SERVER-46845 Allow logging operations to bypass ShardInvalidatedForTargeting exception when accessing shard versions

2 files changed, 28 insertions, 2 deletions

diff --git a/src/mongo/s/chunk_manager.cpp b/src/mongo/s/chunk_manager.cpp
index aa0eb056623..9e1d8a1ae5e 100644
--- a/src/mongo/s/chunk_manager.cpp
+++ b/src/mongo/s/chunk_manager.cpp
@@ -431,7 +431,8 @@ bool RoutingTableHistory::compatibleWith(const RoutingTableHistory& other,
     return other.getVersion(shardName) == getVersion(shardName);
 }
 
-ChunkVersion RoutingTableHistory::getVersion(const ShardId& shardName) const {
+ChunkVersion RoutingTableHistory::_getVersion(const ShardId& shardName,
+                                              bool throwOnStaleShard) const {
     auto it = _shardVersions.find(shardName);
     if (it == _shardVersions.end()) {
         // Shards without explicitly tracked shard versions (meaning they have no chunks) always
@@ -439,7 +440,7 @@ ChunkVersion RoutingTableHistory::getVersion(const ShardId& shardName) const {
         return ChunkVersion(0, 0, _collectionVersion.epoch());
     }
 
-    if (gEnableFinerGrainedCatalogCacheRefresh) {
+    if (throwOnStaleShard && gEnableFinerGrainedCatalogCacheRefresh) {
         uassert(ShardInvalidatedForTargetingInfo(_nss),
                 "shard has been marked stale",
                 !it->second.isStale.load());
@@ -448,6 +449,14 @@ ChunkVersion RoutingTableHistory::getVersion(const ShardId& shardName) const {
     return it->second.shardVersion;
 }
 
+ChunkVersion RoutingTableHistory::getVersion(const ShardId& shardName) const {
+    return _getVersion(shardName, true);
+}
+
+ChunkVersion RoutingTableHistory::getVersionForLogging(const ShardId& shardName) const {
+    return _getVersion(shardName, false);
+}
+
 std::string RoutingTableHistory::toString() const {
     StringBuilder sb;
     sb << "RoutingTableHistory: " << _nss.ns() << " key: " << _shardKeyPattern.toString() << '\n';
diff --git a/src/mongo/s/chunk_manager.h b/src/mongo/s/chunk_manager.h
index d3a67ff1631..6b4f97766ca 100644
--- a/src/mongo/s/chunk_manager.h
+++ b/src/mongo/s/chunk_manager.h
@@ -144,8 +144,19 @@ public:
         return _collectionVersion;
     }
 
+    /**
+     * Retrieves the shard version for the given shard. Will throw a ShardInvalidatedForTargeting
+     * exception if the shard is marked as stale.
+     */
     ChunkVersion getVersion(const ShardId& shardId) const;
 
+    /**
+     * Retrieves the shard version for the given shard. Will not throw if the shard is marked as
+     * stale. Only use when logging the given chunk version -- if the caller must execute logic
+     * based on the returned version, use getVersion() instead.
+     */
+    ChunkVersion getVersionForLogging(const ShardId& shardId) const;
+
     const ChunkInfoMap& getChunkMap() const {
         return _chunkMap;
     }
@@ -193,6 +204,8 @@ private:
      */
     ShardVersionMap _constructShardVersionMap() const;
 
+    ChunkVersion _getVersion(const ShardId& shardName, bool throwOnStaleShard) const;
+
     std::string _extractKeyString(const BSONObj& shardKeyValue) const;
 
     // The shard versioning mechanism hinges on keeping track of the number of times we reload
@@ -317,6 +330,10 @@ public:
         return _rt->getVersion(shardId);
     }
 
+    ChunkVersion getVersionForLogging(const ShardId& shardId) const {
+        return _rt->getVersionForLogging(shardId);
+    }
+
     ConstRangeOfChunks chunks() const {
         return {ConstChunkIterator{_rt->getChunkMap().cbegin(), _clusterTime},
                 ConstChunkIterator{_rt->getChunkMap().cend(), _clusterTime}};