/**
* Cleans up one range of orphaned data starting from a range that overlaps or starts at
* 'startingFromKey'. If empty, startingFromKey is the minimum key of the sharded range.
*
* @return CleanupResult_Continue and 'stoppedAtKey' if orphaned range was found and cleaned
* @return CleanupResult_Done if no orphaned ranges remain
* @return CleanupResult_Error and 'errMsg' if an error occurred
*
* If the collection is not sharded, returns CleanupResult_Done.
*/
CleanupResult cleanupOrphanedData(OperationContext* txn,
const NamespaceString& ns,
const BSONObj& startingFromKeyConst,
const WriteConcernOptions& secondaryThrottle,
BSONObj* stoppedAtKey,
string* errMsg) {
BSONObj startingFromKey = startingFromKeyConst;
CollectionMetadataPtr metadata = shardingState.getCollectionMetadata(ns.toString());
if (!metadata || metadata->getKeyPattern().isEmpty()) {
warning() << "skipping orphaned data cleanup for " << ns.toString()
<< ", collection is not sharded" << endl;
return CleanupResult_Done;
}
BSONObj keyPattern = metadata->getKeyPattern();
if (!startingFromKey.isEmpty()) {
if (!metadata->isValidKey(startingFromKey)) {
*errMsg = stream() << "could not cleanup orphaned data, start key " << startingFromKey
<< " does not match shard key pattern " << keyPattern;
warning() << *errMsg << endl;
return CleanupResult_Error;
}
} else {
startingFromKey = metadata->getMinKey();
}
KeyRange orphanRange;
if (!metadata->getNextOrphanRange(startingFromKey, &orphanRange)) {
LOG(1) << "orphaned data cleanup requested for " << ns.toString() << " starting from "
<< startingFromKey << ", no orphan ranges remain" << endl;
return CleanupResult_Done;
}
orphanRange.ns = ns;
*stoppedAtKey = orphanRange.maxKey;
// We're done with this metadata now, no matter what happens
metadata.reset();
LOG(1) << "orphaned data cleanup requested for " << ns.toString() << " starting from "
<< startingFromKey << ", removing next orphan range"
<< " [" << orphanRange.minKey << "," << orphanRange.maxKey << ")" << endl;
// Metadata snapshot may be stale now, but deleter checks metadata again in write lock
// before delete.
RangeDeleterOptions deleterOptions(orphanRange);
deleterOptions.writeConcern = secondaryThrottle;
deleterOptions.onlyRemoveOrphanedDocs = true;
deleterOptions.fromMigrate = true;
// Must wait for cursors since there can be existing cursors with an older
// CollectionMetadata.
deleterOptions.waitForOpenCursors = true;
deleterOptions.removeSaverReason = "cleanup-cmd";
if (!getDeleter()->deleteNow(txn, deleterOptions, errMsg)) {
warning() << *errMsg << endl;
return CleanupResult_Error;
}
return CleanupResult_Continue;
}
/**
* Cleans up one range of orphaned data starting from a range that overlaps or starts at
* 'startingFromKey'. If empty, startingFromKey is the minimum key of the sharded range.
*
* @return CleanupResult_Continue and 'stoppedAtKey' if orphaned range was found and cleaned
* @return CleanupResult_Done if no orphaned ranges remain
* @return CleanupResult_Error and 'errMsg' if an error occurred
*
* If the collection is not sharded, returns CleanupResult_Done.
*/
CleanupResult cleanupOrphanedData( const NamespaceString& ns,
const BSONObj& startingFromKeyConst,
bool secondaryThrottle,
BSONObj* stoppedAtKey,
string* errMsg ) {
BSONObj startingFromKey = startingFromKeyConst;
CollectionMetadataPtr metadata = shardingState.getCollectionMetadata( ns.toString() );
if ( !metadata || metadata->getKeyPattern().isEmpty() ) {
warning() << "skipping orphaned data cleanup for " << ns.toString()
<< ", collection is not sharded" << endl;
return CleanupResult_Done;
}
BSONObj keyPattern = metadata->getKeyPattern();
if ( !startingFromKey.isEmpty() ) {
if ( !metadata->isValidKey( startingFromKey ) ) {
*errMsg = stream() << "could not cleanup orphaned data, start key "
<< startingFromKey
<< " does not match shard key pattern " << keyPattern;
warning() << *errMsg << endl;
return CleanupResult_Error;
}
}
else {
startingFromKey = metadata->getMinKey();
}
KeyRange orphanRange;
if ( !metadata->getNextOrphanRange( startingFromKey, &orphanRange ) ) {
LOG( 1 ) << "orphaned data cleanup requested for " << ns.toString()
<< " starting from " << startingFromKey
<< ", no orphan ranges remain" << endl;
return CleanupResult_Done;
}
*stoppedAtKey = orphanRange.maxKey;
// We're done with this metadata now, no matter what happens
metadata.reset();
LOG( 1 ) << "orphaned data cleanup requested for " << ns.toString()
<< " starting from " << startingFromKey
<< ", removing next orphan range"
<< " [" << orphanRange.minKey << "," << orphanRange.maxKey << ")"
<< endl;
// Metadata snapshot may be stale now, but deleter checks metadata again in write lock
// before delete.
