/
repl.cpp
1752 lines (1580 loc) · 61.8 KB
/
repl.cpp
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// repl.cpp
/* TODO
PAIRING
_ on a syncexception, don't allow going back to master state?
*/
/**
* 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/>.
*/
/* Collections we use:
local.sources - indicates what sources we pull from as a "slave", and the last update of each
local.oplog.$main - our op log as "master"
local.dbinfo.<dbname>
local.pair.startup - can contain a special value indicating for a pair that we have the master copy.
used when replacing other half of the pair which has permanently failed.
local.pair.sync - { initialsynccomplete: 1 }
*/
#include "stdafx.h"
#include "jsobj.h"
#include "../util/goodies.h"
#include "repl.h"
#include "../util/message.h"
#include "../client/dbclient.h"
#include "pdfile.h"
#include "query.h"
#include "db.h"
#include "commands.h"
#include "security.h"
#include "cmdline.h"
namespace mongo {
extern boost::recursive_mutex &dbMutex;
extern long long oplogSize;
int _updateObjects(const char *ns, BSONObj updateobj, BSONObj pattern, bool upsert, stringstream& ss, bool logOp=false);
void ensureHaveIdIndex(const char *ns);
/* if 1 sync() is running */
int syncing = 0;
/* if true replace our peer in a replication pair -- don't worry about if his
local.oplog.$main is empty.
*/
bool replacePeer = false;
/* "dead" means something really bad happened like replication falling completely out of sync.
when non-null, we are dead and the string is informational
*/
const char *replAllDead = 0;
extern bool autoresync;
time_t lastForcedResync = 0;
IdTracker &idTracker = *( new IdTracker() );
} // namespace mongo
#include "replset.h"
namespace mongo {
PairSync *pairSync = new PairSync();
bool getInitialSyncCompleted() {
return pairSync->initialSyncCompleted();
}
/* --- ReplPair -------------------------------- */
ReplPair *replPair = 0;
/* output by the web console */
const char *replInfo = "";
struct ReplInfo {
ReplInfo(const char *msg) {
replInfo = msg;
}
~ReplInfo() {
replInfo = "?";
}
};
void ReplPair::setMaster(int n, const char *_comment ) {
if ( n == State_Master && !getInitialSyncCompleted() )
return;
info = _comment;
if ( n != state && !cmdLine.quiet )
log() << "pair: setting master=" << n << " was " << state << '\n';
state = n;
}
/* peer unreachable, try our arbiter */
void ReplPair::arbitrate() {
ReplInfo r("arbitrate");
if ( arbHost == "-" ) {
// no arbiter. we are up, let's assume partner is down and network is not partitioned.
setMasterLocked(State_Master, "remote unreachable");
return;
}
auto_ptr<DBClientConnection> conn( newClientConnection() );
string errmsg;
if ( !conn->connect(arbHost.c_str(), errmsg) ) {
log() << "repl: cantconn arbiter " << errmsg << endl;
setMasterLocked(State_CantArb, "can't connect to arb");
return;
}
negotiate( conn.get(), "arbiter" );
}
/* --------------------------------------------- */
class CmdReplacePeer : public Command {
public:
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool logTheOp() {
return false;
}
CmdReplacePeer() : Command("replacepeer") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
if ( replPair == 0 ) {
errmsg = "not paired";
return false;
}
if ( !getInitialSyncCompleted() ) {
errmsg = "not caught up cannot replace peer";
return false;
}
if ( syncing < 0 ) {
errmsg = "replacepeer already invoked";
return false;
}
Timer t;
while ( 1 ) {
if ( syncing == 0 || t.millis() > 20000 )
break;
{
dbtemprelease t;
sleepmillis(10);
}
}
if ( syncing ) {
assert( syncing > 0 );
errmsg = "timeout waiting for sync() to finish";
return false;
}
{
ReplSource::SourceVector sources;
ReplSource::loadAll(sources);
if ( sources.size() != 1 ) {
