switch from jaeger-client to opentelemetry

[richvdh]

The jaeger-client library has been deprecated, and security support is due to end in July 2022. The replacement is opentelemetry.

This will require rewriting, or replacing, https://github.com/erikjohnston/rust-jaeger-python-client.

[MadLittleMods]

This will require rewriting, or replacing, https://github.com/erikjohnston/rust-jaeger-python-client

Got some more context from @erikjohnston on why we need the Rust exporter and it boils down to using a Python reporter/exporter can easily slow down the rest of Synapse. Python is slower than Rust but also the Python global interpreter lock (GIL) prevents multi-threaded work from being faster (🙇 hopefully not too off)

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There is some uncertainty of moving to OpenTelemetry because of drama and unclear from the outside what the current state is of anything. [TODO: any details?]

[MadLittleMods]

There is some uncertainty of moving to OpenTelemetry because of drama and unclear from the outside what the current state is of anything. [TODO: any details?]

This point is no longer relevant. This was touched on in the August backend chapter meeting and turned out to really be of no substance. Perhaps just murmurings when the project was first getting going. But seems like the canonical new choice to go to now.

[yu-re-ka]

opentracing breaks with asyncio changes in Python 3.11, so now would be a good time to migrate