SERVER-56654 Do not use the collection distributed lock for chunk splits

(cherry picked from commit d8401e342a8d273c1f8b466a93a9d002a8b363cb)

2 files changed, 5 insertions, 23 deletions

diff --git a/src/mongo/db/s/split_chunk.cpp b/src/mongo/db/s/split_chunk.cpp
index 89cddf3d812..e9a36fd6575 100644
--- a/src/mongo/db/s/split_chunk.cpp
+++ b/src/mongo/db/s/split_chunk.cpp
@@ -44,7 +44,7 @@
 #include "mongo/db/keypattern.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/query/internal_plans.h"
-#include "mongo/db/s/collection_metadata.h"
+#include "mongo/db/s/active_migrations_registry.h"
 #include "mongo/db/s/collection_sharding_state.h"
 #include "mongo/db/s/shard_filtering_metadata_refresh.h"
 #include "mongo/db/s/sharding_state.h"
@@ -135,21 +135,8 @@ StatusWith<boost::optional<ChunkRange>> splitChunk(OperationContext* opCtx,
                                                    const std::vector<BSONObj>& splitKeys,
                                                    const std::string& shardName,
                                                    const OID& expectedCollectionEpoch) {
-    //
-    // Lock the collection's metadata and get highest version for the current shard
-    // TODO(SERVER-25086): Remove distLock acquisition from split chunk
-    //
-    const std::string whyMessage(
-        str::stream() << "splitting chunk " << redact(chunkRange.toString()) << " in "
-                      << nss.toString());
-    auto scopedDistLock = Grid::get(opCtx)->catalogClient()->getDistLockManager()->lock(
-        opCtx, nss.ns(), whyMessage, DistLockManager::kSingleLockAttemptTimeout);
-    if (!scopedDistLock.isOK()) {
-        return scopedDistLock.getStatus().withContext(
-            str::stream() << "could not acquire collection lock for " << nss.toString()
-                          << " to split chunk "
-                          << chunkRange.toString());
-    }
+    auto scopedSplitOrMergeChunk(uassertStatusOK(
+        ActiveMigrationsRegistry::get(opCtx).registerSplitOrMergeChunk(opCtx, nss, chunkRange)));
 
     // If the shard key is hashed, then we must make sure that the split points are of type
     // NumberLong.
diff --git a/src/mongo/db/s/split_chunk_command.cpp b/src/mongo/db/s/split_chunk_command.cpp
index 896625ff1e0..079dc705eb6 100644
--- a/src/mongo/db/s/split_chunk_command.cpp
+++ b/src/mongo/db/s/split_chunk_command.cpp
@@ -48,11 +48,6 @@
 #include "mongo/util/mongoutils/str.h"
 
 namespace mongo {
-
-using std::string;
-using std::unique_ptr;
-using std::vector;
-
 namespace {
 
 class SplitChunkCommand : public ErrmsgCommandDeprecated {
@@ -117,13 +112,13 @@ public:
 
         auto chunkRange = uassertStatusOK(ChunkRange::fromBSON(cmdObj));
 
-        string shardName;
+        std::string shardName;
         auto parseShardNameStatus = bsonExtractStringField(cmdObj, "from", &shardName);
         uassertStatusOK(parseShardNameStatus);
 
         log() << "received splitChunk request: " << redact(cmdObj);
 
-        vector<BSONObj> splitKeys;
+        std::vector<BSONObj> splitKeys;
         {
             BSONElement splitKeysElem;
             auto splitKeysElemStatus =