Status DBClientShardResolver::chooseWriteHost( const string& shardName,
ConnectionString* shardHost ) const {
// Declare up here for parsing later
string errMsg;
// Special-case for config and admin
if ( shardName == "config" || shardName == "admin" ) {
*shardHost = ConnectionString::parse( configServer.modelServer(), errMsg );
dassert( errMsg == "" );
return Status::OK();
}
//
// First get the information about the shard from the shard cache
//
// Internally uses our shard cache, does no reload
Shard shard = Shard::findIfExists( shardName );
if ( shard.getName() == "" ) {
return Status( ErrorCodes::ShardNotFound,
string("unknown shard name ") + shardName );
}
ConnectionString rawShardHost = ConnectionString::parse( shard.getConnString(), errMsg );
dassert( errMsg == "" );
dassert( rawShardHost.type() == ConnectionString::SET
|| rawShardHost.type() == ConnectionString::MASTER );
if ( rawShardHost.type() == ConnectionString::MASTER ) {
*shardHost = rawShardHost;
return Status::OK();
}
//
// If we need to, then get the particular node we're targeting in the replica set
//
// Does not reload the monitor if it doesn't currently exist
ReplicaSetMonitorPtr replMonitor = ReplicaSetMonitor::get( rawShardHost.getSetName(),
false );
if ( !replMonitor ) {
return Status( ErrorCodes::ReplicaSetNotFound,
string("unknown replica set ") + rawShardHost.getSetName() );
}
try {
// This can throw when we don't find a master!
HostAndPort masterHostAndPort = replMonitor->getMaster();
*shardHost = ConnectionString::parse( masterHostAndPort.toString( true ), errMsg );
dassert( errMsg == "" );
return Status::OK();
}
catch ( const DBException& ) {
return Status( ErrorCodes::HostNotFound,
string("could not contact primary for replica set ")
+ replMonitor->getName() );
}
// Unreachable
dassert( false );
return Status( ErrorCodes::UnknownError, "" );
}
