[Exim] DB connection question(s)

Afternoon folks, from a hot and muggy Zurich where I find myself
visiting for a few days . . . .

Did some changes on an Exim 4.14 installation yesterday to get the alias
lookup off an unmanageable flat file and onto a mysql lookup. Curiously
enough, everything worked fine after the conversion, no problems at all,
despite rigerous testing.

However, since about lunch time today, approx 22 hours after the
conversion went live, there's one helluva delay at exactly that point in
the SMTP conversation where Exim goes to the database to lookup against
the alias table!

Once the first lookup for any SMTP session has been done, any further
lookups in that same session fly through - no delays, which would lead
me to believe that the delay occurs when connecting to the database
itself, not the lookup of the data per se.

Why this should suddenly be so today and not yesterday has got me more
than a little baffled, but ignoring that bit for now, am I correct then
in assuming that for every new SMTP session that requires a lookup from
a database for, for example, aliasing information, creates a new
connection to the database? Or does exim open a connection(s) to the
database on startup and simply re-use connections?

Really really wierd . . .

Thanks for your time folks

Konrad


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* Konrad Michels
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