errmsg = "local.sources.count() != 1, cannot replace peer";
return false;
}
}
{
Helpers::emptyCollection("local.sources");
BSONObj o = fromjson("{\"replacepeer\":1}");
Helpers::putSingleton("local.pair.startup", o);
}
syncing = -1;
replAllDead = "replacepeer invoked -- adjust local.sources hostname then restart this db process";
result.append("info", "adjust local.sources hostname; db restart now required");
return true;
}
} cmdReplacePeer;
class CmdForceDead : public Command {
public:
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool logTheOp() {
return false;
}
CmdForceDead() : Command("forcedead") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
replAllDead = "forced by command";
return true;
}
} cmdForceDead;
/* operator requested resynchronization of replication (on the slave). { resync : 1 } */
class CmdResync : public Command {
public:
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool logTheOp() {
return false;
}
CmdResync() : Command("resync") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
if ( cmdObj.getBoolField( "force" ) ) {
if ( !waitForSyncToFinish( errmsg ) )
return false;
replAllDead = "resync forced";
}
if ( !replAllDead ) {
errmsg = "not dead, no need to resync";
return false;
}
if ( !waitForSyncToFinish( errmsg ) )
return false;
ReplSource::forceResyncDead( "client" );
result.append( "info", "triggered resync for all sources" );
return true;
}
bool waitForSyncToFinish( string &errmsg ) const {
// Wait for slave thread to finish syncing, so sources will be be
// reloaded with new saved state on next pass.
Timer t;
while ( 1 ) {
if ( syncing == 0 || t.millis() > 20000 )
break;
{
dbtemprelease t;
sleepmillis(10);
}
}
if ( syncing ) {
errmsg = "timeout waiting for sync() to finish";
return false;
}
return true;
}
} cmdResync;
class CmdIsMaster : public Command {
public:
virtual bool requiresAuth() { return false; }
virtual bool slaveOk() {
return true;
}
CmdIsMaster() : Command("ismaster") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
/* currently request to arbiter is (somewhat arbitrarily) an ismaster request that is not
authenticated.
we allow unauthenticated ismaster but we aren't as verbose informationally if
one is not authenticated for admin db to be safe.
*/
AuthenticationInfo *ai = currentClient.get()->ai;
bool authed = ai->isAuthorized("admin");
if ( replAllDead ) {
result.append("ismaster", 0.0);
if( authed ) {
if ( replPair )
result.append("remote", replPair->remote);
result.append("info", replAllDead);
}
}
else if ( replPair ) {
result.append("ismaster", replPair->state);
if( authed ) {
result.append("remote", replPair->remote);
if ( !replPair->info.empty() )
result.append("info", replPair->info);
}
}
else {
result.append("ismaster", slave ? 0 : 1);
result.append("msg", "not paired");
}
return true;
}
} cmdismaster;
class CmdIsInitialSyncComplete : public Command {
public:
virtual bool requiresAuth() { return false; }
virtual bool slaveOk() {
return true;
}
CmdIsInitialSyncComplete() : Command( "isinitialsynccomplete" ) {}
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
result.appendBool( "initialsynccomplete", getInitialSyncCompleted() );
return true;
}
} cmdisinitialsynccomplete;
/* negotiate who is master
-1=not set (probably means we just booted)
0=was slave
1=was master
remote,local -> new remote,local
!1,1 -> 0,1
1,!1 -> 1,0
-1,-1 -> dominant->1, nondom->0
0,0 -> dominant->1, nondom->0
1,1 -> dominant->1, nondom->0
{ negotiatemaster:1, i_was:<state>, your_name:<hostname> }
returns:
{ ok:1, you_are:..., i_am:... }
*/
class CmdNegotiateMaster : public Command {
public:
CmdNegotiateMaster() : Command("negotiatemaster") { }
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool) {
