Java thread start time

Can I retrieve the start time of a given java thread in the JVM?

I have a thread dump. I'm looking at some problematic threads. I want to associate the usage time with specific operations in the application log

Solution

Yes, if you run Oracle JDK / openjdk on Linux, you can

The idea is to find the native thread ID (TID) and look at / proc / Java_ Modification time of PID / task / TID pseudo file

If you have a thread dump, this is trivial: the native thread ID will be printed by the thread header

For example, the java process PID is 2086 You type

$jstack 2086

And use the following threads of interest to get the stack trace:

"Thread-26" prio=10 tid=0x00007f96c80c2800 nid=0x86a waiting on condition [0x00007f96c0ff2000]
   java.lang.Thread.State: TIMED_WAITING (sleeping)

Where NID = 0x86a is the native thread ID. 0x86a = 2154, so you want to explore task 2154 of process 2086:

$ls -ld /proc/2086/task/2154
dr-xr-xr-x 6 user user 0 Mar 10 23:12 /proc/2086/task/2154
                         ^^^^^^^^^^^^
                         the thread start time