SERVER-48601 ChunkSplitter should use the same chunk bounds for splitVector and splitChunk

2 files changed, 15 insertions, 1 deletions

diff --git a/src/mongo/db/s/chunk_splitter.cpp b/src/mongo/db/s/chunk_splitter.cpp
index e6cfdf7f50e..6829a678542 100644
--- a/src/mongo/db/s/chunk_splitter.cpp
+++ b/src/mongo/db/s/chunk_splitter.cpp
@@ -305,7 +305,17 @@ void ChunkSplitter::_runAutosplit(std::shared_ptr<ChunkSplitStateDriver> chunkSp
                 "Could not split chunk. Collection is no longer sharded",
                 cm);
 
+        // Best effort checks that the chunk we're splitting hasn't changed bounds or moved shards
+        // since the auto split task was scheduled. Best effort because the chunk metadata may
+        // change after this point.
         const auto chunk = cm->findIntersectingChunkWithSimpleCollation(min);
+        uassert(4860100,
+                "Chunk to be auto split has different boundaries than when the split was initiated",
+                chunk.getRange() == ChunkRange(min, max));
+        uassert(4860101,
+                "Chunk to be auto split isn't owned by this shard",
+                ShardingState::get(opCtx.get())->shardId() == chunk.getShardId());
+
         const auto& shardKeyPattern = cm->getShardKeyPattern();
 
         const auto balancerConfig = Grid::get(opCtx.get())->getBalancerConfiguration();
@@ -386,7 +396,7 @@ void ChunkSplitter::_runAutosplit(std::shared_ptr<ChunkSplitStateDriver> chunkSp
                                                    nss,
                                                    shardKeyPattern,
                                                    cm->getVersion(),
-                                                   ChunkRange(min, max),
+                                                   chunk.getRange(),
                                                    splitPoints));
         chunkSplitStateDriver->commitSplit();
 
diff --git a/src/mongo/s/chunk.h b/src/mongo/s/chunk.h
index e238809d248..77222f92408 100644
--- a/src/mongo/s/chunk.h
+++ b/src/mongo/s/chunk.h
@@ -143,6 +143,10 @@ public:
         return _chunkInfo.getShardIdAt(_atClusterTime);
     }
 
+    const auto& getRange() const {
+        return _chunkInfo.getRange();
+    }
+
     /**
      * Throws MigrationConflict if the history entry valid for the chunk's pinned cluster time, if
      * it has one, is not the most recent entry (meaning the chunk has moved).