mistral/releasenotes/notes/mistral-engine-scale-in-bd348f9237f32481.yaml
Renat Akhmerov d1b8c8bc2c Add a release note for graceful scale-in feature
Change-Id: I9874085555db097c7ae1ae3c2c7cad73b8543ff5
2019-12-09 13:00:22 +07:00

16 lines
866 B
YAML

features:
- |
Mistral engine now supports graceful scale-in. That is, if a number of
engines in a cluster needs to be reduced manually it is now possible to
do w/o breaking currently running workflows. In order to shutdown a
Mistral engine, SIGTERM signal needs to be sent to the corresponding
process. In Unix operatating systems it's a matter of running the command
"kill <engine PID>" in any shell. When this signal is caught by the
process, it has a certain amount of time configured by the
'graceful_shutdown_timeout' property to complete currently running
database transactions and process all buffered RPC messages that have
already been polled from the queue. After this time elapses, the process
will be forced to exit.
By default, the value of the 'graceful_shutdown_timeout' property is
60 (seconds).