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/**
* Copyright (C) 2012 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kReplication
#include "mongo/platform/basic.h"
#include "mongo/db/repl/oplogreader.h"
#include <string>
#include "mongo/client/dbclientinterface.h"
#include "mongo/db/auth/authorization_manager.h"
#include "mongo/db/auth/authorization_manager_global.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/internal_user_auth.h"
#include "mongo/db/dbhelpers.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/repl/oplog.h"
#include "mongo/db/repl/replication_coordinator.h"
#include "mongo/db/repl/storage_interface.h"
#include "mongo/executor/network_interface.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/log.h"
namespace mongo {
using std::shared_ptr;
using std::endl;
using std::string;
namespace repl {
const BSONObj reverseNaturalObj = BSON("$natural" << -1);
bool replAuthenticate(DBClientBase* conn) {
if (isInternalAuthSet())
return conn->authenticateInternalUser();
if (getGlobalAuthorizationManager()->isAuthEnabled())
return false;
return true;
}
const Seconds OplogReader::kSocketTimeout(30);
OplogReader::OplogReader() {
_tailingQueryOptions = QueryOption_SlaveOk;
_tailingQueryOptions |= QueryOption_CursorTailable | QueryOption_OplogReplay;
/* TODO: slaveOk maybe shouldn't use? */
_tailingQueryOptions |= QueryOption_AwaitData;
}
bool OplogReader::connect(const HostAndPort& host) {
if (conn() == NULL || _host != host) {
resetConnection();
_conn = shared_ptr<DBClientConnection>(
new DBClientConnection(false, durationCount<Seconds>(kSocketTimeout)));
string errmsg;
if (!_conn->connect(host, StringData(), errmsg) || !replAuthenticate(_conn.get())) {
resetConnection();
error() << errmsg << endl;
return false;
}
_conn->port().setTag(_conn->port().getTag() |
executor::NetworkInterface::kMessagingPortKeepOpen);
_host = host;
}
return true;
}
void OplogReader::tailCheck() {
if (cursor.get() && cursor->isDead()) {
log() << "old cursor isDead, will initiate a new one" << std::endl;
resetCursor();
}
}
void OplogReader::query(
const char* ns, Query query, int nToReturn, int nToSkip, const BSONObj* fields) {
cursor.reset(
_conn->query(ns, query, nToReturn, nToSkip, fields, QueryOption_SlaveOk).release());
}
void OplogReader::tailingQuery(const char* ns, const BSONObj& query) {
verify(!haveCursor());
LOG(2) << ns << ".find(" << query.toString() << ')' << endl;
cursor.reset(_conn->query(ns, query, 0, 0, nullptr, _tailingQueryOptions).release());
}
void OplogReader::tailingQueryGTE(const char* ns, Timestamp optime) {
BSONObjBuilder gte;
gte.append("$gte", optime);
BSONObjBuilder query;
query.append("ts", gte.done());
tailingQuery(ns, query.done());
}
HostAndPort OplogReader::getHost() const {
return _host;
}
void OplogReader::connectToSyncSource(OperationContext* txn,
const OpTime& lastOpTimeFetched,
ReplicationCoordinator* replCoord) {
const Timestamp sentinelTimestamp(duration_cast<Seconds>(Date_t::now().toDurationSinceEpoch()),
0);
const OpTime sentinel(sentinelTimestamp, std::numeric_limits<long long>::max());
OpTime oldestOpTimeSeen = sentinel;
invariant(conn() == NULL);
while (true) {
HostAndPort candidate = replCoord->chooseNewSyncSource(lastOpTimeFetched.getTimestamp());
if (candidate.empty()) {
if (oldestOpTimeSeen == sentinel) {
// If, in this invocation of connectToSyncSource(), we did not successfully
// connect to any node ahead of us,
// we apparently have no sync sources to connect to.
// This situation is common; e.g. if there are no writes to the primary at
// the moment.
return;
}
// Connected to at least one member, but in all cases we were too stale to use them
// as a sync source.
error() << "too stale to catch up -- entering maintenance mode";
log() << "our last optime : " << lastOpTimeFetched;
log() << "oldest available is " << oldestOpTimeSeen;
log() << "See http://dochub.mongodb.org/core/resyncingaverystalereplicasetmember";
StorageInterface::get(txn)->setMinValid(txn, {lastOpTimeFetched, oldestOpTimeSeen});
auto status = replCoord->setMaintenanceMode(true);
if (!status.isOK()) {
warning() << "Failed to transition into maintenance mode.";
}
bool worked = replCoord->setFollowerMode(MemberState::RS_RECOVERING);
if (!worked) {
warning() << "Failed to transition into " << MemberState(MemberState::RS_RECOVERING)
<< ". Current state: " << replCoord->getMemberState();
}
return;
}
if (!connect(candidate)) {
LOG(2) << "can't connect to " << candidate.toString() << " to read operations";
resetConnection();
replCoord->blacklistSyncSource(candidate, Date_t::now() + Seconds(10));
continue;
}
// Read the first (oldest) op and confirm that it's not newer than our last
// fetched op. Otherwise, we have fallen off the back of that source's oplog.
BSONObj remoteOldestOp(findOne(rsOplogName.c_str(), Query()));
OpTime remoteOldOpTime =
fassertStatusOK(28776, OpTime::parseFromOplogEntry(remoteOldestOp));
// remoteOldOpTime may come from a very old config, so we cannot compare their terms.
if (!lastOpTimeFetched.isNull() &&
lastOpTimeFetched.getTimestamp() < remoteOldOpTime.getTimestamp()) {
// We're too stale to use this sync source.
resetConnection();
replCoord->blacklistSyncSource(candidate, Date_t::now() + Minutes(1));
if (oldestOpTimeSeen.getTimestamp() > remoteOldOpTime.getTimestamp()) {
warning() << "we are too stale to use " << candidate.toString()
<< " as a sync source";
oldestOpTimeSeen = remoteOldOpTime;
}
continue;
}
// TODO: If we were too stale (recovering with maintenance mode on), then turn it off, to
// allow becoming secondary/etc.
// Got a valid sync source.
return;
} // while (true)
}
} // namespace repl
} // namespace mongo
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