Manages creation of server statistics, which are used for diagnostics. More...

#include <ServerStats.h>

Classes
struct	Deferred
	Members that are constructed later, during enable(). More...
class	Lock
	Provides read/write access to stats, protected against concurrent access. More...
class	SignalHandler
	Asks statsDumper thread to dumps stats to the debug log (NOTICE level) on SIGUSR1 signal. More...
Public Member Functions
	ServerStats (Globals &globals)
	Constructor.
	~ServerStats ()
	Destructor.
void	enable ()
	Called after Globals are initialized to finish setting up this class.
void	exit ()
	Prepare for shutdown.
void	dumpToDebugLog () const
	Write the current stats to the debug log (NOTICE level).
Protocol::ServerStats	getCurrent () const
	Calculate and return the current server stats.
Private Types
typedef Core::Time::SteadyClock	SteadyClock
	Used to dump stats periodically.
typedef Core::Time::SystemClock	SystemClock
	Used to include wall time in stats.
Private Member Functions
void	dumpToDebugLog (std::unique_lock< Core::Mutex > &lockGuard) const
	See public dumpToDebugLog() above.
Protocol::ServerStats	getCurrent (std::unique_lock< Core::Mutex > &lockGuard) const
	See public getCurrent() above.
void	statsDumperMain ()
Private Attributes
Globals &	globals
	Server-wide objects.
Core::Mutex	mutex
	Protects all of the following members of this class.
Core::ConditionVariable	statsDumpRequested
	Notified when isStatsDumpRequested is set and when exiting is set.
bool	exiting
	Set to true when statsDumper should exit.
bool	isStatsDumpRequested
	Set to true when statsDumper should write the entire stats to the debug log.
Core::Time::SteadyClock::time_point	lastDumped
	The last time when the stats were written to the debug log.
Protocol::ServerStats	stats
	Partially filled-in structure that is copied as the basis of all calls to getCurrent().
std::unique_ptr< Deferred >	deferred
	See Deferred.

Detailed Description

Manages creation of server statistics, which are used for diagnostics.

Server statistics are gathered in two ways. First, this object maintains a stats structure that modules can fill in by acquiring a Lock and modifying directly. This stats structure is copied every time stats are requested. Second, when stats are requested, getCurrent() will ask certain modules (such as RaftConsensus) to fill in the current information into a copy of the stats structure.

Definition at line 45 of file ServerStats.h.

Member Typedef Documentation

typedef Core::Time::SteadyClock LogCabin::Server::ServerStats::SteadyClock [private]

Used to dump stats periodically.

Definition at line 104 of file ServerStats.h.

typedef Core::Time::SystemClock LogCabin::Server::ServerStats::SystemClock [private]

Used to include wall time in stats.

Definition at line 109 of file ServerStats.h.

Constructor & Destructor Documentation

LogCabin::Server::ServerStats::ServerStats ( Globals & globals ) [explicit]

Constructor.

Definition at line 86 of file ServerStats.cc.

LogCabin::Server::ServerStats::~ServerStats ( )

Destructor.

Definition at line 98 of file ServerStats.cc.

Member Function Documentation

void LogCabin::Server::ServerStats::enable ( )

Called after Globals are initialized to finish setting up this class.

Attaches signal handler and starts stats dumper thread. Starts calling other modules for their state in getCurrent().

Definition at line 103 of file ServerStats.cc.

void LogCabin::Server::ServerStats::exit ( )

Prepare for shutdown.

Waits for the statsDumper thread to exit, and destroys the deferred object (the opposite of enable()).

Definition at line 114 of file ServerStats.cc.

void LogCabin::Server::ServerStats::dumpToDebugLog ( ) const

Write the current stats to the debug log (NOTICE level).

This is preferred over calling getCurrent() followed by NOTICE(), since it will arrange for the next periodic stats dump to be delayed (there's not much sense in a periodic stats dump immediately following a manual stats dump).

Definition at line 127 of file ServerStats.cc.

Protocol::ServerStats LogCabin::Server::ServerStats::getCurrent ( ) const

Calculate and return the current server stats.

Definition at line 134 of file ServerStats.cc.

void LogCabin::Server::ServerStats::dumpToDebugLog ( std::unique_lock< Core::Mutex > & lockGuard ) const [private]