if ( replPair == 0 ) {
massert( "Another mongod instance believes incorrectly that this node is its peer", !cmdObj.getBoolField( "fromArbiter" ) );
// assume that we are an arbiter and should forward the request
string host = cmdObj.getStringField("your_name");
int port = cmdObj.getIntField( "your_port" );
if ( port == INT_MIN ) {
errmsg = "no port specified";
problem() << errmsg << endl;
return false;
}
stringstream ss;
ss << host << ":" << port;
string remote = ss.str();
BSONObj ret;
{
dbtemprelease t;
auto_ptr<DBClientConnection> conn( new DBClientConnection() );
if ( !conn->connect( remote.c_str(), errmsg ) ) {
result.append( "you_are", ReplPair::State_Master );
return true;
}
BSONObjBuilder forwardCommand;
forwardCommand.appendElements( cmdObj );
forwardCommand.appendBool( "fromArbiter", true );
ret = conn->findOne( "admin.$cmd", forwardCommand.done() );
}
BSONObjIterator i( ret );
while( i.moreWithEOO() ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
if ( e.fieldName() != string( "ok" ) )
result.append( e );
}
return ( ret.getIntField("ok") == 1 );
}
int was = cmdObj.getIntField("i_was");
string myname = cmdObj.getStringField("your_name");
if ( myname.empty() || was < -3 ) {
errmsg = "your_name/i_was not specified";
return false;
}
int N = ReplPair::State_Negotiating;
int M = ReplPair::State_Master;
int S = ReplPair::State_Slave;
if ( !replPair->dominant( myname ) ) {
result.append( "you_are", N );
result.append( "i_am", replPair->state );
return true;
}
int me, you;
if ( !getInitialSyncCompleted() || ( replPair->state != M && was == M ) ) {
me=S;
you=M;
}
else {
me=M;
you=S;
}
replPair->setMaster( me, "CmdNegotiateMaster::run()" );
result.append("you_are", you);
result.append("i_am", me);
return true;
}
} cmdnegotiatemaster;
int ReplPair::negotiate(DBClientConnection *conn, string method) {
BSONObjBuilder b;
b.append("negotiatemaster",1);
b.append("i_was", state);
b.append("your_name", remoteHost);
b.append("your_port", remotePort);
BSONObj cmd = b.done();
BSONObj res = conn->findOne("admin.$cmd", cmd);
if ( res.getIntField("ok") != 1 ) {
string message = method + " negotiate failed";
problem() << message << ": " << res.toString() << '\n';
setMasterLocked(State_Confused, message.c_str());
return State_Confused;
}
int x = res.getIntField("you_are");
int remote = res.getIntField("i_am");
// State_Negotiating means the remote node is not dominant and cannot
// choose who is master.
if ( x != State_Slave && x != State_Master && x != State_Negotiating ) {
problem() << method << " negotiate: bad you_are value " << res.toString() << endl;
} else if ( x != State_Negotiating ) {
string message = method + " negotiation";
setMasterLocked(x, message.c_str());
}
return remote;
}
struct TestOpTime {
TestOpTime() {
OpTime t;
for ( int i = 0; i < 10; i++ ) {
OpTime s = OpTime::now();
assert( s != t );
t = s;
}
OpTime q = t;
assert( q == t );
assert( !(q != t) );
}
} testoptime;
/* --------------------------------------------------------------*/
ReplSource::ReplSource() {
replacing = false;
nClonedThisPass = 0;
paired = false;
}
ReplSource::ReplSource(BSONObj o) : nClonedThisPass(0) {
replacing = false;
paired = false;
only = o.getStringField("only");
hostName = o.getStringField("host");
_sourceName = o.getStringField("source");
uassert( "'host' field not set in sources collection object", !hostName.empty() );
uassert( "only source='main' allowed for now with replication", sourceName() == "main" );
BSONElement e = o.getField("syncedTo");
if ( !e.eoo() ) {
uassert( "bad sources 'syncedTo' field value", e.type() == Date || e.type() == Timestamp );
OpTime tmp( e.date() );
syncedTo = tmp;
}
