# AMQP(RabbitMQ) in Ignition **URL:** \ **Category:** Ignition\ **Tags:** perspective, ignition81, scripting\ **Created:** [June 6, 2022, 1:15pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400 "2022-06-06T13:15:34Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![louagejasper](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/louagejasper/32/86311_2.png) [@louagejasper](https://forum.inductiveautomation.com/u/louagejasper)\ **Post date:** [June 6, 2022, 1:15pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/1 "2022-06-06T13:15:34Z")
Hi, I’ve been trying to use AMQP in Ignition, using the amqp-client-5.14.2.jar library. For now, I’ve just added the library to the folder in Ignition, maybe later, I will build a separate module for it. I have used the following code: ```auto from com.rabbitmq.client import Connection from com.rabbitmq.client import Channel from com.rabbitmq.client import Consumer from com.rabbitmq.client import DefaultConsumer from com.rabbitmq.client import ConnectionFactory userName = 'guest' password = 'guest' virtualHost = "/" hostName = "rabbitmq" portNumber = 5672 #15672 exchangeName = 'EXCH' queueName = 'Ignition' routingKey = 'Ignition' def connect(): factory = ConnectionFactory() #"guest"/"guest" by default, limited to localhost connections factory.setUsername(userName) factory.setPassword(password) factory.setVirtualHost(virtualHost) factory.setHost(hostName) factory.setPort(portNumber) conn = factory.newConnection() channel = conn.createChannel() channel.queueBind(queueName, exchangeName, routingKey) autoAck = False channel.basicConsume(queueName, autoAck, "Ignition_Consumer", DefaultConsumer(channel)) ``` This gives me a connection to the broker: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/7/9/797cc69ce1a55917d9f44ba531d4e4476b5d579e.png) Now I lack a bit of knowledge to proceed. Everytime I run the script, I logically get a new connection. In the same script, I have this function: ```auto def close(): system.perspective.print('closing connection ...') channel.close() conn.close() ``` But this function is not connected anymore to the connection I first created, so it gives an error. How do I make sure there is always one connection from my platform to the AMQP broker? And how do I manage that active connection without ? I assume I need something like persistent classes? @pturmel, I’ve seen you talk allot about classes an persistent classes, would you know how I can proceed? Thanks! ---
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [June 6, 2022, 2:34pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/2 "2022-06-06T14:34:16Z")
I’d definitely recommend doing some digging on the forums for “prior art” here. One other thing to note: `system.util.globals` / `system.util.getGlobals()` is a dictionary that persists across the lifetime of the local JVM (so as long as the gateway is up). ---
**Author:** ![louagejasper](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/louagejasper/32/86311_2.png) [@louagejasper](https://forum.inductiveautomation.com/u/louagejasper)\ **Post date:** [June 7, 2022, 8:23am UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/3 "2022-06-07T08:23:05Z")
I did do some digging here > [@\[IGN-5244\]Persist Python Class Object](https://forum.inductiveautomation.com/t/ign-5244-persist-python-class-object/30498): > > I am working in Perspective, but this probably applies to other modules as well. I have created user defined classes in the project scripts and I am instantiating them from a view in Perspective. Is there a place I can persist the instance of the object for use between events by the user? Right now I have it serializing to a property on the view, but when I want to work with the object again I have to de-serialize the object in order to work with it again. Having to write custom de-serialize me… and here > [@system.util.getGlobals() not persisted across Designer Save](https://forum.inductiveautomation.com/t/system-util-getglobals-not-persisted-across-designer-save/33869/14): > > Ok. New module “Life Cycle” w/ system.util.persistent(name) utility function. For v7.9: [https://www.automation-pros.com/ignition/Life%20Cycle-0.9.0.2004121825.modl](https://www.automation-pros.com/ignition/Life%20Cycle-0.9.0.2004121825.modl) For v8.0: [https://www.automation-pros.com/ignition/Life%20Cycle-0.9.0.2004121920-v8.modl](https://www.automation-pros.com/ignition/Life%20Cycle-0.9.0.2004121920-v8.modl) Test with a project script like this: # project script "Life" g = system.util.persistent('LifeTest') count = g.setdefault('editCount', -1) count += 1 g['editCount'] = count def editCount(): return count Print the return from Life.editCou… But I think you guys are a few levels ahead of me. I simply want one always open connection (I need a class for this I think) when Ignition is running and want to speak to this connection when necessary. How can I use `system.util.getGlobals()` to store a class? Is there any example on this? And also, I'm a bit confused about `system.util.getGlobals()`. Are these globals something on your gateway? Because I see they are different when I open a new designer session. \*Edit: Ah, it is the same when you run it in a gateway scope, I see... Now I just need to find how I can store my connections in it. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [June 7, 2022, 11:52am UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/4 "2022-06-07T11:52:40Z")
