diff options
Diffstat (limited to 'src/mongo/s/metadata_loader.cpp')
| -rw-r--r-- | src/mongo/s/metadata_loader.cpp | 427 |
1 files changed, 202 insertions, 225 deletions
diff --git a/src/mongo/s/metadata_loader.cpp b/src/mongo/s/metadata_loader.cpp index 74ca1597a7d..1a0758f5734 100644 --- a/src/mongo/s/metadata_loader.cpp +++ b/src/mongo/s/metadata_loader.cpp @@ -44,265 +44,242 @@ namespace mongo { - using std::unique_ptr; - using std::endl; - using std::make_pair; - using std::map; - using std::pair; - using std::string; - - /** - * This is an adapter so we can use config diffs - mongos and mongod do them slightly - * differently. - * - * The mongod adapter here tracks only a single shard, and stores ranges by (min, max). - */ - class SCMConfigDiffTracker : public ConfigDiffTracker<BSONObj, string> { - public: - SCMConfigDiffTracker(const string& currShard) : _currShard( currShard ) { } - - virtual bool isTracked(const ChunkType& chunk) const { - return chunk.getShard() == _currShard; - } - - virtual pair<BSONObj, BSONObj> rangeFor(const ChunkType& chunk) const { - return make_pair(chunk.getMin(), chunk.getMax()); - } - - virtual string shardFor( const string& name ) const { - return name; - } - - virtual string nameFrom( const string& shard ) const { - return shard; - } +using std::unique_ptr; +using std::endl; +using std::make_pair; +using std::map; +using std::pair; +using std::string; - string _currShard; - }; - - // - // MetadataLoader implementation - // +/** + * This is an adapter so we can use config diffs - mongos and mongod do them slightly + * differently. + * + * The mongod adapter here tracks only a single shard, and stores ranges by (min, max). + */ +class SCMConfigDiffTracker : public ConfigDiffTracker<BSONObj, string> { +public: + SCMConfigDiffTracker(const string& currShard) : _currShard(currShard) {} - MetadataLoader::MetadataLoader() { } + virtual bool isTracked(const ChunkType& chunk) const { + return chunk.getShard() == _currShard; + } - MetadataLoader::~MetadataLoader() { } + virtual pair<BSONObj, BSONObj> rangeFor(const ChunkType& chunk) const { + return make_pair(chunk.getMin(), chunk.getMax()); + } - Status MetadataLoader::makeCollectionMetadata(CatalogManager* catalogManager, - const string& ns, - const string& shard, - const CollectionMetadata* oldMetadata, - CollectionMetadata* metadata) const - { - Status status = _initCollection(catalogManager, ns, shard, metadata); - if (!status.isOK() || metadata->getKeyPattern().isEmpty()) { - return status; - } + virtual string shardFor(const string& name) const { + return name; + } - return initChunks(catalogManager, ns, shard, oldMetadata, metadata ); + virtual string nameFrom(const string& shard) const { + return shard; } - Status MetadataLoader::_initCollection(CatalogManager* catalogManager, - const string& ns, - const string& shard, - CollectionMetadata* metadata) const { + string _currShard; +}; - auto coll = catalogManager->getCollection(ns); - if (!coll.isOK()) { - return coll.getStatus(); - } +// +// MetadataLoader implementation +// - CollectionType collInfo = coll.getValue(); - if (collInfo.getDropped()) { - return Status(ErrorCodes::NamespaceNotFound, - str::stream() << "could not load metadata, collection " - << ns << " was dropped"); - } +MetadataLoader::MetadataLoader() {} - metadata->_keyPattern = collInfo.getKeyPattern().toBSON(); - metadata->fillKeyPatternFields(); - metadata->_shardVersion = ChunkVersion(0, 0, collInfo.getEpoch()); - metadata->_collVersion = ChunkVersion(0, 0, collInfo.getEpoch()); +MetadataLoader::~MetadataLoader() {} - return Status::OK(); +Status MetadataLoader::makeCollectionMetadata(CatalogManager* catalogManager, + const string& ns, + const string& shard, + const CollectionMetadata* oldMetadata, + CollectionMetadata* metadata) const { + Status status = _initCollection(catalogManager, ns, shard, metadata); + if (!status.isOK() || metadata->getKeyPattern().isEmpty()) { + return status; } - Status MetadataLoader::initChunks(CatalogManager* catalogManager, - const string& ns, - const string& shard, - const CollectionMetadata* oldMetadata, - CollectionMetadata* metadata) const - { - map<string, ChunkVersion> versionMap; + return initChunks(catalogManager, ns, shard, oldMetadata, metadata); +} - // Preserve the epoch - versionMap[shard] = metadata->_shardVersion; - OID epoch = metadata->getCollVersion().epoch(); - bool fullReload = true; - - // Check to see if we should use the old version or not. - if ( oldMetadata ) { - - // If our epochs are compatible, it's useful to use the old metadata for diffs - if ( oldMetadata->getCollVersion().hasEqualEpoch( epoch ) ) { - - fullReload = false; - invariant( oldMetadata->isValid() ); - - versionMap[shard] = oldMetadata->_shardVersion; - metadata->_collVersion = oldMetadata->_collVersion; +Status MetadataLoader::_initCollection(CatalogManager* catalogManager, + const string& ns, + const string& shard, + CollectionMetadata* metadata) const { + auto coll = catalogManager->getCollection(ns); + if (!coll.isOK()) { + return coll.getStatus(); + } - // TODO: This could be made more efficient if copying not required, but - // not as frequently reloaded as in mongos. - metadata->_chunksMap = oldMetadata->_chunksMap; + CollectionType collInfo = coll.getValue(); + if (collInfo.getDropped()) { + return Status(ErrorCodes::NamespaceNotFound, + str::stream() << "could not load metadata, collection " << ns + << " was dropped"); + } - LOG( 2 ) << "loading new chunks for collection " << ns - << " using old metadata w/ version " << oldMetadata->getShardVersion() - << " and " << metadata->_chunksMap.size() << " chunks" << endl; - } - else { - warning() << "reloading collection metadata for " << ns << " with new epoch " - << epoch.toString() << ", the current epoch is " - << oldMetadata->getCollVersion().epoch().toString() << endl; - } + metadata->_keyPattern = collInfo.getKeyPattern().toBSON(); + metadata->fillKeyPatternFields(); + metadata->_shardVersion = ChunkVersion(0, 0, collInfo.getEpoch()); + metadata->_collVersion = ChunkVersion(0, 0, collInfo.getEpoch()); + + return Status::OK(); +} + +Status MetadataLoader::initChunks(CatalogManager* catalogManager, + const string& ns, + const string& shard, + const CollectionMetadata* oldMetadata, + CollectionMetadata* metadata) const { + map<string, ChunkVersion> versionMap; + + // Preserve the epoch + versionMap[shard] = metadata->_shardVersion; + OID epoch = metadata->getCollVersion().epoch(); + bool fullReload = true; + + // Check to see if we should use the old version or not. + if (oldMetadata) { + // If our epochs are compatible, it's useful to use the old metadata for diffs + if (oldMetadata->getCollVersion().hasEqualEpoch(epoch)) { + fullReload = false; + invariant(oldMetadata->isValid()); + + versionMap[shard] = oldMetadata->_shardVersion; + metadata->_collVersion = oldMetadata->_collVersion; + + // TODO: This could be made more efficient if copying not required, but + // not as frequently reloaded as in mongos. + metadata->_chunksMap = oldMetadata->_chunksMap; + + LOG(2) << "loading new chunks for collection " << ns + << " using old metadata w/ version " << oldMetadata->getShardVersion() << " and " + << metadata->_chunksMap.size() << " chunks" << endl; + } else { + warning() << "reloading collection metadata for " << ns << " with new epoch " + << epoch.toString() << ", the current epoch is " + << oldMetadata->getCollVersion().epoch().toString() << endl; } + } - // Exposes the new metadata's range map and version to the "differ," who - // would ultimately be responsible of filling them up. - SCMConfigDiffTracker differ( shard ); - differ.attach( ns, metadata->_chunksMap, metadata->_collVersion, versionMap ); - - try { - std::vector<ChunkType> chunks; - Status status = catalogManager->getChunks(differ.configDiffQuery(), 0, &chunks); - if (!status.isOK()) { - if (status == ErrorCodes::HostUnreachable) { - // Make our metadata invalid - metadata->_collVersion = ChunkVersion( 0, 0, OID() ); - metadata->_chunksMap.clear(); - } - return status; - } - - // - // The diff tracker should always find at least one chunk (the highest chunk we saw - // last time). If not, something has changed on the config server (potentially between - // when we read the collection data and when we