MigrationStatuses MigrationManager::executeMigrationsForAutoBalance(
OperationContext* txn,
const vector<MigrateInfo>& migrateInfos,
uint64_t maxChunkSizeBytes,
const MigrationSecondaryThrottleOptions& secondaryThrottle,
bool waitForDelete) {
vector<std::pair<shared_ptr<Notification<Status>>, MigrateInfo>> responses;
for (const auto& migrateInfo : migrateInfos) {
responses.emplace_back(_schedule(txn,
migrateInfo,
false, // Config server takes the collection dist lock
maxChunkSizeBytes,
secondaryThrottle,
waitForDelete),
migrateInfo);
}
MigrationStatuses migrationStatuses;
vector<MigrateInfo> rescheduledMigrations;
// Wait for all the scheduled migrations to complete and note the ones, which failed with a
// LockBusy error code. These need to be executed serially, without the distributed lock being
// held by the config server for backwards compatibility with 3.2 shards.
for (auto& response : responses) {
auto notification = std::move(response.first);
auto migrateInfo = std::move(response.second);
Status responseStatus = notification->get();
if (responseStatus == ErrorCodes::LockBusy) {
rescheduledMigrations.emplace_back(std::move(migrateInfo));
} else {
migrationStatuses.emplace(migrateInfo.getName(), std::move(responseStatus));
}
}
// Schedule all 3.2 compatibility migrations sequentially
for (const auto& migrateInfo : rescheduledMigrations) {
Status responseStatus = _schedule(txn,
migrateInfo,
true, // Shard takes the collection dist lock
maxChunkSizeBytes,
secondaryThrottle,
waitForDelete)
->get();
migrationStatuses.emplace(migrateInfo.getName(), std::move(responseStatus));
}
invariant(migrationStatuses.size() == migrateInfos.size());
return migrationStatuses;
}
MigrationStatuses MigrationManager::executeMigrationsForAutoBalance(
OperationContext* txn,
const vector<MigrateInfo>& migrateInfos,
uint64_t maxChunkSizeBytes,
const MigrationSecondaryThrottleOptions& secondaryThrottle,
bool waitForDelete) {
MigrationStatuses migrationStatuses;
{
std::map<MigrationIdentifier, ScopedMigrationRequest> scopedMigrationRequests;
vector<std::pair<shared_ptr<Notification<RemoteCommandResponse>>, MigrateInfo>> responses;
for (const auto& migrateInfo : migrateInfos) {
// Write a document to the config.migrations collection, in case this migration must be
// recovered by the Balancer. Fail if the chunk is already moving.
auto statusWithScopedMigrationRequest =
ScopedMigrationRequest::writeMigration(txn, migrateInfo, waitForDelete);
if (!statusWithScopedMigrationRequest.isOK()) {
migrationStatuses.emplace(migrateInfo.getName(),
std::move(statusWithScopedMigrationRequest.getStatus()));
continue;
}
scopedMigrationRequests.emplace(migrateInfo.getName(),
std::move(statusWithScopedMigrationRequest.getValue()));
responses.emplace_back(
_schedule(txn, migrateInfo, maxChunkSizeBytes, secondaryThrottle, waitForDelete),
migrateInfo);
}
// Wait for all the scheduled migrations to complete.
for (auto& response : responses) {
auto notification = std::move(response.first);
auto migrateInfo = std::move(response.second);
const auto& remoteCommandResponse = notification->get();
auto it = scopedMigrationRequests.find(migrateInfo.getName());
invariant(it != scopedMigrationRequests.end());
Status commandStatus =
_processRemoteCommandResponse(remoteCommandResponse, &it->second);
migrationStatuses.emplace(migrateInfo.getName(), std::move(commandStatus));
}
}
invariant(migrationStatuses.size() == migrateInfos.size());
return migrationStatuses;
}