ODBC connection failing to reconnect with 2.0.3 (EJAB-764)

Maybe R11B-0 is too old? You could try with R11B-5, or R12B-5, or anything newer if a package is available for your system.
If you are lazy to compile Erlang yourself and you want to know if the problem could be fixed by using a more recent Erlang version, you can try to install ejabberd using ejabberd 2.0.3 binary installer from ProcessOne. It includes Erlang R12B-5, ejabberd, mysql and pgsql drivers.

It reconnects correctly for me using mysql. I don't have a pgsql server to test.

This syntax is wrong, and I'm sure ejabberd didn't start with such line in ejabberd.cfg

I didn't need to change this option.

I installed ejabberd 2.0.3, Erlang/OTP R12B-5, mysql from ejabberd-modules SVN.

Configuration of ejabberd: the default, with this change:

{auth_method, odbc}.
{odbc_server, {mysql, "localhost", "ejadb", "ejauser", "ejapass"}}.

I create an account and login. All correct up to here.

Now I stop the MySQL server:

root@localhost:~# /etc/init.d/mysql stop
Stopping MySQL database server: mysqld.

Immediately, ejabberd starts complaining in ejabberd.log:

...

=ERROR REPORT==== 26-Feb-2009::09:49:58 ===
E(<0.711.0>:ejabberd_odbc:385) : mysql_conn: Failed connecting to "localhost":3306 : {error,
                                                                                      "connect failed : {error,econnrefused}"}

=ERROR REPORT==== 26-Feb-2009::09:49:58 ===
E(<0.710.0>:ejabberd_odbc:347) : MySQL connection failed: connect_failed
Waiting 30 seconds before retrying...


=ERROR REPORT==== 26-Feb-2009::09:49:58 ===
E(<0.646.0>:ejabberd_odbc:385) : mysql_conn: Received unknown signal, exiting

=INFO REPORT==== 26-Feb-2009::09:49:58 ===
I(<0.646.0>:ejabberd_odbc:383) : Closing connection #Port<0.3662>: ok


=ERROR REPORT==== 26-Feb-2009::09:49:58 ===
** Generic server <0.645.0> terminating
** Last message in was {'DOWN',#Ref<0.0.0.9599>,process,<0.646.0>,normal}
** When Server state == {state,<0.646.0>,mysql}
** Reason for termination ==
** connection_dropped

=CRASH REPORT==== 26-Feb-2009::09:49:58 ===
  crasher:
    pid: <0.645.0>
    registered_name: []
    exception exit: connection_dropped
      in function  gen_server:terminate/6
    initial call: ejabberd_odbc:init/1
    ancestors: [ejabberd_odbc_sup_localhost,ejabberd_sup,<0.38.0>]
    messages: []
    links: [<0.308.0>]
    dictionary: []
    trap_exit: false
    status: running
    heap_size: 233
    stack_size: 23
    reductions: 472
  neighbours:

=ERROR REPORT==== 26-Feb-2009::09:49:58 ===
E(<0.661.0>:ejabberd_odbc:385) : mysql_conn: Received unknown signal, exiting

=INFO REPORT==== 26-Feb-2009::09:49:58 ===
I(<0.661.0>:ejabberd_odbc:383) : Closing connection #Port<0.3667>: ok

If I logout and login again the Jabber client, it fails.

Then I start MySQL:

root@localhost:~# /etc/init.d/mysql start
Starting MySQL database server: mysqld.
Checking for corrupt, not cleanly closed and upgrade needing tables..

A few seconds later, ejabberd reports in ejabberd.log a lot of stuff, like:

=PROGRESS REPORT==== 26-Feb-2009::10:16:40 ===
          supervisor: {local,ejabberd_odbc_sup_localhost}
             started: [{pid,<0.821.0>},
                       {name,5},
                       {mfa,{ejabberd_odbc,start_link,["localhost",30000]}},
                       {restart_type,transient},
                       {shutdown,brutal_kill},
                       {child_type,worker}]

Now I login again correctly.