diff options
Diffstat (limited to 'src/mongo/db/range_deleter.h')
| -rw-r--r-- | src/mongo/db/range_deleter.h | 515 |
1 files changed, 256 insertions, 259 deletions
diff --git a/src/mongo/db/range_deleter.h b/src/mongo/db/range_deleter.h index eaf8fa35e1d..f58625f8083 100644 --- a/src/mongo/db/range_deleter.h +++ b/src/mongo/db/range_deleter.h @@ -47,289 +47,286 @@ namespace mongo { - class OperationContext; - struct DeleteJobStats; - struct RangeDeleteEntry; - struct RangeDeleterEnv; - struct RangeDeleterOptions; +class OperationContext; +struct DeleteJobStats; +struct RangeDeleteEntry; +struct RangeDeleterEnv; +struct RangeDeleterOptions; + +/** + * Class for deleting documents for a given namespace and range. It contains a queue of + * jobs to be deleted. Deletions can be "immediate", in which case they are going to be put + * in front of the queue and acted on promptly, or "lazy", in which they would be acted + * upon when they get to the head of the queue. + * + * Threading assumptions: + * + * This class has (currently) one worker thread attacking the queue, one + * job at a time. If we want an immediate deletion, that job is going to + * be performed on the thread that is requesting it. + * + * All calls regarding deletion are synchronized. + * + * Life cycle: + * RangeDeleter* deleter = new RangeDeleter(new ...); + * deleter->startWorkers(); + * ... + * getGlobalServiceContext()->killAllOperations(); // stop all deletes + * deleter->stopWorkers(); + * delete deleter; + */ +class RangeDeleter { + MONGO_DISALLOW_COPYING(RangeDeleter); + +public: + /** + * Creates a new deleter and uses an environment object to delegate external logic like + * data deletion. Takes ownership of the environment. + */ + explicit RangeDeleter(RangeDeleterEnv* env); + + /** + * Destroys this deleter. Must make sure that no threads are working on this queue. Use + * stopWorkers to stop the internal workers, it is an error not to do so. + */ + ~RangeDeleter(); + + // + // Thread management methods + // + + /** + * Starts the background thread to work on this queue. Does nothing if the worker + * thread is already active. + * + * This call is _not_ thread safe and must be issued before any other call. + */ + void startWorkers(); /** - * Class for deleting documents for a given namespace and range. It contains a queue of - * jobs to be deleted. Deletions can be "immediate", in which case they are going to be put - * in front of the queue and acted on promptly, or "lazy", in which they would be acted - * upon when they get to the head of the queue. + * Stops the background thread working on this queue. This will block if there are + * tasks that are being deleted, but will leave the pending tasks in the queue. * - * Threading assumptions: + * Steps: + * 1. Stop accepting new queued deletes. + * 2. Stop all idle workers. + * 3. Waits for all threads to finish any task that is in progress (but see note + * below). * - * This class has (currently) one worker thread attacking the queue, one - * job at a time. If we want an immediate deletion, that job is going to - * be performed on the thread that is requesting it. + * Note: * - * All calls regarding deletion are synchronized. + * + restarting this deleter with startWorkers after stopping it is not supported. * - * Life cycle: - * RangeDeleter* deleter = new RangeDeleter(new ...); - * deleter->startWorkers(); - * ... - * getGlobalServiceContext()->killAllOperations(); // stop all deletes - * deleter->stopWorkers(); - * delete deleter; + * + the worker thread could be running a call in the environment. The thread is + * only going to be returned when the environment decides so. In production, + * KillCurrentOp::killAll can be used to get the thread back from the environment. */ - class RangeDeleter { - MONGO_DISALLOW_COPYING(RangeDeleter); - public: - - /** - * Creates a new deleter and uses an environment object to delegate external logic like - * data deletion. Takes ownership of the environment. - */ - explicit RangeDeleter(RangeDeleterEnv* env); - - /** - * Destroys this deleter. Must make sure that no threads are working on this queue. Use - * stopWorkers to stop the internal workers, it is an error not to do so. - */ - ~RangeDeleter(); - - // - // Thread management