SOLR-17725: CoreAdmin API to upgrade an index in-place to facilitate Solr upgrade across major versions

changelog/unreleased/SOLR-17725-CoreAdmin-API-to-upgrade-an-index-in-place.yml

@@ -0,0 +1,9 @@
+# See https://github.com/apache/solr/blob/main/dev-docs/changelog.adoc
+title: CoreAdmin API (/admin/cores?action=UPGRADECOREINDEX) to upgrade an index in-place
+type: added
+authors:
+  - name: Rahul Goswami
+links:
+  - name: SOLR-17725
+    url: https://issues.apache.org/jira/browse/SOLR-17725
+

solr/api/src/java/org/apache/solr/client/api/model/UpgradeCoreIndexRequestBody.java

@@ -0,0 +1,13 @@
+package org.apache.solr.client.api.model;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+public class UpgradeCoreIndexRequestBody {
+
+  @Schema(description = "Request ID to track this action which will be processed asynchronously.")
+  @JsonProperty
+  public String async;
+
+  @JsonProperty public String updateChain;
+}

solr/api/src/java/org/apache/solr/client/api/model/UpgradeCoreIndexResponse.java

@@ -0,0 +1,22 @@
+package org.apache.solr.client.api.model;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+public class UpgradeCoreIndexResponse extends SolrJerseyResponse {
+  @Schema(description = "The name of the core.")
+  @JsonProperty
+  public String core;
+
+  @Schema(description = "The total number of segments eligible for upgrade.")
+  @JsonProperty
+  public Integer numSegmentsEligibleForUpgrade;
+
+  @Schema(description = "The number of segments successfully upgraded.")
+  @JsonProperty
+  public Integer numSegmentsUpgraded;
+
+  @Schema(description = "Status of the core index upgrade operation.")
+  @JsonProperty
+  public String upgradeStatus;
+}

solr/core/src/java/org/apache/solr/handler/admin/CoreAdminOperation.java

@@ -38,6 +38,7 @@
 import static org.apache.solr.common.params.CoreAdminParams.CoreAdminAction.STATUS;
 import static org.apache.solr.common.params.CoreAdminParams.CoreAdminAction.SWAP;
 import static org.apache.solr.common.params.CoreAdminParams.CoreAdminAction.UNLOAD;
+import static org.apache.solr.common.params.CoreAdminParams.CoreAdminAction.UPGRADECOREINDEX;
 import static org.apache.solr.handler.admin.CoreAdminHandler.CallInfo;
 
 import java.lang.invoke.MethodHandles;
@@ -256,7 +257,8 @@ public enum CoreAdminOperation implements CoreAdminOp {
         final ListCoreSnapshotsResponse response = coreSnapshotAPI.listSnapshots(coreName);
 
         V2ApiUtils.squashIntoSolrResponseWithoutHeader(it.rsp, response);
-      });
+      }),
+  UPGRADECOREINDEX_OP(UPGRADECOREINDEX, new UpgradeCoreIndexOp());
 
   final CoreAdminParams.CoreAdminAction action;
   final CoreAdminOp fun;

solr/core/src/java/org/apache/solr/handler/admin/UpgradeCoreIndexOp.java

@@ -0,0 +1,66 @@
+package org.apache.solr.handler.admin;
+
+import org.apache.solr.client.api.model.UpgradeCoreIndexRequestBody;
+import org.apache.solr.client.api.model.UpgradeCoreIndexResponse;
+import org.apache.solr.common.SolrException;
+import org.apache.solr.common.params.CommonAdminParams;
+import org.apache.solr.common.params.CoreAdminParams;
+import org.apache.solr.common.params.SolrParams;
+import org.apache.solr.common.params.UpdateParams;
+import org.apache.solr.common.util.NamedList;
+import org.apache.solr.core.CoreContainer;
+import org.apache.solr.handler.admin.api.UpgradeCoreIndex;
+import org.apache.solr.handler.api.V2ApiUtils;
+import org.apache.solr.request.SolrQueryRequest;
+import org.apache.solr.response.SolrQueryResponse;
+
+public class UpgradeCoreIndexOp implements CoreAdminHandler.CoreAdminOp {
+  @FunctionalInterface
+  public interface UpgradeCoreIndexFactory {
+    UpgradeCoreIndex create(
+        CoreContainer coreContainer,
+        CoreAdminHandler.CoreAdminAsyncTracker coreAdminAsyncTracker,
+        SolrQueryRequest req,
+        SolrQueryResponse rsp);
+  }
+
+  static UpgradeCoreIndexFactory UPGRADE_CORE_INDEX_FACTORY = UpgradeCoreIndex::new;
+
+  @Override
+  public boolean isExpensive() {
+    return true;
+  }
+
+  @Override
+  public void execute(CoreAdminHandler.CallInfo it) throws Exception {
+
+    assert it.handler.coreContainer != null;
+    if (it.handler.coreContainer.isZooKeeperAware()) {
+      throw new SolrException(
+          SolrException.ErrorCode.BAD_REQUEST,
+          "action=UPRGADECOREINDEX is not supported in SolrCloud mode. As an alternative, in order to upgrade index, configure LatestVersionMergePolicyFactory in solrconfig.xml and reindex the data in your collection.");
+    }
+
+    SolrParams params = it.req.getParams();
+    String cname = params.required().get(CoreAdminParams.CORE);
+    final boolean isAsync = params.get(CommonAdminParams.ASYNC) != null;
+    final var requestBody = new UpgradeCoreIndexRequestBody();
+    requestBody.updateChain = params.get(UpdateParams.UPDATE_CHAIN);
+
+    UpgradeCoreIndex upgradeCoreIndexApi =
+        UPGRADE_CORE_INDEX_FACTORY.create(
+            it.handler.coreContainer, it.handler.coreAdminAsyncTracker, it.req, it.rsp);
+    final UpgradeCoreIndexResponse response =
+        upgradeCoreIndexApi.upgradeCoreIndex(cname, requestBody);
+    V2ApiUtils.squashIntoSolrResponseWithoutHeader(it.rsp, response);
+
+    if (isAsync) {
+      final var opResponse = new NamedList<>();
+      V2ApiUtils.squashIntoNamedListWithoutHeader(opResponse, response);
+      // REQUESTSTATUS is returning the inner response NamedList as a positional array
+      // ([k1,v1,k2,v2...]).
+      // so converting to a map
+      it.rsp.addResponse(opResponse.asMap(1));
+    }
+  }
+}