// Deprecated, will move to the strategy itself
Shard Request::primaryShard() const {
assert( _didInit );
if ( _chunkManager ) {
if ( _chunkManager->numChunks() > 1 )
throw UserException( 8060 , "can't call primaryShard on a sharded collection" );
return _chunkManager->findChunk( _chunkManager->getShardKey().globalMin() )->getShard();
}
Shard s = _config->getShard( getns() );
uassert( 10194 , "can't call primaryShard on a sharded collection!" , s.ok() );
return s;
}
/**
* Special internal logic to run reduced version handshake for empty namespace operations to
* shards.
*
* Eventually this should go completely away, but for now many commands rely on unversioned but
* mongos-specific behavior on mongod (auditing and replication information in commands)
*/
static bool initShardVersionEmptyNS(DBClientBase * conn_in) {
bool ok;
BSONObj result;
DBClientBase* conn = NULL;
try {
// May throw if replica set primary is down
conn = getVersionable( conn_in );
dassert( conn ); // errors thrown above
// Check to see if we've already initialized this connection
if (connectionShardStatus.hasAnySequenceSet(conn))
return false;
// Check to see if this is actually a shard and not a single config server
// NOTE: Config servers are registered only by the name "config" in the shard cache, not
// by host, so lookup by host will fail unless the host is also a shard.
Shard shard = Shard::findIfExists(conn->getServerAddress());
if (!shard.ok())
return false;
LOG(1) << "initializing shard connection to " << shard.toString() << endl;
ok = setShardVersion(*conn,
"",
configServer.modelServer(),
ChunkVersion(),
NULL,
true,
result);
}
catch( const DBException& ) {
// NOTE: Replica sets may fail to initShardVersion because future calls relying on
// correct versioning must later call checkShardVersion on the primary.
// Secondary queries and commands may not call checkShardVersion, but secondary ops
// aren't versioned at all.
if ( conn_in->type() != ConnectionString::SET ) {
throw;
}
// NOTE: Only old-style cluster operations will talk via DBClientReplicaSets - using
// checkShardVersion is required (which includes initShardVersion information) if these
// connections are used.
OCCASIONALLY {
warning() << "failed to initialize new replica set connection version, "
<< "will initialize on first use" << endl;
}
return false;
}
// Record the connection wire version if sent in the response, initShardVersion is a
// handshake for mongos->mongod connections.
if ( !result["minWireVersion"].eoo() ) {
int minWireVersion = result["minWireVersion"].numberInt();
int maxWireVersion = result["maxWireVersion"].numberInt();
conn->setWireVersions( minWireVersion, maxWireVersion );
}
LOG(3) << "initial sharding result : " << result << endl;
connectionShardStatus.setSequence(conn, "", 0);
return ok;
}