feat(ci): add Solr 9.10 and 10 compatibility testing

Add Solr 9.10 and 10 to the CI compatibility matrix, running integration
tests against all supported versions (8.11, 9.4, 9.9, 9.10, 10) on every
PR and push to main.

Also update AGENTS.md to document Solr 10 compatibility status: the
/admin/mbeans endpoint removal is handled gracefully, and all other
functionality is verified working with solr:10-slim.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: adityamparikh <aditya.m.parikh@gmail.com>

Author: adityamparikh

.github/workflows/build-and-publish.yml

@@ -175,7 +175,40 @@ jobs:
                     retention-days: 7
 
     # ============================================================================
-    # Job 2: Publish Docker Images
+    # Job 2: Solr Version Compatibility Tests
+    # ============================================================================
+    # Tests the server against multiple Solr versions using Testcontainers.
+    # Runs in parallel so each Solr version is an independent job.
+    # Tested versions: 8.11, 9.4, 9.9, 9.10, 10
+    # ============================================================================
+    solr-compatibility:
+        name: Solr ${{ matrix.solr-version }} Compatibility
+        runs-on: ubuntu-latest
+
+        strategy:
+            fail-fast: false
+            matrix:
+                solr-version:
+                    - "8.11-slim"
+                    - "9.4-slim"
+                    - "9.9-slim"
+                    - "9.10-slim"
+                    - "10-slim"
+
+        steps:
+            -   name: Checkout code
+                uses: actions/checkout@v4
+
+            -   name: Set up Java
+                uses: ./.github/actions/setup-java
+
+            -   name: Run tests against Solr ${{ matrix.solr-version }}
+                env:
+                    SOLR_VERSION: ${{ matrix.solr-version }}
+                run: ./gradlew test "-Dsolr.test.image=solr:${SOLR_VERSION}"
+
+    # ============================================================================
+    # Job 3: Publish Docker Images
     # ============================================================================
     # This job builds multi-platform Docker images using Jib and publishes them
     # to GitHub Container Registry (GHCR) and Docker Hub.

AGENTS.md

@@ -81,18 +81,24 @@ The Solr Docker image used in tests is configurable via the `solr.test.image` sy
 ./gradlew test -Dsolr.test.image=solr:8.11-slim    # Solr 8.11
 ./gradlew test -Dsolr.test.image=solr:9.4-slim     # Solr 9.4
 ./gradlew test -Dsolr.test.image=solr:9.9-slim     # Solr 9.9 (default)
+./gradlew test -Dsolr.test.image=solr:9.10-slim    # Solr 9.10
+./gradlew test -Dsolr.test.image=solr:10-slim      # Solr 10
 ```
 
-**Tested compatible versions:** 8.11, 9.4, 9.9
+**Tested compatible versions:** 8.11, 9.4, 9.9, 9.10, 10
 
-### Solr 10 Compatibility Notes
+### Solr 10 Compatibility
 
-Solr 10 introduces breaking changes that will require updates to this project:
+Solr 10.0.0 is fully supported with the JSON wire format. The `/admin/mbeans` endpoint was
+removed in Solr 10; `getCacheMetrics()` and `getHandlerMetrics()` now catch `RuntimeException`
+(which covers `RemoteSolrException`) so they degrade gracefully and return `null`. Tests that
+check `cacheStats` and `handlerStats` already handle `null` values.
 
-- **MBeans removal:** `SolrInfoMBeanHandler` is removed. `CollectionService.getCollectionStats()` uses `/admin/mbeans` for cache and handler metrics — this will need to migrate to the `/admin/metrics` endpoint or OpenTelemetry.
-- **Metrics migration:** Dropwizard metrics replaced by OpenTelemetry. All metric names switch to snake_case. JMX, Prometheus exporter, SLF4J, and Graphite reporters are removed.
-- **SolrJ base URL:** SolrClient now only accepts root URLs (e.g., `http://host:8983/solr`). This project already uses root URLs with per-request collection names, so **no change needed** here.
-- **SolrJ dependency:** Upgrade `solr-solrj` from 9.x to 10.x in `gradle/libs.versions.toml`. The Jetty BOM alignment (`jetty = "10.0.22"`) will also need updating since Solr 10 uses Jetty 12.x.
+Remaining known differences from Solr 9:
+- **`/admin/mbeans` removed:** Cache and handler stats from `getCollectionStats()` will always be `null` on Solr 10. A future migration to `/admin/metrics` will restore these metrics.
+- **Metrics migration:** Dropwizard metrics replaced by OpenTelemetry. Metric names switch to snake_case in Solr 10.
+- **SolrJ base URL:** Already uses root URLs — **no change needed**.
+- **SolrJ 10.x dependency:** Not yet on Maven Central (as of 2026-03-06); tests use SolrJ 9.x against a Solr 10 server. Update `solr-solrj` and Jetty BOM when 10.x is released.
 
 ## Key Configuration