[SOLR-16354] Migrate from Jaeger/OpenTracing to OTEL

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Done
• Affects Version/s: 9.0
• Labels: opentelemetry otel tracing
• Assignee: Unassigned
• Reporter: Jan Høydahl
• Created: 24/Aug/22 13:39
• Updated: 08/Sep/23 18:22
• Resolved: 08/Sep/23 18:22

Description

Umbrella issue for introducing OTEL (OpenTelemetry) in Solr.

Solr-core has OpenTracing instrumentation. And in jaegertracer-configurator module, we use the Jaeger client to export traces on Jaeger/Thrift format. Jaeger clients are deprecated - https://www.jaegertracing.io/docs/1.37/client-libraries/#deprecating-jaeger-clients and the world is anyway moving to OTEL/OTLP protocol for tracing.

Here is a proposed path forward:

Phase 1 - getting rid of the deprecated jaeger client

We'll keeping OpenTracing instrumentation in solr-core. Using the opentelemetry-opentracing shim we can use OTEL java-client instead.

1. Introduce a new 'otel' module, exposing an OTLP trace exporter (grpc or http)
2. Add otel-jaeger exporter support to the 'otel' module for those who still need it
3. Deprecate the 'jaegertracer-configurator' for removal in 10.0 (since jaeger-client will be very dead by then)
4. Remove jaegertracer-configurator in main
5. Optionally we can quite easily add Zipkin or other support using the OTEL java client as well

Phase 2 - replace OpenTracing instrumentation with OTEL instrumentation

it is recommended to migrate instrumentation from OTO to OTEL, see migration guide: https://opentelemetry.io/docs/migration/opentracing/

Once that is done, the 'otel' module will expose the OTEL "Tracer" instead of the OT "Tracer" through shim.