SERVER-44598 Shards do not treat the IGNORED version as "intended sharded"

3 files changed, 36 insertions, 3 deletions

diff --git a/src/mongo/s/chunk_version.cpp b/src/mongo/s/chunk_version.cpp
index 3f25d474a4a..80d545328fc 100644
--- a/src/mongo/s/chunk_version.cpp
+++ b/src/mongo/s/chunk_version.cpp
@@ -80,6 +80,13 @@ StatusWith<ChunkVersion> ChunkVersion::fromBSON(const BSONObj& obj) {
         version._epoch = epochPart.OID();
     }
 
+    if (it.more()) {
+        // Expect _canThrowSSVOnIgnored
+        BSONElement canThrowSSVOnIgnoredPart = it.next();
+
+        version._canThrowSSVOnIgnored = canThrowSSVOnIgnoredPart && canThrowSSVOnIgnoredPart.Bool();
+    }
+
     return version;
 }
 
@@ -117,6 +124,9 @@ void ChunkVersion::appendWithField(BSONObjBuilder* out, StringData field) const
     BSONArrayBuilder arr(out->subarrayStart(field));
     arr.appendTimestamp(_combined);
     arr.append(_epoch);
+    if (_canThrowSSVOnIgnored) {
+        arr.append(_canThrowSSVOnIgnored);
+    }
 }
 
 void ChunkVersion::appendLegacyWithField(BSONObjBuilder* out, StringData field) const {
@@ -128,6 +138,9 @@ BSONObj ChunkVersion::toBSON() const {
     BSONArrayBuilder b;
     b.appendTimestamp(_combined);
     b.append(_epoch);
+    if (_canThrowSSVOnIgnored) {
+        b.append(_canThrowSSVOnIgnored);
+    }
     return b.arr();
 }
 
@@ -136,7 +149,8 @@ void ChunkVersion::legacyToBSON(StringData field, BSONObjBuilder* out) const {
 }
 
 std::string ChunkVersion::toString() const {
-    return str::stream() << majorVersion() << "|" << minorVersion() << "||" << _epoch;
+    return str::stream() << majorVersion() << "|" << minorVersion() << "||" << _epoch
+                         << (_canThrowSSVOnIgnored ? "|||canThrowSSVOnIgnored" : "");
 }
 
 }  // namespace mongo
diff --git a/src/mongo/s/chunk_version.h b/src/mongo/s/chunk_version.h
index fea48dc0ace..12628629d3b 100644
--- a/src/mongo/s/chunk_version.h
+++ b/src/mongo/s/chunk_version.h
@@ -56,11 +56,12 @@ public:
      */
     static constexpr StringData kShardVersionField = "shardVersion"_sd;
 
-    ChunkVersion() : _combined(0), _epoch(OID()) {}
+    ChunkVersion() : _combined(0), _epoch(OID()), _canThrowSSVOnIgnored(false) {}
 
     ChunkVersion(uint32_t major, uint32_t minor, const OID& epoch)
         : _combined(static_cast<uint64_t>(minor) | (static_cast<uint64_t>(major) << 32)),
-          _epoch(epoch) {}
+          _epoch(epoch),
+          _canThrowSSVOnIgnored(false) {}
 
     static StatusWith<ChunkVersion> parseFromCommand(const BSONObj& obj) {
         return parseWithField(obj, kShardVersionField);
@@ -134,6 +135,14 @@ public:
             version.epoch() == IGNORED().epoch();
     }
 
+    /**
+     * Indicates that the shard version checking must be skipped but StaleShardVersion error
+     * must be thrown if the metadata is not loaded
+     */
+    void canThrowSSVOnIgnored() {
+        _canThrowSSVOnIgnored = true;
+    }
+
     void incMajor() {
         uassert(
             31180,
@@ -175,6 +184,9 @@ public:
         return _epoch;
     }
 
+    const bool getCanThrowSSVOnIgnored() const {
+        return _canThrowSSVOnIgnored;
+    }
     //
     // Explicit comparison operators - versions with epochs have non-trivial comparisons.
     // > < operators do not check epoch cases.  Generally if using == we need to handle
@@ -251,6 +263,12 @@ public:
 private:
     uint64_t _combined;
     OID _epoch;
+
+    /**
+     * Temporary flag to indicate shards that a router is able to process and retry
+     * multi-write operations. This should be removed by 4.4
+     */
+    bool _canThrowSSVOnIgnored;
 };
 
 inline std::ostream& operator<<(std::ostream& s, const ChunkVersion& v) {
diff --git a/src/mongo/s/write_ops/write_op.cpp b/src/mongo/s/write_ops/write_op.cpp
index 85a547e84c5..822b9578268 100644
--- a/src/mongo/s/write_ops/write_op.cpp
+++ b/src/mongo/s/write_ops/write_op.cpp
@@ -99,6 +99,7 @@ Status WriteOp::targetWrites(OperationContext* opCtx,
             // can't retry half a regular multi-write.
             if (endpoints.size() > 1u && !inTransaction) {
                 endpoint.shardVersion = ChunkVersion::IGNORED();
+                endpoint.shardVersion.canThrowSSVOnIgnored();
             }
 
             targetedWrites->push_back(new TargetedWrite(std::move(endpoint), ref));