) com.zaxxer.hikari.pool.HikariProxyConnection.setAutoCommit(HikariProxyConnection.java) … Over the 12 test runs I have performed, I found a 53% decrease in throughput when using virtual threads: http://ec2-18-188-185-212.us-east-2.compute.amazonaws.com:8080/web-report/ My example code is located here: https://github.com/wcrowell/rest-mysql-app/ The JMX test I used is located here: https://github.com/wcrowell/rest-mysql-app/blob/main/virtual-thread-test.jmx This test makes a POST request to save a record to MySQL: http://ec2-18-117-196-158.us-east-2.compute.amazonaws.com:8080/vt/save Regards, William Crowell This e-mail may contain information that is privileged or confidential. If you are not the intended recipient, please delete the e-mail and any attachments and notify us immediately.
java.lang.ClassNotFoundException for listener class
Hello all. I have developed a web application using Eclipse as an IDE and test environment and it runs as expected. Then I have built a war file and deployed it under another Tomcat instance. In both case tomcat version is 8.5 Under this last instance the application can't start and in the log files I find: 07-Sep-2023 07:48:18.173 SEVERE [http-nio-8080-exec-129] org.apache.catalina.core.StandardContext.listenerStart Error configuring application listener of class [it.archimede.met.obliterazione.zse.servlet.CreaConnessione] java.lang.ClassNotFoundException: it.archimede.met.obliterazione.zse.servlet.CreaConnessione at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1358) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1180) at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:545) at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:526) at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:150) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4613) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5155) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:743) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:705) at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:614) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:486) at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1634) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:607) at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:286) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1562) at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:990) at org.apache.catalina.manager.HTMLManagerServlet.deployInternal(HTMLManagerServlet.java:320) at org.apache.catalina.manager.HTMLManagerServlet.doPost(HTMLManagerServlet.java:209) at javax.servlet.http.HttpServlet.service(HttpServlet.java:652) at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.filters.CsrfPreventionFilter.doFilter(CsrfPreventionFilter.java:211) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:109) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:668) at org.apache.catalina.valves.RequestFilterValve.process(RequestFilterValve.java:348) at org.apache.catalina.valves.RemoteAddrValve.invoke(RemoteAddrValve.java:52) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690) at
