UnixODBC connection pool does not release idle connections

[AlanChao2025]

I have set the connection pooling CPTimeout to 60 seconds in unixODBC, but after a connection has been idle for more than 60 seconds, it's not being released. Why is this happening?

I am using ODBC Driver 18 for SQL Server, unixODBC 2.3.11, and the operating system is AlmaLinux 9.4.

/etc/odbcinst.ini：
[ODBC Driver 18 for SQL Server]
Description=Microsoft ODBC Driver 18 for SQL Server
Driver=/opt/microsoft/msodbcsql18/lib64/libmsodbcsql-18.2.so.2.1
UsageCount=1
CPTimeout=60

[ODBC]
Pooling=Yes
PoolMaxSize=15
PoolWaitTimeout=30

[lurcher]

Can you see if 2.3.12 or even better 2.3.13pre (or the current code in git) does the same?

[AlanChao2025]

Can you see if 2.3.12 or even better 2.3.13pre (or the current code in git) does the same?

How should I properly close idle connections in a connection pool?
I keep seeing idle connections appear in the file descriptors.