tree 58c6cd0b08da389abfd0c57e208ca578ffb4848d
parent 3daa09953508753105a48056e71fa593f94e971e
author Antonio Barone <syntonyze@gmail.com> 1603456306 +0200
committer Antonio Barone <syntonyze@gmail.com> 1603883506 +0100

Separate replicas from masters

Not having a specific placement strategy for replicas might cause them
to be deployed on the same ec2-instance as the masters.

If tasks are running on the same instance, both source and destination
IP are the same when being received by the target instance and this
causes packets to be dropped as per convention for L4 networking[1].

Ensure replicas are never deployed to the same ec2-instance as the
masters by creating a dedicated ASG for them and forcing the placement
on ec2-instances labelled as 'replica'.

[1]https://aws.amazon.com/premiumsupport/knowledge-center/target-connection-fails-load-balancer/

Bug: Issue 13585
Change-Id: I3e0cb3c0a85865f80129e6fa4d1763bd242a21a5