Status AuthzManagerExternalStateMongos::createIndex(
const NamespaceString& collectionName,
const BSONObj& pattern,
bool unique,
const BSONObj& writeConcern) {
return clusterCreateIndex(collectionName, pattern, unique, writeConcern, NULL);
}
void Balancer::_doBalanceRound( DBClientBase& conn, vector<CandidateChunkPtr>* candidateChunks ) {
verify( candidateChunks );
//
// 1. Check whether there is any sharded collection to be balanced by querying
// the ShardsNS::collections collection
//
auto_ptr<DBClientCursor> cursor = conn.query(CollectionType::ConfigNS, BSONObj());
if ( NULL == cursor.get() ) {
warning() << "could not query " << CollectionType::ConfigNS
<< " while trying to balance" << endl;
return;
}
vector< string > collections;
while ( cursor->more() ) {
BSONObj col = cursor->nextSafe();
// sharded collections will have a shard "key".
if ( ! col[CollectionType::keyPattern()].eoo() &&
! col[CollectionType::noBalance()].trueValue() ){
collections.push_back( col[CollectionType::ns()].String() );
}
else if( col[CollectionType::noBalance()].trueValue() ){
LOG(1) << "not balancing collection " << col[CollectionType::ns()].String()
<< ", explicitly disabled" << endl;
}
}
cursor.reset();
if ( collections.empty() ) {
LOG(1) << "no collections to balance" << endl;
return;
}
//
// 2. Get a list of all the shards that are participating in this balance round
// along with any maximum allowed quotas and current utilization. We get the
// latter by issuing db.serverStatus() (mem.mapped) to all shards.
//
// TODO: skip unresponsive shards and mark information as stale.
//
ShardInfoMap shardInfo;
Status loadStatus = DistributionStatus::populateShardInfoMap(&shardInfo);
if (!loadStatus.isOK()) {
warning() << "failed to load shard metadata" << causedBy(loadStatus) << endl;
return;
}
if (shardInfo.size() < 2) {
LOG(1) << "can't balance without more active shards" << endl;
return;
}
OCCASIONALLY warnOnMultiVersion( shardInfo );
//
// 3. For each collection, check if the balancing policy recommends moving anything around.
//
for (vector<string>::const_iterator it = collections.begin(); it != collections.end(); ++it ) {
const string& ns = *it;
OwnedPointerMap<string, OwnedPointerVector<ChunkType> > shardToChunksMap;
cursor = conn.query(ChunkType::ConfigNS,
QUERY(ChunkType::ns(ns)).sort(ChunkType::min()));
set<BSONObj> allChunkMinimums;
while ( cursor->more() ) {
BSONObj chunkDoc = cursor->nextSafe().getOwned();
auto_ptr<ChunkType> chunk(new ChunkType());
string errmsg;
if (!chunk->parseBSON(chunkDoc, &errmsg)) {
error() << "bad chunk format for " << chunkDoc
<< ": " << errmsg << endl;
return;
}
allChunkMinimums.insert(chunk->getMin().getOwned());
OwnedPointerVector<ChunkType>*& chunkList =
shardToChunksMap.mutableMap()[chunk->getShard()];
if (chunkList == NULL) {
chunkList = new OwnedPointerVector<ChunkType>();
}
chunkList->mutableVector().push_back(chunk.release());
}
cursor.reset();
if (shardToChunksMap.map().empty()) {
LOG(1) << "skipping empty collection (" << ns << ")";
continue;
}
for (ShardInfoMap::const_iterator i = shardInfo.begin(); i != shardInfo.end(); ++i) {
// this just makes sure there is an entry in shardToChunksMap for every shard
OwnedPointerVector<ChunkType>*& chunkList =
shardToChunksMap.mutableMap()[i->first];
if (chunkList == NULL) {
chunkList = new OwnedPointerVector<ChunkType>();
}
}
DistributionStatus status(shardInfo, shardToChunksMap.map());
// load tags
Status result = clusterCreateIndex(TagsType::ConfigNS,
BSON(TagsType::ns() << 1 << TagsType::min() << 1),
true, // unique
WriteConcernOptions::AllConfigs,
NULL);
if ( !result.isOK() ) {
warning() << "could not create index tags_1_min_1: " << result.reason() << endl;
continue;
}
cursor = conn.query(TagsType::ConfigNS,
QUERY(TagsType::ns(ns)).sort(TagsType::min()));
vector<TagRange> ranges;
while ( cursor->more() ) {
BSONObj tag = cursor->nextSafe();
TagRange tr(tag[TagsType::min()].Obj().getOwned(),
tag[TagsType::max()].Obj().getOwned(),
tag[TagsType::tag()].String());
ranges.push_back(tr);
uassert(16356,
str::stream() << "tag ranges not valid for: " << ns,
status.addTagRange(tr) );
}
cursor.reset();
DBConfigPtr cfg = grid.getDBConfig( ns );
if ( !cfg ) {
warning() << "could not load db config to balance " << ns << " collection" << endl;
continue;
}
// This line reloads the chunk manager once if this process doesn't know the collection
// is sharded yet.
ChunkManagerPtr cm = cfg->getChunkManagerIfExists( ns, true );
if ( !cm ) {
warning() << "could not load chunks to balance " << ns << " collection" << endl;
continue;
}
// loop through tags to make sure no chunk spans tags; splits on tag min. for all chunks
bool didAnySplits = false;
for ( unsigned i = 0; i < ranges.size(); i++ ) {
BSONObj min = ranges[i].min;
min = cm->getShardKey().extendRangeBound( min, false );
if ( allChunkMinimums.count( min ) > 0 )
continue;
didAnySplits = true;
log() << "ns: " << ns << " need to split on "
<< min << " because there is a range there" << endl;
ChunkPtr c = cm->findIntersectingChunk( min );
vector<BSONObj> splitPoints;
splitPoints.push_back( min );
BSONObj res;
if ( !c->multiSplit( splitPoints, res ) ) {
error() << "split failed: " << res << endl;
}
else {
LOG(1) << "split worked: " << res << endl;
}
break;
}
if ( didAnySplits ) {
// state change, just wait till next round
continue;
}
CandidateChunk* p = _policy->balance( ns, status, _balancedLastTime );
if ( p ) candidateChunks->push_back( CandidateChunkPtr( p ) );
}
}