if ( !getDeleter()->deleteNow( ns.toString(),
orphanRange.minKey,
orphanRange.maxKey,
keyPattern,
secondaryThrottle,
errMsg ) ) {
warning() << *errMsg << endl;
return CleanupResult_Error;
}
return CleanupResult_Continue;
}
bool mergeChunks( OperationContext* txn,
const NamespaceString& nss,
const BSONObj& minKey,
const BSONObj& maxKey,
const OID& epoch,
string* errMsg ) {
//
// Get sharding state up-to-date
//
ConnectionString configLoc = ConnectionString::parse( shardingState.getConfigServer(),
*errMsg );
if ( !configLoc.isValid() ){
warning() << *errMsg << endl;
return false;
}
//
// Get the distributed lock
//
ScopedDistributedLock collLock( configLoc, nss.ns() );
collLock.setLockMessage( stream() << "merging chunks in " << nss.ns() << " from "
<< minKey << " to " << maxKey );
Status acquisitionStatus = collLock.tryAcquire();
if (!acquisitionStatus.isOK()) {
*errMsg = stream() << "could not acquire collection lock for " << nss.ns()
<< " to merge chunks in [" << minKey << "," << maxKey << ")"
<< causedBy(acquisitionStatus);
warning() << *errMsg << endl;
return false;
}
//
// We now have the collection lock, refresh metadata to latest version and sanity check
//
ChunkVersion shardVersion;
Status status = shardingState.refreshMetadataNow(txn, nss.ns(), &shardVersion);
if ( !status.isOK() ) {
*errMsg = str::stream() << "could not merge chunks, failed to refresh metadata for "
<< nss.ns() << causedBy( status.reason() );
warning() << *errMsg << endl;
return false;
}
if ( epoch.isSet() && shardVersion.epoch() != epoch ) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " has changed" << " since merge was sent" << "(sent epoch : "
<< epoch.toString()
<< ", current epoch : " << shardVersion.epoch().toString() << ")";
warning() << *errMsg << endl;
return false;
}
CollectionMetadataPtr metadata = shardingState.getCollectionMetadata( nss.ns() );
if ( !metadata || metadata->getKeyPattern().isEmpty() ) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " is not sharded";
warning() << *errMsg << endl;
return false;
}
dassert( metadata->getShardVersion().equals( shardVersion ) );
if ( !metadata->isValidKey( minKey ) || !metadata->isValidKey( maxKey ) ) {
*errMsg = stream() << "could not merge chunks, the range "
<< rangeToString( minKey, maxKey ) << " is not valid"
<< " for collection " << nss.ns() << " with key pattern "
<< metadata->getKeyPattern();
warning() << *errMsg << endl;
return false;
}
//
// Get merged chunk information
//
ChunkVersion mergeVersion = metadata->getCollVersion();
mergeVersion.incMinor();
OwnedPointerVector<ChunkType> chunksToMerge;
ChunkType itChunk;
itChunk.setMin( minKey );
itChunk.setMax( minKey );
itChunk.setNS( nss.ns() );
itChunk.setShard( shardingState.getShardName() );
while ( itChunk.getMax().woCompare( maxKey ) < 0 &&
metadata->getNextChunk( itChunk.getMax(), &itChunk ) ) {
auto_ptr<ChunkType> saved( new ChunkType );
itChunk.cloneTo( saved.get() );
chunksToMerge.mutableVector().push_back( saved.release() );
}
if ( chunksToMerge.empty() ) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " range starting at " << minKey
<< " and ending at " << maxKey
<< " does not belong to shard " << shardingState.getShardName();
warning() << *errMsg << endl;
return false;
}
//
// Validate the range starts and ends at chunks and has no holes, error if not valid
//
BSONObj firstDocMin = ( *chunksToMerge.begin() )->getMin();
BSONObj firstDocMax = ( *chunksToMerge.begin() )->getMax();
// minKey is inclusive
bool minKeyInRange = rangeContains( firstDocMin, firstDocMax, minKey );
if ( !minKeyInRange ) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " range starting at " << minKey
<< " does not belong to shard " << shardingState.getShardName();
warning() << *errMsg << endl;
return false;
}
BSONObj lastDocMin = ( *chunksToMerge.rbegin() )->getMin();
BSONObj lastDocMax = ( *chunksToMerge.rbegin() )->getMax();
// maxKey is exclusive
bool maxKeyInRange = lastDocMin.woCompare( maxKey ) < 0 &&
lastDocMax.woCompare( maxKey ) >= 0;
