Using psycopg.connect hangs for around 90 seconds on the latest versions of psycopg2-binary

[bvanelli]

This is a bug tracker

Please complete the following information:

• OS: MacOS 14.6.1 (23G93)
• Psycopg version: 2.9.9 (dt dec pq3 ext lo64)
• Python version: 3.10.0
• PostgreSQL version: tested with Debian 16.4-1.pgdg120+1 running on docker
• pip version: 2.9.9

Describe the bug

I noticed the hanging of psycopg2-binary starting from version 2.9.6. Here is the script I used (pg must be started via docker):

import time
import psycopg2

# run docker with
# docker run --name postgres -e POSTGRES_PASSWORD=postgres -p 5432:5432 -d postgres
t = time.perf_counter()
conn = psycopg2.connect("dbname=postgres user=postgres password=postgres host=localhost")
t_elapsed = time.perf_counter() - t
print(f"Elapsed time on version {psycopg2.__version__} was  {t_elapsed:.2f}")

Seems like this bug was introduced in version 2.9.7, here are the outputs:

psycopg2 version	Output
2.9.6	Elapsed time on version 2.9.6 (dt dec pq3 ext lo64) was 0.07
2.9.7	Elapsed time on version 2.9.7 (dt dec pq3 ext lo64) was 90.19
2.9.8	Elapsed time on version 2.9.8 (dt dec pq3 ext lo64) was 90.24
2.9.9	Elapsed time on version 2.9.9 (dt dec pq3 ext lo64) was 90.20

With debug I could go as far as the Python wrapper goes, up to the call:

    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)

Could this somehow be unrelated to the python wrapper, but rather to the libpg under it?

[bvanelli]

Here is the diff between the versions: https://github.com/psycopg/psycopg2/compare/2.9.6..2.9.7

Possible causes:

• OPENSSL_VERSION upgraded from 1_1_1t to 1_1_1v
• LIBPQ_VERSION upgraded from 15_0 to 15_3
• Changing { goto exit; } to { goto error; } on psycopg/psycopgmodule.c

[dvarrazzo]

Usually on macOS it is some exotic connection method timing out, such as GSS. See #1645 for example.

[bvanelli]

Thanks @dvarrazzo , I tried looking for a related issue yesterday but I could not find anything, this issue you mentioned is exactly what was needed.

For anyone that may com to this thread, the solution was to go to Ticket Viewer and remove all entries. It had some expired tickets:

Not it connects as expected 👍