EMS server unresponsive

EMS preallocates linear datastore range chunks per sender. Too many concurrent producers (> 10 000) causes a lot of random I/O writes and as a result whole EMS server becomes unresponsive. Limit number of producers and consumers or buy fast SSD storage.

Although EMS messages are swapped to disk their headers and internal indices are kept in memory, so for every 1M messages you need 1GB RAM.