Hello @misterhd ,
There could be many reasons why swapping fails. It can be because of high CPU load, network failure, or the Garbage Collection on any side of the communication (KNIME Server, KNIME Executor).
If an Executor crashes all the jobs kept in its memory (the ones that are being executing when the crash occurs, or the already executed ones that are still in the Executor’s memory) will be lost (“VANISHED”).
On the other hand when an Executor is gracefully shutdown then all jobs currently in memory are swapped back to disk. (They aren’t lost.) Please see more info about the Execution lifecycle here.
Hope it helps!
Cheers!