odbc_log: Unable to retrieve database handle. CDR failed.

Asterisk PBXI correctly configured ODBC connection on Asterisk server to MSSQL database in Always On cluster.

The working configuration was as follows:

CentOS 7 ODBC configuration

# cat /etc/odbc.ini

Description = Connection to mssql_aag_listener. Store CDR data.
Driver = FreeTDS
Server = mssql_aag_listener\instancename
Database = asteriskcdr
Port =
Option =
Stmt =
Trace = yes
TraceFile = /var/log/odbc_cdrtomssql-connector.log

# cat /etc/odbcinst.ini

[FreeTDS] # This is your identifier! You’ll need it in odbc.ini
Description = FreeTDS Driver
Driver = /usr/lib64/libtdsodbc.so

Asterisk ODBC configuration

# cat cdr_odbc.conf
table=cdr ;”cdr” is default table name
;usegmtime=no ; set to “yes” to log in GMT
;hrtime=yes ;Enables microsecond accuracy with the billsec and duration fields
;newcdrcolumns=yes ; Enable logging of post-1.8 CDR columns (peeraccount, linkedid, sequence)

# cat res_odbc.conf

enabled => yes
dsn => cdrtomssql-connector
username => LetmeIn
password => SomeSecurePassword
pre-connect => yes
logging => no

Asterisk modules are aware of Data Source names from res_odbc.conf and not from system’s odbc.ini !

So lookup flow will be as follows : [module config].conf -> res_odbc.conf -> odbc.ini

Thus “dsn” from cdr_odbc.conf is the section name from res_odbc.conf and “dsn” from res_odbc.conf is the section name from odbc.ini

Database and table was already created on MS SQL server.

After reloading Asterisk and applying configuration I saw the following error in Asterisk console:

ERROR[23876]: cdr_odbc.c:174 odbc_log: Unable to retrieve database handle. CDR failed.

I checked configuration files several times and made sure that everything is correct.

odbc show cdrtomssql command showed that connection is established but error persist and database was empty:

CLI> odbc show cdrtomssql

ODBC DSN Settings

Name: cdrtomssql
DSN: cdrtomssql-connector
Number of active connections: 1 (out of 1)

DB password was strong and contained special characters “<“, “[” and “~”

When I started to debug connection manually with isql command, dsn name, DB login and password I got an idea when I saw the following error:

# isql -v cdrtomssql-connector asterisk Un<drvZB
bash: [d~rvZB: No such file or directory

Bash interprets special character!

That’s what happens: Asterisk sends the password without escaping special characters.

Despite the fact that both:

# isql -v cdrtomssql-connector asterisk 'Un<drvZB'


# isql -v cdrtomssql-connector asterisk Un\<drvZB

worked from Bash prompt it did not work from Asterisk’s res_odbc.conf.

So I had to remove “<” from the password string.

Want me to do this for you? Drop me a line: itgalaxyzzz {at} gmail [dot] com