[SR-Users] [sr-dev] new module db_kazoo

Luis Azedo luis at 2600hz.com
Tue Sep 9 14:12:27 CEST 2014

Hi Daniel,

you can check our current code at https://github.com/2600hz/kazoo-kamailio/tree/4.0https://github.com/2600hz/kazoo-kamailio/tree/4.0

this is already compatible with master from kamailio (tests running ok).

we will start to update the docs when we commit to master and will get it ready before 4.2.

>>For a better clarification, do the json payloads flowing via AMQP have a structure specific for kazoo? I mean the object structure, how are the fields name set, from the name of the columns? Is there a >>wrapper to specify the command (e.g., insert, delete, select)? Or maybe you can provide an example of such object...

No, the payloads are what you want. here's a sample on how we are using to  handle REGISTER messages

            if ($sht(auth_cache=>$Au) != $null && pv_auth_check("$fd", "$sht(auth_cache=>$Au)", "0", "0")) {
                xlog("L_INFO", "$ci|log|authenticated $Au via cached SIP creds");
            } else {
                ## RABBITMQ - Credentials fetch
                ## build the payload
>>>                $var(amqp_payload_request) = "{'Event-Category' : 'directory' , 'Event-Name' : 'authn_req', 'Method' : 'REGISTER', 'Auth-Realm' : '" + $fd + "', 'Auth-User' : '" + $fU + "', 'From' : '" + $fu + "', 'To' : '" + $tu +"' }";

                $var(amqp_routing_key) = "authn.req." + $(fd{kz.encode});  // kz.encode is a helper function to encode properly to amqp

               if(kazoo_query("callmgr", $var(amqp_routing_key), $var(amqp_payload_request))) {       // kazoo_query publishes and expects answer
                    xlog("L_DBG", "$ci|log|amqp_result = $kzR");   // $kzR is the result payload
                   $var(password) = $(kzR{kz.json,Auth-Password});
                   // kz.json is a helper to extract values from payload, nested values are permitted
                   // it could be something like $(kzR{kz.json,Channels[0].switch_url })
                   if($var(password) != $null) {
                      if (!pv_auth_check("$fd", "$var(password)", "0", "0")) {

we build the payload and publish it to rabbitmq, in this case we wait for a correlated msg to get the result.
kazoo_publish -> sends only
kazoo_query -> sends and waits for correlated answer

here's an example on how we subscribe to a exchange

    #!ifdef PRESENCE-ROLE
    $var(payload) = "{ 'exchange' : 'dialoginfo' , 'type' : 'direct', 'queue' : 'BLF-QUEUE-MY_HOSTNAME', 'routing' : 'BLF-MY_HOSTNAME', 'auto_delete' : 0, 'durable' : 1, 'no_ack' : 0, 'wait_for_consumer_ack' : 1 }";

and how we react when we get a message

    xlog("L_INFO", "received $(kzE{kz.json,Event-Package}) update for $(kzE{kz.json,From})");
    pres_refresh_watchers("$(kzE{kz.json,From})", "$(kzE{kz.json,Event-Package})", 1);

the event_route name is built from the payload we receive on the subscription
kazoo:consumer-event - fixed
-presence - taken from parameter amqp_consumer_event_key
-update - taken from parameter amqp_consumer_event_subkey

amqp_consumer_event_key and amqp_consumer_event_subkey are for now parameters for the module but we want to make by subscription.
from the above example we will change it to
$var(payload) = "{ 'key' : 'fieldname', 'subkey' : 'fieldname', 'exchange' : 'dialoginfo' , 'type' : 'direct', 'queue' : 'BLF-QUEUE-MY_HOSTNAME', 'routing' : 'BLF-MY_HOSTNAME', 'auto_delete' : 0, 'durable' : 1, 'no_ack' : 0, 'wait_for_consumer_ack' : 1 }";

right now, all interaction is made from configuration script.
the long term will be to create a bind structure so that other modules can interact directly with it.

let me know if that helps


From: Daniel-Constantin Mierla [miconda at gmail.com]
Sent: Tuesday, September 09, 2014 4:45 AM
To: Kamailio (SER) - Development Mailing List; sr-users at lists.sip-router.org
Cc: Engineering
Subject: Re: [sr-dev] new module db_kazoo


thanks for this contribution!