BSONObj dbsObj = o.getObjectField("dbsNextPass");
if ( !dbsObj.isEmpty() ) {
BSONObjIterator i(dbsObj);
while ( 1 ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
addDbNextPass.insert( e.fieldName() );
}
}
dbsObj = o.getObjectField("incompleteCloneDbs");
if ( !dbsObj.isEmpty() ) {
BSONObjIterator i(dbsObj);
while ( 1 ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
incompleteCloneDbs.insert( e.fieldName() );
}
}
lastSavedLocalTs_ = OpTime( o.getField( "localLogTs" ).date() );
}
/* Turn our C++ Source object into a BSONObj */
BSONObj ReplSource::jsobj() {
BSONObjBuilder b;
b.append("host", hostName);
b.append("source", sourceName());
if ( !only.empty() )
b.append("only", only);
if ( !syncedTo.isNull() )
b.appendTimestamp("syncedTo", syncedTo.asDate());
b.appendTimestamp("localLogTs", lastSavedLocalTs_.asDate());
BSONObjBuilder dbsNextPassBuilder;
int n = 0;
for ( set<string>::iterator i = addDbNextPass.begin(); i != addDbNextPass.end(); i++ ) {
n++;
dbsNextPassBuilder.appendBool(i->c_str(), 1);
}
if ( n )
b.append("dbsNextPass", dbsNextPassBuilder.done());
BSONObjBuilder incompleteCloneDbsBuilder;
n = 0;
for ( set<string>::iterator i = incompleteCloneDbs.begin(); i != incompleteCloneDbs.end(); i++ ) {
n++;
incompleteCloneDbsBuilder.appendBool(i->c_str(), 1);
}
if ( n )
b.append("incompleteCloneDbs", incompleteCloneDbsBuilder.done());
return b.obj();
}
void ReplSource::save() {
BSONObjBuilder b;
assert( !hostName.empty() );
b.append("host", hostName);
// todo: finish allowing multiple source configs.
// this line doesn't work right when source is null, if that is allowed as it is now:
//b.append("source", _sourceName);
BSONObj pattern = b.done();
BSONObj o = jsobj();
log( 1 ) << "Saving repl source: " << o << endl;
stringstream ss;
setClient("local.sources");
int u = _updateObjects("local.sources", o, pattern, true/*upsert for pair feature*/, ss);
assert( u == 1 || u == 4 );
cc().clearns();
if ( replacing ) {
/* if we were in "replace" mode, we now have synced up with the replacement,
so turn that off.
*/
replacing = false;
wassert( replacePeer );
replacePeer = false;
Helpers::emptyCollection("local.pair.startup");
}
}
static void addSourceToList(ReplSource::SourceVector &v, ReplSource& s, const BSONObj &spec, ReplSource::SourceVector &old) {
if ( !s.syncedTo.isNull() ) { // Don't reuse old ReplSource if there was a forced resync.
for ( ReplSource::SourceVector::iterator i = old.begin(); i != old.end(); ) {
if ( s == **i ) {
v.push_back(*i);
old.erase(i);
return;
}
i++;
}
}
v.push_back( shared_ptr< ReplSource >( new ReplSource( s ) ) );
}
/* we reuse our existing objects so that we can keep our existing connection
and cursor in effect.
*/
void ReplSource::loadAll(SourceVector &v) {
SourceVector old = v;
v.clear();
bool gotPairWith = false;
if ( !cmdLine.source.empty() ) {
setClient("local.sources");
// --source <host> specified.
// check that no items are in sources other than that
// add if missing
auto_ptr<Cursor> c = findTableScan("local.sources", BSONObj());
int n = 0;
while ( c->ok() ) {
n++;
ReplSource tmp(c->current());
if ( tmp.hostName != cmdLine.source ) {
log() << "E10000 --source " << cmdLine.source << " != " << tmp.hostName << " from local.sources collection" << endl;
log() << "terminating after 30 seconds" << endl;
sleepsecs(30);
dbexit( EXIT_REPLICATION_ERROR );
}
if ( tmp.only != cmdLine.only ) {
log() << "E10001 --only " << cmdLine.only << " != " << tmp.only << " from local.sources collection" << endl;
log() << "terminating after 30 seconds" << endl;
sleepsecs(30);
dbexit( EXIT_REPLICATION_ERROR );
}
c->advance();
}
uassert( "E10002 local.sources collection corrupt?", n<2 );
if ( n == 0 ) {
// source missing. add.
