On Wed, Apr 18, 2018 at 11:40:51AM +0200, Fabien COELHO wrote:
>> - double-write buffers use a pre-decided numbers of pages (32 for the
>> checkpointer, 128 divided into 4 buckets for the backends), which are
>> synced into disk once each batch is full.
>
>> - The double-write file of the checkpointer uses ordering of pages using
>> blocks number and files to minimize the number of syncs to happen, using
>> a custom sequential I/O algorithm.
>
> I'm not sure from reading the descriptions.
>
> Are these particular features related/similar to 9cd00c4 "Checkpoint sorting
> and balancing" and 428b1d6 "Allow to trigger kernel writeback after a
> configurable number of writes", committed in February 2016?
Not real direct links that I know of, but the work which has been done
could be benefitial for checkpoints which need to handle doublle-write
streams.
--
Michael