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/**
* Copyright (C) 2008 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/>.
*/
#include "pch.h"
#include "../repl.h"
#include "../client.h"
#include "../../client/dbclient.h"
#include "rs.h"
#include "../oplogreader.h"
#include "../../util/mongoutils/str.h"
#include "../dbhelpers.h"
#include "rs_optime.h"
#include "../oplog.h"
namespace mongo {
using namespace mongoutils;
using namespace bson;
void dropAllDatabasesExceptLocal();
// add try/catch with sleep
void isyncassert(const string& msg, bool expr) {
if( !expr ) {
string m = str::stream() << "initial sync " << msg;
theReplSet->sethbmsg(m, 0);
uasserted(13404, m);
}
}
void ReplSetImpl::syncDoInitialSync() {
createOplog();
while( 1 ) {
try {
_syncDoInitialSync();
break;
}
catch(DBException& e) {
sethbmsg("initial sync exception " + e.toString(), 0);
sleepsecs(30);
}
}
}
/* todo : progress metering to sethbmsg. */
static bool clone(const char *master, string db) {
string err;
return cloneFrom(master, err, db, false,
/* slave_ok */ true, true, false, /*mayYield*/true, /*mayBeInterrupted*/false);
}
void _logOpObjRS(const BSONObj& op);
static void emptyOplog() {
writelock lk(rsoplog);
Client::Context ctx(rsoplog);
NamespaceDetails *d = nsdetails(rsoplog);
// temp
if( d && d->stats.nrecords == 0 )
return; // already empty, ok.
LOG(1) << "replSet empty oplog" << rsLog;
d->emptyCappedCollection(rsoplog);
}
const Member* ReplSetImpl::getMemberToSyncTo() {
bool buildIndexes = true;
// wait for 2N pings before choosing a sync target
if (_cfg) {
int needMorePings = config().members.size()*2 - HeartbeatInfo::numPings;
if (needMorePings > 0) {
OCCASIONALLY log() << "waiting for " << needMorePings << " pings from other members before syncing" << endl;
return NULL;
}
buildIndexes = myConfig().buildIndexes;
}
Member *closest = 0;
// find the member with the lowest ping time that has more data than me
// Make two attempts. The first attempt, we ignore those nodes with
// slave delay higher than our own. The second attempt includes such
// nodes, in case those are the only ones we can reach.
for (int attempts = 0; attempts < 2; ++attempts) {
for (Member *m = _members.head(); m; m = m->next()) {
if (m->hbinfo().up() &&
// make sure members with buildIndexes sync from other members w/indexes
(!buildIndexes || (buildIndexes && m->config().buildIndexes)) &&
(m->state() == MemberState::RS_PRIMARY ||
(m->state() == MemberState::RS_SECONDARY &&
m->hbinfo().opTime > lastOpTimeWritten)) &&
(!closest || m->hbinfo().ping < closest->hbinfo().ping)) {
if ( attempts == 0 &&
myConfig().slaveDelay < m->config().slaveDelay ) {
break; // skip this one in the first attempt
}
closest = m;
}
}
if (closest) break; // no need for second attempt
}
{
lock lk(this);
if (!closest) {
_currentSyncTarget = NULL;
return NULL;
}
_currentSyncTarget = closest;
}
sethbmsg( str::stream() << "syncing to: " << closest->fullName(), 0);
return const_cast<Member*>(closest);
}
/**
* Do the initial sync for this member.
*/
void ReplSetImpl::_syncDoInitialSync() {
sethbmsg("initial sync pending",0);
// if this is the first node, it may have already become primary
if ( box.getState().primary() ) {
sethbmsg("I'm already primary, no need for initial sync",0);
return;
}
const Member *source = getMemberToSyncTo();
if (!source) {
sethbmsg("initial sync need a member to be primary or secondary to do our initial sync", 0);
sleepsecs(15);
return;
}
string sourceHostname = source->h().toString();
OplogReader r;
if( !r.connect(sourceHostname) ) {
sethbmsg( str::stream() << "initial sync couldn't connect to " << source->h().toString() , 0);
sleepsecs(15);
return;
}
BSONObj lastOp = r.getLastOp(rsoplog);
if( lastOp.isEmpty() ) {
sethbmsg("initial sync couldn't read remote oplog", 0);
sleepsecs(15);
return;
}
OpTime startingTS = lastOp["ts"]._opTime();
if (replSettings.fastsync) {
log() << "fastsync: skipping database clone" << rsLog;
}
else {
sethbmsg("initial sync drop all databases", 0);
dropAllDatabasesExceptLocal();
sethbmsg("initial sync clone all databases", 0);
list<string> dbs = r.conn()->getDatabaseNames();
for( list<string>::iterator i = dbs.begin(); i != dbs.end(); i++ ) {
string db = *i;
if( db != "local" ) {
sethbmsg( str::stream() << "initial sync cloning db: " << db , 0);
bool ok;
{
writelock lk(db);
Client::Context ctx(db);
ok = clone(sourceHostname.c_str(), db);
}
if( !ok ) {
sethbmsg( str::stream() << "initial sync error clone of " << db << " failed sleeping 5 minutes" ,0);
sleepsecs(300);
return;
}
}
}
}
sethbmsg("initial sync query minValid",0);
isyncassert( "initial sync source must remain readable throughout our initial sync", source->state().readable() );
/* our cloned copy will be strange until we apply oplog events that occurred
through the process. we note that time point here. */
BSONObj minValid = r.getLastOp(rsoplog);
isyncassert( "getLastOp is empty ", !minValid.isEmpty() );
OpTime mvoptime = minValid["ts"]._opTime();
assert( !mvoptime.isNull() );
/* apply relevant portion of the oplog
*/
{
isyncassert( str::stream() << "initial sync source must remain readable throughout our initial sync [2] state now: " << source->state().toString() , source->state().readable() );
if( ! initialSyncOplogApplication(source, /*applyGTE*/startingTS, /*minValid*/mvoptime) ) { // note we assume here that this call does not throw
log() << "replSet initial sync failed during applyoplog" << rsLog;
emptyOplog(); // otherwise we'll be up!
lastOpTimeWritten = OpTime();
lastH = 0;
log() << "replSet cleaning up [1]" << rsLog;
{
writelock lk("local.");
Client::Context cx( "local." );
cx.db()->flushFiles(true);
}
log() << "replSet cleaning up [2]" << rsLog;
sleepsecs(5);
return;
}
}
sethbmsg("initial sync finishing up",0);
assert( !box.getState().primary() ); // wouldn't make sense if we were.
{
writelock lk("local.");
Client::Context cx( "local." );
cx.db()->flushFiles(true);
try {
log() << "replSet set minValid=" << minValid["ts"]._opTime().toString() << rsLog;
}
catch(...) { }
Helpers::putSingleton("local.replset.minvalid", minValid);
cx.db()->flushFiles(true);
}
sethbmsg("initial sync done",0);
}
}
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