Wietse Venema wrote:
Mark Goodge:
My question is: if the time taken to restart Postfix is not an issue,
but throughput performance while Postfix is running is a primary
concern, is it still worth hashing the incoming and active queues?
The purpose of "queue hashing" is to limit the number of files per
directory. It's not needed normally if the file system can handle
order 10K files per directory.
The size of the active queue has an upper limit, so you use the
lowest amount of "queue hashing" that works.
In the case that the incoming queue gets really congested with a
million messages, hashing the incoming queue won't help (and changing
it will take time). The problem, and its solution, is downstream.
If you change the incoming directory into multiple levels of
subdirectories then Postfix will be slower under normal conditions.
How much depends on file system caching.
The defer and deferred directories may contain a large number of
files when a downstream site is unreachable. These are hashed to
avoid file system meltdown. Deferred mail delivieries are not time
critical, so it is not a problem if it takes a little longer on
systems with near-empty queues.
OK, that's a very clear answer, that you very much.
Mark
--
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