[HELP] Nasty bug


#1

Hi all,
I’m using Asterisk for a couple of months - problem free. Yesterday, one of VOIP providers (Sipmedia aka Myphonecompany) had conectivity problems - dns timeout kind of problems, that killed Asterisk for good. Even the console was VEEEERY slow to respond. Once I disabled the (8) registrations to Sipmedia everything returned to sanity but I think Asterisk should have some immunity from DNS problems.


#2

You should be able get round that sort of problem by resolving the domain name manually and putting the IP address in the config file(s). That way, Asterisk doesn’t have to look it up and it’s then immune from dodgy DNS delays. Of course, you will have to keep an eye on it as, if the IP address associated with the domain name changes, Asterisk won’t pick it up.


#3

Hmmm, that’s a lot of work to maintain IPs by hand. I’d rather resolve the DNS locally and update the zone files with a cron job. But that’s not the point, is it ? This kind of things shouldn’t happen. It’s like your car wouldn’t start and run because it’s out of windshield washing fluid. Actually I’ve heard somebody that has spent a lot of money on a custom motorcycle and he found out in the middle of nowhere that the ignition was run trough the brake lights - so when the bulb was gone so was the engine.


#4

Yeah, that might be easier. An alternative could be an include file in sip.conf or something…

Well, yeah, maybe they shouldn’t. But DNS does weird things sometimes. I’ve had a few strange things happen over the last few years due to dodgy DNS - things that i would never have expected to happen because of a name resolution problem. These sorts of phenomena have noticeably appeared since the internet got really big half a dozen years ago. Although that could be just coincidence.

I don’t know if it’s the resolver library routines that have got weird bugs in them or if it’s the applications or if it’s something happening in the various network layers (which shouldn’t really be affected by DNS issues, but you never know). It could be an Asterisk bug, but chances are it’s not really.


#5

I already stated that DNS was timing out. This is not a problem with the resolver and not an unexpected behaviour - it’s just not common. The fact that all Asterisk is freezing - including local extensions that resolve just fine - is the issue here. Clearly, there are hacks to avoid impact of such occurence but I still think Asterisk should handle such events gracefully.