[Feature] php-amqplib Integration

[orlandothoeny]

As a developer, I'd like to see information about RabbitMQ messages inside traces.

Solution
Support for the php-amqplib library, which is as far as I could research the most widely used RabbitMQ client for PHP.

Alternatives I've considered
Implementing custom instrumentation myself. I would prefer to have this out of the box though.

Interesting methods
Methods I personally am interested in:

AMQPChannel

• PhpAmqpLib\Channel\AMQPChannel::basic_publish()
• PhpAmqpLib\Channel\AMQPChannel::basic_consume()
• PhpAmqpLib\Channel\AMQPChannel::basic_get()
• PhpAmqpLib\Channel\AMQPChannel::basic_ack()
• PhpAmqpLib\Channel\AMQPChannel::basic_nack()
• PhpAmqpLib\Channel\AMQPChannel::basic_cancel()

Especially interesting parameters: Exchange, Queue, Routing Key

AbstractConnection

• PhpAmqpLib\Connection\AbstractConnection::connect()
• PhpAmqpLib\Connection\AbstractConnection::reconnect()

It might make sense to extend this list.

[morrisonlevi]

Thank you for including some interesting bits for us to investigate with this feature request!

A few notes while doing a tiny bit of research:

• There's an RFC draft about propagating the trace context in the AMQP protocol: https://w3c.github.io/trace-context-amqp/. It was published 2022-03-21. This could potentially be used for connecting the distributed trace, if the info was added by the publisher.
• Open Telemetry has some semantic conventions for messaging systems, which should be supported if possible. They define various span attributes, like messaging.system with a value of rabbitmq, and there's a RabbitMQ specific one: messaging.rabbitmq.routing_key.

[bwoebi]

Hey @orlandothoeny,

We've just released 0.87.0 which includes an php-ampqlib integration!

Feel free to try it out and tell us whether it satisfies your expectations :-)

[orlandothoeny]

Hi @bwoebi,

Cool, great work!

What I observed in our setup:
We only have 2 resources: connect and one where we had a connection error and the whole PHP stack trace is used as resource name. But no basic_ack or basic_get, etc. which we also call.

[PROFeNoM]

Hi @orlandothoeny,

There was indeed a dumb mistake that would cause an issue in the tracer when an error was happening during the connection.

Now, onto the fact that you only have 2 resources. Have you tried running with DD_TRACE_DEBUG set to 1? Is there anything special that stands out?

[orlandothoeny]

Hi @PROFeNoM

Now we have proper resources, I can't reproduce it anymore.