/**
* @ return true if not in sharded mode
or if version for this client is ok
*/
bool shardVersionOk( const string& ns , string& errmsg, ConfigVersion& received, ConfigVersion& wanted ) {
if ( ! shardingState.enabled() )
return true;
if ( ! isMasterNs( ns.c_str() ) ) {
// right now connections to secondaries aren't versioned at all
return true;
}
ShardedConnectionInfo* info = ShardedConnectionInfo::get( false );
if ( ! info ) {
// this means the client has nothing sharded
// so this allows direct connections to do whatever they want
// which i think is the correct behavior
return true;
}
if ( info->inForceVersionOkMode() ) {
return true;
}
// TODO : all collections at some point, be sharded or not, will have a version
// (and a ShardChunkManager)
received = info->getVersion( ns );
wanted = shardingState.getVersion( ns );
if( received.isWriteCompatibleWith( wanted ) ) return true;
//
// Figure out exactly why not compatible, send appropriate error message
// The versions themselves are returned in the error, so not needed in messages here
//
// Check epoch first, to send more meaningful message, since other parameters probably
// won't match either
if( ! wanted.hasCompatibleEpoch( received ) ){
errmsg = str::stream() << "version epoch mismatch detected for " << ns << ", "
<< "the collection may have been dropped and recreated";
return false;
}
if( ! wanted.isSet() && received.isSet() ){
errmsg = str::stream() << "this shard no longer contains chunks for " << ns << ", "
<< "the collection may have been dropped";
return false;
}
if( wanted.isSet() && ! received.isSet() ){
errmsg = str::stream() << "this shard contains versioned chunks for " << ns << ", "
<< "but no version set in request";
return false;
}
if( wanted.majorVersion() != received.majorVersion() ){
//
// Could be > or < - wanted is > if this is the source of a migration,
// wanted < if this is the target of a migration
//
errmsg = str::stream() << "version mismatch detected for " << ns << ", "
<< "stored major version " << wanted.majorVersion()
<< " does not match received " << received.majorVersion();
return false;
}
// Those are all the reasons the versions can mismatch
verify( false );
return false;
}
bool run(const string& , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
// Steps
// 1. check basic config
// 2. extract params from command
// 3. fast check
// 4. slow check (LOCKS)
// step 1
lastError.disableForCommand();
ShardedConnectionInfo* info = ShardedConnectionInfo::get( true );
// make sure we have the mongos id for writebacks
if ( ! checkMongosID( info , cmdObj["serverID"] , errmsg ) )
return false;
bool authoritative = cmdObj.getBoolField( "authoritative" );
// check config server is ok or enable sharding
if ( ! checkConfigOrInit( cmdObj["configdb"].valuestrsafe() , authoritative , errmsg , result ) )
return false;
// check shard name/hosts are correct
if ( cmdObj["shard"].type() == String ) {
shardingState.gotShardName( cmdObj["shard"].String() );
shardingState.gotShardHost( cmdObj["shardHost"].String() );
}
// Handle initial shard connection
if( cmdObj["version"].eoo() && cmdObj["init"].trueValue() ){
result.append( "initialized", true );
return true;
}
// we can run on a slave up to here
if ( ! isMaster( "admin" ) ) {
result.append( "errmsg" , "not master" );
result.append( "note" , "from post init in setShardVersion" );
return false;
}
// step 2
string ns = cmdObj["setShardVersion"].valuestrsafe();
if ( ns.size() == 0 ) {
errmsg = "need to specify namespace";
return false;
}
if( ! ConfigVersion::canParseBSON( cmdObj, "version" ) ){
errmsg = "need to specify version";
return false;
}
const ConfigVersion version = ConfigVersion::fromBSON( cmdObj, "version" );
// step 3
const ConfigVersion oldVersion = info->getVersion(ns);
const ConfigVersion globalVersion = shardingState.getVersion(ns);
oldVersion.addToBSON( result, "oldVersion" );
if ( globalVersion.isSet() && version.isSet() ) {
// this means there is no reset going on an either side
// so its safe to make some assumptions
if ( version.isWriteCompatibleWith( globalVersion ) ) {
// mongos and mongod agree!
if ( ! oldVersion.isWriteCompatibleWith( version ) ) {
if ( oldVersion < globalVersion &&
oldVersion.hasCompatibleEpoch(globalVersion) )
{
info->setVersion( ns , version );
}
else if ( authoritative ) {
// this means there was a drop and our version is reset
info->setVersion( ns , version );
}
else {
result.append( "ns" , ns );
result.appendBool( "need_authoritative" , true );
errmsg = "verifying drop on '" + ns + "'";
return false;
}
}
return true;
}
}
// step 4
// this is because of a weird segfault I saw and I can't see why this should ever be set
massert( 13647 , str::stream() << "context should be empty here, is: " << cc().getContext()->ns() , cc().getContext() == 0 );
Lock::GlobalWrite setShardVersionLock; // TODO: can we get rid of this??
if ( oldVersion.isSet() && ! globalVersion.isSet() ) {
// this had been reset
info->setVersion( ns , ChunkVersion( 0, OID() ) );
}
if ( ! version.isSet() && ! globalVersion.isSet() ) {
// this connection is cleaning itself
info->setVersion( ns , ChunkVersion( 0, OID() ) );
return true;
}
if ( ! version.isSet() && globalVersion.isSet() ) {
if ( ! authoritative ) {
result.appendBool( "need_authoritative" , true );
result.append( "ns" , ns );
globalVersion.addToBSON( result, "globalVersion" );
errmsg = "dropping needs to be authoritative";
return false;
}
log() << "wiping data for: " << ns << endl;
globalVersion.addToBSON( result, "beforeDrop" );
// only setting global version on purpose
// need clients to re-find meta-data
shardingState.resetVersion( ns );
info->setVersion( ns , ChunkVersion( 0, OID() ) );
return true;
}
// TODO: Refactor all of this
if ( version < oldVersion && version.hasCompatibleEpoch( oldVersion ) ) {
errmsg = "this connection already had a newer version of collection '" + ns + "'";
result.append( "ns" , ns );
version.addToBSON( result, "newVersion" );
globalVersion.addToBSON( result, "globalVersion" );
return false;
}
// TODO: Refactor all of this
if ( version < globalVersion && version.hasCompatibleEpoch( globalVersion ) ) {
while ( shardingState.inCriticalMigrateSection() ) {
log() << "waiting till out of critical section" << endl;
dbtemprelease r;
shardingState.waitTillNotInCriticalSection( 10 );
}
errmsg = "shard global version for collection is higher than trying to set to '" + ns + "'";
result.append( "ns" , ns );
version.addToBSON( result, "version" );
globalVersion.addToBSON( result, "globalVersion" );
result.appendBool( "reloadConfig" , true );
return false;
}
if ( ! globalVersion.isSet() && ! authoritative ) {
// Needed b/c when the last chunk is moved off a shard, the version gets reset to zero, which
// should require a reload.
while ( shardingState.inCriticalMigrateSection() ) {
log() << "waiting till out of critical section" << endl;
dbtemprelease r;
shardingState.waitTillNotInCriticalSection( 10 );
}
// need authoritative for first look
result.append( "ns" , ns );
result.appendBool( "need_authoritative" , true );
errmsg = "first time for collection '" + ns + "'";
return false;
}
Timer relockTime;
{
dbtemprelease unlock;
ChunkVersion currVersion = version;
if ( ! shardingState.trySetVersion( ns , currVersion ) ) {
errmsg = str::stream() << "client version differs from config's for collection '" << ns << "'";
result.append( "ns" , ns );
// If this was a reset of a collection, inform mongos to do a full reload
if( ! currVersion.isSet() ){
ConfigVersion( 0, OID() ).addToBSON( result, "version" );
result.appendBool( "reloadConfig", true );
}
else{
version.addToBSON( result, "version" );
}
globalVersion.addToBSON( result, "globalVersion" );
return false;
}
}
if ( relockTime.millis() >= ( cmdLine.slowMS - 10 ) ) {
log() << "setShardVersion - relocking slow: " << relockTime.millis() << endl;
}
info->setVersion( ns , version );
return true;
}