Re: shared-memory based stats collector

On 1/1/19 7:03 PM, Andres Freund wrote:
> Hi,
>
> On 2019-01-01 18:39:12 +0100, Tomas Vondra wrote:
>> On 11/29/18 1:18 PM, Alvaro Herrera wrote:
>>> On 2018-Nov-28, Tomas Vondra wrote:
>>>
>>>>> v10-0004-Shared-memory-based-stats-collector.patch
>>>>> updated not to touch guc.
>>>>> v10-0005-Remove-the-GUC-stats_temp_directory.patch
>>>>> collected all guc-related changes.
>>>>> updated not to break other programs.
>>>>> v10-0006-Split-out-backend-status-monitor-part-from-pgstat.patch
>>>>> basebackup.c requires both bestats.h and pgstat.h
>>>>> v10-0007-Documentation-update.patch
>>>>> small change related to 0005.
>>>>
>>>> I need to do a more thorough review of part 0006, but these patches
>>>> seems quite fine to me. I'd however merge 0007 into the other relevant
>>>> parts (it seems like a mix of docs changes for 0004, 0005 and 0006).
>>>
>>> Looking at 0001 - 0003 it seems OK to keep each as separate commits, but
>>> I suggest to have 0004+0006 be a single commit, mostly because
>>> introducing a bunch of "new" code in 0004 and then moving it over to
>>> bestatus.c in 0006 makes "git blame" doubly painful. And I think
>>> committing 0005 and not 0007 makes the documentation temporarily buggy,
>>> so I see no reason to think of this as two commits, one being 0004+0006
>>> and the other 0005+0007. And even those could conceivably be pushed
>>> together instead of as a single patch. (But be sure to push very early
>>> in your work day, to have plenty of time to deal with any resulting
>>> buildfarm problems.)
>>>
>>
>> Kyotaro-san, do you agree with committing the patch the way Alvaro
>> proposed? That is, 0001-0003 as separate commits, and 0004+0006 and
>> 0005+0007 together. The plan seems reasonable to me.
>
> Do you guys think these patches are ready already? I'm a bit doubtful, and
> failures here could have quite wide-ranging symptoms.
>

I agree it's a sensitive part of the code, so additional reviews would
be welcome of course. I've done as much review and testing as possible,
and overall it seems in a fairly good shape. Do you have any particular
concerns / ideas what to look for?

regards

--
Tomas Vondra http://www.2ndQuadrant.com
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