ReplSource s;
s.hostName = cmdLine.source;
s.only = cmdLine.only;
s.save();
}
}
else {
try {
massert("--only requires use of --source", cmdLine.only.empty());
} catch ( ... ) {
dbexit( EXIT_BADOPTIONS );
}
}
if ( replPair ) {
const string &remote = replPair->remote;
setClient( "local.sources" );
// --pairwith host specified.
// check that no items are in sources other than that
// add if missing
auto_ptr<Cursor> c = findTableScan("local.sources", BSONObj());
int n = 0;
while ( c->ok() ) {
n++;
ReplSource tmp(c->current());
if ( tmp.hostName != remote ) {
log() << "E10003 pairwith " << remote << " != " << tmp.hostName << " from local.sources collection" << endl;
log() << "terminating after 30 seconds" << endl;
sleepsecs(30);
dbexit( EXIT_REPLICATION_ERROR );
}
c->advance();
}
uassert( "E10002 local.sources collection corrupt?", n<2 );
if ( n == 0 ) {
// source missing. add.
ReplSource s;
s.hostName = remote;
s.save();
}
}
setClient("local.sources");
auto_ptr<Cursor> c = findTableScan("local.sources", BSONObj());
while ( c->ok() ) {
ReplSource tmp(c->current());
if ( replPair && tmp.hostName == replPair->remote && tmp.sourceName() == "main" ) {
gotPairWith = true;
tmp.paired = true;
if ( replacePeer ) {
// peer was replaced -- start back at the beginning.
tmp.syncedTo = OpTime();
tmp.replacing = true;
}
}
addSourceToList(v, tmp, c->current(), old);
c->advance();
}
cc().clearns();
if ( !gotPairWith && replPair ) {
/* add the --pairwith server */
shared_ptr< ReplSource > s( new ReplSource() );
s->paired = true;
s->hostName = replPair->remote;
s->replacing = replacePeer;
v.push_back(s);
}
}
BSONObj opTimeQuery = fromjson("{\"getoptime\":1}");
bool ReplSource::throttledForceResyncDead( const char *requester ) {
if ( time( 0 ) - lastForcedResync > 600 ) {
forceResyncDead( requester );
lastForcedResync = time( 0 );
return true;
}
return false;
}
void ReplSource::forceResyncDead( const char *requester ) {
if ( !replAllDead )
return;
SourceVector sources;
ReplSource::loadAll(sources);
for( SourceVector::iterator i = sources.begin(); i != sources.end(); ++i ) {
(*i)->forceResync( requester );
}
replAllDead = 0;
}
void ReplSource::forceResync( const char *requester ) {
BSONObj info;
{
dbtemprelease t;
connect();
bool ok = conn->runCommand( "admin", BSON( "listDatabases" << 1 ), info );
massert( "Unable to get database list", ok );
}
BSONObjIterator i( info.getField( "databases" ).embeddedObject() );
while( i.moreWithEOO() ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
string name = e.embeddedObject().getField( "name" ).valuestr();
if ( !e.embeddedObject().getBoolField( "empty" ) ) {
if ( name != "local" ) {
if ( only.empty() || only == name ) {
resyncDrop( name.c_str(), requester );
}
}
}
}
syncedTo = OpTime();
addDbNextPass.clear();
save();
}
string ReplSource::resyncDrop( const char *db, const char *requester ) {
log() << "resync: dropping database " << db << endl;
string dummyns = string( db ) + ".";
setClient(dummyns.c_str());
assert( cc().database()->name == db );
dropDatabase(dummyns.c_str());
return dummyns;
}
/* grab initial copy of a database from the master */
bool ReplSource::resync(string db) {
string dummyNs = resyncDrop( db.c_str(), "internal" );
setClient( dummyNs.c_str() );
{
log() << "resync: cloning database " << db << endl;
ReplInfo r("resync: cloning a database");
string errmsg;
bool ok = cloneFrom(hostName.c_str(), errmsg, cc().database()->name, false, /*slaveok*/ true, /*replauth*/ true, /*snapshot*/false);
if ( !ok ) {
problem() << "resync of " << db << " from " << hostName << " failed " << errmsg << endl;
throw SyncException();
}
}
log() << "resync: done " << db << endl;
return true;
}
void ReplSource::applyOperation(const BSONObj& op) {
log( 6 ) << "applying op: " << op << endl;
stringstream ss;
BSONObj o = op.getObjectField("o");
const char *ns = op.getStringField("ns");
// operation type -- see logOp() comments for types
const char *opType = op.getStringField("op");
try {
if ( *opType == 'i' ) {
const char *p = strchr(ns, '.');
if ( p && strcmp(p, ".system.indexes") == 0 ) {
// updates aren't allowed for indexes -- so we will do a regular insert. if index already
// exists, that is ok.
