ChunkManager::ChunkManager( DBConfig * config , string ns , ShardKeyPattern pattern , bool unique ) :
_config( config ) , _ns( ns ) , _key( pattern ) , _unique( unique ){
Chunk temp(0);
ScopedDbConnection conn( temp.modelServer() );
auto_ptr<DBClientCursor> cursor = conn->query( temp.getNS() , BSON( "ns" << ns ) );
while ( cursor->more() ){
BSONObj d = cursor->next();
if ( d["isMaxMarker"].trueValue() ){
continue;
}
Chunk * c = new Chunk( this );
c->unserialize( d );
_chunks.push_back( c );
c->_id = d["_id"].wrap().getOwned();
}
conn.done();
if ( _chunks.size() == 0 ){
Chunk * c = new Chunk( this );
c->_ns = ns;
c->setMin(_key.globalMin());
c->setMax(_key.globalMax());
c->_shard = config->getPrimary();
c->_markModified();
_chunks.push_back( c );
log() << "no chunks for:" << ns << " so creating first: " << c->toString() << endl;
}
_sequenceNumber = ++NextSequenceNumber;
}
Chunk * Chunk::split( const BSONObj& m ){
uassert( 10165 , "can't split as shard that doesn't have a manager" , _manager );
log(1) << " before split on: " << m << "\n"
<< "\t self : " << toString() << endl;
uassert( 10166 , "locking namespace on server failed" , lockNamespaceOnServer( getShard() , _ns ) );
Chunk * s = new Chunk( _manager );
s->_ns = _ns;
s->_shard = _shard;
s->setMin(m.getOwned());
s->setMax(_max);
s->_markModified();
_markModified();
_manager->_chunks.push_back( s );
setMax(m.getOwned());
log(1) << " after split:\n"
<< "\t left : " << toString() << "\n"
<< "\t right: "<< s->toString() << endl;
_manager->save();
return s;
}
bool Chunk::moveAndCommit( const string& to , string& errmsg ){
uassert( 10167 , "can't move shard to its current location!" , to != getShard() );
log() << "moving chunk ns: " << _ns << " moving chunk: " << toString() << " " << _shard << " -> " << to << endl;
string from = _shard;
ShardChunkVersion oldVersion = _manager->getVersion( from );
BSONObj filter;
{
BSONObjBuilder b;
getFilter( b );
filter = b.obj();
}
ScopedDbConnection fromconn( from );
BSONObj startRes;
bool worked = fromconn->runCommand( "admin" ,
BSON( "movechunk.start" << _ns <<
"from" << from <<
"to" << to <<
"filter" << filter
) ,
startRes
);
if ( ! worked ){
errmsg = (string)"movechunk.start failed: " + startRes.toString();
fromconn.done();
return false;
}
// update config db
setShard( to );
// need to increment version # for old server
Chunk * randomChunkOnOldServer = _manager->findChunkOnServer( from );
if ( randomChunkOnOldServer )
randomChunkOnOldServer->_markModified();
_manager->save();
BSONObj finishRes;
{
ShardChunkVersion newVersion = _manager->getVersion( from );
if ( newVersion == 0 && oldVersion > 0 ){
newVersion = oldVersion;
newVersion++;
_manager->save();
}
else if ( newVersion <= oldVersion ){
log() << "newVersion: " << newVersion << " oldVersion: " << oldVersion << endl;
uassert( 10168 , "version has to be higher" , newVersion > oldVersion );
}
BSONObjBuilder b;
b << "movechunk.finish" << _ns;
b << "to" << to;
b.appendTimestamp( "newVersion" , newVersion );
b.append( startRes["finishToken"] );
worked = fromconn->runCommand( "admin" ,
b.done() ,
finishRes );
}
if ( ! worked ){
errmsg = (string)"movechunk.finish failed: " + finishRes.toString();
fromconn.done();
return false;
}
fromconn.done();
return true;
}
