Re: LDC - Load Distributed Checkpoints with PG8.3b2 on Solaris

"Jignesh K. Shah"  wrote:

> I am running tests with PG8.3b2 on Solaris 10 8/07 and I still see IO 
> flood when checkpoint happens.

Are there any i/o tuning knobs in Solaris? LDC in 8.3 expects writing
activity in kernel is strong enough to keep dirty pages in kernel
in a small number. i.e, fsync should be cheap.

Larger shared_buffers, checkpoint_timeout, checkpoint_segments and
checkpoint_completion_target make checkpoints more smooth.
But there is a trade-off between smoothness and recovery time.

Stronger writer processes in kernel make checkpoints more smooth.
But there is a trade-off between smoothness and throughput.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center