The point of those topics is that you _ **CAN’T** _ just “store a class”. You will leak gobs of gateway memory if you try to do it naively. On this topic, you will simply have to study and test until you understand it. I strongly recommend testing on a non-production gateway. ---
**Author:** ![louagejasper](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/louagejasper/32/86311_2.png) [@louagejasper](https://forum.inductiveautomation.com/u/louagejasper)\ **Post date:** [June 7, 2022, 12:04pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/5 "2022-06-07T12:04:22Z")
Oh, ok… So referring back to my original code: ```auto conn = factory.newConnection() ``` How would I typically refer back to a connection made in a script? Would the connection have some identifier, which I would need to store in globals and use later? Ofcourse, I’m testing all new things in local containers. ---
**Author:** ![Chris\_Bingham](https://avatars.discourse-cdn.com/v4/letter/c/e5b9ba/32.png) [@Chris\_Bingham](https://forum.inductiveautomation.com/u/Chris_Bingham)\ **Post date:** [July 13, 2022, 3:45pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/6 "2022-07-13T15:45:11Z")
We are heading down the same path. Currently working on a module which wraps the latest AMQP Client library. You can reference the same global variables within each of your functions: ```auto def close(): global conn // Added global channel // Added system.perspective.print('closing connection ...') channel.close() conn.close() ``` Have you made progress on a ‘unique connection identifier’? Found this related StackOverflow thread: > ---
**Author:** ![louagejasper](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/louagejasper/32/86311_2.png) [@louagejasper](https://forum.inductiveautomation.com/u/louagejasper)\ **Post date:** [July 14, 2022, 2:04pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/7 "2022-07-14T14:04:27Z")
Hi Chris, Yes I did. I store my connection in getGlobals, and this seems to work across sessions. ```auto def connect(): factory = ConnectionFactory() factory.setUsername(userName) factory.setPassword(password) factory.setVirtualHost(virtualHost) factory.setHost(hostName) factory.setPort(portNumber) g = system.util.getGlobals() if not "AMQP" in g: g["AMQP"] = {} gAMQP = g["AMQP"] if not "conn" in gAMQP: conn = factory.newConnection() gAMQP["conn"] = conn else: conn = gAMQP["conn"] if not "channel" in gAMQP: channel = conn.createChannel() gAMQP["channel"] = channel channel.queueBind(queueName, exchangeName, routingKey) #with basicConsume, we become a consumer, so we will be taking all messages from the queue and process it #Keep in mind this is pub/sub, but will automatically read all messages in queue on connect tag = channel.basicConsume(queueName, autoAck, newMessage, cancel, shutdown) gAMQP["consumerTag"] = tag else: channel = gAMQP["channel"] ``` Yes, we will be working on an AMQP module as well, somewhere in the future. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [July 14, 2022, 2:34pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/8 "2022-07-14T14:34:17Z")
> [@louagejasper](#): > > I store my connection in getGlobals Racy. Try this: ```python import thread # Returns channel. If was a new channel, consumerTag is created too. def conditionalConnect(): g = system.util.getGlobals() # Ensure gAMQP exists in a thread-safe manner gAMQP = g.setdefault("AMQP", {}) # Attempt to get the channel unlocked for speed channel = gAMQP.get("channel") if channel: return channel # Obtain and use lock channelLock = _g.get('channelLock', None) if channelLock is None: channelLock = _g.setdefault('channelLock', thread.allocate_lock()) with channelLock: # Retry under the lock in case another thread was already in the # creation sequence. channel = gAMQP.get("channel") if channel: return channel # Nope. Connect and create and consume. factory = ConnectionFactory() factory.setUsername(userName) factory.setPassword(password) factory.setVirtualHost(virtualHost) factory.setHost(hostName) factory.setPort(portNumber) conn = factory.newConnection() channel = newConn.createChannel() channel.queueBind(queueName, exchangeName, routingKey) #with basicConsume, we become a consumer, so we will be taking all messages from the queue and process it #Keep in mind this is pub/sub, but will automatically read all messages in queue on connect tag = channel.basicConsume(queueName, autoAck, newMessage, cancel, shutdown) gAMQP['conn'] = conn gAMQP['channel'] = channel gAMQP["consumerTag"] = tag return channel ``` ---
**Author:** ![louagejasper](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/louagejasper/32/86311_2.png) [@louagejasper](https://forum.inductiveautomation.com/u/louagejasper)\ **Post date:** [July 14, 2022, 3:12pm UTC](https://forum.inductiveautomation.com/t/amqp-rabbitmq-in-ignition/60400/9 "2022-07-14T15:12:24Z")
Thanks for the upgrade!