SOLR-17600 (Part 2/4): Migrate Core Configuration classes from MapSerializable by isaric · Pull Request #4464 · apache/solr

isaric · 2026-05-25T13:21:07Z

This is Part 2 of 4 to deprecate and remove the MapSerializable interface as part of SOLR-17600.

This PR migrates Core Configuration classes (e.g., SolrConfig, PluginInfo, ConfigOverlay) to use MapWriter.

Note: This PR is part of a stacked series and is built on top of Part 1 (#4463). It currently displays the commits from Part 1 as well, but they will automatically drop from this PR's diff once Part 1 is merged into main.

Copilot

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR migrates several Solr config/metadata classes and related call sites from the legacy MapSerializable#toMap(...) pattern to the newer MapWriter#writeMap(...) API, updating tests and various admin/handler code paths accordingly.

Changes:

Replace MapSerializable implementations with MapWriter (writeMap) across core config-related classes.
Update call sites to materialize map-like structures via SimpleOrderedMap or Utils.convertToMap(...) instead of toMap(new HashMap<>()).
Adjust tests/assertions to reflect the new MapWriter/SimpleOrderedMap based conversions.

Reviewed changes

Copilot reviewed 37 out of 37 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
solr/core/src/test/org/apache/solr/update/SolrIndexConfigTest.java	Update test to use `SimpleOrderedMap` and `MapWriter` assertions.
solr/core/src/test/org/apache/solr/handler/designer/TestSchemaDesignerAPI.java	Use `SimpleOrderedMap` instead of `SolrParams#toMap(...)`.
solr/core/src/test/org/apache/solr/core/TestConfig.java	Switch default mapping checks to `SimpleOrderedMap`.
solr/core/src/test/org/apache/solr/core/CacheConfigTest.java	Convert `CacheConfig` to map via `SimpleOrderedMap`.
solr/core/src/test/org/apache/solr/api/NodeConfigClusterPluginsSourceTest.java	Convert `MapWriter` config to map via `SimpleOrderedMap`.
solr/core/src/java/org/apache/solr/update/SolrIndexConfig.java	Migrate `SolrIndexConfig` from `MapSerializable` to `MapWriter`.
solr/core/src/java/org/apache/solr/update/IndexFingerprint.java	Migrate `IndexFingerprint` to `MapWriter`; update `toString()` materialization.
solr/core/src/java/org/apache/solr/search/CacheConfig.java	Migrate `CacheConfig` to `MapWriter`.
solr/core/src/java/org/apache/solr/schema/IndexSchema.java	Migrate `SchemaProps` to `MapWriter`; adjust property retrieval to `SimpleOrderedMap`.
solr/core/src/java/org/apache/solr/handler/export/ExportWriterStream.java	Materialize nested `MapWriter` values using `SimpleOrderedMap`.
solr/core/src/java/org/apache/solr/handler/designer/ManagedSchemaDiff.java	Convert `SimpleOrderedMap` to `Map` via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/SplitShardAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/SplitCoreAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/RequestSyncShardAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/RequestCoreRecoveryAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/RequestBufferUpdatesAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/RequestApplyCoreUpdatesAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/RejoinLeaderElectionAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/RebalanceLeadersAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/PrepareCoreRecoveryAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/OverseerOperationAPI.java	Convert request payload using `SimpleOrderedMap` instead of `toMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/MoveReplicaAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/ModifyCollectionAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/MigrateDocsAPI.java	Convert request payload to v1 param map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/InstallShardData.java	Convert message payload into `ZkNodeProps` via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/api/CreateCore.java	Convert v1 params to request body via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/ZookeeperInfoHandler.java	Convert `DocCollection` to map via `Utils.convertToMap(...)`.
solr/core/src/java/org/apache/solr/handler/admin/IndexSizeEstimator.java	Materialize `MapWriter` values via `SimpleOrderedMap`.
solr/core/src/java/org/apache/solr/handler/admin/BaseHandlerApiSupport.java	Switch anonymous params object to `MapWriter#writeMap`.
solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java	Update config introspection logic to use `MapWriter`/`SimpleOrderedMap`.
solr/core/src/java/org/apache/solr/handler/ClusterAPI.java	Replace payload `toMap(...)` with `SimpleOrderedMap` conversion.
solr/core/src/java/org/apache/solr/filestore/ClusterFileStore.java	Copy metadata into unknown properties via `SimpleOrderedMap`.
solr/core/src/java/org/apache/solr/core/SolrConfig.java	Migrate `SolrConfig` and inner config holders to `MapWriter`.
solr/core/src/java/org/apache/solr/core/RequestParams.java	Migrate `RequestParams` and `ParamSet` to `MapWriter`.
solr/core/src/java/org/apache/solr/core/PluginInfo.java	Migrate `PluginInfo` to `MapWriter`.
solr/core/src/java/org/apache/solr/core/ConfigOverlay.java	Migrate `ConfigOverlay` to `MapWriter`.
solr/core/src/java/org/apache/solr/api/NodeConfigClusterPluginsSource.java	Use `NamedList#asMap(...)` for plugin initArgs config.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

