SERVER-73751 MovePrimary shouldn't copy indexes of sharded collections

(cherry picked from commit c636ba3a9914fd3eddc905d8b1dfc50668e239b4)

3 files changed, 19 insertions, 6 deletions

diff --git a/jstests/sharding/clone_catalog_data.js b/jstests/sharding/clone_catalog_data.js
index 94d3ee8fd8f..2d47e1a05e3 100644
--- a/jstests/sharding/clone_catalog_data.js
+++ b/jstests/sharding/clone_catalog_data.js
@@ -106,14 +106,18 @@
     checkOptions(c2, Object.keys(coll2Options));
     checkUUID(c2, coll2uuid);
 
-    function checkIndexes(collName, expectedIndexes) {
+    function checkIndexes(collName, expectedIndexes, shardedColl) {
         var res = toShard.getDB('test').runCommand({listIndexes: collName});
         assert.commandWorked(res, 'Failed to get indexes for collection ' + collName);
         var indexes = res.cursor.firstBatch;
         indexes.sort(sortByName);
 
-        // There should be 3 indexes on each collection - the _id one, and the 2 we created.
-        assert.eq(indexes.length, 3);
+        // TODO SERVER-74252: once 7.0 becomes LastLTS we can assume that the movePrimary will never
+        // copy indexes of sharded collections.
+        if (shardedColl)
+            assert(indexes.length === 1 || indexes.length === 3);
+        else
+            assert(indexes.length === 3);
 
         indexes.forEach((index, i) => {
             var expected;
@@ -127,8 +131,8 @@
         });
     }
 
-    checkIndexes('coll1', coll1Indexes);
-    checkIndexes('coll2', coll2Indexes);
+    checkIndexes('coll1', coll1Indexes, /*shardedColl*/ false);
+    checkIndexes('coll2', coll2Indexes, /*shardedColl*/ true);
 
     // Verify that the data from the unsharded collections resides on the new primary shard, and was
     // copied as part of the clone.
diff --git a/jstests/sharding/move_primary_clone_test.js b/jstests/sharding/move_primary_clone_test.js
index 404562e7cd1..74b1f2023ee 100644
--- a/jstests/sharding/move_primary_clone_test.js
+++ b/jstests/sharding/move_primary_clone_test.js
@@ -58,7 +58,10 @@ function checkCollectionsCopiedCorrectly(fromShard, toShard, sharded, barUUID, f
         var indexes = res.cursor.firstBatch;
         indexes.sort(sortByName);
 
-        assert.eq(indexes.length, 2);
+        if (sharded)
+            assert(indexes.length == 1 || indexes.length == 2);
+        else
+            assert(indexes.length == 2);
 
         indexes.forEach((index, i) => {
             var expected;
diff --git a/src/mongo/db/cloner.cpp b/src/mongo/db/cloner.cpp
index 8ea31c0e57e..49d7bf850a9 100644
--- a/src/mongo/db/cloner.cpp
+++ b/src/mongo/db/cloner.cpp
@@ -545,6 +545,12 @@ Status Cloner::copyDb(OperationContext* opCtx,
 
     // now build the secondary indexes
     for (auto&& params : createCollectionParams) {
+        // Indexes of sharded collections are not copied: the primary shard is not required to
+        // have all indexes. The listIndexes cmd is sent to the shard owning the MinKey value.
+        if (params.shardedColl) {
+            continue;
+        }
+
         LOGV2(20422,
               "copying indexes for: {collectionInfo}",
               "Copying indexes",