Manages a pool of web servers and a queue of incoming requests. More...

#include <LoadBalancer.h>

Public Member Functions
	LoadBalancer (int numServers, int maxTime, int queueMin, int queueMax, int scalingCooldown, double newRequestProb, int minRequestTime, int maxRequestTime, const std::string &logFileName)
	Constructs a LoadBalancer with the given configuration. More...

	~LoadBalancer ()
	Destructor. Frees all server instances and closes the log file. More...

void	addBlockedIP (const std::string &startIP, const std::string &stopIP)
	Adds a blocked IP address range to the firewall. More...

void	initializeQueue ()
	Populates the request queue with an initial batch of requests (servers * 100). More...

void	run ()
	Runs the load balancer simulation for the configured number of clock cycles. More...

void	printSummary ()
	Prints a summary of simulation statistics to the log and console. More...

int	getQueueSize () const
	Returns the current number of pending requests in the queue. More...

int	getServerCount () const
	Returns the current number of active servers. More...

Private Member Functions
bool	isBlockedIP (const std::string &ip) const
	Checks if an IP address falls within any blocked firewall range. More...

void	checkScaling ()
	Checks queue thresholds and adds or removes servers as needed. More...

void	generateNewRequest ()
	Randomly generates a new request and adds it to the queue (based on probability). More...

void	assignRequest ()
	Assigns pending requests from the queue to available servers. More...

void	tickAllServers ()
	Advances all servers by one clock cycle and marks finished servers as available. More...

void	log (const std::string &message, const std::string &color="")
	Logs a message to the log file and prints it to the console. More...

Static Private Member Functions
static unsigned long	ipToLong (const std::string &ip)
	Converts a dotted-decimal IP address string to an unsigned long. More...

Private Attributes
std::queue< Request >	requestQueue
	FIFO queue of pending requests. More...

std::queue< WebServer * >	availableQueue
	Queue of idle servers ready for assignment. More...

std::vector< WebServer * >	servers
	All active server instances. More...

std::vector< std::pair< std::string, std::string > >	firewallRange
	Blocked IP ranges (start, end) More...

int	currTime
	Current simulation clock cycle. More...

int	maxTime
	Total number of clock cycles to simulate. More...

int	cooldownRemaining
	Clock cycles remaining before next scaling action. More...

int	nextServerId
	ID to assign to the next created server. More...

int	queueMin
	Lower queue threshold per server for scaling down. More...

int	queueMax
	Upper queue threshold per server for scaling up. More...

int	scalingCooldown
	Cooldown period (cycles) between scaling actions. More...

double	generateRequestProbability
	Probability of generating a new request each cycle. More...

int	minRequestTime
	Minimum processing time for generated requests. More...

int	maxRequestTime
	Maximum processing time for generated requests. More...

int	totalProcessedRequests
	Total requests successfully processed. More...

int	totalRejectedRequests
	Total requests rejected by the firewall. More...

int	serversAdded
	Number of servers added during simulation. More...

int	serversRemoved
	Number of servers removed during simulation. More...

int	startingQueueSize
	Queue size after initial population. More...

std::ofstream	logFile
	Output stream for the log file. More...

Detailed Description

Manages a pool of web servers and a queue of incoming requests.

The LoadBalancer distributes requests to available servers using a FIFO queue, dynamically scales the server pool based on queue thresholds, and provides IP-based firewall filtering to block requests from specified address ranges.

Definition at line 26 of file LoadBalancer.h.

Constructor & Destructor Documentation

◆ LoadBalancer()

LoadBalancer::LoadBalancer	(	int	numServers,
		int	maxTime,
		int	queueMin,
		int	queueMax,
		int	scalingCooldown,
		double	newRequestProb,
		int	minRequestTime,
		int	maxRequestTime,
		const std::string &	logFileName
	)

Constructs a LoadBalancer with the given configuration.

