lohajoin.blogg.se - Torchat delayed messages waiting to be sent

TORCHAT DELAYED MESSAGES WAITING TO BE SENT CODE

Common mistake Creating only 1 waiting queue To achieve exponential backoff, you can simply increase the expiration time of the message on each retry. If you've configured everything properly, after 10 seconds, you'll see that the same message is now in the primary-queue. If you don't see any messages in the waiting-queue, refresh the page. Add any message in the "Payload" section.This means the message will stay in the waiting-queue for 10 seconds. In "Properties", add expiration and set its value to 10000 (10 seconds).Now expand the "Publish message" section and add the following details: Go to Queues tab and click on waiting-queue. That means, the message will stay in the waiting-queue only for 10 seconds and then it'll move to the primary-queue.

To know whether this routing is working properly, we'll publish a message to the waiting-queue with TTL of 10 seconds. Now expand Bindings and add the following details: Step 4: Set up Exchange Bindings for RoutingĪfter creating these 2 queues successfully, again go to Exchanges tab and click on the exchange that we created in step 2.

Click on Dead letter routing key, set the value: primary.

To add the Arguments, click on Dead letter exchange, set the value: my-exchange.

To do that, go to Queues tab and "Add a new queue".įor the first queue, you just need to configure these 2 fields: (Discussion on what type of exchange is out of scope for this blog)Īs we discussed above, we need to create 2 queues.

Select the Virtual host: my-host or whatever virtual host you just created in step 1.

Now, go to the Exchanges tab and "Add a new exchange". Here, I created a virtual host named: my-host. I generally prefer to create a virtual host because it provides logical grouping and separation of the resources. Implementation using Management Dashboard Step 1: Create a Virtual HostĪfter logging into the Management Dashboard, create a virtual host if you haven't already. Instead, I'll use the Management Dashboard.

TORCHAT DELAYED MESSAGES WAITING TO BE SENT CODE

To keep this simple and straightforward, I don't want to code this in any particular language. Now, if we draw a diagram, it would look something like this ( Don't get overwhelmed by this diagram): If you don't want to send them immediately, you can skip the first 2 steps and directly insert the messages into the waiting queue. Keep increasing the TTL after each retry to achieve exponential backoff in case of failure.After that specific TTL, messages will be routed to the primary queue using the Exchange and can be consumed for trying again.If you don't get success, add the TTL and push it to the waiting queue.Try to send the notification to the clients immediately.Keep pushing the messages to the primary queue.For the particular webhooks use case, I decided to use this approach: It requires 2 queues (let's call them primary queue and waiting queue) and 1 exchange. To understand this approach, you must check out the links above to understand what are these two items. Using Dead Letter Exchange with Message TTL I found the Dead Letter Exchange with Message TTL approach significantly better than this plugin (Of course there are some limitations but at least this approach brings more consistency). That means if you set the message to be sent after a minute, an hour, or maybe a day and something happens to your servers, the messages are being consumed immediately once the server comes up. While writing this blog, it has one particular limitation that may bring inconsistencies to your application: If something happens to the RabbitMQ server or it restarts, your timers are lost. You can go to the plugin's Github repository and check the limitations. But you need to think twice before using this in the production environment. If you don't care too much about the timers you can go ahead with this very simple solution. If you want to jump to the implementation, you can read this article.

Let's look at the community plugin first.

Use Dead Letter Exchange with message TTL.

Use a community plugin rabbitmq_delayed_message_exchange ( not recommended for production environment).

There are many use cases of scheduled or delayed messages, and I wanted to use RabbitMQ for sending the webhook notifications to the clients with exponential backoff if they fail to receive the notifications.īut, RabbitMQ uses the AMQP protocol that doesn't have any native feature to send scheduled or delayed messages.