How many channes per dialer and more multiserver questions

[jselvin]

Hello,

Is there a maximum amount of channels that each dialer can accomodate?

I'm planning a setup like this and I need to know if its doable:

1 big beast mysql server. Dual or Quad 6-core Xeon 6350, 4x73gb 15k rpm SAS RAID 10, Raid card with 512 or 1024mb cache, 24gb of ram.

How many agents/channels/dialers or however its best measured do you think the Database server could handle? Do I need multiple NICS to handle more load?

This machine will handle multiple vicidial databases, one database per office/group/dialer.

The dialers will be a combination of dialer and webserver. And I'd like to know if its possible to have up to 50 agents on a single dialer/web ?

I need to know how many channels each of these 3 should be able to handle, using the following options:

Predictive outbound. 5 lines/agent.
G711 codec,
Recording should be done in RAM and immediately transfered to another machine for conversion etc. Is it possible to setup a machine to function as a ramdrive over the network? 1000gb/s network.
Only recording on demand.

Low version:
Dell R310
Intel® Celeron® G1101, 2C, 2.26GHz, 2M Cache
4gb Dual Ranked Ram
2x160gb 7200rpm sata
RAID 1 software raid or only one disk no raid...
Redundant Powersupply

Medium
same setup as low
but with
Intel® Core™ i3-530, 2C/4T, 2.93GHz, 4M Cache

High
Dell R310
Intel® Xeon® X3450, 4C, 2.66Ghz, 8MB Cache
SAS disc and hardware raid controller RAID 1


Where is the main requirement on hardware when it comes to the dialer/web, seems processor - but is it worth using 4 cores, or even 6 cores or do I have to scale using more dialers instead? I believe that having up to 30-35 agents one the medium should be ok, but I don't know.

Been using Vicidial since March and so far haven't had a single fault on the system that can be attributed vicidial. There's been several mistakes attributed the administrator (me) though.... =)

If someone could give me some pointers regarding these questions I'd be thrilled.

Thank you and have a nice weekend.

Jimmy

[williamconley]

I'd like to know if its possible to have up to 50 agents on a single dialer/web

rule of thumb is 25 agents per machine. but this depends on many factors. however, core2Quad 2.4ghz without recording or compression 25 is a good thumb rule.

Is it possible to setup a machine to function as a ramdrive over the network?

It is almost as possible to set up a network machine as a RAMDrive as it is to use 75 bicycles as a commuter bus. (the concept of RAMDRIVE precludes any communication outside RAM, and it's fairly obvious that the network card would be an "out of RAM" scenario: so NO). But if you want to build a system to mix the calls off the asterisk server ... the processing power for mixing the calls may be saved, but some processing power would be necessary to transfer the call off the box anyway. If you just wait until shift end to transfer the calls off, you can mix / xfer without any processor hit during the shift at all.

is it worth using 4 cores, or even 6 cores or do I have to scale using more dialers instead?

it's more about cost of the processors vs cost of a whole extra box. you don't get double the performance by having 4 cores instead of 2 cores, but then again you don't have double the cost either, by a long shot.

Been using Vicidial since March

If you are already using VICIdial, you already have your basic information gathering tool. the running system will begin to die when you reach 50% (as in half of the available processing power is actively booked).

Different people experience different forms of death such as more than one client landing in a conference room with an agent and/or other unpredictable "poor decisions" by the VICIdial system that are absolutely not present when the system isn't loaded.

If you have NOT experienced any of these issues ... you have not yet hit your load balance limit. Put more agents on (overlap a couple shifts) and find out where the barrier is with your present operational settings.

I would, however, completely avoid the Celeron.

[jselvin]

Thank you very much williamconley

I though about the ramdrive scenario and I think it'll maximum be 2-3 recordings taking place simultaneously - so I'll handle it in ramdrive and convert after the shift.

About the 4-6cores, they regarding the dialer servers - my main worry was if there was absolutely no point in using 4-6 core cpus - if asterisk has a built in limit of some kind... But I'll try out some different options here.

My current system is running all in one - so I have some difficulties getting usable readings of it..

[williamconley]

Asterisk has no limitations that would apply to this situation that i know of. i have run single instances of Asterisk with 1000 channels. If you have enough power to handle it.

Vicidial does have a tendency to open a lot of files and create a lot of sql connections, and the recent installs (since 2.0.3?) with proper installers have raised the connection and open file limits fairly high. but even if you did hit a limit there, you would just raise the limit farther.

Capacity limits in VICIdial are almost always CPU vs Bandwidth.

[Kumba]

For the database, spend all your money on RAM and hard-drives with multiple platters and a hardware caching raid controller. The ViciDial DB is I/O bound, meaning CPU has little effect in the over-all well being of things. I would look into finding a 15K SAS drive with 4-platters. This will give you better random IOPS which is what you want with a DB. Chances are your 73GB SAS drives are 2-platter versions, or even 1-platter if they are current generation. As far as CPU goes, two quad-core CPU's should be more then enough for what you want to do. If the money is trivial then you can also go with dual octal-core CPUs. 24GB of ECC RAM is also good.

As far as the dialers go, I am not sure why you want to reinvent how ViciDial works with the Ram Disk. Both ViciBox and GoAutoDial already enable a ram-disk to record to, and then mix them off the ram disk and onto hard-drive for transfer. If you want to save CPU time by not compressing them then that is an option as well. What we recommend to most client is a quad-core 2.0+ ghz CPU, 4GB of ram (8GB if you do LONG sale pitches or heavy inbound), and a simple RAID-1 using enterprise-class SATA or basic entry-level SAS drives. The Dialer is mostly bound to CPU resources and software design ceilings. RAM and the Hard-Drive are only needed for the recordings.

The web server follows under the same guidelines as the dialer, other then Apache/PHP scales better then asterisk. You will probably need a web server for every 150 active agents you have. If you include the webserver onto the dialer you will have to drastically lower this number as load spikes in apache and asterisk will easily start competing with each other to see who can get the most.

As far as max number of agents on a machine, there is no limit. You can put 500 on there if you want. It won't work worth a damn, but you can. What we normally see is a general breakdown within asterisk once you breach the 250-ish channel mark. At this point asterisk starts to suffer from various deadlocks, audio quality issues, and vicidial can start getting confused. Since you are handling every call twice in a lot of aspects of ViciDial, we would normally rate our above spec dialer at 25-30 agents, with approximately 100-125 line capacity. Obviously this is highly relative to what you are doing and how you are doing it.

[jselvin]

thank you Kumba

can you recommend a model/manufacturer that has 4 platters?

[Kumba]

Well, they are almost always going to be the biggest drives within that generation.

You are going to have to go to the manufacturer's website and read the white papers on the drives. They will tell you what they are.

I wouldn't worry about getting the latest and greatest drive technology. Unless you are using SAS expanders there isn't much benefit to it currently. We use 3Gb/S SAS on an LSI 8404ELP w/BBU and Seagate 15K.4 147GB or Fujitsu MAX3147RC 147GB.