Re: Fix checkpoint skip logic on idle systems by tracking LSN progress

On Thursday, November 10, 2016, Joshua D. Drake <jd(at)commandprompt(dot)com>
wrote:

> On 11/10/2016 09:33 AM, David Steele wrote:
>
>> On 11/10/16 10:28 AM, Stephen Frost wrote:
>>
>> diff --git a/src/backend/access/transam/xlog.c
>>>> b/src/backend/access/transam/xlog.c
>>>>
>>> [...]
>>>
>>>> + if (log_checkpoints)
>>>> + ereport(LOG, (errmsg("checkpoint
>>>> skipped")));
>>>>
>>>
>>> Do we really need to log that we're skipping a checkpoint..? As the
>>> point of this is to avoid write activity on a system which is idle, it
>>> doesn't make sense to me to add a new cause for writes to happen when
>>> we're idle.
>>>
>>
>> log_checkpoints is not enabled by default, though, so if the user does
>> enable it don't you think they would want to know when checkpoints
>> *don't* happen?
>>
>
> Yes but I don't know that it needs to be anywhere below DEBUG2 (vs
> log_checkpoints).
>

Agreed. You certainly may wish to log checkpoints, even on an embedded or
low I/o system, but logging that nothing is happening doesn't seem useful
except perhaps for debugging.

Thanks!

Stephen