What is the purpose of taking multiple thread dump?

[Former Member]

I am curious to know that why we need to provide multiple thread dump when troubleshooting? I guess what I am asking is what is the difference between a thread dump and a simple log file. Would be grateful if someone could explain this to me. Thank you very much in advance.

[Former Member]

Because a single state is not overly interesting to observe. You always need to compare a few dumps to see if a given thread is stuck for example. You want to know if that thread waiting on resource X is still waiting on it after 30 seconds. This would indicate a problem very often. That is why threads that didn't change their state are shown in red in the thread dump viewer.

It is the same as when looking at work processes in SM50. You always do a few refreshes there to see if the work or if the are hanging/blocked.

Cheers Michael

Edit: It is like you and your buddy are drinking at a bar. Your buddy goes to the bathroom, if he comes back bevor you finish your beer (and order another one <-> take the next thread dump) everything is fine. If you have to order the 3rd beer and he is still not back (still in bathroom state) you start to worry

[Former Member]

Thank you

[Former Member]

SAP NetWeaver Java Application Server is multi-threads. When an application is executed on the Java stack,a number of threads are created and destroyed as required by that application. Threads allow a sequence of executing instructions to run independently from other threads, but they can also share data with other threads. If there is a performance problem on the server process, it is only possible to monitor the status of the server process using standard tools. You cannot monitor thread statuses with standard tools, however. This is because threads exist within a server process in the Java application server, and information about these threads is not easily available. To solve this, Thread Dump Analysis allows you to take a u201Csnapshotu201D of the state of all Java threads in the server process at a particular time. Using this information, you can identify the particular Java application that may be causing problems.