openstack-ansible/releasenotes/notes/new-override-rabbitmq_memory_high_watermark-1d12effe59153605.yaml
Jean-Philippe Evrard 2cc067222c Bump SHAs for master
Change-Id: I2df6bc4659ced61bc1796645a515274535dd7911
2019-05-19 13:59:26 +00:00

20 lines
1014 B
YAML

---
features:
- |
The override ``rabbitmq_memory_high_watermark`` can be used to set the
maximum size of the erlang Virtual Machine before the garbage collection
is triggered. The default is lowered to ``0.2``, from ``0.4`` as the
garbage collection can require 2x of allocated amount during its
operation. This can result in a equivalent use of ``0.4``, resulting in
40% of memory usage, visible to the rabbitMQ container. The original
default setting of ``0.4`` can lead to 80% memory allocation of rabbitMQ,
potentially leading to a scenario where the underlying Linux kernel
is killing the process due to shortage of virtual memory.
upgrade:
- |
The rabbitMQ high watermark is set to ``0.2`` rather than ``0.4`` to
prevent possible OOM situations, which limits the maximum memory usage
by rabbitMQ to 40% rather than 80% of the memory visible to the rabbitMQ
container. The override ``rabbitmq_memory_high_watermark`` can be used
to alter the limit.