Status DatabasesCloner::startup() {
UniqueLock lk(_mutex);
invariant(!_active);
_active = true;
if (!_status.isOK() && _status.code() != ErrorCodes::NotYetInitialized) {
return _status;
}
_status = Status::OK();
// Schedule listDatabase command which will kick off the database cloner per result db.
Request listDBsReq(_source,
"admin",
BSON("listDatabases" << true),
rpc::ServerSelectionMetadata(true, boost::none).toBSON());
_listDBsScheduler = stdx::make_unique<RemoteCommandRetryScheduler>(
_exec,
listDBsReq,
stdx::bind(&DatabasesCloner::_onListDatabaseFinish, this, stdx::placeholders::_1),
RemoteCommandRetryScheduler::makeRetryPolicy(
numListDatabasesRetries,
executor::RemoteCommandRequest::kNoTimeout,
RemoteCommandRetryScheduler::kAllRetriableErrors));
auto s = _listDBsScheduler->startup();
if (!s.isOK()) {
_setStatus_inlock(s);
_failed_inlock(lk);
}
return _status;
}
// Initial Sync
Status DatabasesCloner::start() {
_active = true;
if (!_status.isOK() && _status.code() != ErrorCodes::NotYetInitialized) {
return _status;
}
_status = Status::OK();
log() << "starting cloning of all databases";
// Schedule listDatabase command which will kick off the database cloner per result db.
Request listDBsReq(_source,
"admin",
BSON("listDatabases" << true),
rpc::ServerSelectionMetadata(true, boost::none).toBSON());
CBHStatus s = _exec->scheduleRemoteCommand(
listDBsReq,
stdx::bind(&DatabasesCloner::_onListDatabaseFinish, this, stdx::placeholders::_1));
if (!s.isOK()) {
_setStatus(s);
_failed();
}
_doNextActions();
return _status;
}
Status DatabasesCloner::startup() noexcept {
LockGuard lk(_mutex);
switch (_state) {
case State::kPreStart:
_state = State::kRunning;
break;
case State::kRunning:
return Status(ErrorCodes::InternalError, "databases cloner already started");
case State::kShuttingDown:
return Status(ErrorCodes::ShutdownInProgress, "databases cloner shutting down");
case State::kComplete:
return Status(ErrorCodes::ShutdownInProgress, "databases cloner completed");
}
if (!_status.isOK() && _status.code() != ErrorCodes::NotYetInitialized) {
return _status;
}
// Schedule listDatabase command which will kick off the database cloner per result db. We only
// retrieve database names since computing & fetching all database stats can be costly on the
// remote node when there are a large number of collections.
Request listDBsReq(_source,
"admin",
BSON("listDatabases" << true << "nameOnly" << true),
ReadPreferenceSetting::secondaryPreferredMetadata(),
nullptr);
_listDBsScheduler = stdx::make_unique<RemoteCommandRetryScheduler>(
_exec,
listDBsReq,
[this](const auto& x) { this->_onListDatabaseFinish(x); },
RemoteCommandRetryScheduler::makeRetryPolicy(
numInitialSyncListDatabasesAttempts.load(),
executor::RemoteCommandRequest::kNoTimeout,
RemoteCommandRetryScheduler::kAllRetriableErrors));
_status = _listDBsScheduler->startup();
if (!_status.isOK()) {
_state = State::kComplete;
return _status;
}
return Status::OK();
}
