pt-online-schema-change -- can't get it to stop quitting w/ "Threads_running=108 exceeds its critical threshold 100" I've got an InnoDB table over 50GB with indexes. The query I'm running looks like this:

pt-online-schema-change h=localhost,D=db,t=table --critical-load="Threads_running=100" --check-slave-lag "h=XX.XX.XX.XX" --max-lag 10
--execute --pass PASS 
--alter "REORGANIZE PARTITION max INTO (
PARTITION p19 VALUES LESS THAN ( UNIX_TIMESTAMP('2016-05-01 00:00:00') ),
PARTITION p20 VALUES LESS THAN ( UNIX_TIMESTAMP('2016-06-01 00:00:00') ),
PARTITION max VALUES LESS THAN maxvalue
)"


No matter what settings I use, I get the Threads_running issue. I have also tried:

--chunk-size 100 (also tried 20)

--max-load="Threads_running=20"

Shouldn't it just wait until threads running gets lowered? Why does it keep quitting? I could raise the critical load to allow 200 threads, but I'm afraid of the server crashing.

Any advice?
The problem was that every now and then an unrelated query put a lot of stress on the server and was causing the threads running to nearly max out. It was doing this regularly before the schema change was first run.