StatusWith<CursorId> ClusterFind::runQuery(OperationContext* txn,
const CanonicalQuery& query,
const ReadPreferenceSetting& readPref,
std::vector<BSONObj>* results) {
invariant(results);
// Projection on the reserved sort key field is illegal in mongos.
if (query.getParsed().getProj().hasField(ClusterClientCursorParams::kSortKeyField)) {
return {ErrorCodes::BadValue,
str::stream() << "Projection contains illegal field '"
<< ClusterClientCursorParams::kSortKeyField
<< "': " << query.getParsed().getProj()};
}
auto dbConfig = grid.catalogCache()->getDatabase(txn, query.nss().db().toString());
if (dbConfig.getStatus() == ErrorCodes::NamespaceNotFound) {
// If the database doesn't exist, we successfully return an empty result set without
// creating a cursor.
return CursorId(0);
} else if (!dbConfig.isOK()) {
return dbConfig.getStatus();
}
std::shared_ptr<ChunkManager> chunkManager;
std::shared_ptr<Shard> primary;
dbConfig.getValue()->getChunkManagerOrPrimary(txn, query.nss().ns(), chunkManager, primary);
// Re-target and re-send the initial find command to the shards until we have established the
// shard version.
for (size_t retries = 1; retries <= kMaxStaleConfigRetries; ++retries) {
auto cursorId = runQueryWithoutRetrying(
txn, query, readPref, chunkManager.get(), std::move(primary), results);
if (cursorId.isOK()) {
return cursorId;
}
auto status = std::move(cursorId.getStatus());
if (status != ErrorCodes::SendStaleConfig && status != ErrorCodes::RecvStaleConfig &&
status != ErrorCodes::HostUnreachable) {
// Errors other than receiving a stale config message from mongoD or an unreachable host
// are fatal to the operation.
return status;
}
LOG(1) << "Received error status for query " << query.toStringShort() << " on attempt "
<< retries << " of " << kMaxStaleConfigRetries << ": " << status;
chunkManager = dbConfig.getValue()->getChunkManagerIfExists(txn, query.nss().ns(), true);
if (!chunkManager) {
dbConfig.getValue()->getChunkManagerOrPrimary(
txn, query.nss().ns(), chunkManager, primary);
}
}
return {ErrorCodes::StaleShardVersion,
str::stream() << "Retried " << kMaxStaleConfigRetries
<< " times without establishing shard version on a reachable host."};
}
StatusWith<CursorId> ClusterFind::runQuery(OperationContext* txn,
const CanonicalQuery& query,
const ReadPreferenceSetting& readPref,
std::vector<BSONObj>* results) {
invariant(results);
auto dbConfig = grid.catalogCache()->getDatabase(txn, query.nss().db().toString());
if (dbConfig.getStatus() == ErrorCodes::DatabaseNotFound) {
// If the database doesn't exist, we successfully return an empty result set without
// creating a cursor.
return CursorId(0);
} else if (!dbConfig.isOK()) {
return dbConfig.getStatus();
}
std::shared_ptr<ChunkManager> chunkManager;
std::shared_ptr<Shard> primary;
dbConfig.getValue()->getChunkManagerOrPrimary(query.nss().ns(), chunkManager, primary);
// Re-target and re-send the initial find command to the shards until we have established the
// shard version.
for (size_t retries = 1; retries <= kMaxStaleConfigRetries; ++retries) {
auto cursorId = runQueryWithoutRetrying(
txn, query, readPref, chunkManager.get(), std::move(primary), results);
if (cursorId.isOK()) {
return cursorId;
}
auto status = std::move(cursorId.getStatus());
if (status != ErrorCodes::RecvStaleConfig) {
// Errors other than receiving a stale config message from mongoD are fatal to the
// operation.
return status;
}
LOG(1) << "Received stale config for query " << query.toStringShort() << " on attempt "
<< retries << " of " << kMaxStaleConfigRetries << ": " << status.reason();
invariant(chunkManager);
chunkManager = chunkManager->reload(txn);
}
return {ErrorCodes::StaleShardVersion,
str::stream() << "Retried " << kMaxStaleConfigRetries
<< " times without establishing shard version."};
}
StatusWith<CursorId> ClusterFind::runQuery(OperationContext* txn,
const CanonicalQuery& query,
const ReadPreferenceSetting& readPref,
std::vector<BSONObj>* results,
BSONObj* viewDefinition) {
invariant(results);
// Projection on the reserved sort key field is illegal in mongos.
if (query.getQueryRequest().getProj().hasField(ClusterClientCursorParams::kSortKeyField)) {
return {ErrorCodes::BadValue,
str::stream() << "Projection contains illegal field '"
<< ClusterClientCursorParams::kSortKeyField
<< "': "
<< query.getQueryRequest().getProj()};
}
auto dbConfig = Grid::get(txn)->catalogCache()->getDatabase(txn, query.nss().db().toString());
if (dbConfig.getStatus() == ErrorCodes::NamespaceNotFound) {
// If the database doesn't exist, we successfully return an empty result set without
// creating a cursor.
return CursorId(0);
} else if (!dbConfig.isOK()) {
return dbConfig.getStatus();
}
std::shared_ptr<ChunkManager> chunkManager;
std::shared_ptr<Shard> primary;
dbConfig.getValue()->getChunkManagerOrPrimary(txn, query.nss().ns(), chunkManager, primary);
// Re-target and re-send the initial find command to the shards until we have established the
// shard version.
for (size_t retries = 1; retries <= kMaxStaleConfigRetries; ++retries) {
auto cursorId = runQueryWithoutRetrying(
txn, query, readPref, chunkManager.get(), std::move(primary), results, viewDefinition);
if (cursorId.isOK()) {
return cursorId;
}
auto status = std::move(cursorId.getStatus());
if (!ErrorCodes::isStaleShardingError(status.code()) &&
status != ErrorCodes::ShardNotFound) {
// Errors other than trying to reach a non existent shard or receiving a stale
// metadata message from MongoD are fatal to the operation. Network errors and
// replication retries happen at the level of the AsyncResultsMerger.
return status;
}
LOG(1) << "Received error status for query " << redact(query.toStringShort())
<< " on attempt " << retries << " of " << kMaxStaleConfigRetries << ": "
<< redact(status);
const bool staleEpoch = (status == ErrorCodes::StaleEpoch);
if (staleEpoch) {
if (!dbConfig.getValue()->reload(txn)) {
// If the reload failed that means the database wasn't found, so successfully return
// an empty result set without creating a cursor.
return CursorId(0);
}
}
chunkManager =
dbConfig.getValue()->getChunkManagerIfExists(txn, query.nss().ns(), true, staleEpoch);
if (!chunkManager) {
dbConfig.getValue()->getChunkManagerOrPrimary(
txn, query.nss().ns(), chunkManager, primary);
}
}
return {ErrorCodes::StaleShardVersion,
str::stream() << "Retried " << kMaxStaleConfigRetries
<< " times without successfully establishing shard version."};
}