Possible via a Perlbal plugin?
André Cruz
andre.cruz at segula.pt
Wed Apr 18 14:55:43 UTC 2007
On Apr 18, 2007, at 3:44 PM, Brad Fitzpatrick wrote:
> Bot both uri hashing and sticky sessions come down to the basic
> problem
> of: what to do in subsequent requests when that old node is out of
> the
> pool or down? What are all the tunables for this policy/timeouts/etc?
>
In my situation, if the intended backend is not available then tough
luck, ignore the preference and use the best available one. In the
applications I have here the sticky sessions are needed purely for
efficiency (a cache that is not replicated across all nodes).
I would like to be able to configure the sticky session trigger and
timeout. Some applications require sticky sessions just to do some
auth checks and don't need them afterwards...
A small configurable timeout to wait for the backend to come up would
be nice, but not a must-have. If it's not up, what can you do?
> And in your case, how do requests waiting for a specific backend
> compete
> for requests waiting for any backend? Imagine 3*(n+1) queues, n per
> backend (high+normal+low priorities), then then high+normal+low
> priorities
> for ANY backend.
>
Well... I guess clients that specify a backend should have precedence
over others with the same priority but for any backend (since some
kind of flow is already active), but I would be satisfied if they
just received the same treatment as all the other requests.. But I
don't prioritize requests here so I'm biased.
Hope this helps,
André Cruz
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