Connection pooling issues with unixODBC, IBM DB2, and pyodbc - db2

Question

tldr; Have a working setup of Python->DB2, using unixODBC, but connection pooling is not working.
I've tried using the driver directly:
conn = pyodbc.connect('DRIVER=/opt/ibm/db2/lib/libdb2.so;Hostname=mydb2.domain.com;PORT=1234;DATABASE=database1;UID=user1;PWD=password1')
By driver name:
conn = pyodbc.connect('DRIVER=DB2;Hostname=mydb2.domain.com;PORT=1234;DATABASE=database1;UID=user1;PWD=password1')
DSN:
conn = pyodbc.connect('DSN=server1UID=user1;PWD=password1')
I've been using this Python script to test:
import sys
import timeit
#import pypyodbc as pyodbc
import pyodbc
#conn = pypyodbc.connect('DSN=server1;UID=user1;PWD=password1')
def query():
try:
conn = pyodbc.connect('DSN=server1;UID=user1;PWD=password1')
cur = conn.cursor()
cur.execute("select current timestamp from sysibm.sysdummy1")
row = cur.fetchone()
print('.', end='', flush=True)
conn.close()
except Exception as ex:
print(ex, end='', flush=True)
t = timeit.Timer(query)
count = 50
duration = t.timeit(count)
print("\n{count} # {duration}/sec".format(count=count, duration=count/duration))
(When logging is enabled, in odbcinst.ini, it shows a connection open/close for every query)
In my dev environment the above gets around ~10 query/sec
If the connection is created outside of the loop, and cached, then ~120 query/sec
If I install the ibm_db_dbi and use connect the results are ~10 query/sec, and using pconnect ~60 query/sec.
I've also tried iODBC, but I can't get it to connect at all, and on Windows, using ODBC, connection pooling appears to be working as expected.
Why unixODBC and not ibm_db_dbi?
connect doesn't pool
pconnect fails catastrophically, and never recovers, after network interruptions. It's also half the speed of a cached connection.
pyodbc seems better maintained than the IBM driver.
Setup:
Debian Jessie
Docker 1.7 container
IBM DB2 ODBC v10.5 library installed
unixODBC 2.3.4
Python 3.5
pyodbc 3.0.10
Configuration:
odbcinst.ini
[ODBC]
Pooling = Yes
Trace = No
TraceFile = /var/log/odbc.log
[DB2]
Description = IBM DB2 Adapter
Driver = /opt/ibm/db2/lib/libdb2.so
Driver64 = /opt/ibm/db2/lib/libdb2o.so
FileUsage = 1
DontDLClose = 1
CPTimeout = 1000
CPTimeToLive = 100
Threading = 2
Pooling = Yes
odbc.ini
[server1]
Description = Server 1
Driver = DB2
db2cli.ini
[server1]
Database = database1
Protocol = TCPIP
Hostname = mydb2.domain.com
ServiceName = 1234
References:
Using IBM DB2 with unixODBC (from unixodbc.org)
Setting up unixODBC with a remote DB2
Setting up the unixODBC driver manager (from IBM)
Similar question on SO that is stale, unanswered

Answer 1

It looks like you have Pooling = Yes in the wrong place, it needs to be under the [ODBC] heading, not the driver heading
http://www.unixodbc.org/doc/conn_pool.html