From the user’s list (thanks to Adam Guthrie and Lukas Weiss)

Short form: Apparently there’s a java 8 bug that’s the root cause, not fixed 
until Java 9: https://bugs.openjdk.java.net/browse/JDK-8129861

I have _not_ verified this, but we’ve had sporadic reports (Shawn?) of same. 
CommitTracker is the only place in the code that calls newScheduledThreadPool 
with 0.

From what I can tell, this isn’t fixed in Java until 9.

If the fix is just changing that call to use 1, it’s trivial but would require 
a respin of 7.7 to get out in the field.

Should I raise a JIRA? ‘cause we should be seeing it in Solr 8 and master too. 
Although we should be seeing this in Solr 8 too, although it should disappear 
in Master when we require Java 11.



************E-mail below.
Hi,
Apologies, I can’t figure out how to reply to the Solr mailing list.
I just ran across the same high CPU usage issue. I believe it’’s caused by 
this commit which was introduced in Solr 7.7.0 
https://github.com/apache/lucene-solr/commit/eb652b84edf441d8369f5188cdd5e3ae2b151434#diff-e54b251d166135a1afb7938cfe152bb5
There is a bug in JDK versions <=8 where using 0 threads in the 
ScheduledThreadPool causes high CPU usage: 
https://bugs.openjdk.java.net/browse/JDK-8129861
Oddly, the latest version 
of solr/core/src/java/org/apache/solr/update/CommitTracker.java on 
master still uses 0 executors as the default. Presumably most everyone is 
using JDK 9 or greater which has the bug fixed, so they don’t experience 
the bug.
Feel free to relay this back to the mailing list.
Thanks,
Adam Guthrie


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to