Status _findAllCollections(const ConnectionString& configLoc,
bool optionalEpochs,
OwnedPointerMap<string, CollectionType>* collections)
{
scoped_ptr<ScopedDbConnection> connPtr;
try {
connPtr.reset(ScopedDbConnection::getInternalScopedDbConnection(configLoc, 30));
ScopedDbConnection& conn = *connPtr;
scoped_ptr<DBClientCursor> cursor(_safeCursor(conn->query(CollectionType::ConfigNS,
Query())));
while (cursor->more()) {
BSONObj collDoc = cursor->nextSafe();
CollectionType* coll = new CollectionType();
string errMsg;
coll->parseBSON(collDoc, &errMsg);
// Needed for the v3 to v4 upgrade
bool epochNotSet = !coll->isEpochSet() || !coll->getEpoch().isSet();
if (optionalEpochs && epochNotSet) {
// Set our epoch to something here, just to allow
coll->setEpoch(OID::gen());
}
if (errMsg != "" || !coll->isValid(&errMsg)) {
return Status(ErrorCodes::UnsupportedFormat,
stream() << "invalid collection " << collDoc
<< " read from the config server" << causedBy(errMsg));
}
if (coll->isDroppedSet() && coll->getDropped()) {
continue;
}
if (optionalEpochs && epochNotSet) {
coll->setEpoch(OID());
}
collections->mutableMap().insert(make_pair(coll->getNS(), coll));
}
}
catch (const DBException& e) {
return e.toStatus();
}
connPtr->done();
return Status::OK();
}
Status MetadataLoader::initCollection( const string& ns,
const string& shard,
CollectionMetadata* metadata ) const
{
//
// Bring collection entry from the config server.
//
BSONObj collDoc;
{
try {
ScopedDbConnection conn( _configLoc.toString(), 30 );
collDoc = conn->findOne( CollectionType::ConfigNS, QUERY(CollectionType::ns()<<ns));
conn.done();
}
catch ( const DBException& e ) {
string errMsg = str::stream() << "could not query collection metadata"
<< causedBy( e );
// We deliberately do not return conn to the pool, since it was involved
// with the error here.
return Status( ErrorCodes::HostUnreachable, errMsg );
}
}
string errMsg;
if ( collDoc.isEmpty() ) {
errMsg = str::stream() << "could not load metadata, collection " << ns << " not found";
warning() << errMsg << endl;
return Status( ErrorCodes::NamespaceNotFound, errMsg );
}
CollectionType collInfo;
if ( !collInfo.parseBSON( collDoc, &errMsg ) || !collInfo.isValid( &errMsg ) ) {
errMsg = str::stream() << "could not parse metadata for collection " << ns
<< causedBy( errMsg );
warning() << errMsg << endl;
return Status( ErrorCodes::FailedToParse, errMsg );
}
if ( collInfo.isDroppedSet() && collInfo.getDropped() ) {
errMsg = str::stream() << "could not load metadata, collection " << ns
<< " was dropped";
warning() << errMsg << endl;
return Status( ErrorCodes::NamespaceNotFound, errMsg );
}
if ( collInfo.isKeyPatternSet() && !collInfo.getKeyPattern().isEmpty() ) {
// Sharded collection, need to load chunks
metadata->_keyPattern = collInfo.getKeyPattern();
metadata->_shardVersion = ChunkVersion( 0, 0, collInfo.getEpoch() );
metadata->_collVersion = ChunkVersion( 0, 0, collInfo.getEpoch() );
return Status::OK();
}
else if ( collInfo.isPrimarySet() && collInfo.getPrimary() == shard ) {
// A collection with a non-default primary
// Empty primary field not allowed if set
dassert( collInfo.getPrimary() != "" );
metadata->_keyPattern = BSONObj();
metadata->_shardVersion = ChunkVersion( 1, 0, collInfo.getEpoch() );
metadata->_collVersion = metadata->_shardVersion;
return Status::OK();
}
else {
// A collection with a primary that doesn't match this shard or is empty, the primary
// may have changed before we loaded.
errMsg = // br
str::stream() << "collection " << ns << " does not have a shard key "
<< "and primary "
<< ( collInfo.isPrimarySet() ? collInfo.getPrimary() : "" )
<< " does not match this shard " << shard;
warning() << errMsg << endl;
metadata->_collVersion = ChunkVersion( 0, 0, OID() );
return Status( ErrorCodes::RemoteChangeDetected, errMsg );
}
}