Re: [PATCH] guc-ify the formerly hard-coded MAX_SEND_SIZE to max_wal_send

On Sat, Jan 7, 2017 at 7:48 PM, Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com> wrote:

> On 1/5/17 12:55 PM, Jonathon Nelson wrote:
>
>> Attached please find a patch for PostgreSQL 9.4 which changes the
>> maximum amount of data that the wal sender will send at any point in
>> time from the hard-coded value of 128KiB to a user-controllable value up
>> to 16MiB. It has been primarily tested under 9.4 but there has been some
>> testing with 9.5.
>>
>
> To make sure this doesn't get lost, please add it to
> https://commitfest.postgresql.org. Please verify the patch will apply
> against current HEAD and pass make check-world.

Attached please find a revision of the patch, changed in the following ways:

1. removed a call to debug2.
2. applies cleanly against master (as of 8c5722948e831c1862a39da2bb5d79
3a6f2aabab)
3. one small indentation fix, one small verbiage fix.
4. switched to calculating the upper bound using XLOG_SEG_SIZE rather than
hard-coding 16384.
5. the git author is - obviously - different.

make check-world passes.
I have added it to the commitfest.
I have verified with strace that up to 16MB sends are being used.
I have verified that the GUC properly grumps about values greater than
XLOG_SEG_SIZE / 1024 or smaller than 4.

--
Jon