Create worker (child) processes, and pass new connections evenly among them. More...
#include <loadbalancer.h>
Inheritance diagram for LoadBalancer:
Collaboration diagram for LoadBalancer:
Public Member Functions | |
| LoadBalancer (const TaskConfig &tc) | |
| SocketConnection * | newClient (int fd, const char *, uint16_t, ServerSocket *) override |
| double | start () override |
| bool | tlsSetKey (ServerSocket *conn, const std::string &crt_path, const std::string &key_path, const std::string &password) override |
| Use SSL certificate for a listening socket. | |
| void | serverRemoved (ServerSocket *s) override |
| void | processFinished (int pid, int wstatus) override |
| Will be called to notify when an external process has terminated. | |
 Public Member Functions inherited from Task | |
| Task (const std::string &task_name) | |
| Create a task with the given name. More... | |
| virtual | ~Task () |
| virtual double | timerEvent () |
| void | resetTimer (double s) |
| Run timerEvent after s seconds instead of previous value. | |
| bool | finishedOK () const |
| Return true if the task has finished normally. More... | |
| bool | wasKilled () const |
| Return true if the task is finished and was aborted by another task. More... | |
| bool | wasError () const |
| Return true if the task terminated with an error. More... | |
| bool | wasTimeout () const |
| Return true if the task terminated with a timeout. More... | |
| bool | hasStarted () const |
| void | killChildTaskWhenFinished () |
| virtual bool | adoptConnection (Socket *conn) |
| virtual void | connAdded (SocketConnection *) |
| virtual void | connRemoved (SocketConnection *) |
| virtual void | serverAdded (ServerSocket *) |
| std::string | result () const |
| To get the "result" of the task after it has finished. | |
| std::set< Socket * > | getMyConnections () const |
| Return all current connections. | |
| bool | isActive (Socket *conn) const |
| Return true if the connection still exists. | |
| void | wakeUp () |
| Restart all idle connections. | |
| bool | wakeUpConnection (SocketConnection *s) |
| If s is idle, restart it and return true. Otherwise return false. | |
| void | cancelConnection (SocketConnection *s) |
| Terminate and remove a connection. | |
| std::string | message () const |
| Return the current (outgoing) message. | |
| bool | startObserving (Task *to) |
| void | executeHandler (Task *receiver, const std::string &message) |
| double | elapsed () const |
| Return number of seconds since the task was started. More... | |
| virtual Task * | createWorkerTask (unsigned int wno) |
| virtual void | finishWorkerTask (unsigned int) |
| virtual void | newWorkerChannel (SocketReceiver *, unsigned int) |
| virtual void | workerMessage (SocketReceiver *, const char *buf, size_t len) |
| Called if parent/worker sends a message through a SocketReceiver: | |
| virtual PollState | connectionReady (SocketConnection *) |
| virtual PollState | msgFromConnection (SocketConnection *, const std::string &) |
| uint64_t | bytesSent () const |
| Number of bytes sent through SocketConnection objects owned by me. | |
| uint64_t | bytesReceived () const |
| Number of bytes received through SocketConnection objects owned by me. | |
| void | resetByteCount () |
| Reset the values for the methods Task::bytesSent and Task::bytesReceived. | |
| void | notifyBytesSent (uint64_t n) |
| Notify the task that data has been sent on its behalf. More... | |
| void | notifyBytesReceived (uint64_t n) |
| Notify the task that data has been received on its behalf. More... | |
| Public Member Functions inherited from Logger | |
| Logger (std::string label) | |
| std::string | label () const |
| Return the object's log label. | |
| void | resetLabel (const std::string &new_label) |
| Modify the object's log label. | |
Protected Member Functions | |
| size_t | nextWorker () const |
| Return a worker number. | |
| void | rotateNextWorker () |
| void | doPass (int fd, size_t wid, ServerSocket *srv) |
| Pass a connection to a worker process. | |
| void | new_worker (size_t i) |
| Create a new worker process. | |
| void | removeWorker (pid_t pid) |
| Remove a worker process. | |
| std::string | workerConfig (unsigned int i=0) const |
| Return configuration of a worker process. | |
| void | setMaxRetries (unsigned int n) |
| Max number of times to restart failed worker processes. | |
| Protected Member Functions inherited from Task | |
| bool | addConnection (SocketConnection *conn) |
| bool | addConnected (SocketConnection *conn) |
| bool | addServer (ServerSocket *conn) |
| As Task::addConnected, but with a server connection. | |
| bool | parseListen (const TaskConfig &tc, const std::string &log_label) |
| void | setResult (const std::string &res) |
| virtual void | setError (const std::string &msg) |
| virtual void | setTimeout () |
| void | setMessage (const std::string &msg) |
| virtual void | taskFinished (Task *task) |
| virtual void | taskMessage (Task *task) |
| virtual void | handleExecution (Task *sender, const std::string &message) |
| Callback to execute code on behalf of another Task. | |
| bool | terminated () const |
| Return true if task is finished. More... | |
| void | addNewTask (Task *task, Task *parent=nullptr) |
