/**
* Updates the remote cached version on the remote shard host (primary, in the case of replica
* sets) if needed with a fully-qualified shard version for the given namespace:
* config server(s) + shard name + shard version
*
* If no remote cached version has ever been set, an initial shard version is sent.
*
* If the namespace is empty and no version has ever been sent, the config server + shard name
* is sent to the remote shard host to initialize the connection as coming from mongos.
* NOTE: This initialization is *best-effort only*. Operations which wish to correctly version
* must send the namespace.
*
* Config servers are special and are not (unless otherwise a shard) kept up to date with this
* protocol. This is safe so long as config servers only contain unversioned collections.
*
* It is an error to call checkShardVersion with an unversionable connection (isVersionableCB).
*
* @return true if we contacted the remote host
*/
bool checkShardVersion( DBClientBase * conn_in , const string& ns , ChunkManagerPtr refManager, bool authoritative , int tryNumber ) {
// TODO: cache, optimize, etc...
// Empty namespaces are special - we require initialization but not versioning
if (ns.size() == 0) {
return initShardVersionEmptyNS(conn_in);
}
DBConfigPtr conf = grid.getDBConfig( ns );
if ( ! conf )
return false;
DBClientBase* conn = getVersionable( conn_in );
verify(conn); // errors thrown above
unsigned long long officialSequenceNumber = 0;
ShardPtr primary;
ChunkManagerPtr manager;
if (authoritative)
conf->getChunkManagerIfExists(ns, true);
conf->getChunkManagerOrPrimary(ns, manager, primary);
if (manager)
officialSequenceNumber = manager->getSequenceNumber();
// Check this manager against the reference manager
if( manager ){
Shard shard = Shard::make( conn->getServerAddress() );
if (refManager && !refManager->compatibleWith(*manager, shard.getName())) {
const ChunkVersion refVersion(refManager->getVersion(shard.getName()));
const ChunkVersion currentVersion(manager->getVersion(shard.getName()));
string msg(str::stream() << "manager ("
<< currentVersion.toString()
<< " : " << manager->getSequenceNumber() << ") "
<< "not compatible with reference manager ("
<< refVersion.toString()
<< " : " << refManager->getSequenceNumber() << ") "
<< "on shard " << shard.getName()
<< " (" << shard.getAddress().toString() << ")");
throw SendStaleConfigException(ns,
msg,
refVersion,
currentVersion);
}
}
else if( refManager ){
Shard shard = Shard::make(conn->getServerAddress());
string msg( str::stream() << "not sharded ("
<< ( (manager.get() == 0) ? string( "<none>" ) :
str::stream() << manager->getSequenceNumber() )
<< ") but has reference manager ("
<< refManager->getSequenceNumber() << ") "
<< "on conn " << conn->getServerAddress() << " ("
<< conn_in->getServerAddress() << ")" );
throw SendStaleConfigException(ns,
msg,
refManager->getVersion(shard.getName()),
ChunkVersion::UNSHARDED());
}
// Do not send setShardVersion to collections on the config servers - this causes problems
// when config servers are also shards and get SSV with conflicting names.
// TODO: Make config servers regular shards
if (primary && primary->getName() == "config") {
return false;
}
// Has the ChunkManager been reloaded since the last time we updated the shard version over
// this connection? If we've never updated the shard version, do so now.
unsigned long long sequenceNumber = 0;
if (connectionShardStatus.getSequence(conn, ns, &sequenceNumber)) {
if (sequenceNumber == officialSequenceNumber) {
return false;
}
}
// Now that we're sure we're sending SSV and not to a single config server, get the shard
Shard shard = Shard::make(conn->getServerAddress());
ChunkVersion version = ChunkVersion(0, 0, OID());
if (manager)
version = manager->getVersion(shard.getName());
LOG(1) << "setting shard version of " << version << " for " << ns << " on shard "
<< shard.toString();
LOG(3) << "last version sent with chunk manager iteration " << sequenceNumber
<< ", current chunk manager iteration is " << officialSequenceNumber;
BSONObj result;
if (setShardVersion(*conn,
ns,
configServer.modelServer(),
version,
manager.get(),
authoritative,
result)) {
LOG(1) << " setShardVersion success: " << result;
connectionShardStatus.setSequence( conn , ns , officialSequenceNumber );
return true;
}
LOG(1) << " setShardVersion failed!\n" << result << endl;
if ( result["need_authoritative"].trueValue() )
massert( 10428 , "need_authoritative set but in authoritative mode already" , ! authoritative );
if ( ! authoritative ) {
// use the original connection and get a fresh versionable connection
// since conn can be invalidated (or worse, freed) after the failure
checkShardVersion(conn_in, ns, refManager, 1, tryNumber + 1);
return true;
}
if ( result["reloadConfig"].trueValue() ) {
if( result["version"].timestampTime() == 0 ){
warning() << "reloading full configuration for " << conf->name()
<< ", connection state indicates significant version changes";
// reload db
conf->reload();
}
else {
// reload config
conf->getChunkManager( ns , true );
}
}
const int maxNumTries = 7;
if ( tryNumber < maxNumTries ) {
LOG( tryNumber < ( maxNumTries / 2 ) ? 1 : 0 )
<< "going to retry checkShardVersion shard: " << shard.toString() << " " << result;
sleepmillis( 10 * tryNumber );
// use the original connection and get a fresh versionable connection
// since conn can be invalidated (or worse, freed) after the failure
checkShardVersion(conn_in, ns, refManager, true, tryNumber + 1);
return true;
}
string errmsg = str::stream() << "setShardVersion failed shard: " << shard.toString()
<< " " << result;
log() << " " << errmsg << endl;
massert( 10429 , errmsg , 0 );
return true;
}
