PostCommitEventExecutor may hang under load

Since NXP-7796 post commit event processing is done using an executor service.
The size of the thread pool must be 2 time bigger than the number of concurrent thread that commit or it will hangs.
The reason is that the postcommit job also perform a commit and submit a
new job to the executor, if there is no thread available it waits until the timeout (10min in bulk mode).
Note that the executor will not create more than core pool size because the queue is unbound.
This explains why the import part of the daily bench fails since core pool size have been decrease from 100 to 4.