theDataFileMgr.insert(ns, (void*) o.objdata(), o.objsize());
}
else {
// do upserts for inserts as we might get replayed more than once
BSONElement _id;
if( !o.getObjectID(_id) ) {
/* No _id. This will be very slow. */
Timer t;
_updateObjects(ns, o, o, true, ss);
if( t.millis() >= 2 ) {
RARELY OCCASIONALLY log() << "warning, repl doing slow updates (no _id field) for " << ns << endl;
}
}
else {
BSONObjBuilder b;
b.append(_id);
/* erh 10/16/2009 - this is probably not relevant any more since its auto-created, but not worth removing */
RARELY ensureHaveIdIndex(ns); // otherwise updates will be slow
_updateObjects(ns, o, b.done(), true, ss);
}
}
}
else if ( *opType == 'u' ) {
RARELY ensureHaveIdIndex(ns); // otherwise updates will be super slow
_updateObjects(ns, o, op.getObjectField("o2"), op.getBoolField("b"), ss);
}
else if ( *opType == 'd' ) {
if ( opType[1] == 0 )
deleteObjects(ns, o, op.getBoolField("b"));
else
assert( opType[1] == 'b' ); // "db" advertisement
}
else if ( *opType == 'n' ) {
// no op
}
else {
BufBuilder bb;
BSONObjBuilder ob;
assert( *opType == 'c' );
_runCommands(ns, o, ss, bb, ob, true, 0);
}
}
catch ( UserException& e ) {
log() << "sync: caught user assertion " << e << " while applying op: " << op << endl;;
}
catch ( DBException& e ) {
log() << "sync: caught db exception " << e << " while applying op: " << op << endl;;
}
}
/* local.$oplog.main is of the form:
{ ts: ..., op: <optype>, ns: ..., o: <obj> , o2: <extraobj>, b: <boolflag> }
...
see logOp() comments.
*/
void ReplSource::sync_pullOpLog_applyOperation(BSONObj& op, OpTime *localLogTail) {
log( 6 ) << "processing op: " << op << endl;
// skip no-op
if ( op.getStringField( "op" )[ 0 ] == 'n' )
return;
char clientName[MaxClientLen];
const char *ns = op.getStringField("ns");
nsToClient(ns, clientName);
if ( *ns == '.' ) {
problem() << "skipping bad op in oplog: " << op.toString() << endl;
return;
}
else if ( *ns == 0 ) {
problem() << "halting replication, bad op in oplog:\n " << op.toString() << endl;
replAllDead = "bad object in oplog";
throw SyncException();
}
if ( !only.empty() && only != clientName )
return;
dblock lk;
if ( localLogTail && replPair && replPair->state == ReplPair::State_Master ) {
updateSetsWithLocalOps( *localLogTail, true ); // allow unlocking
updateSetsWithLocalOps( *localLogTail, false ); // don't allow unlocking or conversion to db backed storage
}
if ( replAllDead ) {
// hmmm why is this check here and not at top of this function? does it get set between top and here?
