std::vector<AsyncRequestsSender::Response> TransactionRouter::abortTransaction(
OperationContext* opCtx, bool isImplicit) {
// The router has yet to send any commands to a remote shard for this transaction.
// Return the same error that would have been returned by a shard.
uassert(ErrorCodes::NoSuchTransaction,
"no known command has been sent by this router for this transaction",
!_participants.empty());
auto abortCmd = BSON("abortTransaction" << 1);
std::vector<AsyncRequestsSender::Request> abortRequests;
for (const auto& participantEntry : _participants) {
abortRequests.emplace_back(ShardId(participantEntry.first), abortCmd);
}
// Implicit aborts log earlier.
if (!isImplicit) {
LOG(0) << _txnIdToString() << " Aborting transaction on " << _participants.size()
<< " shard(s)";
}
return gatherResponses(opCtx,
NamespaceString::kAdminDb,
ReadPreferenceSetting{ReadPreference::PrimaryOnly},
Shard::RetryPolicy::kIdempotent,
abortRequests);
}
std::vector<AsyncRequestsSender::Response> scatterGatherUnversionedTargetAllShards(
OperationContext* opCtx,
StringData dbName,
const BSONObj& cmdObj,
const ReadPreferenceSetting& readPref,
Shard::RetryPolicy retryPolicy) {
return gatherResponses(
opCtx, dbName, readPref, retryPolicy, buildUnversionedRequestsForAllShards(opCtx, cmdObj));
}
std::vector<AsyncRequestsSender::Response> scatterGatherVersionedTargetByRoutingTable(
OperationContext* opCtx,
StringData dbName,
const NamespaceString& nss,
const CachedCollectionRoutingInfo& routingInfo,
const BSONObj& cmdObj,
const ReadPreferenceSetting& readPref,
Shard::RetryPolicy retryPolicy,
const BSONObj& query,
const BSONObj& collation) {
const auto requests =
buildVersionedRequestsForTargetedShards(opCtx, nss, routingInfo, cmdObj, query, collation);
return gatherResponses(opCtx, dbName, readPref, retryPolicy, requests);
}
AsyncRequestsSender::Response executeCommandAgainstDatabasePrimary(
OperationContext* opCtx,
StringData dbName,
const CachedDatabaseInfo& dbInfo,
const BSONObj& cmdObj,
const ReadPreferenceSetting& readPref,
Shard::RetryPolicy retryPolicy) {
auto responses =
gatherResponses(opCtx,
dbName,
readPref,
retryPolicy,
buildUnversionedRequestsForShards(
opCtx, {dbInfo.primaryId()}, appendDbVersionIfPresent(cmdObj, dbInfo)));
return std::move(responses.front());
}
std::vector<AsyncRequestsSender::Response> scatterGatherOnlyVersionIfUnsharded(
OperationContext* opCtx,
const NamespaceString& nss,
const BSONObj& cmdObj,
const ReadPreferenceSetting& readPref,
Shard::RetryPolicy retryPolicy) {
auto routingInfo =
uassertStatusOK(Grid::get(opCtx)->catalogCache()->getCollectionRoutingInfo(opCtx, nss));
std::vector<AsyncRequestsSender::Request> requests;
if (routingInfo.cm()) {
// An unversioned request on a sharded collection can cause a shard that has not owned data
// for the collection yet to implicitly create the collection without all the collection
// options. So, we signal to shards that they should not implicitly create the collection.
requests = buildUnversionedRequestsForAllShards(opCtx, cmdObj);
} else {
requests = buildVersionedRequestsForTargetedShards(
opCtx, nss, routingInfo, cmdObj, BSONObj(), BSONObj());
}
return gatherResponses(opCtx, nss.db(), readPref, retryPolicy, requests);
}
void TransactionRouter::_clearPendingParticipants(OperationContext* opCtx) {
const auto pendingParticipants = _getPendingParticipants();
// Send abort to each pending participant. This resets their transaction state and guarantees no
// transactions will be left open if the retry does not re-target any of these shards.
std::vector<AsyncRequestsSender::Request> abortRequests;
for (const auto& participant : pendingParticipants) {
abortRequests.emplace_back(participant, BSON("abortTransaction" << 1));
}
auto responses = gatherResponses(opCtx,
NamespaceString::kAdminDb,
ReadPreferenceSetting{ReadPreference::PrimaryOnly},
Shard::RetryPolicy::kIdempotent,
abortRequests);
// Verify each abort succeeded or failed with NoSuchTransaction, which may happen if the
// transaction was already implicitly aborted on the shard.
for (const auto& response : responses) {
_assertAbortStatusIsOkOrNoSuchTransaction(response);
}
// Remove each aborted participant from the participant list. Remove after sending abort, so
// they are not added back to the participant list by the transaction tracking inside the ARS.
for (const auto& participant : pendingParticipants) {
invariant(_participants.erase(participant));
}
// If there are no more participants, also clear the coordinator id because a new one must be
// chosen by the retry.
if (_participants.empty()) {
_coordinatorId.reset();
return;
}
// If participants were created by an earlier command, the coordinator must be one of them.
invariant(_coordinatorId);
invariant(_participants.count(*_coordinatorId) == 1);
}
