CPU High load Solution idea

After Tomcat is started on the server, use top to view CPU usage to 200%, although the server is configured with 8 cores, but the business volume is large and cannot be carried. As a result, troubleshoot the problem by using the following methods:

1. View the number of processes with high CPU usage:

650) this.width=650; "title=" image "style=" border-top:0px; border-right:0px; Background-image:none; border-bottom:0px; padding-top:0px; padding-left:0px; border-left:0px; padding-right:0px "border=" 0 "alt=" image "src=" http://s3.51cto.com/wyfs02/M01/6E/E2/ Wkiol1wkt-2rfdevaacrjify5rm475.jpg "" 359 "height="/>

According to the top command, it is found that the Java process with PID 14586 consumes up to 200% CPU and fails.

Via PS aux | grep pid command, you can further determine that there is a problem with the Tomcat process. But how exactly does the problem lie?

show the list of threads first :

PS-MP Pid-o Thread,tid,time

650) this.width=650; "title=" image "style=" border-top:0px; border-right:0px; Background-image:none; border-bottom:0px; padding-top:0px; padding-left:0px; margin:0px; border-left:0px; padding-right:0px "border=" 0 "alt=" image "src=" http://s3.51cto.com/wyfs02/M02/6E/E2/ Wkiol1wkt-3rylzpaabtlshc8oe003.jpg "" 244 "height="/>

650) this.width=650; "title=" image "style=" border-top:0px; border-right:0px; Background-image:none; border-bottom:0px; padding-top:0px; padding-left:0px; margin:0px; border-left:0px; padding-right:0px "border=" 0 "alt=" image "src=" http://s3.51cto.com/wyfs02/M00/6E/E2/ Wkiol1wkt-2h7hajaabc1we425u014.jpg "" 244 "height="/>

Find the most time-consuming thread ID: 14634,14635

Next, convert the required thread ID to 16 binary format:

printf "%x\n" tid

650) this.width=650; "title=" image "style=" border-top:0px; border-right:0px; Background-image:none; border-bottom:0px; padding-top:0px; padding-left:0px; margin:0px; border-left:0px; padding-right:0px "border=" 0 "alt=" image "src=" http://s3.51cto.com/wyfs02/M01/6E/E2/ Wkiol1wkt-7ikstoaaabliwuzyq437.jpg "" 244 "height="/>

650) this.width=650; "title=" image "style=" border-top:0px; border-right:0px; Background-image:none; border-bottom:0px; padding-top:0px; padding-left:0px; margin:0px; border-left:0px; padding-right:0px "border=" 0 "alt=" image "src=" http://s3.51cto.com/wyfs02/M02/6E/E2/ Wkiol1wkt-7gj0xsaaacranupua667.jpg "" 244 "height="/>

Last print thread's stack information:

Jstack PID |grep tid-a 30

650) this.width=650; "title=" image "style=" border-top:0px; border-right:0px; Background-image:none; border-bottom:0px; padding-top:0px; padding-left:0px; margin:0px; border-left:0px; padding-right:0px "border=" 0 "alt=" image "src=" http://s3.51cto.com/wyfs02/M00/6E/E2/wKioL1WKt--Bq_ Hjaacwa-2qmrq814.jpg "" 244 "height=" 148 "/>

Again, look at the other thread. This is also the case, after analysis, developed that the previous version of the thread to obtain data has been waiting, the change version is: every 5 minutes to start the process, add container functions and so on. The details have to be developed to understand.

Finally, summarize the methods and techniques for troubleshooting CPU failures:

1. Top command: Linux command. You can view real-time CPU usage. You can also view CPU usage for the most recent period of time.

2, PS command: Linux command. Powerful process status monitoring commands. You can view the current CPU usage of the process and threads in the process. The sampled data that belongs to the current state.

3, the Jstack:java provides the command. You can view the current thread stack run of a process. Depending on the output of this command, you can locate the current running state of all threads of a process, run code, deadlock, and so on.

4, Pstack:linux command. You can view the current thread stack run of a process.

CPU High load Solution idea