stx-openstack: etcd 1MB size limit will prevent scaling up openstack workers
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
StarlingX |
Fix Released
|
Medium
|
Angie Wang |
Bug Description
Brief Description
-----------------
Etcd is designed to store small key/value pairs. Helm/Tiller stores it's release information in
configmaps which will have that underlying limit. As worker nodes scale out in an Openstack
installation the configmap for the Nova and Neutron releases will grow in size proportional to the number of Openstack workers as each contain per/host override information. When this limit is reached, the stx-openstack application will apply successfully but the release configmap will not
be saved. Once this occurs, Helm/Tiller will have lost track of the applied k8s resources. Armada re-applies of the stx-openstack application will fail. Manual cleanup the k8s resources will be required.
This LP needs to investigate:
a) The current limits (i.e. how many workers are currently supported)
b) Is there an Etcd option to increase this size (maybe --max-request-
c) Use an alternative Helm storage backend (https:/
Severity
--------
Major: System will hit a worker scalability limit in < 20 nodes.
Steps to Reproduce
------------------
Keep adding worker nodes and observe the size of the release configmap for neutron increase
Expected Behavior
------------------
Helm release information should be stored/maintained regardless of the number of workers
Actual Behavior
----------------
See description.
Reproducibility
---------------
100% reproducible
System Configuration
-------
Multi-node 2 controller + N workers
Branch/Pull Time/Commit
-------
Latest master branch
Last Pass
---------
This is the first time attempting scaling workers up to 20
Timestamp/Logs
--------------
N/A
Test Activity
-------------
Developer
Workaround
----------
N/A
stx.5.0 / medium priority - this is a scaling issues for systems w/ more than 20 workers. Will not hold up stx.4.0 on this at this late state.