if ( !maxKeyInRange ) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " range ending at " << maxKey
<< " does not belong to shard " << shardingState.getShardName();
warning() << *errMsg << endl;
return false;
}
bool validRangeStartKey = firstDocMin.woCompare( minKey ) == 0;
bool validRangeEndKey = lastDocMax.woCompare( maxKey ) == 0;
if ( !validRangeStartKey || !validRangeEndKey ) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " does not contain a chunk "
<< ( !validRangeStartKey ? "starting at " + minKey.toString() : "" )
<< ( !validRangeStartKey && !validRangeEndKey ? " or " : "" )
<< ( !validRangeEndKey ? "ending at " + maxKey.toString() : "" );
warning() << *errMsg << endl;
return false;
}
if ( chunksToMerge.size() == 1 ) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " already contains chunk for " << rangeToString( minKey, maxKey );
warning() << *errMsg << endl;
return false;
}
bool holeInRange = false;
// Look for hole in range
ChunkType* prevChunk = *chunksToMerge.begin();
ChunkType* nextChunk = NULL;
for ( OwnedPointerVector<ChunkType>::const_iterator it = chunksToMerge.begin();
it != chunksToMerge.end(); ++it ) {
if ( it == chunksToMerge.begin() ) continue;
nextChunk = *it;
if ( prevChunk->getMax().woCompare( nextChunk->getMin() ) != 0 ) {
holeInRange = true;
break;
}
prevChunk = nextChunk;
}
if ( holeInRange ) {
dassert( NULL != nextChunk );
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " has a hole in the range " << rangeToString( minKey, maxKey )
<< " at " << rangeToString( prevChunk->getMax(),
nextChunk->getMin() );
warning() << *errMsg << endl;
return false;
}
//
// Run apply ops command
//
BSONObj applyOpsCmd = buildApplyOpsCmd( chunksToMerge,
shardVersion,
mergeVersion );
bool ok;
BSONObj result;
try {
ScopedDbConnection conn( configLoc, 30.0 );
ok = conn->runCommand( "config", applyOpsCmd, result );
if ( !ok ) *errMsg = result.toString();
conn.done();
}
catch( const DBException& ex ) {
ok = false;
*errMsg = ex.toString();
}
if ( !ok ) {
*errMsg = stream() << "could not merge chunks for " << nss.ns()
<< ", writing to config failed" << causedBy( errMsg );
warning() << *errMsg << endl;
return false;
}
//
// Install merged chunk metadata
//
{
Lock::DBLock writeLk(txn->lockState(), nss.db(), newlm::MODE_X);
shardingState.mergeChunks(txn, nss.ns(), minKey, maxKey, mergeVersion);
}
//
// Log change
//
BSONObj mergeLogEntry = buildMergeLogEntry( chunksToMerge,
shardVersion,
mergeVersion );
configServer.logChange( "merge", nss.ns(), mergeLogEntry );
return true;
}
bool mergeChunks(OperationContext* txn,
const NamespaceString& nss,
const BSONObj& minKey,
const BSONObj& maxKey,
const OID& epoch,
string* errMsg) {
//
// Get sharding state up-to-date
//
ConnectionString configLoc = ConnectionString::parse(shardingState.getConfigServer(), *errMsg);
if (!configLoc.isValid()) {
warning() << *errMsg << endl;
return false;
}
//
// Get the distributed lock
//
string whyMessage = stream() << "merging chunks in " << nss.ns() << " from " << minKey << " to "
<< maxKey;
auto scopedDistLock = grid.catalogManager()->getDistLockManager()->lock(nss.ns(), whyMessage);
if (!scopedDistLock.isOK()) {
*errMsg = stream() << "could not acquire collection lock for " << nss.ns()
<< " to merge chunks in [" << minKey << "," << maxKey << ")"
<< causedBy(scopedDistLock.getStatus());
warning() << *errMsg << endl;
return false;
}
//
// We now have the collection lock, refresh metadata to latest version and sanity check
//
ChunkVersion shardVersion;
Status status = shardingState.refreshMetadataNow(txn, nss.ns(), &shardVersion);
if (!status.isOK()) {
*errMsg = str::stream() << "could not merge chunks, failed to refresh metadata for "
<< nss.ns() << causedBy(status.reason());
warning() << *errMsg << endl;
return false;
}
if (epoch.isSet() && shardVersion.epoch() != epoch) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns() << " has changed"
<< " since merge was sent"
<< "(sent epoch : " << epoch.toString()
<< ", current epoch : " << shardVersion.epoch().toString() << ")";
warning() << *errMsg << endl;
return false;
}