methods - // - - /** - * Starts the background thread to work on this queue. Does nothing if the worker - * thread is already active. - * - * This call is _not_ thread safe and must be issued before any other call. - */ - void startWorkers(); - - /** - * Stops the background thread working on this queue. This will block if there are - * tasks that are being deleted, but will leave the pending tasks in the queue. - * - * Steps: - * 1. Stop accepting new queued deletes. - * 2. Stop all idle workers. - * 3. Waits for all threads to finish any task that is in progress (but see note - * below). - * - * Note: - * - * + restarting this deleter with startWorkers after stopping it is not supported. - * - * + the worker thread could be running a call in the environment. The thread is - * only going to be returned when the environment decides so. In production, - * KillCurrentOp::killAll can be used to get the thread back from the environment. - */ - void stopWorkers(); - - // - // Queue manipulation methods - can be called by anyone. - // - - /** - * Adds a new delete to the queue. - * - * If notifyDone is not NULL, it will be signaled after the delete is completed. - * Note that this will happen only if the delete was actually queued. - * - * Returns true if the task is queued and false If the given range is blacklisted, - * is already queued, or stopWorkers() was called. - */ - bool queueDelete(OperationContext* txn, - const RangeDeleterOptions& options, - Notification* notifyDone, - std::string* errMsg); - - /** - * Removes the documents specified by the range. Unlike queueTask, this call - * blocks and the deletion is performed by the current thread. - * - * Returns true if the deletion was performed. False if the range is blacklisted, - * was already queued, or stopWorkers() was called. - */ - bool deleteNow(OperationContext* txn, - const RangeDeleterOptions& options, - std::string* errMsg); - - // - // Introspection methods - // - - // Note: original contents of stats will be cleared. Caller owns the returned stats. - void getStatsHistory(std::vector<DeleteJobStats*>* stats) const; - - size_t getTotalDeletes() const; - size_t getPendingDeletes() const; - size_t getDeletesInProgress() const; - - // - // Methods meant to be only used for testing. Should be treated like private - // methods. - // - - /** Returns a BSON representation of the queue contents. For debugging only. */ - BSONObj toBSON() const; - - private: - // Ownership is transferred to here. - void recordDelStats(DeleteJobStats* newStat); - - - struct NSMinMax; - - struct NSMinMaxCmp { - bool operator()(const NSMinMax* lhs, const NSMinMax* rhs) const; - }; - - typedef std::deque<RangeDeleteEntry*> TaskList; // owned here - - typedef std::set<NSMinMax*, NSMinMaxCmp> NSMinMaxSet; // owned here - - /** Body of the worker thread */ - void doWork(); - - /** Returns true if the range doesn't intersect with one other range */ - bool canEnqueue_inlock(StringData ns, - const BSONObj& min, - const BSONObj& max, - std::string* errMsg) const; - - /** Returns true if stopWorkers() was called. This call is synchronized. */ - bool stopRequested() const; - - std::unique_ptr<RangeDeleterEnv> _env; - - // Initially not active. Must be started explicitly. - std::unique_ptr<stdx::thread> _worker; - - // Protects _stopRequested. - mutable stdx::mutex _stopMutex; - - // If set, no other delete taks should be accepted. - bool _stopRequested; - - // No delete is in progress. Used to make sure that there is no activity - // in this deleter, and therefore is safe to destroy it. Must be used in - // conjunction with _stopRequested. - stdx::condition_variable _nothingInProgressCV; - - // Protects all the data structure below this. - mutable stdx::mutex _queueMutex; - - // _taskQueue has a task ready to work on. - stdx::condition_variable _taskQueueNotEmptyCV; - - // Queue for storing the list of ranges that have cursors pending on it. - // - // Note: pointer life cycle is not handled here. - TaskList _notReadyQueue; - - // Queue for storing the list of ranges that are ready to be removed. - // - // Note: pointer life cycle is not handled here. - TaskList _taskQueue; - - // Set of all deletes - deletes waiting for cursors, waiting to be acted upon - // and in