Re: Add checkpoint and redo LSN to LogCheckpointEnd log message

On 2022/02/01 10:44, Nathan Bossart wrote:
> On Tue, Feb 01, 2022 at 12:23:10AM +0530, Bharath Rupireddy wrote:
>> On Tue, Feb 1, 2022 at 12:00 AM Nathan Bossart <nathandbossart(at)gmail(dot)com> wrote:
>>> I think the pg_controldata change needs some extra spaces for alignment,
>>> but otherwise these patches seem reasonable to me.
>>
>> Thanks. My bad it was. Changed in v6.

- (errmsg("restartpoint complete: wrote %d buffers (%.1f%%); "
+ (errmsg("restartpoint complete: lsn=%X/%X, redo lsn=%X/%X; "
+ "wrote %d buffers (%.1f%%); "
"%d WAL file(s) added, %d removed, %d recycled; "
"write=%ld.%03d s, sync=%ld.%03d s, total=%ld.%03d s; "
"sync files=%d, longest=%ld.%03d s, average=%ld.%03d s; "
"distance=%d kB, estimate=%d kB",
+ LSN_FORMAT_ARGS(ControlFile->checkPointCopy.redo),
+ LSN_FORMAT_ARGS(ControlFile->checkPoint),

The order of arguments for LSN seems wrong. LSN_FORMAT_ARGS(ControlFile->checkPoint) should be specified ahead of LSN_FORMAT_ARGS(ControlFile->checkPointCopy.redo)?

Could you tell me why the information for LSN is reported earlierly in the log message? Since ordinally users would be more interested in the information about I/O by checkpoint, the information for LSN should be placed later? Sorry if this was already discussed.

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION