SOLR-16699: Expose creationTimeMillis in COLSTATUS API

solr/CHANGES.txt

@@ -86,6 +86,8 @@ Improvements
 * SOLR-17119: When registering or updating a ConfigurablePlugin through the `/cluster/plugin` API,
   config validation exceptions are now propagated to the callers. (Yohann Callea)
 
+* SOLR-16699: Add Collection creation time to the Collection Status API response (Julien Pilourdault, Paul McArthur, David Smiley)
+
 Optimizations
 ---------------------
 (No changes)

solr/core/src/java/org/apache/solr/cloud/DistributedClusterStateUpdater.java

@@ -31,6 +31,7 @@
 import static org.apache.solr.common.params.CollectionParams.CollectionAction.MODIFYCOLLECTION;
 
 import java.lang.invoke.MethodHandles;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EnumMap;
@@ -636,7 +637,8 @@ private ClusterState fetchStateForCollection() throws KeeperException, Interrupt
               data,
               Collections.emptySet(),
               updater.getCollectionName(),
-              zkStateReader.getZkClient());
+              zkStateReader.getZkClient(),
+              Instant.ofEpochMilli(stat.getCtime()));
 
       return clusterState;
     }

solr/core/src/java/org/apache/solr/cloud/overseer/ClusterStateMutator.java

@@ -19,6 +19,7 @@
 import static org.apache.solr.common.params.CommonParams.NAME;
 
 import java.lang.invoke.MethodHandles;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -133,9 +134,18 @@ public ZkWriteCommand createCollection(ClusterState clusterState, ZkNodeProps me
     }
 
     assert !collectionProps.containsKey(CollectionAdminParams.COLL_CONF);
+
+    // This instance does not fully capture what will be persisted: the zkNodeVersion and
+    // creationTime will only be definitively set in ZK. Hence, the defaults passed here.
     DocCollection newCollection =
         DocCollection.create(
-            cName, slices, collectionProps, router, -1, stateManager.getPrsSupplier(cName));
+            cName,
+            slices,
+            collectionProps,
+            router,
+            -1,
+            Instant.EPOCH,
+            stateManager.getPrsSupplier(cName));
 
     return new ZkWriteCommand(cName, newCollection);
   }

solr/core/src/java/org/apache/solr/cloud/overseer/CollectionMutator.java

@@ -176,6 +176,7 @@ public ZkWriteCommand modifyCollection(final ClusterState clusterState, ZkNodePr
             props,
             coll.getRouter(),
             coll.getZNodeVersion(),
+            coll.getCreationTime(),
             stateManager.getPrsSupplier(coll.getName()));
     if (replicaOps == null) {
       return new ZkWriteCommand(coll.getName(), collection);

solr/core/src/java/org/apache/solr/cloud/overseer/ZkStateWriter.java

@@ -20,6 +20,7 @@
 
 import com.codahale.metrics.Timer;
 import java.lang.invoke.MethodHandles;
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
@@ -303,18 +304,21 @@ public ClusterState writePendingUpdates(
                       c.getProperties(),
                       c.getRouter(),
                       stat.getVersion(),
+                      Instant.ofEpochMilli(stat.getCtime()),
                       PerReplicaStatesOps.getZkClientPrsSupplier(reader.getZkClient(), path));
               clusterState = clusterState.copyWith(name, newCollection);
             } else {
               log.debug("going to create_collection {}", path);
-              reader.getZkClient().create(path, data, CreateMode.PERSISTENT, true);
+              Stat stat = new Stat();
+              reader.getZkClient().create(path, data, CreateMode.PERSISTENT, true, stat);
               DocCollection newCollection =
                   DocCollection.create(
                       name,
                       c.getSlicesMap(),
                       c.getProperties(),
                       c.getRouter(),
                       0,
+                      Instant.ofEpochMilli(stat.getCtime()),
                       PerReplicaStatesOps.getZkClientPrsSupplier(reader.getZkClient(), path));
               clusterState = clusterState.copyWith(name, newCollection);
             }

solr/core/src/java/org/apache/solr/core/backup/BackupManager.java

@@ -24,6 +24,7 @@
 import java.lang.invoke.MethodHandles;
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
@@ -221,7 +222,10 @@ public DocCollection readCollectionState(String collectionName) throws IOExcepti
         repository.openInput(zkStateDir, COLLECTION_PROPS_FILE, IOContext.DEFAULT)) {
       byte[] arr = new byte[(int) is.length()]; // probably ok since the json file should be small.
       is.readBytes(arr, 0, (int) is.length());
-      ClusterState c_state = ClusterState.createFromJson(-1, arr, Collections.emptySet(), null);
+      // set a default created date, we don't aim at reading actual zookeeper state. The restored
+      // collection will have a new creation date when persisted in zookeeper.
+      ClusterState c_state =
+          ClusterState.createFromJson(-1, arr, Collections.emptySet(), Instant.EPOCH, null);
       return c_state.getCollection(collectionName);
     }
   }

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

@@ -183,6 +183,8 @@ public void getClusterStatus(NamedList<Object> results)
       collectionStatus = getCollectionStatus(docCollection, name, requestedShards);
 
       collectionStatus.put("znodeVersion", clusterStateCollection.getZNodeVersion());
+      collectionStatus.put(
+          "creationTimeMillis", clusterStateCollection.getCreationTime().toEpochMilli());
 
       if (collectionVsAliases.containsKey(name) && !collectionVsAliases.get(name).isEmpty()) {
         collectionStatus.put("aliases", collectionVsAliases.get(name));

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

@@ -103,6 +103,7 @@ public void getColStatus(NamedList<Object> results) {
       }
       SimpleOrderedMap<Object> colMap = new SimpleOrderedMap<>();
       colMap.add("znodeVersion", coll.getZNodeVersion());
+      colMap.add("creationTimeMillis", coll.getCreationTime().toEpochMilli());
       Map<String, Object> props = new TreeMap<>(coll.getProperties());
       props.remove("shards");
       colMap.add("properties", props);

solr/core/src/test/org/apache/solr/cloud/ClusterStateTest.java

@@ -16,6 +16,7 @@
  */
 package org.apache.solr.cloud;
 
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -60,17 +61,21 @@ public void testStoreAndRead() {
     slices.put("shard2", slice2);
     collectionStates.put(
         "collection1",
-        DocCollection.create("collection1", slices, props, DocRouter.DEFAULT, 0, null));
+        DocCollection.create(
+            "collection1", slices, props, DocRouter.DEFAULT, 0, Instant.EPOCH, null));
     collectionStates.put(
         "collection2",
-        DocCollection.create("collection2", slices, props, DocRouter.DEFAULT, 0, null));
+        DocCollection.create(
+            "collection2", slices, props, DocRouter.DEFAULT, 0, Instant.EPOCH, null));
 
     ClusterState clusterState = new ClusterState(liveNodes, collectionStates);
     assertFalse(clusterState.getCollection("collection1").getProperties().containsKey("shards"));
 
     byte[] bytes = Utils.toJSON(clusterState);
 
-    ClusterState loadedClusterState = ClusterState.createFromJson(-1, bytes, liveNodes, null);
+    Instant creationTime = Instant.now();
+    ClusterState loadedClusterState =
+        ClusterState.createFromJson(-1, bytes, liveNodes, creationTime, null);
     assertFalse(
         loadedClusterState.getCollection("collection1").getProperties().containsKey("shards"));
 
@@ -96,13 +101,18 @@ public void testStoreAndRead() {
             .get("node1")
             .getStr("prop2"));
 
-    loadedClusterState = ClusterState.createFromJson(-1, new byte[0], liveNodes, null);
+    assertEquals(creationTime, loadedClusterState.getCollection("collection1").getCreationTime());
+    assertEquals(creationTime, loadedClusterState.getCollection("collection2").getCreationTime());
+
+    loadedClusterState =
+        ClusterState.createFromJson(-1, new byte[0], liveNodes, Instant.now(), null);
 
     assertEquals(
         "Provided liveNodes not used properly", 2, loadedClusterState.getLiveNodes().size());
     assertEquals("Should not have collections", 0, loadedClusterState.getCollectionsMap().size());
 
