[asterisk-users] IOPS required by Asterisk for Call Recording

[Ron Wheeler]

I am surprised about the network. It should go before the disk if you 
have a lot of short transactions. There is a high percentage of overhead 
on streams of short messages.
Make sure that you check at each point where messages are passing.

Have you done any mathematical modeling of the disk and network traffic?

Try changing your RAM to see if raising it (or lowering it if that is 
easier) affects the problem.

What is your CPU utilization like at 80 calls?

How many open files do you have at 80 calls? is this near the limit?

Can you adjust the quality of the recordings to reduce the bits stored 
for each second of audio?
What happens when you do this?

Ron

On 29/01/2014 7:34 AM, Amit wrote:
> Thanks Ron.
> I will try to get these readings. About RAM disk, I will study on how 
> to create RAM disk and conduct this test again.
> There is no bottleneck on network.
>
> After 80 calls, I see call drops, delay in responding, time out, 
> re-transmission of SIP messages. If load is reduced, it settles again 
> to normal.
>
> *Thanks & Regards,*
> Amit Patkar
>
>
>
> On 1/28/2014 12:32 AM, Ron Wheeler wrote:
>> Can you get a reading of the total number of I/Os during your test? 
>> Peak IOPS?
>> That might tell you very quickly about the storage pattern that 
>> Asterisk uses.
>>
>> Can you configure a RAM drive to see if disk is really the 
>> bottleneck. May need to add some more RAM memory to your configuration.
>>
>> What is your network capacity? Usually one can write faster than the 
>> network can deliver - just to make sure that you are chasing the 
>> right bottleneck.
>>
>> What happens at 80 calls to tell you that you have run out of IOPS?
>>
>> Sorry for more questions than answers.
>>
>> Ron
>>
>>
>>
>> On 25/01/2014 12:26 AM, Amit wrote:
>>> Thanks for response.
>>> How do I derive the requirement? I need to size IO system to record multiple calls concurrently.
>>> I ran test with following configuration
>>> Quad Core Xeon with 4GB RAM
>>> 250GB SATA disk (No RAID)
>>> Linux (CentOS 5.9)
>>> Asterisk 1.8.20
>>>
>>> I failed to record more than 80 calls.
>>>
>>> If I run test with simple IVR, I achieved 400+ calls with same server.
>>> So write seem to be an issue.
>>> Is there any way to tune / optimize / configure for better write performance?
>>>
>>> I am not sure if I need to post this query on developers list? Please guide...
>>>
>>> Regards
>>> Amit Patkar
>>>
>>> Message: 1
>>> Date: Fri, 24 Jan 2014 11:46:39 -0400
>>> From: Mike<ispbuilder at gmail.com>
>>> To: Asterisk Users Mailing List - Non-Commercial Discussion
>>> 	<asterisk-users at lists.digium.com>
>>> Subject: Re: [asterisk-users] IOPS required by Asterisk for Call
>>> 	Recording
>>> Message-ID:<52E28ADF.8020409 at gmail.com>
>>> Content-Type: text/plain; charset="iso-8859-1"
>>>
>>> On 14-01-24 11:16 AM, Amit wrote:
>>>> If I assume that Asterisk will write data on disk every second for
>>>> each call, I will need disk array to support minimum of 500 IOPS.
>>>> Where as if Asterisk push data every 2 seconds, I can deal with array
>>>> supporting 250 IOPS.
>>>> But if I assume that Asterisk will write data on disk for every RTP
>>>> packet received, as and when received, I will need disk IO system with
>>>> approx 25000 IOPS assuming 20 ms RTP packet.
>>> You're assuming that asterisk will perform an fsync() after each write.
>>> If asterisk writes without an fsync after each write, then the OS will
>>> schedule writes intelligently based on RAM/disk IO available rather than
>>> scheduling each one as a separate write.
>>>
>>> Looking at the code for ast_writestream() there doesn't appear to be an
>>> fsync() type call after each write, but someone more familiar with the
>>> internals of Asterisk would be better able to verify that.
>>
>> -- 
>> Ron Wheeler
>> President
>> Artifact Software Inc
>> email:rwheeler at artifact-software.com
>> skype: ronaldmwheeler
>> phone: 866-970-2435, ext 102
>
>
>
>


-- 
Ron Wheeler
President
Artifact Software Inc
email: rwheeler at artifact-software.com
skype: ronaldmwheeler
phone: 866-970-2435, ext 102

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