any idea why the owned by might be missing if I create a thread dump? Problem is that we created this as we had an issue, bounced the server and issue is gone. We know that something was blocked but now we cannot find what, or better to say by what.
Thanks in advance,
Thanks. Well - I dont see a whole lot unusual here. It just means that none of these threads in waiting state are actually waiting on one of these monitors.
You can click on each thread and look at the stack trace to see where these threads are waiting. It just seems they are not waiting on one of these monitors owned by other threads
I am confused as they are in the state "blocked" and ~1000 of them, which is very unusual as usually every 5 mins we have just 4 of them running for around 200ms. The status blocked somehow indicates to me that they are waiting for something, not sure what they are waiting for ...
Does this make sense to you?
Well - it seems that most of your blocked threads are stuck in this call stack:
# Class Method Line Source File
0 java.util.Arrays copyOf(char, int) 2367 Arrays.java
1 java.lang.AbstractStringBuilder expandCapacity(int) 130 AbstractStringBuilder.java
2 java.lang.AbstractStringBuilder ensureCapacityInternal(int) 114 AbstractStringBuilder.java
3 java.lang.AbstractStringBuilder append(java.lang.String) 415 AbstractStringBuilder.java
4 java.lang.StringBuilder append(java.lang.String) 132 StringBuilder.java
5 java.lang.StringBuilder append(java.lang.Object) 128 StringBuilder.java
6 javax.management.ObjectInstance toString() 152 ObjectInstance.java
7 ORG.oclc.infra.util.SortedVector compareTo(java.lang.Object, java.lang.Object) 148 SortedVector.java
8 ORG.oclc.infra.util.SortedVector sort() 136 SortedVector.java
9 ORG.oclc.infra.util.SortedVector sortVector(java.lang.Object) 83 SortedVector.java
10 ORG.oclc.infra.util.SortedVector <init>(java.lang.Object) 69 SortedVector.java
11 ORG.oclc.infra.ops.api.OpsMBeanClient getAllObjectInstances(java.lang.String) 1189 OpsMBeanClient.java
These are all threads that handle MBean Requests. I dont see these threads waiting on monitors though
Same here. I build an unit test for this code (some old stuff where I don't even know then it was written nor by whom to ask).
In the end it sorts, thats it and calls compare, also not that hard. In the unit test it is fine for more then 200 elements and 50 threads. No block. But in the environment for some reason the code code stuck and I have no clue why.
I wonder if the thread dump could be converted to a normal one, maybe here we could see more. As more then 1000 of these threads is quite un-usual. Sorting Strings / well here javax.management.ObjectInstance.ObjectInstance(String, String) should not be an issue. Even if the code is old.