progress. Includes both queued and immediate deletes. - // - // queued delete life cycle: new @ queuedDelete, delete @ doWork - // deleteNow life cycle: deleteNow stack variable - NSMinMaxSet _deleteSet; + void stopWorkers(); - // Keeps track of number of tasks that are in progress, including the inline deletes. - size_t _deletesInProgress; - - // Protects _statsHistory - mutable stdx::mutex _statsHistoryMutex; - std::deque<DeleteJobStats*> _statsHistory; - }; + // + // Queue manipulation methods - can be called by anyone. + // + /** + * Adds a new delete to the queue. + * + * If notifyDone is not NULL, it will be signaled after the delete is completed. + * Note that this will happen only if the delete was actually queued. + * + * Returns true if the task is queued and false If the given range is blacklisted, + * is already queued, or stopWorkers() was called. + */ + bool queueDelete(OperationContext* txn, + const RangeDeleterOptions& options, + Notification* notifyDone, + std::string* errMsg); /** - * Simple class for storing statistics for the RangeDeleter. + * Removes the documents specified by the range. Unlike queueTask, this call + * blocks and the deletion is performed by the current thread. + * + * Returns true if the deletion was performed. False if the range is blacklisted, + * was already queued, or stopWorkers() was called. */ - struct DeleteJobStats { - Date_t queueStartTS; - Date_t queueEndTS; - Date_t deleteStartTS; - Date_t deleteEndTS; - Date_t waitForReplStartTS; - Date_t waitForReplEndTS; - - long long int deletedDocCount; - - DeleteJobStats(): deletedDocCount(0) { - } - }; + bool deleteNow(OperationContext* txn, const RangeDeleterOptions& options, std::string* errMsg); + + // + // Introspection methods + // - struct RangeDeleterOptions { - RangeDeleterOptions(const KeyRange& range); + // Note: original contents of stats will be cleared. Caller owns the returned stats. + void getStatsHistory(std::vector<DeleteJobStats*>* stats) const; - const KeyRange range; + size_t getTotalDeletes() const; + size_t getPendingDeletes() const; + size_t getDeletesInProgress() const; - WriteConcernOptions writeConcern; - std::string removeSaverReason; - bool fromMigrate; - bool onlyRemoveOrphanedDocs; - bool waitForOpenCursors; + // + // Methods meant to be only used for testing. Should be treated like private + // methods. + // + + /** Returns a BSON representation of the queue contents. For debugging only. */ + BSONObj toBSON() const; + +private: + // Ownership is transferred to here. + void recordDelStats(DeleteJobStats* newStat); + + + struct NSMinMax; + + struct NSMinMaxCmp { + bool operator()(const NSMinMax* lhs, const NSMinMax* rhs) const; }; - /** - * For internal use only. - */ - struct RangeDeleteEntry { - RangeDeleteEntry(const RangeDeleterOptions& options); + typedef std::deque<RangeDeleteEntry*> TaskList; // owned here - const RangeDeleterOptions options; + typedef std::set<NSMinMax*, NSMinMaxCmp> NSMinMaxSet; // owned here - // Sets of cursors to wait to close until this can be ready - // for deletion. - std::set<CursorId> cursorsToWait; + /** Body of the worker thread */ + void doWork(); - // Not owned here. - // Important invariant: Can only be set and used by one thread. - Notification* notifyDone; + /** Returns true if the range doesn't intersect with one other range */ + bool canEnqueue_inlock(StringData ns, + const BSONObj& min, + const BSONObj& max, + std::string* errMsg) const; - // Time since the last time we reported this object. - Date_t lastLoggedTS; + /** Returns true if stopWorkers() was called. This call is synchronized. */ + bool stopRequested() const; - DeleteJobStats stats; + std::unique_ptr<RangeDeleterEnv> _env; - // For debugging only - BSONObj toBSON() const; - }; + // Initially not active. Must be started explicitly. + std::unique_ptr<stdx::thread> _worker; + + // Protects _stopRequested. + mutable stdx::mutex _stopMutex; + + // If set, no other delete taks should be accepted. + bool _stopRequested; + + // No delete is in progress. Used to make sure that there is no activity + // in this deleter, and therefore is safe to destroy it. Must be used in + // conjunction with _stopRequested. + stdx::condition_variable _nothingInProgressCV; + + // Protects all the