Hello Tharindu,
Wednesday, July 23, 2008, 6:35:33 AM, you wrote:
TRB> Dear Mark/All,
TRB> Our trading system is writing to local and/or array volume at 10k
TRB> messages per second.
TRB> Each message is about 700bytes in size.
TRB> Before ZFS, we used UFS.
TRB> Even with UFS, there was evey 5 second peak due to fsflush invocation.
TRB> However each peak is about ~5ms.
TRB> Our application can not recover from such higher latency.
TRB> So we used several tuning parameters (tune_r_* and autoup) to decrease
TRB> the flush interval.
TRB> As a result peaks came down to ~1.5ms. But it is still too high for our
TRB> application.
TRB> I believe, if we could reduce ZFS sync interval down to ~1s, peaks will
TRB> be reduced to ~1ms or less.
TRB> We like <1ms peaks per second than 5ms peak per 5 second :-)
TRB> Are there any tunable, so i can reduce ZFS sync interval.
TRB> If there is no any tunable, can not I use "mdb" for the job ...?
TRB> This is not general and we are ok with increased I/O rate.
TRB> Please advice/help.
txt_time/D
btw:
10,000 * 700 = ~7MB
What's your storage subsystem? Any, even small, raid device with write
cache should help.
--
Best regards,
Robert Milkowski mailto:milek at task.gda.pl
http://milek.blogspot.com
