From d1b8c8bc2c05d1fab26ae9bb081dc002e231b070 Mon Sep 17 00:00:00 2001 From: Renat Akhmerov Date: Mon, 9 Dec 2019 13:00:22 +0700 Subject: [PATCH] Add a release note for graceful scale-in feature Change-Id: I9874085555db097c7ae1ae3c2c7cad73b8543ff5 --- .../mistral-engine-scale-in-bd348f9237f32481.yaml | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 releasenotes/notes/mistral-engine-scale-in-bd348f9237f32481.yaml diff --git a/releasenotes/notes/mistral-engine-scale-in-bd348f9237f32481.yaml b/releasenotes/notes/mistral-engine-scale-in-bd348f9237f32481.yaml new file mode 100644 index 000000000..94eb97b41 --- /dev/null +++ b/releasenotes/notes/mistral-engine-scale-in-bd348f9237f32481.yaml @@ -0,0 +1,15 @@ +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 " 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).