read the chunks data). - // - int diffsApplied = differ.calculateConfigDiff(chunks); - if ( diffsApplied > 0 ) { - // Chunks found, return ok - LOG(2) << "loaded " << diffsApplied << " chunks into new metadata for " << ns - << " with version " << metadata->_collVersion; - - metadata->_shardVersion = versionMap[shard]; - metadata->fillRanges(); - - invariant( metadata->isValid() ); - return Status::OK(); - } - else if ( diffsApplied == 0 ) { - - // No chunks found, the collection is dropping or we're confused - // If this is a full reload, assume it is a drop for backwards compatibility - // TODO: drop the config.collections entry *before* the chunks and eliminate this - // ambiguity - - string errMsg = - str::stream() << "no chunks found when reloading " << ns - << ", previous version was " - << metadata->_collVersion.toString() - << ( fullReload ? ", this is a drop" : "" ); - - warning() << errMsg << endl; - - metadata->_collVersion = ChunkVersion( 0, 0, OID() ); - metadata->_chunksMap.clear(); + // Exposes the new metadata's range map and version to the "differ," who + // would ultimately be responsible of filling them up. + SCMConfigDiffTracker differ(shard); + differ.attach(ns, metadata->_chunksMap, metadata->_collVersion, versionMap); - return fullReload ? Status( ErrorCodes::NamespaceNotFound, errMsg ) : - Status( ErrorCodes::RemoteChangeDetected, errMsg ); - } - else { - // Invalid chunks found, our epoch may have changed because we dropped/recreated - // the collection. - string errMsg = str::stream() << "invalid chunks found when reloading " << ns - << ", previous version was " - << metadata->_collVersion.toString() - << ", this should be rare"; - warning() << errMsg; - - metadata->_collVersion = ChunkVersion( 0, 0, OID() ); + try { + std::vector<ChunkType> chunks; + Status status = catalogManager->getChunks(differ.configDiffQuery(), 0, &chunks); + if (!status.isOK()) { + if (status == ErrorCodes::HostUnreachable) { + // Make our metadata invalid + metadata->_collVersion = ChunkVersion(0, 0, OID()); metadata->_chunksMap.clear(); - - return Status(ErrorCodes::RemoteChangeDetected, errMsg); } + return status; } - catch (const DBException& e) { - // We deliberately do not return connPtr to the pool, since it was involved with the - // error here. - return Status(ErrorCodes::HostUnreachable, - str::stream() << "problem querying chunks metadata" << causedBy(e)); + + // + // The diff tracker should always find at least one chunk (the highest chunk we saw + // last time). If not, something has changed on the config server (potentially between + // when we read the collection data and when we read the chunks data). + // + int diffsApplied = differ.calculateConfigDiff(chunks); + if (diffsApplied > 0) { + // Chunks found, return ok + LOG(2) << "loaded " << diffsApplied << " chunks into new metadata for " << ns + << " with version " << metadata->_collVersion; + + metadata->_shardVersion = versionMap[shard]; + metadata->fillRanges(); + + invariant(metadata->isValid()); + return Status::OK(); + } else if (diffsApplied == 0) { + // No chunks found, the collection is dropping or we're confused + // If this is a full reload, assume it is a drop for backwards compatibility + // TODO: drop the config.collections entry *before* the chunks and eliminate this + // ambiguity + + string errMsg = str::stream() + << "no chunks found when reloading " << ns << ", previous version was " + << metadata->_collVersion.toString() << (fullReload ? ", this is a drop" : ""); + + warning() << errMsg << endl; + + metadata->_collVersion = ChunkVersion(0, 0, OID()); + metadata->_chunksMap.clear(); + + return fullReload ? Status(ErrorCodes::NamespaceNotFound, errMsg) + : Status(ErrorCodes::RemoteChangeDetected, errMsg); + } else { + // Invalid chunks found, our epoch may have changed because we dropped/recreated + // the collection. + string errMsg = str::stream() + << "invalid chunks found when reloading " << ns << ", previous version was " + << metadata->_collVersion.toString() << ", this should be rare"; + warning() << errMsg; + + metadata->_collVersion = ChunkVersion(0, 0, OID()); + metadata->_chunksMap.clear(); + + return