Parameters

numServers	Initial number of web servers to create
maxTime	Total simulation time in clock cycles
queueMin	Lower queue threshold per server for scaling down
queueMax	Upper queue threshold per server for scaling up
scalingCooldown	Cooldown period between scaling actions
newRequestProb	Probability of generating a new request each cycle
minRequestTime	Minimum processing time for requests
maxRequestTime	Maximum processing time for requests
logFileName	Path to the output log file

Definition at line 19 of file LoadBalancer.cpp.

◆ ~LoadBalancer()

LoadBalancer::~LoadBalancer ( )

Destructor. Frees all server instances and closes the log file.

Definition at line 53 of file LoadBalancer.cpp.

Member Function Documentation

◆ addBlockedIP()

void LoadBalancer::addBlockedIP	(	const std::string &	startIP,
		const std::string &	stopIP
	)

Adds a blocked IP address range to the firewall.

Parameters

startIP	Start of the blocked IP range
stopIP	End of the blocked IP range

Definition at line 65 of file LoadBalancer.cpp.

◆ assignRequest()

void LoadBalancer::assignRequest ( )

private

Assigns pending requests from the queue to available servers.

Definition at line 156 of file LoadBalancer.cpp.

◆ checkScaling()

void LoadBalancer::checkScaling ( )

private

Checks queue thresholds and adds or removes servers as needed.

Definition at line 172 of file LoadBalancer.cpp.

◆ generateNewRequest()

void LoadBalancer::generateNewRequest ( )

private

Randomly generates a new request and adds it to the queue (based on probability).

Definition at line 127 of file LoadBalancer.cpp.

◆ getQueueSize()

int LoadBalancer::getQueueSize ( ) const

Returns the current number of pending requests in the queue.

Returns: The request queue size

Definition at line 61 of file LoadBalancer.cpp.

◆ getServerCount()

int LoadBalancer::getServerCount ( ) const

Returns the current number of active servers.

Returns: The server count

Definition at line 62 of file LoadBalancer.cpp.

◆ initializeQueue()

void LoadBalancer::initializeQueue ( )

Populates the request queue with an initial batch of requests (servers * 100).

Definition at line 105 of file LoadBalancer.cpp.

◆ ipToLong()

unsigned long LoadBalancer::ipToLong ( const std::string & ip )

staticprivate

Converts a dotted-decimal IP address string to an unsigned long.

Parameters

ip	The IP address string (e.g. "192.168.1.1")

Returns: The numeric representation of the IP address

Definition at line 70 of file LoadBalancer.cpp.

◆ isBlockedIP()

bool LoadBalancer::isBlockedIP ( const std::string & ip ) const

private

Checks if an IP address falls within any blocked firewall range.

Parameters

ip	The IP address to check

Returns: true if the IP is blocked, false otherwise

Definition at line 89 of file LoadBalancer.cpp.

◆ log()

void LoadBalancer::log	(	const std::string &	message,
		const std::string &	color = `""`
	)

private

Logs a message to the log file and prints it to the console.

Parameters

message	The message to log
color	ANSI color code for console output (empty string for no color)

Definition at line 225 of file LoadBalancer.cpp.

◆ printSummary()

void LoadBalancer::printSummary ( )

Prints a summary of simulation statistics to the log and console.

Definition at line 264 of file LoadBalancer.cpp.

◆ run()

void LoadBalancer::run ( )

Runs the load balancer simulation for the configured number of clock cycles.

Definition at line 238 of file LoadBalancer.cpp.

◆ tickAllServers()

void LoadBalancer::tickAllServers ( )

private

Advances all servers by one clock cycle and marks finished servers as available.

Definition at line 143 of file LoadBalancer.cpp.

Member Data Documentation

◆ availableQueue

std::queue<WebServer*> LoadBalancer::availableQueue

private

Queue of idle servers ready for assignment.

Definition at line 29 of file LoadBalancer.h.

◆ cooldownRemaining

int LoadBalancer::cooldownRemaining

private

Clock cycles remaining before next scaling action.

