[asterisk-users] Error - Failed to extend from xxx to xxx

[Stuart Elvish]

Hi List,

I have a problem with Asterisk 1.6.1.6 realtime (MySQL databases
hosted on a separate machine). When Asterisk is in verbose mode, it
prints messages saying "failed to extend from 512 to 664" (quite a few
lines in a block) and then the last message is mostly "failed to
extend from 512 to 663". The number of lines varies unpredictably.

The full message (in the logs) is:
[Jun 26 04:02:30] VERBOSE[3257] utils.c: failed to extend from 512 to 664

I haven't been able to track down much information about this using
web searches but it appears (based on what I have read) that perhaps
it is a database connection issue. There doesn't appear to be any
problem in terms of network connectivity or database load on the
database server which would lead to this situation. The Asterisk
server is also well resourced generally running at <10% load.

The system is designed for high availability so the extensions
re-register quite frequently (which is no problem as the extensions
are on an internal network) and there are approximately 1,570
extensions with more being added each week. We use cached RT peers.
The database is used for CDR's, sip.conf and voicemail.conf but
extensions.conf is static.

So with all the above information, I am leaning towards the error
being related to the database connection for real time and it
occurring when an extension re-registers.

Any thoughts?

Thanks in advance.

Stuart Elvish