data structure below this. + mutable stdx::mutex _queueMutex; + + // _taskQueue has a task ready to work on. + stdx::condition_variable _taskQueueNotEmptyCV; + + // Queue for storing the list of ranges that have cursors pending on it. + // + // Note: pointer life cycle is not handled here. + TaskList _notReadyQueue; + + // Queue for storing the list of ranges that are ready to be removed. + // + // Note: pointer life cycle is not handled here. + TaskList _taskQueue; + + // Set of all deletes - deletes waiting for cursors, waiting to be acted upon + // and in progress. Includes both queued and immediate deletes. + // + // queued delete life cycle: new @ queuedDelete, delete @ doWork + // deleteNow life cycle: deleteNow stack variable + NSMinMaxSet _deleteSet; + + // Keeps track of number of tasks that are in progress, including the inline deletes. + size_t _deletesInProgress; + + // Protects _statsHistory + mutable stdx::mutex _statsHistoryMutex; + std::deque<DeleteJobStats*> _statsHistory; +}; + + +/** + * Simple class for storing statistics for the RangeDeleter. + */ +struct DeleteJobStats { + Date_t queueStartTS; + Date_t queueEndTS; + Date_t deleteStartTS; + Date_t deleteEndTS; + Date_t waitForReplStartTS; + Date_t waitForReplEndTS; + + long long int deletedDocCount; + + DeleteJobStats() : deletedDocCount(0) {} +}; + +struct RangeDeleterOptions { + RangeDeleterOptions(const KeyRange& range); + + const KeyRange range; + + WriteConcernOptions writeConcern; + std::string removeSaverReason; + bool fromMigrate; + bool onlyRemoveOrphanedDocs; + bool waitForOpenCursors; +}; + +/** + * For internal use only. + */ +struct RangeDeleteEntry { + RangeDeleteEntry(const RangeDeleterOptions& options); + + const RangeDeleterOptions options; + + // Sets of cursors to wait to close until this can be ready + // for deletion. + std::set<CursorId> cursorsToWait; + + // Not owned here. + // Important invariant: Can only be set and used by one thread. + Notification* notifyDone; + + // Time since the last time we reported this object. + Date_t lastLoggedTS; + + DeleteJobStats stats; + + // For debugging only + BSONObj toBSON() const; +}; + +/** + * Class for encapsulating logic used by the RangeDeleter class to perform its tasks. + */ +struct RangeDeleterEnv { + virtual ~RangeDeleterEnv() {} /** - * Class for encapsulating logic used by the RangeDeleter class to perform its tasks. + * Deletes the documents from the given range. This method should be + * responsible for making sure that the proper contexts are setup + * to be able to perform deletions. + * + * Must be a synchronous call. Docs should be deleted after call ends. + * Must not throw Exceptions. */ - struct RangeDeleterEnv { - virtual ~RangeDeleterEnv() {} - - /** - * Deletes the documents from the given range. This method should be - * responsible for making sure that the proper contexts are setup - * to be able to perform deletions. - * - * Must be a synchronous call. Docs should be deleted after call ends. - * Must not throw Exceptions. - */ - virtual bool deleteRange(OperationContext* txn, - const RangeDeleteEntry& taskDetails, - long long int* deletedDocs, - std::string* errMsg) = 0; - - /** - * Gets the list of open cursors on a given namespace. The openCursors is an - * output parameter that will contain all the cursors open after this is called. - * Assume that openCursors is empty when passed in. - * - * Must be a synchronous call. CursorIds should be populated after call. - * Must not throw exception. - */ - virtual void getCursorIds(OperationContext* txn, - StringData ns, - std::set<CursorId>* openCursors) = 0; - }; + virtual bool deleteRange(OperationContext* txn, + const RangeDeleteEntry& taskDetails, + long long int* deletedDocs, + std::string* errMsg) = 0; + + /** + * Gets the list of open cursors on a given namespace. The openCursors is an + * output parameter that will contain all the cursors open after this is called. + * Assume that openCursors is empty when passed in. + * + * Must be a synchronous call. CursorIds should be populated after call. + * Must not throw exception. + */ + virtual void getCursorIds(OperationContext* txn, + StringData ns, + std::set<CursorId>* openCursors) = 0; +}; -} // namespace mongo +} // namespace mongo |