Re: Proposal: recent access based routing for primary-replica setups

Hi Nadav,

Thank you for the patch!

I have one question. How do you provide a password (sr_check_password)
while executing replication_delay_source_cmd as sr_check_user? In my
understanding replication_delay_source_cmd is executed through su
command in your patch. In this case su command tries to read the
password from terminal. I don't see such a code in the patch.

BTW, I start to think that executing replication_delay_source_cmd as
sr_check_user might not be a good idea. sr_check_user is a database
user, not OS user. In PostgreSQL they are not necessarily the
same. Also doing su in pgpool process needs to be very carefully to
avoid vulnerability. Probably we just execute it as pgpool OS user?

Lastly when I apply the patches using git apply, there are some
trailing space errors.

$ git apply ~/external-lag-feature-implementation.patch
/home/t-ishii/external-lag-feature-implementation.patch:314: trailing whitespace.

/home/t-ishii/external-lag-feature-implementation.patch:317: trailing whitespace.

/home/t-ishii/external-lag-feature-implementation.patch:318: trailing whitespace.
cmd_len = strlen(escaped_cmd) +
/home/t-ishii/external-lag-feature-implementation.patch:320: trailing whitespace.

/home/t-ishii/external-lag-feature-implementation.patch:322: trailing whitespace.
snprintf(full_command, cmd_len, "su - %s -c '%s'",
warning: squelched 4 whitespace errors
warning: 9 lines add whitespace errors.

$ git apply ~/external-lag-feature-tests.patch
/home/t-ishii/external-lag-feature-tests.patch:87: trailing whitespace.
- test_parsing.sh: Unit test for parsing logic
/home/t-ishii/external-lag-feature-tests.patch:440: trailing whitespace.
# Test 2: Float values
warning: 2 lines add whitespace errors.

Also I have some compilation errors after patching the source
code. See attached compilation log.

Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp