sigram commented on code in PR #5316:
URL: https://github.com/apache/solr/pull/5316#discussion_r4529419032
##########
solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc:
##########
@@ -180,6 +180,87 @@ To deploy an extra context, or to customize how the Solr
webapp itself is deploy
=== Testing Framework
Standard `solr.xml` configuration used by `MiniSolrCloudCluster` turns off
metrics by default (`metricsEnabled=false`) unlike the previous versions of
Solr where metrics were enabled by default. Tests that need to access metrics
should enable them by setting `System.setProperty("metricsEnabled", "true")` in
test suite initialization.
+=== OpenTelemetry
+
+The new OTEL based metric system introduced in 10.0 is considered BETA, and
some breaking changes are to be expected in this and coming minor releases.
+
+==== OTLP protocols
+
+The `opentelemetry` module no longer includes some dependencies, dropping gRPC
support out-of-the-box.
+The default export protocol for tracing has changed from `grpc` to
`http/protobuf` (OTLP port `4318` instead of `4317`).
+The default for the separate OTLP metrics exporter's
`solr.metrics.otlpExporterProtocol` has likewise changed from `grpc` to `http`.
+
+Use of gRPC can be restored by adding the required gRPC & Netty jars to the
`opentelemetry` module's lib directory, and setting
`OTEL_EXPORTER_OTLP_PROTOCOL=grpc` (tracing) and/or
`solr.metrics.otlpExporterProtocol=grpc` (metrics) as needed.
+
+==== OTLP Metric Names Changed to Dot-Separated Format
+
+*Breaking change for OTLP consumers.*
+
+Solr's metric names exported via OTLP now follow the
https://opentelemetry.io/docs/specs/semconv/general/naming/[OpenTelemetry
semantic convention] of using dot-separated names instead of the
underscore-separated names used in Solr 10.0.
+
+For example, `solr_core_requests` is now `solr.core.requests`, and
`solr_node_executor` is now `solr.node.executor`.
+
+*Prometheus output is unaffected.* The OTel Prometheus exporter automatically
converts dots to underscores, so the `/admin/metrics?wt=prometheus` endpoint
continues to produce the same metric names as before (e.g.,
`solr_core_requests_total`).
+
+*Workaround for OTLP consumers depending on the old names:*
+Users who consume Solr metrics via OTLP and rely on the 10.0 underscore-format
names can use metric renaming or transformation features in their OpenTelemetry
Collector pipeline to convert the new dot-separated names back to the old
format during the transition.
+
+==== Metric that are Removed or Changed
Review Comment:
Metric -> Metrics
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
