Jules Gosnell wrote: [...]
As for the amount of state that each node carries, there should not be a problem in each node specifying a higher or lower threshold at which to migrate or passivate sessions (i.e. number of active sessions it can carry). Although, as discussed in the previous posting, you need to be able to tell your lb about migration.I see. I understand why you need to tell your lb about migrations and, if I understand it correctly, this is mainly an optimization. However, you are not compeled to keep the lb aware of migrations:
I assume that in the cookies or in the URL will be embedded the identifiers of the replica. If the primary node fails, the lb can try any available servers. This server is part of the domain and by using the cookies or the URL of the incoming request, it can request to the replica the session attached to the incoming request.
What is really interesting is that this server becomes now the primary and the other replica do not need to be updated.
My idea here is to provide a pluggable 'sort()' strategy, which the deployer can provide.
Cool.
- Is it not an overhead to have b-1 replica? AFAIK, a single secondary should be enough.
This will be a deployment-time decision. I simply chose b=3 as a common example - I am sure b=2 will also be widely used.
OK.
Thanks, Gianny
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