SERVER-33234 dropIndexes on mongos should ignore IndexNotFound from individual shards if some shard returned success

(cherry picked from commit f2e168877ab5efb45ec583ca3b4d05a423fe9d54)

1 files changed, 12 insertions, 2 deletions

diff --git a/src/mongo/s/commands/commands_public.cpp b/src/mongo/s/commands/commands_public.cpp
index d1613c8967c..6f2249f37c5 100644
--- a/src/mongo/s/commands/commands_public.cpp
+++ b/src/mongo/s/commands/commands_public.cpp
@@ -274,6 +274,13 @@ public:
         const NamespaceString nss(parseNsCollectionRequired(dbName, cmdObj));
         LOG(1) << "dropIndexes: " << nss << " cmd:" << redact(cmdObj);
 
+        // If the collection is sharded, we target all shards rather than just shards that own
+        // chunks for the collection, because some shard may have previously owned chunks but no
+        // longer does (and so, may have the index). However, we ignore NamespaceNotFound errors
+        // from individual shards, because some shards may have never owned chunks for the
+        // collection. We additionally ignore IndexNotFound errors, because the index may not have
+        // been built on a shard if the earlier createIndexes command coincided with the shard
+        // receiving its first chunk for the collection (see SERVER-31715).
         auto shardResponses = uassertStatusOK(
             scatterGatherOnlyVersionIfUnsharded(opCtx,
                                                 dbName,
@@ -281,8 +288,11 @@ public:
                                                 filterCommandRequestForPassthrough(cmdObj),
                                                 ReadPreferenceSetting::get(opCtx),
                                                 Shard::RetryPolicy::kNotIdempotent));
-        return appendRawResponses(
-            opCtx, &errmsg, &output, std::move(shardResponses), {ErrorCodes::NamespaceNotFound});
+        return appendRawResponses(opCtx,
+                                  &errmsg,
+                                  &output,
+                                  std::move(shardResponses),
+                                  {ErrorCodes::NamespaceNotFound, ErrorCodes::IndexNotFound});
     }
 } dropIndexesCmd;