I had a similar issue, and following previous answers (thanks!), I was able to search and find how to handle correctly the ThreadPoolExecutor terminaison.
In my case, that just fix my progressive increase of similar blocked threads:
ExecutorService::awaitTermination(x, TimeUnit)
and ExecutorService::shutdownNow()
(if necessary) in my finally clause.For information, I've used the following commands to detect thread count & list locked threads:
ps -u javaAppuser -L|wc -l
jcmd `ps -C java -o pid=` Thread.print >> threadPrintDayA.log
jcmd `ps -C java -o pid=` Thread.print >> threadPrintDayAPlusOne.log
cat threadPrint*.log |grep "pool-"|wc -l