-    loadedClusterState = ClusterState.createFromJson(-1, (byte[]) null, liveNodes, null);
+    loadedClusterState =
+        ClusterState.createFromJson(-1, (byte[]) null, liveNodes, Instant.now(), null);
 
     assertEquals(
         "Provided liveNodes not used properly", 2, loadedClusterState.getLiveNodes().size());

solr/core/src/test/org/apache/solr/cloud/CollectionsAPISolrJTest.java

@@ -27,6 +27,7 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
@@ -1209,4 +1210,34 @@ public void testModifyCollectionAttribute() throws IOException, SolrServerExcept
                 .unsetAttribute("non_existent_attr")
                 .process(cluster.getSolrClient()));
   }
+
+  @Test
+  public void testCollectionCreationTime() throws SolrServerException, IOException {
+    Instant beforeCreation = Instant.now();
+
+    String collectionName = getSaferTestName();
+    CollectionAdminRequest.createCollection(collectionName, "conf", 1, 1)
+        .setPerReplicaState(SolrCloudTestCase.USE_PER_REPLICA_STATE)
+        .process(cluster.getSolrClient());
+
+    cluster.waitForActiveCollection(collectionName, 1, 1);
+
+    Instant afterCreation = Instant.now();
+
+    CollectionAdminRequest.ColStatus req = CollectionAdminRequest.collectionStatus(collectionName);
+    CollectionAdminResponse response = req.process(cluster.getSolrClient());
+    assertEquals(0, response.getStatus());
+
+    NamedList<?> colStatus = (NamedList<?>) response.getResponse().get(collectionName);
+    Long creationTimeMillis = (Long) colStatus._get("creationTimeMillis", null);
+    assertNotNull("creationTimeMillis was not included in COLSTATUS response", creationTimeMillis);
+
+    Instant creationTime = Instant.ofEpochMilli(creationTimeMillis);
+    assertTrue(
+        "COLSTATUS creationTimeMillis should be after the test started",
+        creationTime.isAfter(beforeCreation));
+    assertTrue(
+        "COLSTATUS creationTimeMillis should not be after the collection creation was completed",
+        creationTime.isBefore(afterCreation));
+  }
 }

solr/core/src/test/org/apache/solr/cloud/OverseerCollectionConfigSetProcessorTest.java

@@ -30,6 +30,7 @@
 import static org.mockito.Mockito.when;
 
 import java.lang.invoke.MethodHandles;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -688,6 +689,7 @@ private void handleCreateCollMessageProps(ZkNodeProps props) {
                       props.getProperties(),
                       DocRouter.DEFAULT,
                       0,
+                      Instant.EPOCH,
                       distribStateManagerMock.getPrsSupplier(collName))));
       }
       if (CollectionParams.CollectionAction.ADDREPLICA.isEqual(props.getStr("operation"))) {

solr/core/src/test/org/apache/solr/cloud/SliceStateTest.java

@@ -16,6 +16,7 @@
  */
 package org.apache.solr.cloud;
 
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -59,7 +60,8 @@ public void testDefaultSliceState() {
 
     ClusterState clusterState = new ClusterState(liveNodes, collectionStates);
     byte[] bytes = Utils.toJSON(clusterState);
-    ClusterState loadedClusterState = ClusterState.createFromJson(-1, bytes, liveNodes, null);
+    ClusterState loadedClusterState =
+        ClusterState.createFromJson(-1, bytes, liveNodes, Instant.now(), null);
 
     assertSame(
         "Default state not set to active",

solr/core/src/test/org/apache/solr/cloud/api/collections/SimpleCollectionCreateDeleteTest.java

@@ -16,6 +16,7 @@
  */
 package org.apache.solr.cloud.api.collections;
 
+import java.time.Instant;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
@@ -123,7 +124,11 @@ public void testPropertiesOfReplica() throws Exception {
 
     DocCollection c =
         ClusterState.createFromCollectionMap(
-                0, (Map<String, Object>) Utils.fromJSON(node.data), Collections.emptySet(), null)
+                0,
+                (Map<String, Object>) Utils.fromJSON(node.data),
+                Collections.emptySet(),
+                Instant.EPOCH,
+                null)
             .getCollection(collectionName);
 
     Set<String> knownKeys =

solr/core/src/test/org/apache/solr/cloud/api/collections/TestCollectionAPI.java

@@ -17,6 +17,7 @@
 package org.apache.solr.cloud.api.collections;
 
 import java.io.IOException;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -491,7 +492,10 @@ private void clusterStatusWithCollection() throws IOException, SolrServerExcepti
       Map<String, Object> collection = (Map<String, Object>) collections.get(COLLECTION_NAME);
       assertNotNull(collection);
       assertEquals("conf1", collection.get("configName"));
-      //      assertEquals("1", collection.get("nrtReplicas"));
+
+      Instant creationTime = Instant.ofEpochMilli((long) collection.get("creationTimeMillis"));
+      assertEquals(
+          creationTime, client.getClusterState().getCollection(COLLECTION_NAME).getCreationTime());
     }
   }