SERVER-71924 Reduce verbosity of chunk merge change log event

(cherry picked from commit 04df1909dad97e26e26d45e6dfabf60ec67e20a9)

1 files changed, 5 insertions, 19 deletions

diff --git a/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp b/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp
index 2a4789e6b14..10683089620 100644
--- a/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp
+++ b/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp
@@ -940,25 +940,11 @@ StatusWith<BSONObj> ShardingCatalogManager::commitChunksMerge(
 
     // 5. log changes
     BSONObjBuilder logDetail;
-    {
-        initialVersion.appendLegacyWithField(&logDetail, "prevShardVersion");
-        mergeVersion.appendLegacyWithField(&logDetail, "mergedVersion");
-        logDetail.append("owningShard", shardId);
-        BSONArrayBuilder b(logDetail.subarrayStart("merged"));
-
-        // Pad some slack to avoid exceeding max BSON size
-        const auto kBSONObjMaxLogDetailSize = BSONObjMaxUserSize - 3 * 1024;
-        for (const auto& chunkToMerge : *chunksToMerge) {
-            auto chunkBSON = chunkToMerge.toConfigBSON();
-
-            // Truncate the log if BSON log size exceeds BSONObjMaxUserSize
-            if (logDetail.len() + chunkBSON.objsize() >= kBSONObjMaxLogDetailSize) {
-                logDetail.append("mergedChunksArrayTruncatedToDontExceedMaxBSONSize", true);
-                break;
-            }
-            b.append(chunkBSON);
-        }
-    }
+    initialVersion.appendLegacyWithField(&logDetail, "prevShardVersion");
+    mergeVersion.appendLegacyWithField(&logDetail, "mergedVersion");
+    logDetail.append("owningShard", shardId);
+    chunkRange.append(&logDetail);
+    logDetail.append("numChunks", static_cast<int>(chunksToMerge->size()));
 
     ShardingLogging::get(opCtx)->logChange(
         opCtx, "merge", nss.ns(), logDetail.obj(), WriteConcernOptions());