| Insert another Task for execution by the EventLoop. | |
| void | addNewThread (Task *task, const std::string &name="ThreadLoop", std::ostream *log_file=nullptr, Task *parent=nullptr) |
| Run task in a new thread. | |
| void | getMyTasks (std::set< Task * > &tset) |
| Add all my child tasks to the given set. | |
| void | abortMyTasks () |
| Terminate all my child tasks. | |
| void | abortTask (Task *task) |
| Terminate a task. | |
| void | abortAllTasks () |
| Terminate all tasks and exit the EventLoop. | |
| int | runProcess (const char *const argv[]) |
| WorkerProcess * | createWorker (std::ostream *log_file=nullptr, unsigned int channels=1, unsigned int wno=0) |
| Run task returned by this->createWorkerTask in a child process. Return nullptr on failure. | |
| WorkerProcess * | createWorker (const std::string &log_file_name, unsigned int channels=1, unsigned int wno=0) |
| Run task returned by this->createWorkerTask in a child process. Return nullptr on failure. | |
| Protected Member Functions inherited from Logger | |
| std::ostream & | errno_log () const |
| Write a line of error log after a failed system call has set the global errno to a non-zero value. More... | |
| std::ostream & | err_log () const |
| Write a line of error log. More... | |
| std::ostream & | warn_log () const |
| Write a line of warning log. More... | |
| std::ostream & | log () const |
| Write a line of info log. More... | |
| std::ostream & | dbg_log () const |
| Write a line of debug log. More... | |
Additional Inherited Members | |
| Static Public Member Functions inherited from Logger | |
| static void | setLogFile (std::ostream &stream) |
| Set global log destination. More... | |
| static void | reopenLogFile (const std::string &filename) |
| If current log is a file (ofstream), reopen it with new filename: | |
| static void | setLogLimit (unsigned int loglines=0, unsigned int warnlines=0, unsigned int errlines=0) |
| Set max number of lines of info/warn/err log. More... | |
| static void | sayTime (std::ostream &stream) |
| Write current local time to the given stream. | |
| static bool | inError () |
| Return true if any error has been logged (globally since start) | |
| static std::ostream & | err_log (const std::string &label) |
| Write a line of error log. More... | |
| static std::ostream & | warn_log (const std::string &label) |
| Write a line of warning log. More... | |
| static std::ostream & | log (const std::string &label) |
| Write a line of info log. More... | |
| static void | flushLogFile () |
| static void | pauseLogging () |
| Disable all log output until next call to Logger::setLogFile. | |
| static double | secondsSince (const TimePoint &t) |
| static double | secondsTo (const TimePoint &t) |
| static int64_t | msSince (const TimePoint &t) |
| static int64_t | msTo (const TimePoint &t) |
| static bool | hasExpired (const TimePoint &t) |
| Return true if current time is after the given TimePoint. | |
| static TimePoint | timeNow () |
| Return current time. | |
| static TimePoint | timeAfter (double s) |
| Return current time plus s seconds. | |
| static TimePoint | timeMax () |
| Return a very distant time. | |
| static std::chrono::microseconds | toUs (double t) |
| Convert s (seconds) to std::chrono::microseconds. | |
| static std::string | dateString (time_t t=0) |
| Return local time, formatted as 2023-10-14T09:38:47+0200. | |
| static std::string | dateString2 (time_t t=0) |
| Return local time, formatted as Sat, 14 Oct 2023 09:38:47. | |
| static std::string | createHashKey (unsigned int length=20) |
| Return a random string. More... | |
Detailed Description
Create worker (child) processes, and pass new connections evenly among them.
New clients are passed to the worker processes using a round-robin algorithm. Override the Task::newClient method to use a more sophisticated algorithm.
Member Function Documentation
◆ newClient()
|
overridevirtual |
Ignore this unless the task is a server task. If a new remote connection is made through any ServerSocket object owned by us, the client socket, ip address and port number will be passed to the below method. Override it to create and return an object of a subclass to SocketConnection, otherwise the client socket will be closed. The object will be owned by the implementation and will be deleted when the connection has been closed. You must create the object with new.
Reimplemented from Task.
◆ rotateNextWorker()
|
inlineprotected |
Move on to next worker (in a round-robin fashion) for LoadBalancer::nextWorker.
◆ serverRemoved()
|
overridevirtual |
This will be called when a server socket object has been removed from this task, just before it is deleted. If you need to know that, override this method.
Reimplemented from Task.
◆ start()
|
overridevirtual |
When the EventLoop starts executing a task, it will call its start method. All non-trivial initialization, e.g. creating new socket connections, should be performed in the start method.
If the task needs a timer, the start method must return the number of seconds until timerEvent should be called, or <= 0 if you don't want it to be called.
Reimplemented from Task.
The documentation for this class was generated from the following files:
- src/framework/loadbalancer.h
- src/framework/loadbalancer.cpp
