346 lines
11 KiB
C++
346 lines
11 KiB
C++
/*
|
|
* Copyright (c) 2018 MariaDB Corporation Ab
|
|
*
|
|
* Use of this software is governed by the Business Source License included
|
|
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
|
|
*
|
|
* Change Date: 2022-01-01
|
|
*
|
|
* On the date above, in accordance with the Business Source License, use
|
|
* of this software will be governed by version 2 or later of the General
|
|
* Public License.
|
|
*/
|
|
#pragma once
|
|
|
|
#include <maxscale/ccdefs.hh>
|
|
|
|
#include <atomic>
|
|
#include <maxbase/semaphore.hh>
|
|
#include <maxbase/worker.hh>
|
|
#include <maxscale/monitor.h>
|
|
|
|
namespace maxscale
|
|
{
|
|
|
|
class MonitorInstance : public MXS_MONITOR_INSTANCE
|
|
, protected maxbase::Worker
|
|
{
|
|
public:
|
|
MonitorInstance(const MonitorInstance&) = delete;
|
|
MonitorInstance& operator=(const MonitorInstance&) = delete;
|
|
|
|
virtual ~MonitorInstance();
|
|
|
|
/**
|
|
* @brief Current state of the monitor.
|
|
*
|
|
* Since the state is written to by the admin thread, the value returned in other threads cannot be fully
|
|
* trusted. The state should only be read in the admin thread or operations launched by the admin thread.
|
|
*
|
|
* @return @c MONITOR_STATE_RUNNING if the monitor is running,
|
|
* @c MONITOR_STATE_STOPPING if the monitor is stopping, and
|
|
* @c MONITOR_STATE_STOPPED if the monitor is stopped.
|
|
*/
|
|
monitor_state_t monitor_state() const;
|
|
|
|
/**
|
|
* @brief Find out whether the monitor is running.
|
|
*
|
|
* @return True, if the monitor is running, false otherwise.
|
|
*
|
|
* @see state().
|
|
*/
|
|
bool is_running() const
|
|
{
|
|
return monitor_state() == MONITOR_STATE_RUNNING;
|
|
}
|
|
|
|
/**
|
|
* @brief Starts the monitor.
|
|
*
|
|
* - Calls @c has_sufficient_permissions(), if it has not been done earlier.
|
|
* - Updates the 'script' and 'events' configuration paramameters.
|
|
* - Calls @c configure().
|
|
* - Starts the monitor thread.
|
|
*
|
|
* - Once the monitor thread starts, it will
|
|
* - Load the server journal and update @c m_master.
|
|
* - Call @c pre_loop().
|
|
* - Enter a loop where it, until told to shut down, will
|
|
* - Check whether there are maintenance requests.
|
|
* - Call @c tick().
|
|
* - Call @c process_state_changes()
|
|
* - Hang up failed servers.
|
|
* - Store the server journal (@c m_master assumed to reflect the current situation).
|
|
* - Sleep until time for next @c tick().
|
|
* - Call @c post_loop().
|
|
*
|
|
* @param param The parameters of the monitor.
|
|
*
|
|
* @return True, if the monitor started, false otherwise.
|
|
*/
|
|
bool start(const MXS_CONFIG_PARAMETER* params);
|
|
|
|
/**
|
|
* @brief Stops the monitor.
|
|
*
|
|
* When the function returns, the monitor has stopped.
|
|
*/
|
|
void stop();
|
|
|
|
/**
|
|
* @brief Write diagnostics
|
|
*
|
|
* The implementation should write diagnostic information to the
|
|
* provided dcb. The default implementation writes nothing.
|
|
*
|
|
* @param dcb The dcb to write to.
|
|
*/
|
|
virtual void diagnostics(DCB* dcb) const;
|
|
|
|
/**
|
|
* @brief Obtain diagnostics
|
|
*
|
|
* The implementation should create a JSON object and fill it with diagnostics
|
|
* information. The default implementation returns an object that is populated
|
|
* with the keys 'script' and 'events' if they have been set, otherwise the
|
|
* object is empty.
|
|
*
|
|
* @return An object, if there is information to return, NULL otherwise.
|
|
*/
|
|
virtual json_t* diagnostics_json() const;
|
|
|
|
/**
|
|
* Get current time from the monotonic clock.
|
|
*
|
|
* @return Current time
|
|
*/
|
|
static int64_t get_time_ms();
|
|
|
|
protected:
|
|
MonitorInstance(MXS_MONITOR* pMonitor);
|
|
|
|
/**
|
|
* @brief Should the monitor shut down?
