bool run(const string& , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
string ns = cmdObj["getShardVersion"].valuestrsafe();
if ( ns.size() == 0 ) {
errmsg = "need to specify full namespace";
return false;
}
result.append( "configServer" , shardingState.getConfigServer() );
result.appendTimestamp( "global" , shardingState.getVersion(ns).toLong() );
ShardedConnectionInfo* info = ShardedConnectionInfo::get( false );
result.appendBool( "inShardedMode" , info != 0 );
if ( info )
result.appendTimestamp( "mine" , info->getVersion(ns).toLong() );
else
result.appendTimestamp( "mine" , 0 );
if ( cmdObj["fullMetadata"].trueValue() ) {
CollectionMetadataPtr metadata = shardingState.getCollectionMetadata( ns );
if ( metadata ) result.append( "metadata", metadata->toBSON() );
else result.append( "metadata", BSONObj() );
}
return true;
}
bool mergeChunks(OperationContext* txn,
const NamespaceString& nss,
const BSONObj& minKey,
const BSONObj& maxKey,
const OID& epoch,
string* errMsg) {
// Get the distributed lock
string whyMessage = stream() << "merging chunks in " << nss.ns() << " from " << minKey << " to "
<< maxKey;
auto scopedDistLock = grid.catalogManager(txn)->distLock(
txn, nss.ns(), whyMessage, DistLockManager::kSingleLockAttemptTimeout);
if (!scopedDistLock.isOK()) {
*errMsg = stream() << "could not acquire collection lock for " << nss.ns()
<< " to merge chunks in [" << minKey << "," << maxKey << ")"
<< causedBy(scopedDistLock.getStatus());
warning() << *errMsg;
return false;
}
ShardingState* shardingState = ShardingState::get(txn);
//
// 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;
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;
return false;
}
shared_ptr<CollectionMetadata> metadata = shardingState->getCollectionMetadata(nss.ns());
if (!metadata || metadata->getKeyPattern().isEmpty()) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " is not sharded";
warning() << *errMsg;
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;
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;
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;
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;
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;
return false;
}
if (chunksToMerge.size() == 1) {
*errMsg = stream() << "could not merge chunks, collection " << nss.ns()
<< " already contains chunk for " << rangeToString(minKey, maxKey);
warning() << *errMsg;
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;
return false;
}
}
//
// Run apply ops command
//
Status applyOpsStatus = runApplyOpsCmd(txn, 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(txn)->logChange(txn, "merge", nss.ns(), mergeLogEntry);
return true;
}