Status(ErrorCodes::RemoteChangeDetected, errMsg); } + } catch (const DBException& e) { + // We deliberately do not return connPtr to the pool, since it was involved with the + // error here. + return Status(ErrorCodes::HostUnreachable, + str::stream() << "problem querying chunks metadata" << causedBy(e)); } +} + +Status MetadataLoader::promotePendingChunks(const CollectionMetadata* afterMetadata, + CollectionMetadata* remoteMetadata) const { + // Ensure pending chunks are applicable + bool notApplicable = (NULL == afterMetadata || NULL == remoteMetadata) || + (afterMetadata->getShardVersion() > remoteMetadata->getShardVersion()) || + (afterMetadata->getShardVersion().epoch() != remoteMetadata->getShardVersion().epoch()); + if (notApplicable) + return Status::OK(); - Status MetadataLoader::promotePendingChunks( const CollectionMetadata* afterMetadata, - CollectionMetadata* remoteMetadata ) const { - - // Ensure pending chunks are applicable - bool notApplicable = - ( NULL == afterMetadata || NULL == remoteMetadata ) || - ( afterMetadata->getShardVersion() > remoteMetadata->getShardVersion() ) || - ( afterMetadata->getShardVersion().epoch() != - remoteMetadata->getShardVersion().epoch() ); - if ( notApplicable ) return Status::OK(); - - // The chunks from remoteMetadata are the latest version, and the pending chunks - // from afterMetadata are the latest version. If no trickery is afoot, pending chunks - // should match exactly zero or one loaded chunk. + // The chunks from remoteMetadata are the latest version, and the pending chunks + // from afterMetadata are the latest version. If no trickery is afoot, pending chunks + // should match exactly zero or one loaded chunk. - remoteMetadata->_pendingMap = afterMetadata->_pendingMap; + remoteMetadata->_pendingMap = afterMetadata->_pendingMap; - // Resolve our pending chunks against the chunks we've loaded - for ( RangeMap::iterator it = remoteMetadata->_pendingMap.begin(); - it != remoteMetadata->_pendingMap.end(); ) { + // Resolve our pending chunks against the chunks we've loaded + for (RangeMap::iterator it = remoteMetadata->_pendingMap.begin(); + it != remoteMetadata->_pendingMap.end();) { + if (!rangeMapOverlaps(remoteMetadata->_chunksMap, it->first, it->second)) { + ++it; + continue; + } - if ( !rangeMapOverlaps( remoteMetadata->_chunksMap, it->first, it->second ) ) { - ++it; - continue; - } + // Our pending range overlaps at least one chunk - // Our pending range overlaps at least one chunk + if (rangeMapContains(remoteMetadata->_chunksMap, it->first, it->second)) { + // Chunk was promoted from pending, successful migration + LOG(2) << "verified chunk " << rangeToString(it->first, it->second) + << " was migrated earlier to this shard" << endl; - if ( rangeMapContains( remoteMetadata->_chunksMap, it->first, it->second ) ) { + remoteMetadata->_pendingMap.erase(it++); + } else { + // Something strange happened, maybe manual editing of config? + RangeVector overlap; + getRangeMapOverlap(remoteMetadata->_chunksMap, it->first, it->second, &overlap); - // Chunk was promoted from pending, successful migration - LOG( 2 ) << "verified chunk " << rangeToString( it->first, it->second ) - << " was migrated earlier to this shard" << endl; + string errMsg = str::stream() + << "the remote metadata changed unexpectedly, pending range " + << rangeToString(it->first, it->second) + << " does not exactly overlap loaded chunks " << overlapToString(overlap); - remoteMetadata->_pendingMap.erase( it++ ); - } - else { - - // Something strange happened, maybe manual editing of config? - RangeVector overlap; - getRangeMapOverlap( remoteMetadata->_chunksMap, - it->first, - it->second, - &overlap ); - - string errMsg = str::stream() - << "the remote metadata changed unexpectedly, pending range " - << rangeToString( it->first, it->second ) - << " does not exactly overlap loaded chunks " - << overlapToString( overlap ); - - return Status( ErrorCodes::RemoteChangeDetected, errMsg ); - } + return Status(ErrorCodes::RemoteChangeDetected, errMsg); } - - return Status::OK(); } + return Status::OK(); +} + -} // namespace mongo +} // namespace mongo |