|
|
*
|
|
* @return True, if the monitor should shut down, false otherwise.
|
|
*/
|
|
bool should_shutdown() const
|
|
{
|
|
return atomic_load_int32(&m_shutdown) != 0;
|
|
}
|
|
|
|
/**
|
|
* @brief Should the disk space status be updated.
|
|
*
|
|
* @param pMonitored_server The monitored server in question.
|
|
*
|
|
* @return True, if the disk space should be checked, false otherwise.
|
|
*/
|
|
bool should_update_disk_space_status(const MXS_MONITORED_SERVER* pMonitored_server) const;
|
|
|
|
/**
|
|
* @brief Update the disk space status of a server.
|
|
*
|
|
* After the call, the bit @c SERVER_DISK_SPACE_EXHAUSTED will be set on
|
|
* @c pMonitored_server->pending_status if the disk space is exhausted
|
|
* or cleared if it is not.
|
|
*/
|
|
void update_disk_space_status(MXS_MONITORED_SERVER* pMonitored_server);
|
|
|
|
/**
|
|
* @brief Configure the monitor.
|
|
*
|
|
* When the monitor is started, this function will be called in order
|
|
* to allow the concrete implementation to configure itself from
|
|
* configuration parameters. The default implementation returns true.
|
|
*
|
|
* @return True, if the monitor could be configured, false otherwise.
|
|
*
|
|
* @note If false is returned, then the monitor will not be started.
|
|
*/
|
|
virtual bool configure(const MXS_CONFIG_PARAMETER* pParams);
|
|
|
|
/**
|
|
* @brief Check whether the monitor has sufficient rights
|
|
*
|
|
* The implementation should check whether the monitor user has sufficient
|
|
* rights to access the servers. The default implementation returns True.
|
|
*
|
|
* @return True, if the monitor user has sufficient rights, false otherwise.
|
|
*/
|
|
virtual bool has_sufficient_permissions() const;
|
|
|
|
/**
|
|
* @brief Flush pending server status to each server.
|
|
*
|
|
* This function is expected to flush the pending status to each server.
|
|
* The default implementation simply copies monitored_server->pending_status
|
|
* to server->status.
|
|
*/
|
|
virtual void flush_server_status();
|
|
|
|
/**
|
|
* @brief Monitor the servers
|
|
*
|
|
* This function is called once per monitor round, and the concrete
|
|
* implementation should probe all servers and set server status bits.
|
|
*/
|
|
virtual void tick() = 0;
|
|
|
|
/**
|
|
* @brief Called before the monitor loop is started
|
|
*
|
|
* The default implementation does nothing.
|
|
*/
|
|
virtual void pre_loop();
|
|
|
|
/**
|
|
* @brief Called after the monitor loop has ended.
|
|
*
|
|
* The default implementation does nothing.
|
|
*/
|
|
virtual void post_loop();
|
|
|
|
/**
|
|
* @brief Called after tick returns
|
|
*
|
|
* The default implementation will call @mon_process_state_changes.
|
|
*/
|
|
virtual void process_state_changes();
|
|
|
|
MXS_MONITOR* m_monitor; /**< The generic monitor structure. */
|
|
MXS_MONITORED_SERVER* m_master; /**< Master server */
|
|
|
|
private:
|
|
std::atomic<bool> m_thread_running; /**< Thread state. Only visible inside MonitorInstance. */
|
|
int32_t m_shutdown; /**< Non-zero if the monitor should shut down. */
|
|
bool m_checked; /**< Whether server access has been checked. */
|
|
mxb::Semaphore m_semaphore; /**< Semaphore for synchronizing with monitor thread. */
|
|
int64_t m_loop_called; /**< When was the loop called the last time. */
|
|
|
|
bool pre_run() final;
|
|
void post_run() final;
|
|
|
|
bool call_run_one_tick(Worker::Call::action_t action);
|
|
void run_one_tick();
|
|
};
|
|
|
|
class MonitorInstanceSimple : public MonitorInstance
|
|
{
|
|
public:
|
|
MonitorInstanceSimple(const MonitorInstanceSimple&) = delete;
|
|
MonitorInstanceSimple& operator=(const MonitorInstanceSimple&) = delete;
|
|
|
|
protected:
|
|
MonitorInstanceSimple(MXS_MONITOR* pMonitor)
|
|
: MonitorInstance(pMonitor)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* @brief Update server information
|
|
*
|
|
* The implementation should probe the server in question and update
|
|
* the server status bits.
