openstack
/
kuryr-kubernetes
Code Issues Proposed changes

Update HA doc with corections and minor fixes 

Update HA doc with corrections and fixes to typos and mistakes.

Change-Id: I8c27f7c8584bb53bd63c036ebceaf90e893cb78d
This commit is contained in:
ashish.billore 2019-02-07 16:55:58 +09:00 committed by Ashish Billore
parent 53fba9a478
commit d4b31ae944
1 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
doc/source/devref/high_availability.rst
View File

@ -72,13 +72,13 @@ Kuryr Controller Implementation
The main issue with having multiple controllers is task division. All of the
controllers are watching the same endpoints and getting the same notifications,
but those notifications cannot be processed by multiple controllers at once,
because we end up with a huge race conditon, where each controller creates
Neutron resources but only on succeeds to put the annotation on the Kubernetes
because we end up with a huge race condition, where each controller creates
Neutron resources but only one succeeds to put the annotation on the Kubernetes
resource it is processing.
This is obviously unacceptable so as a first step we're implementing A/P HA,
where only the leader is working on the resources and the rest waits in
standby. This will be implemented by periodically calling the leader-elector
where only the leader is working on the resources and the other instances wait
as standby. This will be implemented by periodically calling the leader-elector
API to check the current leader. On leader change:
* Pod losing the leadership will stop its Watcher. Please note that it will be
@ -105,7 +105,7 @@ hit. Those can happen in two cases:
Kubernetes resource by creating resources again.
* During leader transition (short period after a leader died, but before its
lease expired and periodic task on other controllers noticed that; this
shouldn't exceed 10 s) some K8s resources are deleted. New leader will not
shouldn't exceed 10s) some K8s resources are deleted. New leader will not
get the notification about the deletion and those will go unnoticed.
Both of this issues can be tackled by garbage-collector mechanism that will