diff options
| -rw-r--r-- | src/mongo/db/commands/list_collections.cpp | 7 | ||||
| -rw-r--r-- | src/mongo/s/commands_public.cpp | 170 |
2 files changed, 135 insertions, 42 deletions
diff --git a/src/mongo/db/commands/list_collections.cpp b/src/mongo/db/commands/list_collections.cpp index e9da451096e..3863a05f18b 100644 --- a/src/mongo/db/commands/list_collections.cpp +++ b/src/mongo/db/commands/list_collections.cpp @@ -83,8 +83,11 @@ namespace mongo { BSONElement filterElt = jsobj["filter"]; if (!filterElt.eoo()) { if (filterElt.type() != mongo::Object) { - return appendCommandStatus(result, Status(ErrorCodes::BadValue, - "\"filter\" must be an object")); + return appendCommandStatus( + result, + Status(ErrorCodes::TypeMismatch, + str::stream() << "\"filter\" must be of type Object, not " << + typeName(filterElt.type()))); } StatusWithMatchExpression statusWithMatcher = MatchExpressionParser::parse(filterElt.Obj()); diff --git a/src/mongo/s/commands_public.cpp b/src/mongo/s/commands_public.cpp index 29cbb1b5413..0f3ced2ec5b 100644 --- a/src/mongo/s/commands_public.cpp +++ b/src/mongo/s/commands_public.cpp @@ -2731,15 +2731,16 @@ namespace mongo { return ok; } - class CmdListCollections : public PublicGridCommand { - public: - CmdListCollections() : PublicGridCommand( "listCollections" ) {} - virtual void addRequiredPrivileges(const std::string& dbname, - const BSONObj& cmdObj, - std::vector<Privilege>* out) { - ActionSet actions; - actions.addAction(ActionType::listCollections); - out->push_back(Privilege(ResourcePattern::forDatabaseName(dbname), actions)); + /** + * Template algorithm for commands that operate by passing through commands to + * the shard primary, and then fall back to an aggregation on the shard primary + * if the command isn't available. This is primarily an abstraction of the implementation + * of listCollections and listIndexes. + */ + class ListPassthroughWithAggFallbackCommand : public PublicGridCommand { + protected: + explicit ListPassthroughWithAggFallbackCommand(const char* name) : + PublicGridCommand(name) { } bool run(OperationContext* txn, const string& dbName, @@ -2748,57 +2749,146 @@ namespace mongo { string& errmsg, BSONObjBuilder& result, bool) { - DBConfigPtr conf = grid.getDBConfig( dbName , false ); + DBConfigPtr conf = grid.getDBConfig(dbName , false); if (!conf) { errmsg = str::stream() << "Failed to load db sharding metadata for " << dbName; return false; } - bool retval = passthrough( conf, cmdObj, result ); + BSONObj cmdResultObj; + BSONObjBuilder listCmdResultBuilder; + if (passthrough(conf, cmdObj, listCmdResultBuilder)) { + cmdResultObj = listCmdResultBuilder.done(); + } + else { + BSONObj listCmdResult = listCmdResultBuilder.done(); + Status status = getStatusFromCommandResult(listCmdResult); + invariant(!status.isOK()); + if (ErrorCodes::CommandNotFound != status) { + result.appendElements(listCmdResult); + return false; + } - Status storeCursorStatus = storePossibleCursor(conf->getPrimary().getConnString(), - result.asTempObj()); - if (!storeCursorStatus.isOK()) { - return appendCommandStatus(result, storeCursorStatus); + const BSONObj aggCmdObj = buildAggregationEquivalent(dbName, cmdObj); + LOG(1) << "Falling back due to old shard server version from " << cmdObj << + " to " << aggCmdObj; + BSONObjBuilder aggCmdResultBuilder; + if (passthrough(conf, aggCmdObj, aggCmdResultBuilder)) { + cmdResultObj = aggCmdResultBuilder.obj(); + } + else { + result.appendElements(aggCmdResultBuilder.done()); + return false; + } + } + invariant(cmdResultObj["ok"].trueValue()); // passthrough() would have returned + // false, otherwise. + Status status = storePossibleCursor(conf->getPrimary().getConnString(), + cmdResultObj); + if (!status.isOK()) { + return appendCommandStatus(result, status); } + result.appendElements(cmdResultObj); + return true; + } + + private: + /** + * Returns a BSON object describing the aggregation command to run on a 2.6 mongod + * if that mongod doesn't support the command described by cmdObj directly. + */ + virtual BSONObj buildAggregationEquivalent( + const std::string& dbName, const