Opening connections to pgcat is very slow #616
Comments
|
I think we are victims of |
|
FYI pgbouncer uses TCP_NODELAY. I'm not sure if you meant disabling NOdelay or disabling THE delay. https://github.com/pgbouncer/pgbouncer/blob/e6ce619785c93392794976c1e936e8c9f589a5ad/src/util.c#L229 |
|
Disable the delay. Enable |
|
I'm happy to give this a test on my workload. |
zsand
added a commit
to zsand/pgcat
that referenced
this issue
May 25, 2024
This commit adds the TCP_NODELAY option to the socket configuration in
`configure_socket` function. Without this option, we observed significant
performance issues when executing SELECT queries with large responses.
Before the fix:
postgres=> SELECT repeat('a', 1); SELECT repeat('a', 8153);
Time: 1.368 ms
Time: 41.364 ms
After the fix:
postgres=> SELECT repeat('a', 1); SELECT repeat('a', 8153);
Time: 1.332 ms
Time: 1.528 ms
By setting TCP_NODELAY, we eliminate the Nagle's algorithm delay, which
results in a substantial improvement in response times for large queries.
This problem was discussed in postgresml#616.
|
We've encountered similar performance issues with SELECT queries returning large results. Applying the fix from this pull request #749 significantly improved our performance. |
levkk
pushed a commit
that referenced
this issue
May 26, 2024
…ies (#749) This commit adds the TCP_NODELAY option to the socket configuration in `configure_socket` function. Without this option, we observed significant performance issues when executing SELECT queries with large responses. Before the fix: postgres=> SELECT repeat('a', 1); SELECT repeat('a', 8153); Time: 1.368 ms Time: 41.364 ms After the fix: postgres=> SELECT repeat('a', 1); SELECT repeat('a', 8153); Time: 1.332 ms Time: 1.528 ms By setting TCP_NODELAY, we eliminate the Nagle's algorithm delay, which results in a substantial improvement in response times for large queries. This problem was discussed in #616.
AndrewJackson2020
pushed a commit
to AndrewJackson2020/pgcat
that referenced
this issue
Sep 3, 2024
…ies (postgresml#749) This commit adds the TCP_NODELAY option to the socket configuration in `configure_socket` function. Without this option, we observed significant performance issues when executing SELECT queries with large responses. Before the fix: postgres=> SELECT repeat('a', 1); SELECT repeat('a', 8153); Time: 1.368 ms Time: 41.364 ms After the fix: postgres=> SELECT repeat('a', 1); SELECT repeat('a', 8153); Time: 1.332 ms Time: 1.528 ms By setting TCP_NODELAY, we eliminate the Nagle's algorithm delay, which results in a substantial improvement in response times for large queries. This problem was discussed in postgresml#616.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Describe the bug
I'm running the following command on pgcat.minimal.toml it takes 5 seconds before any queries are being sent by
pgbench, indicating that it takes 5 seconds to open 100 connections to localhost. This scales linearly and it takes 50 seconds to open 1000 connections.The text was updated successfully, but these errors were encountered: