On Fri, 7 Jul 2006, andy rost wrote:
is that 100k context switches over 10 seconds or one second? that
might be something to check out. pg 8.1 is regarded as the solution
to any cs problem, though.
According to man top, that's 100K per second. I'm interested in your
recommendation but am not sure what "pg 8.1" references
pg 8.1 means PostgreSQL 8.1.x (preferably 8.1.4) which is said to resolve many
context switch issues.
can you please approximate roughly how many transactions per second
your server is handling while you are getting the 20 load condition
(and, if possible, broken down into read and write transactions)?
Do you have any suggestions on how I might obtain these metrics?
Every five minutes do:
select sum(xact_commit) + sum(xact_rollback) as transactions from pg_stat_database;
and then divide the difference by 300 and that's your transactions per second:
select sum(xact_commit) + sum(xact_rollback) as transactions from
pg_stat_database;
transactions
--------------
231894522
(1 row)
<wait 300 seconds>
select sum(xact_commit) + sum(xact_rollback) as transactions from
pg_stat_database;
transactions
--------------
231907346
(1 row)
(231907346-231894522)/300 = 42.74666666666666666666 TPS
--
Jeff Frost, Owner <jeff@xxxxxxxxxxxxxxxxxxxxxx>
Frost Consulting, LLC http://www.frostconsultingllc.com/
Phone: 650-780-7908 FAX: 650-649-1954
