RV: Checkpoint Duration - HDR - Sync/Async
Posted in 2003
Hi everyboy,
I really would appreciate your comments about this subject.
Thanks in advance
-----Mensaje original-----
De: Francisco Roldan [mailto:froldan@5b.com.gt]
Enviado el: Mi'rcoles, 01 de Octubre de 2003 12:30 p.m.
Para: informix-list@iiug.org
Asunto: Checkpoint Duration - HDR - Sync/Async
Hi everybody,
my environment :
Two identical servers running AIX 4.3.3 - IDS 7.3.1 UD1
running HDR between both database servers
DRINTERVAL : 360 segs (=> ASYNCHRONOUS)I have only one production database on Buffered Logging Mode.
I implemented HDR in order to protect the data changed after the last
backup, and to be able to execute reports/DSS-querys on the secondary
server (in that order).
I read that the checkpoint between primary and secondary servers running HDR
are synchronous, regardless of DRINTERVAL parameter is
-1 (=> SYNCHRONOUS) or not.
When i execute a very heavy dss query on my secondary server, it affects the
performance on this server and i have noticed that it affects the duration
of the checkpoint on both servers (even getting 6 times the normal
duration).
It is logic if i consider that the checkpoints between primary and secondary
servers are synchronous, am i right ? or am i missing something else that
could be affecting the checkpoints duration on both servers?
Is it possible to minimize the impact on the primary server's checkpoint
duration ? For examble by tunning some parameters like DRINTERVAL,
CKPTINTVL(240 segs. on my servers), or the difference between these values
(I am just guessing). Or the Logging mode on my only production database.
Thanks in advance
Regards
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