BSONObj& cmdObj) = 0; + }; + + class CmdListCollections : public ListPassthroughWithAggFallbackCommand { + public: + CmdListCollections() : ListPassthroughWithAggFallbackCommand( "listCollections" ) {} + virtual void addRequiredPrivileges(const std::string& dbname, + const BSONObj& cmdObj, + std::vector<Privilege>* out) { + ActionSet actions; + actions.addAction(ActionType::listCollections); + out->push_back(Privilege(ResourcePattern::forDatabaseName(dbname), actions)); + } - return retval; + private: + virtual BSONObj buildAggregationEquivalent( + const std::string& dbName, const BSONObj& cmdObj) { + static const long long defaultBatchSize = std::numeric_limits<long long>::max(); + long long batchSize; + uassertStatusOK(parseCommandCursorOptions(cmdObj, defaultBatchSize, &batchSize)); + const BSONElement filterElt = cmdObj["filter"]; + if (!filterElt.eoo() && filterElt.type() != Object) { + uasserted(ErrorCodes::TypeMismatch, + str::stream() << "\"filter\" must be of type Object, not " << + typeName(filterElt.type())); + } + + BSONObjBuilder aggCmdObjBuilder; + aggCmdObjBuilder << + "aggregate" << "system.namespaces" << + "cursor" << BSON("batchSize" << batchSize); + { + BSONArrayBuilder pipelineBuilder(aggCmdObjBuilder.subarrayStart("pipeline")); + pipelineBuilder << + // Filter out namespaces with "$" in their name. These are always indexes, + // except for the master/slave oplog local.oplog.$main; however mongos + // cannot be used to observe the contents of nodes' local databases, so we + // make no exception for it here. + BSON("$match" << + BSON("name" << BSONRegEx("^[^$]*$"))) << + // Sort by name, for consistency with listCollections behavior on mongod. + BSON("$sort" << + BSON("name" << 1)) << + // Remove the database name qualification of the namespace name. + BSON("$project" << + BSON("name" << + BSON("$substr" << + BSON_ARRAY("$name" << + static_cast<long long>(1 + dbName.size()) << + -1)) << + "options" << 1)); + if (!filterElt.eoo()) { + pipelineBuilder << BSON("$match" << filterElt.Obj()); + } + } + return aggCmdObjBuilder.obj(); } } cmdListCollections; - class CmdListIndexes : public PublicGridCommand { + class CmdListIndexes : public ListPassthroughWithAggFallbackCommand { public: - CmdListIndexes() : PublicGridCommand( "listIndexes" ) {} + CmdListIndexes() : ListPassthroughWithAggFallbackCommand( "listIndexes" ) {} virtual void addRequiredPrivileges(const std::string& dbname, const BSONObj& cmdObj, std::vector<Privilege>* out) { - string ns = parseNs( dbname, cmdObj ); ActionSet actions; actions.addAction(ActionType::listIndexes); out->push_back(Privilege(parseResourcePattern(dbname, cmdObj), actions)); } - bool run(OperationContext* txn, const string& dbName, - BSONObj& cmdObj, - int, - string& errmsg, - BSONObjBuilder& result, - bool) { - DBConfigPtr conf = grid.getDBConfig( dbName , false ); - if (!conf) { - errmsg = str::stream() << "Failed to load db sharding metadata for " << dbName; - return false; - } - - bool retval = passthrough( conf, cmdObj, result ); - - Status storeCursorStatus = storePossibleCursor(conf->getPrimary().getConnString(), - result.asTempObj()); - if (!storeCursorStatus.isOK()) { - return appendCommandStatus(result, storeCursorStatus); - } - - return retval; + private: + virtual BSONObj buildAggregationEquivalent( + const std::string& dbName, const BSONObj& cmdObj) { + const BSONElement firstElement = cmdObj.firstElement(); + uassert(28606, + str::stream() << + "Argument to listIndexes must be a non-empty String, but found " << + firstElement.toString(false) << " with type " << + typeName(firstElement.type()), + (firstElement.type() == String && + NamespaceString::validCollectionName(firstElement.valueStringData()))); + + static const long long defaultBatchSize = std::numeric_limits<long long>::max(); + long long batchSize; + uassertStatusOK(parseCommandCursorOptions(cmdObj, defaultBatchSize, &batchSize)); + + return BSON( + "aggregate" << "system.indexes" << + "cursor" << BSON("batchSize" << batchSize) << + "pipeline" << BSON_ARRAY( + BSON("$match" << BSON("ns" << parseNs(dbName, cmdObj))))); } } cmdListIndexes; |