On 04/01/2017 16:02, David Oswell wrote: > Hello all, > > wondering if anyone has seen similar behaviour - sorry if already reported, > googling hasn't found much other than a somewhat similar older issue on APR > going to 100% CPU when idle due to a poll loop/timeout issue - however this > seems a bit different as this is only occurring with SSL; > > Running (ESX Based): > Server version: Apache Tomcat/8.5.9 > Server built: Dec 5 2016 20:18:12 UTC > Server number: 8.5.9.0 > OS Name: Windows Server 2012 R2 > OS Version: 6.3 > Architecture: amd64 > JVM Version: 1.8.0_112-b15 > JVM Vendor: Oracle Corporation > Apache Tomcat Native library 1.2.10 using APR version 1.5.2. > > APR capabilities: IPv6 [true], sendfile [true], accept filters [false], > random [true]. > APR/OpenSSL configuration: useAprConnector [false], useOpenSSL [true] > OpenSSL successfully initialized (OpenSSL 1.0.2j 26 Sep 2016) > > Server setup as 4 vCPU / 8GB mem > > Problem: > After running load on the server (this is a QA system, so just load tests) > Tomcat goes to 70-100% CPU usage when it should be idle. > This only occurs when putting load on the SSL connectors w/APR. When > re-applying load (to SSL connector), the CPU usage drops to appropriate > levels for the load, but then returns to the higher idle CPU usage. > If applying load back to the non-SSL connector, CPU usage stays high > (higher than after a restart and sending to non-SSL connector first). > > Performing the same load tests on non-SSL (still with APR), or non-APR > connectors CPU returns to idle after the load run is completed. > > The load applied is 8 persistent connections, which send basic POST > requests, the service does some basic operations and responds, generally - > if not maxed out - in 1-2ms. > Even when using 1 connection, the CPU usage stays constant when the > requests stop. > Again this only occurs when using the SSL/APR connector, if using a non-APR > connector, or the APR-non-SSL connector it's fine. > > It seems to be a problem with just how APR-SSL works or possibly OpenSSL ?
An issue with the Tomcat code is more likely than with the OpenSSL code. It sounds like one or more threads is entering a fairly tight loop. Use a combination of top to find out which thread(s) is(are) using the CPU and then a thread dump to find where in the code it is happening. Then add a breakpoint at that point in the code, run your test and once the high CPU starts, attach your IDE and step through the code to see where/how the loop is happening. Instructions for running Tomcat under a debugger are on the Wiki. The more of the above you are able to complete, the simpler it is going to be to get this fixed. Mark > Not sure how to further isolate to see which one is the problem. > > > SSL Connector setup: > <Connector port="8443" > protocol="org.apache.coyote.http11.Http11AprProtocol" > maxThreads="150" > SSLEnabled="true" > maxKeepAliveRequests="-1"> > <SSLHostConfig> > <Certificate > certificateFile="conf/localhost-rsa-cert.pem" > certificateKeyFile="conf/localhost-rsa-key.pem" > certificateKeyPassword="password" > type="RSA" /> > </SSLHostConfig> > </Connector> > > Non-SSL Connector: > <Connector port="8080" > protocol="org.apache.coyote.http11.Http11AprProtocol" > connectionTimeout="20000" > maxKeepAliveRequests="-1" > redirectPort="8443" > > </Connector> > > Initializing ProtocolHandler ["http-apr-8080"] > Initializing ProtocolHandler ["https-openssl-apr-8443"] > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
