Re: Spread checkpoint sync - Mailing list pgsql-hackers

From Greg Smith
Subject Re: Spread checkpoint sync
Date
Msg-id 4CF6BE5F.8040801@2ndquadrant.com
Whole thread Raw
In response to Re: Spread checkpoint sync  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Responses Re: Spread checkpoint sync  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
List pgsql-hackers
Heikki Linnakangas wrote:
> Do you have any idea how to autotune the delay between fsyncs?

I'm thinking to start by counting the number of relations that need them 
at the beginning of the checkpoint.  Then use the same basic math that 
drives the spread writes, where you assess whether you're on schedule or 
not based on segment/time progress relative to how many have been sync'd 
out of that total.  At a high level I think that idea translates over 
almost directly into the existing write spread code.  Was hoping for a 
sanity check from you in particular about whether that seems reasonable 
or not before diving into the coding.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services and Support        www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books



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