log() << "replAllDead, throwing SyncException\n";
throw SyncException();
}
bool justCreated;
try {
justCreated = setClient(ns);
} catch ( AssertionException& ) {
problem() << "skipping bad(?) op in oplog, setClient() failed, ns: '" << ns << "'\n";
addDbNextPass.erase(clientName);
return;
}
bool empty = clientIsEmpty();
bool incompleteClone = incompleteCloneDbs.count( clientName ) != 0;
log( 6 ) << "ns: " << ns << ", justCreated: " << justCreated << ", empty: " << empty << ", incompleteClone: " << incompleteClone << endl;
// always apply admin command command
// this is a bit hacky -- the semantics of replication/commands aren't well specified
if ( strcmp( clientName, "admin" ) == 0 && *op.getStringField( "op" ) == 'c' ) {
applyOperation( op );
cc().clearns();
return;
}
if ( justCreated || empty || incompleteClone ) {
// we must add to incomplete list now that setClient has been called
incompleteCloneDbs.insert( clientName );
if ( nClonedThisPass ) {
/* we only clone one database per pass, even if a lot need done. This helps us
avoid overflowing the master's transaction log by doing too much work before going
back to read more transactions. (Imagine a scenario of slave startup where we try to
clone 100 databases in one pass.)
*/
addDbNextPass.insert( clientName );
} else {
if ( incompleteClone ) {
log() << "An earlier initial clone of '" << clientName << "' did not complete, now resyncing." << endl;
}
save();
setClient( ns );
nClonedThisPass++;
resync(cc().database()->name);
addDbNextPass.erase(clientName);
incompleteCloneDbs.erase( clientName );
}
save();
} else {
bool mod;
if ( replPair && replPair->state == ReplPair::State_Master ) {
BSONObj id = idForOp( op, mod );
if ( !idTracker.haveId( ns, id ) ) {
applyOperation( op );
} else if ( idTracker.haveModId( ns, id ) ) {
log( 6 ) << "skipping operation matching mod id object " << op << endl;
BSONObj existing;
if ( Helpers::findOne( ns, id, existing ) )
logOp( "i", ns, existing );
} else {
log( 6 ) << "skipping operation matching changed id object " << op << endl;
}
} else {
applyOperation( op );
}
addDbNextPass.erase( clientName );
}
cc().clearns();
}
BSONObj ReplSource::idForOp( const BSONObj &op, bool &mod ) {
mod = false;
const char *opType = op.getStringField( "op" );
BSONObj o = op.getObjectField( "o" );
switch( opType[ 0 ] ) {
case 'i': {
BSONObjBuilder idBuilder;
BSONElement id;
if ( !o.getObjectID( id ) )
return BSONObj();
idBuilder.append( id );
return idBuilder.obj();
}
case 'u': {
BSONObj o2 = op.getObjectField( "o2" );
if ( strcmp( o2.firstElement().fieldName(), "_id" ) != 0 )
return BSONObj();
if ( o.firstElement().fieldName()[ 0 ] == '$' )
mod = true;
return o2;
}
case 'd': {
if ( opType[ 1 ] != '\0' )
return BSONObj(); // skip "db" op type
return o;
}
default:
break;
}
return BSONObj();
}
void ReplSource::updateSetsWithOp( const BSONObj &op, bool mayUnlock ) {
if ( mayUnlock ) {
idTracker.mayUpgradeStorage();
}
bool mod;
BSONObj id = idForOp( op, mod );
if ( !id.isEmpty() ) {
const char *ns = op.getStringField( "ns" );
// Since our range of local ops may not be the same as our peer's
// range of unapplied ops, it is always necessary to rewrite objects
// to the oplog after a mod update.
if ( mod )
idTracker.haveModId( ns, id, true );
idTracker.haveId( ns, id, true );
}
}
void ReplSource::syncToTailOfRemoteLog() {
string _ns = ns();
BSONObj last = conn->findOne( _ns.c_str(), Query().sort( BSON( "$natural" << -1 ) ) );
if ( !last.isEmpty() ) {
BSONElement ts = last.findElement( "ts" );
massert( "non Date ts found", ts.type() == Date || ts.type() == Timestamp );
syncedTo = OpTime( ts.date() );
}
}
OpTime ReplSource::nextLastSavedLocalTs() const {
setClient( "local.oplog.$main" );
auto_ptr< Cursor > c = findTableScan( "local.oplog.$main", BSON( "$natural" << -1 ) );
if ( c->ok() )
return OpTime( c->current().getField( "ts" ).date() );
return OpTime();
}