|
|
*/
|
|
virtual void update_server_status(MXS_MONITORED_SERVER* pMonitored_server) = 0;
|
|
|
|
/**
|
|
* @brief Called right at the beginning of @c tick().
|
|
*
|
|
* The default implementation does nothing.
|
|
*/
|
|
virtual void pre_tick();
|
|
|
|
/**
|
|
* @brief Called right before the end of @c tick().
|
|
*
|
|
* The default implementation does nothing.
|
|
*/
|
|
virtual void post_tick();
|
|
|
|
private:
|
|
/**
|
|
* @brief Monitor the servers
|
|
*
|
|
* This function is called once per monitor round and will for each server:
|
|
*
|
|
* - Do nothing, if the server is in maintenance.
|
|
* - Store the previous status of the server.
|
|
* - Set the pending status of the monitored server object
|
|
* to the status of the corresponding server object.
|
|
* - Ensure that there is a connection to the server.
|
|
* If there is, @c update_server_status() is called.
|
|
* If there is not, the pending status will be updated accordingly and
|
|
* @c update_server_status() will *not* be called.
|
|
* - After the call, update the error count of the server if it is down.
|
|
*/
|
|
void tick(); // final
|
|
};
|
|
|
|
/**
|
|
* The purpose of the template MonitorApi is to provide an implementation
|
|
* of the monitor C-API. The template is instantiated with a class that
|
|
* provides the actual behaviour of a monitor.
|
|
*/
|
|
template<class MonitorInstance>
|
|
class MonitorApi
|
|
{
|
|
public:
|
|
MonitorApi() = delete;
|
|
MonitorApi(const MonitorApi&) = delete;
|
|
MonitorApi& operator=(const MonitorApi&) = delete;
|
|
|
|
static MXS_MONITOR_INSTANCE* createInstance(MXS_MONITOR* pMonitor)
|
|
{
|
|
MonitorInstance* pInstance = NULL;
|
|
MXS_EXCEPTION_GUARD(pInstance = MonitorInstance::create(pMonitor));
|
|
return pInstance;
|
|
}
|
|
|
|
static void destroyInstance(MXS_MONITOR_INSTANCE* pInstance)
|
|
{
|
|
MXS_EXCEPTION_GUARD(delete static_cast<MonitorInstance*>(pInstance));
|
|
}
|
|
|
|
static bool startMonitor(MXS_MONITOR_INSTANCE* pInstance,
|
|
const MXS_CONFIG_PARAMETER* pParams)
|
|
{
|
|
bool started = false;
|
|
MXS_EXCEPTION_GUARD(started = static_cast<MonitorInstance*>(pInstance)->start(pParams));
|
|
return started;
|
|
}
|
|
|
|
static void stopMonitor(MXS_MONITOR_INSTANCE* pInstance)
|
|
{
|
|
MXS_EXCEPTION_GUARD(static_cast<MonitorInstance*>(pInstance)->stop());
|
|
}
|
|
|
|
static void diagnostics(const MXS_MONITOR_INSTANCE* pInstance, DCB* pDcb)
|
|
{
|
|
MXS_EXCEPTION_GUARD(static_cast<const MonitorInstance*>(pInstance)->diagnostics(pDcb));
|
|
}
|
|
|
|
static json_t* diagnostics_json(const MXS_MONITOR_INSTANCE* pInstance)
|
|
{
|
|
json_t* pJson = NULL;
|
|
MXS_EXCEPTION_GUARD(pJson = static_cast<const MonitorInstance*>(pInstance)->diagnostics_json());
|
|
return pJson;
|
|
}
|
|
|
|
static MXS_MONITOR_API s_api;
|
|
};
|
|
|
|
template<class MonitorInstance>
|
|
MXS_MONITOR_API MonitorApi<MonitorInstance>::s_api =
|
|
{
|
|
&MonitorApi<MonitorInstance>::createInstance,
|
|
&MonitorApi<MonitorInstance>::destroyInstance,
|
|
&MonitorApi<MonitorInstance>::startMonitor,
|
|
&MonitorApi<MonitorInstance>::stopMonitor,
|
|
&MonitorApi<MonitorInstance>::diagnostics,
|
|
&MonitorApi<MonitorInstance>::diagnostics_json,
|
|
};
|
|
}
|