+    new NamedList<>(attributes).writeMap(ew);
+    if (initArgs != null) {
+      new SimpleOrderedMap<>(initArgs).writeMap(ew);
+    }
+    if (children == null || children.isEmpty()) {
+      return;
+    }
+
+    for (PluginInfo child : children) {
+      child.writeMap(ew);
    }


+                  && !((List) o).isEmpty()
                  && ((List) o).get(0) instanceof String) {


…ializable

dsmiley · 2026-05-30T19:16:50Z

+      } else if (old instanceof List) {
+        ((List<Object>) old).add(child);


as it was before, can use Java 17 instanceof auto cast to 'list" here

dsmiley · 2026-05-30T20:04:12Z

+      ew.put(IndexSchema.LUCENE_MATCH_VERSION_PARAM, luceneMatchVersion.toString());
+    }

+    ew.put("updateHandler", new SimpleOrderedMap<>(getUpdateHandlerInfo()));


I suspect you could place the MapWriter directly into the value of EntryWriter, without the SimpleOrderedMap copy. In the context of implementing writeMap (as is done here), this should be universally true, I think.

dsmiley · 2026-05-30T20:16:50Z

+            new SimpleOrderedMap<>(
+                m -> {
+                  new NamedList<>(items).writeMap(m);
+                }));


can't this be simply items I think (as it was) -- why the double conversion to NamedList and then to SimpleOrderedMap?

dsmiley · 2026-05-30T20:19:12Z

-          for (PluginInfo info : infos) l.add(info);
-          result.put(tag, l);
+          ArrayList<MapWriter> writers = new ArrayList<>();
+          infos.forEach(info -> writers.add(new SimpleOrderedMap<>(info)));


use of SimpleOrderedMap copy constructor / conversion seems needless

And same for other side of the if condition

dsmiley · 2026-05-30T20:19:56Z

+          ew.put(tag, writers);
        } else {
-          result.put(tag, infos.get(0));
+          ew.put(tag, new SimpleOrderedMap<>(m -> infos.getFirst().writeMap(m)));


can't be as before?

dsmiley · 2026-05-30T20:22:15Z

-    return result;
+    ew.put(
+        "requestDispatcher",
+        new SimpleOrderedMap<>(


The purpose of MapWriter is to write a map as efficiently as possible, ideally without an intermediary forced map (or NamedList / SimpleOrderedMap or other data structure conversions/copies). Prior to MapWriter, Solr used MapSerializable which forced the creation of maps.

I'll skip repeating this point but it applies to many changes in this commit.

dsmiley · 2026-05-30T20:26:22Z


  public Map<String, Object> getNamedPropertyValues(String name, SolrParams params) {
-    return new SchemaProps(name, params, this).toMap(new LinkedHashMap<>());
+    return new SimpleOrderedMap<>(new SchemaProps(name, params, this));


Use LinkedHashMap here as this method isn't apparently isolated for serialization

dsmiley · 2026-05-30T20:27:45Z

-    // TODO: Should not create new HashMap?
-    return new HashMap<>(args);
+  public void writeMap(EntryWriter ew) throws IOException {
+    new NamedList<>(args).writeMap(ew);


surely we can do better (no NamedList creatoin). note the comment that was deleted -- same concept.

dsmiley · 2026-05-30T20:30:24Z

+        .putIfNotNull("mergeScheduler", mergeSchedulerInfo)
+        .putIfNotNull("metrics", metricsInfo)
+        .putIfNotNull("mergePolicyFactory", mergePolicyFactoryInfo)
+        .putIfNotNull("mergedSegmentWarmer", mergedSegmentWarmerInfo);


Copilot AI review requested due to automatic review settings May 25, 2026 13:21

github-actions Bot added tests cat:search cat:index cat:api cat:schema cat:packagemanager labels May 25, 2026

This was referenced May 25, 2026

SOLR-17600 (Part 3/4): Migrate SolrJ and Utilities from MapSerializable #4465

Open

SOLR-17600 (Part 4/4): Delete MapSerializable interface #4466

Open

Copilot AI reviewed May 25, 2026

View reviewed changes

isaric force-pushed the SOLR-17600-2-core-config branch from d94547f to 37d86fe Compare May 25, 2026 13:37

isaric added 2 commits May 26, 2026 07:55

SOLR-17600 (Part 1/4): Migrate V2 API Payloads from MapSerializable

74d671e

SOLR-17600 (Part 2/4): Migrate Core Configuration classes from MapSer…

d0fa05e

…ializable

isaric force-pushed the SOLR-17600-2-core-config branch from 37d86fe to d0fa05e Compare May 26, 2026 05:55

dsmiley reviewed May 30, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

SOLR-17600 (Part 2/4): Migrate Core Configuration classes from MapSerializable#4464

SOLR-17600 (Part 2/4): Migrate Core Configuration classes from MapSerializable#4464
isaric wants to merge 2 commits into
apache:mainfrom
isaric:SOLR-17600-2-core-config

isaric commented May 25, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

dsmiley May 30, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

		&& !((List) o).isEmpty()
		&& ((List) o).get(0) instanceof String) {

		} else if (old instanceof List) {
		((List<Object>) old).add(child);

Conversation

isaric commented May 25, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants