BSONObj buildApplyOpsCmd( const OwnedPointerVector<ChunkType>& chunksToMerge,
const ChunkVersion& currShardVersion,
const ChunkVersion& newMergedVersion ) {
BSONObjBuilder applyOpsCmdB;
BSONArrayBuilder updatesB( applyOpsCmdB.subarrayStart( "applyOps" ) );
// The chunk we'll be "expanding" is the first chunk
const ChunkType* chunkToMerge = *chunksToMerge.begin();
// Fill in details not tracked by metadata
ChunkType mergedChunk;
chunkToMerge->cloneTo( &mergedChunk );
mergedChunk.setName( Chunk::genID( chunkToMerge->getNS(), chunkToMerge->getMin() ) );
mergedChunk.setMax( ( *chunksToMerge.vector().rbegin() )->getMax() );
mergedChunk.setVersion( newMergedVersion );
updatesB.append( buildOpMergeChunk( mergedChunk ) );
// Don't remove chunk we're expanding
OwnedPointerVector<ChunkType>::const_iterator it = chunksToMerge.begin();
for ( ++it; it != chunksToMerge.end(); ++it ) {
ChunkType* chunkToMerge = *it;
chunkToMerge->setName( Chunk::genID( chunkToMerge->getNS(), chunkToMerge->getMin() ) );
updatesB.append( buildOpRemoveChunk( *chunkToMerge ) );
}
updatesB.done();
applyOpsCmdB.append( "preCondition",
buildOpPrecond( chunkToMerge->getNS(),
chunkToMerge->getShard(),
currShardVersion ) );
return applyOpsCmdB.obj();
}
Status ChunkManager::createFirstChunks(OperationContext* txn,
const ShardId& primaryShardId,
const vector<BSONObj>* initPoints,
const set<ShardId>* initShardIds) {
// TODO distlock?
// TODO: Race condition if we shard the collection and insert data while we split across
// the non-primary shard.
vector<BSONObj> splitPoints;
vector<ShardId> shardIds;
calcInitSplitsAndShards(txn, primaryShardId, initPoints, initShardIds, &splitPoints, &shardIds);
// this is the first chunk; start the versioning from scratch
ChunkVersion version(1, 0, OID::gen());
log() << "going to create " << splitPoints.size() + 1 << " chunk(s) for: " << _ns
<< " using new epoch " << version.epoch();
for (unsigned i = 0; i <= splitPoints.size(); i++) {
BSONObj min = i == 0 ? _keyPattern.getKeyPattern().globalMin() : splitPoints[i - 1];
BSONObj max =
i < splitPoints.size() ? splitPoints[i] : _keyPattern.getKeyPattern().globalMax();
ChunkType chunk;
chunk.setName(Chunk::genID(_ns, min));
chunk.setNS(_ns);
chunk.setMin(min);
chunk.setMax(max);
chunk.setShard(shardIds[i % shardIds.size()]);
chunk.setVersion(version);
Status status = grid.catalogManager(txn)
->insertConfigDocument(txn, ChunkType::ConfigNS, chunk.toBSON());
if (!status.isOK()) {
const string errMsg = str::stream()
<< "Creating first chunks failed: " << status.reason();
error() << errMsg;
return Status(status.code(), errMsg);
}
version.incMinor();
}
_version = ChunkVersion(0, 0, version.epoch());
return Status::OK();
}
/**
* Stores ranges for a particular collection and shard starting from some version
*/
void storeCollectionRanges( const NamespaceString& nss,
const string& shardName,
const vector<KeyRange>& ranges,
const ChunkVersion& startVersion ) {
// Get key pattern from first range
ASSERT_GREATER_THAN( ranges.size(), 0u );
CollectionType coll;
coll.setNS( nss.ns() );
coll.setKeyPattern( ranges.begin()->keyPattern );
coll.setEpoch( startVersion.epoch() );
coll.setUpdatedAt( 1ULL );
string errMsg;
ASSERT( coll.isValid( &errMsg ) );
DBDirectClient client(&_txn);
client.update( CollectionType::ConfigNS,
BSON( CollectionType::ns( coll.getNS() ) ),
coll.toBSON(), true, false );
ChunkVersion nextVersion = startVersion;
for ( vector<KeyRange>::const_iterator it = ranges.begin(); it != ranges.end(); ++it ) {
ChunkType chunk;
// TODO: We should not rely on the serialized ns, minkey being unique in the future,
// causes problems since it links string serialization to correctness.
chunk.setName( Chunk::genID( nss, it->minKey ) );
chunk.setShard( shardName );
chunk.setNS( nss.ns() );
chunk.setVersion( nextVersion );
chunk.setMin( it->minKey );
chunk.setMax( it->maxKey );
nextVersion.incMajor();
client.insert( ChunkType::ConfigNS, chunk.toBSON() );
}
}