Definition at line 35 of file LoadBalancer.h.

◆ currTime

int LoadBalancer::currTime

private

Current simulation clock cycle.

Definition at line 33 of file LoadBalancer.h.

◆ firewallRange

std::vector<std::pair<std::string, std::string> > LoadBalancer::firewallRange

private

Blocked IP ranges (start, end)

Definition at line 31 of file LoadBalancer.h.

◆ generateRequestProbability

double LoadBalancer::generateRequestProbability

private

Probability of generating a new request each cycle.

Definition at line 42 of file LoadBalancer.h.

◆ logFile

std::ofstream LoadBalancer::logFile

private

Output stream for the log file.

Definition at line 53 of file LoadBalancer.h.

◆ maxRequestTime

int LoadBalancer::maxRequestTime

private

Maximum processing time for generated requests.

Definition at line 44 of file LoadBalancer.h.

◆ maxTime

int LoadBalancer::maxTime

private

Total number of clock cycles to simulate.

Definition at line 34 of file LoadBalancer.h.

◆ minRequestTime

int LoadBalancer::minRequestTime

private

Minimum processing time for generated requests.

Definition at line 43 of file LoadBalancer.h.

◆ nextServerId

int LoadBalancer::nextServerId

private

ID to assign to the next created server.

Definition at line 36 of file LoadBalancer.h.

◆ queueMax

int LoadBalancer::queueMax

private

Upper queue threshold per server for scaling up.

Definition at line 40 of file LoadBalancer.h.

◆ queueMin

int LoadBalancer::queueMin

private

Lower queue threshold per server for scaling down.

Definition at line 39 of file LoadBalancer.h.

◆ requestQueue

std::queue<Request> LoadBalancer::requestQueue

private

FIFO queue of pending requests.

Definition at line 28 of file LoadBalancer.h.

◆ scalingCooldown

int LoadBalancer::scalingCooldown

private

Cooldown period (cycles) between scaling actions.

Definition at line 41 of file LoadBalancer.h.

◆ servers

std::vector<WebServer*> LoadBalancer::servers

private

All active server instances.

Definition at line 30 of file LoadBalancer.h.

◆ serversAdded

int LoadBalancer::serversAdded

private

Number of servers added during simulation.

Definition at line 49 of file LoadBalancer.h.

◆ serversRemoved

int LoadBalancer::serversRemoved

private

Number of servers removed during simulation.

Definition at line 50 of file LoadBalancer.h.

◆ startingQueueSize

int LoadBalancer::startingQueueSize

private

Queue size after initial population.

Definition at line 51 of file LoadBalancer.h.

◆ totalProcessedRequests

int LoadBalancer::totalProcessedRequests

private

Total requests successfully processed.

Definition at line 47 of file LoadBalancer.h.

◆ totalRejectedRequests

int LoadBalancer::totalRejectedRequests

private

Total requests rejected by the firewall.

Definition at line 48 of file LoadBalancer.h.

The documentation for this class was generated from the following files:

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ LoadBalancer()

◆ ~LoadBalancer()

Member Function Documentation

◆ addBlockedIP()

◆ assignRequest()

◆ checkScaling()

◆ generateNewRequest()

◆ getQueueSize()

◆ getServerCount()

◆ initializeQueue()

◆ ipToLong()

◆ isBlockedIP()

◆ log()

◆ printSummary()

◆ run()

◆ tickAllServers()

Member Data Documentation

◆ availableQueue

◆ cooldownRemaining

◆ currTime

◆ firewallRange

◆ generateRequestProbability

◆ logFile

◆ maxRequestTime

◆ maxTime

◆ minRequestTime

◆ nextServerId

◆ queueMax

◆ queueMin

◆ requestQueue

◆ scalingCooldown

◆ servers

◆ serversAdded

◆ serversRemoved

◆ startingQueueSize

◆ totalProcessedRequests

◆ totalRejectedRequests