CollectionMetadataPtr metadata = shardingState.getCollectionMetadata(nss.ns());
if (!metadata || metadata->getKeyPattern().isEmpty()) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " is not sharded";
warning() << *errMsg << endl;
return false;
}
dassert(metadata->getShardVersion().equals(shardVersion));
if (!metadata->isValidKey(minKey) || !metadata->isValidKey(maxKey)) {
*errMsg = stream() << "could not merge chunks, the range " << rangeToString(minKey, maxKey)
<< " is not valid"
<< " for collection " << nss.ns() << " with key pattern "
<< metadata->getKeyPattern();
warning() << *errMsg << endl;
return false;
}
//
// Get merged chunk information
//
ChunkVersion mergeVersion = metadata->getCollVersion();
mergeVersion.incMinor();
std::vector<ChunkType> chunksToMerge;
ChunkType itChunk;
itChunk.setMin(minKey);
itChunk.setMax(minKey);
itChunk.setNS(nss.ns());
itChunk.setShard(shardingState.getShardName());
while (itChunk.getMax().woCompare(maxKey) < 0 &&
metadata->getNextChunk(itChunk.getMax(), &itChunk)) {
chunksToMerge.push_back(itChunk);
}
if (chunksToMerge.empty()) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " range starting at " << minKey << " and ending at " << maxKey
<< " does not belong to shard " << shardingState.getShardName();
warning() << *errMsg << endl;
return false;
}
//
// Validate the range starts and ends at chunks and has no holes, error if not valid
//
BSONObj firstDocMin = chunksToMerge.front().getMin();
BSONObj firstDocMax = chunksToMerge.front().getMax();
// minKey is inclusive
bool minKeyInRange = rangeContains(firstDocMin, firstDocMax, minKey);
if (!minKeyInRange) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " range starting at " << minKey << " does not belong to shard "
<< shardingState.getShardName();
warning() << *errMsg << endl;
return false;
}
BSONObj lastDocMin = chunksToMerge.back().getMin();
BSONObj lastDocMax = chunksToMerge.back().getMax();
// maxKey is exclusive
bool maxKeyInRange = lastDocMin.woCompare(maxKey) < 0 && lastDocMax.woCompare(maxKey) >= 0;
if (!maxKeyInRange) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " range ending at " << maxKey << " does not belong to shard "
<< shardingState.getShardName();
warning() << *errMsg << endl;
return false;
}
bool validRangeStartKey = firstDocMin.woCompare(minKey) == 0;
bool validRangeEndKey = lastDocMax.woCompare(maxKey) == 0;
if (!validRangeStartKey || !validRangeEndKey) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " does not contain a chunk "
<< (!validRangeStartKey ? "starting at " + minKey.toString() : "")
<< (!validRangeStartKey && !validRangeEndKey ? " or " : "")
<< (!validRangeEndKey ? "ending at " + maxKey.toString() : "");
warning() << *errMsg << endl;
return false;
}
if (chunksToMerge.size() == 1) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " already contains chunk for " << rangeToString(minKey, maxKey);
warning() << *errMsg << endl;
return false;
}
// Look for hole in range
for (size_t i = 1; i < chunksToMerge.size(); ++i) {
if (chunksToMerge[i - 1].getMax().woCompare(chunksToMerge[i].getMin()) != 0) {
*errMsg =
stream() << "could not merge chunks, collection " << nss.ns()
<< " has a hole in the range " << rangeToString(minKey, maxKey) << " at "
<< rangeToString(chunksToMerge[i - 1].getMax(), chunksToMerge[i].getMin());
warning() << *errMsg << endl;
return false;
}
}
//
// Run apply ops command
//
Status applyOpsStatus = runApplyOpsCmd(chunksToMerge, shardVersion, mergeVersion);
if (!applyOpsStatus.isOK()) {
warning() << applyOpsStatus;
return false;
}
//
// Install merged chunk metadata
//
{
ScopedTransaction transaction(txn, MODE_IX);
Lock::DBLock writeLk(txn->lockState(), nss.db(), MODE_IX);
Lock::CollectionLock collLock(txn->lockState(), nss.ns(), MODE_X);
shardingState.mergeChunks(txn, nss.ns(), minKey, maxKey, mergeVersion);
}
//
// Log change
//
BSONObj mergeLogEntry = buildMergeLogEntry(chunksToMerge, shardVersion, mergeVersion);
grid.catalogManager()->logChange(
txn->getClient()->clientAddress(true), "merge", nss.ns(), mergeLogEntry);
return true;
}