Do you have a link to the module source code or can you send it attached? We need to review a bit and check if everything is in place (e.g., license, documentation).

For a better clarification, do the json payloads flowing via AMQP have a structure specific for kazoo? I mean the object structure, how are the fields name set, from the name of the columns? Is there a wrapper to specify the command (e.g., insert, delete, select)? Or maybe you can provide an example of such object...

Kazoo is an open source application, therefore the new module has no barrier in getting inside kamailio repository. My questions were related more to see if worth considering a new name.

To get it in our git repository, we expect that you or someone else from 2600hz is willing to maintain it for at least one year. You will get write access over ssh to git repository to be able to push the new module and commit to it in the future. I will write a separate email directly to you with the required details for access.


On 09/09/14 12:22, Luis Azedo wrote:
Hello Awesome Kamailio Community,
We are writing on behalf of 2600hz, where we have been using Kamailio for some time now and are very pleased with our results! So, seems time to commit something back, dontchya think?

We would like to present to you a new module, to hopefully be included in master.   We call it db_kazoo (although a new name is fine too).

db_kazoo is a general purpose AMQP connector (connects to our rabbitmq-server). It exposes publish/consume capabilities into Kamailio. Why is this amazing, you ask? Well even if you didn’t ask, we will explain…

>From a high-level, the purpose of the module might be for things like:
- Integrate to an AMQP application to make real-time routing decisions (instead of using, say, a SQL database)
- Provide a real-time integration into your program, instead of your database, so you can overlay additional logic in your preferred language while also utilizing a message bus
- Utilize messaging to have a distributed messaging layer, such that machines processing requests/responses/events can go up/down or share the workload and your Kamailio node will still be happy

With this module, someone can:
1 - publish json payloads to rabbitmq
2 - publish json payloads to rabbitmq and wait for correlated response message
3 - subscribe to an exchange with a routing key

The module works with a main forked process that does the communication with rabbitmq for issuing publishes, waiting for replies and consuming messages. When it consumes a message it defers the process to a worker process so that it doesn't block this main process.

The worker process issues an event-route where we can act on the received payload. The name of the event-route is composed by values extracted from the payload.

Consumed messages have the option of being acknowledge in two ways:
1 - immediately when received
2 - after processing by the worker

One unique feature of our implementation revolves around failover of the message bus itself. In our design, the module supports multiple RabbitMQ servers and will fallback from one to the next in a list of RabbitMQ servers if the connection fails to the current connected server. When using acknowledge in db_kazoo with clustering in RabbitMQ, we have simulated and experienced full reconnects while in the middle of processing pending messages. In this way, when we get disconnected from one server we proved that, even at high speeds, we are able to connect to the next in the list and continue interacting with our application.

We have run a variety of sipp load tests on this module and believe it is ready for prime time. We monitored memory, response accuracy and overall stability and it seemed OK. But we would, of course, love for others to help us find what we have missed, or contribute more features, or overall just use the work we slaved over for so many hours. Or just make comments and suggestions!

If nothing else, we hope we’ve provided something useful to the Kamailio community, as you all have provided useful items to us.

Thanks to everyone for all the work on Kamailio and related products.

Look forward to hearing from you all.

This is our first formal / large contribution to Kamailio so if we’ve done something wrong process, code or otherwise please let us know!

sr-dev mailing list
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Daniel-Constantin Mierla
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Next Kamailio Advanced Trainings 2014 - http://www.asipto.com
Sep 22-25, Berlin, Germany
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