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 8c5722948e831c1862a39da2bb5d793a6f2aabab)
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.