[asterisk-biz] Asterisk 1.4.22.1 and zombies

[Sabine Jordan]

Hello Murf,

first of all, thank you for your help.

The old posting from years ago, was not my problem, it was just a
problem someone had which I've found searching the internet to find a
solution to our problem. It was the only thing that I found similiar to
our problem, or at least it seemed similiar to our problem. But I am not
that experienced with asterisk, so I might be wrong assuming that.

Well, we use Open Suse 11 on this system. We don't use zap, we just use
SIP and ztdummy, because ztdummy it's required to use MeetMe. The system
where the problem occurs is our application server. we do also have a
gateway where we use zap to accept incoming calls, which we transfer
using sip protocol to the applications server. The caller gets
transfered to agents from there or he meets other callers in conference
rooms. The script we use connects the caller to agents, or opens
confrence rooms...

I try not using the word zombie again ;) I will call them defunct
processes instead.

I'll take a closer look on the system an check all the things that
you've mentioned on Monday. But maybe you have some other hints with the
additional information I've given now.

Kind regards and have a nice weekend.

Sabine


Sabine Jordan wrote:
>> Hello all,
>>
>> I've read the following posting at lists.digium.com from November 2006:
>>
>> http://lists.digium.com/pipermail/asterisk-users/2006-November/172261.html
>>
>> I know it's been a while ago and unfortunately there where no replies.
>> Maybe someone has solved the problem anyway and could help me, because
>> we have the same problem running asterisk 1.4.22.1. We already updated
>> from a previous version, but the problem remains the same...
>>
>> We have some php-scripts from where we run asterisk-applications which
>> seem to work fine for a while until the first zombie appears. After the
>> first zombie has appeared all other hangups seem to generate zombies as
>> well. After a while the zombies disappear until it all starts again. But
>> there are times when we have more than 1500 zombies which is alarming.
>>
>> Some informmation about the script:
>>
>> - every db-connection is closed
>> - the script is closed with an "exit"
>> - script works fine until after some time the first zombie appears
>>
>> pstree |grep asterisk
>>
>>      |-safe_asterisk---asterisk-+-173*[asterisk.php]
>>      |                          `-37*[{asterisk}]
>>
>>
>> Has someone solved the problem in the past and/or could give me a hint?
>>
>> Thank you in advance.
> 
> 
> 
> Hung channel problems have been fairly challenging to fix, especially
> the ones like yours, that don't happen all the time.
> 
> It's good you updated to 1.4; after reading the letter you 
> referenced from the archives, these statements concerned me:
> 
>         "We are running Asterisk-1.0.12 in a CentOS 4-4.2 system, kernel
>         2.6.9-42.0.3.ELsmp.
>                 
>         "Currenly we can not easily migrate from asterisk-1.0.x to 1.2.x
>         
> 
> The reason no-one probably responded to your first message, is your
> asterisk version was so ancient, they could only conclude that the 
> problem might be solved in the last 3 or so years.
> 
> Oh, and I'd not use the word "zombie"; it is pretty descriptive, but
> in the core of asterisk, the word is being used for a channel that
> has been masqueraded. Masquerading is a process that duplicates a
> channel
> and gives almost all the active components, including its name to the
> new channel. The old channel gets a name like "Sip/1-1<ZOMBIE>".
> This happens with parking, xfers, etc.
> 
> It might help to do these sorts of things when you are seeing lots
> of hung channels:
> 
> 1. "core show threads"
> 2. "core show channels"
> 3  "core set verbose 10"
> 4  "core set debug 10"
> 5. sip show channels   (if you are using sip channels)
> 6. sip show history.... on a hung channel
> 
> You didn't mention what kind of channels you were involved;
> Dahdi (zap) or Sip or what?
> 
> If everything goes fine and then, all on a sudden, you start
> accumulating dead/hung channels, you have to ask yourself,
> what might be going on that would explain the buildup? What
> is different?  It might be a network difficulty, a DNS server
> problem, a database system hiccup, or some other non-obvious
> problem that might come, and go away. Look for warning and
> error messages in system logs, /var/log/asterisk/messages,
> and other system logs.
> 
> Turning up verbosity will show you what applications are
> being executed in the dialplan. If you see a lot of 
> an app being executed, but not the following one, 
> then you might be hanging in that app... and so on.
> 
> If you are serious about solving a problem, you have
> to put on your detective hat and pull out your notebook
> and start experimenting, probing, and testing. Not all
> problems are because of bugs in Asterisk!
> 
> murf
> 
> 
> 
> 
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