/mls-project/php/Standardization/DeliveryScheduler.php

<?php
/**
 * MLS Factory Data Standardization
 * Class DeliveryScheduler
 * Schedule different rets server class for delivery
 * @category Data_Standardization
 * @package  Data_Standardization_DeliveryScheduler
 * @version  1.0
 * @author   Amrutha Viswanath <incubator319@hotmail.com>
 * @date    22-NOV-2016
 */

Class DeliveryScheduler 
{
    /*
     * Database connection variable
     * @var object
     */
    private $_dbCron;
    
    /*
     * Maximum number of php extraction scripts allowed
     * @var integer
     */
    private $_maxNoOfProcesses;
    
    /*
     * Mimimum amount of RAM needed to run a php extraction script
     * @var integer
     */
    private $_minRam;   
    
    /*
     * GMT time when the scheduler started
     * @var datetime
     */
    private $_schedulerStartedgmtTime;
    
    /*
     * Maximum waiting time for the scheduler in minutes
     * @var integer
     */
    private $_waitimeTimeLimitMinutes;
    
    /*
     * Already scheduled crons array
     * @var array
     */
    private $_ranServerCrons = array(0);
    
    /*
     * Already scheduled classes array
     * @var array
     */
    private $_ranServerClasses = array(0);
    
    /*
     * Mysql where condition to apply the cron flag filter
     * @var String
     */
    private $_sqlWhereCondition;
    
    /**
     * DeliveryScheduler construct
     * Constructor, Initilizes variables _dbCron
     * @param Integer $cronflag Flag to identify the servers to run in that particular cron
     * @author  Sanjay <incubator228@hotmail.com>
     * @date    06-AUG-2014
     * @modified  Amrutha Viswanath <incubator319@hotmail.com>
     * @date    22-NOV-2016
     */
    public function __construct($cronflag = 0)
    {
        Common::displayMessages(' + Scheduler started');
        Common::displayMessages(" + Establishing database(cron) connection");
        $configArr  = parse_ini_file("config/config.ini", true);
        $this->_dbCron = new Db('cron');
        Common::displayMessages(' + Established DB connection');
        if ($cronflag) {
            $this->_sqlWhereCondition = " AND s.incremental_server_flag = '$cronflag' ";
        }
        $this->_minRam                  = defined('MIN_RAM') ? MIN_RAM : 20480;
        $this->_maxNoOfProcesses        = defined('MAX_NO_PROCESSES') ? MAX_NO_PROCESSES : 50;
        $this->_waitimeTimeLimitMinutes = defined('SCHEDULER_MAX_WAITING_TIME') ? SCHEDULER_MAX_WAITING_TIME : 14;
        $this->_schedulerStartedgmtTime = gmdate('Y-m-d H:i:s');
        $this->_schedulerStartedgmtTimeObj  = new DateTime($this->_schedulerStartedgmtTime);
        $this->updateAllStoppedProcesses();
        //exit;
        $this->runScheduler();
        $this->_dbCron = null;
    }
    
    /**
     * DeliveryScheduler updateAllStoppedProcesses
     * update all stopped processes's cron status to "cron updated" so that it will taken for next delivery
     * @author  Amrutha Viswanath <incubator319@hotmail.com>
     * @date    22-NOV-2016
     */
    private function updateAllStoppedProcesses()
    {
        $notExistProcessesStatusIdArr = array();
        
        $sql = "SELECT s3.id as monitorId, s3.process_id 
                FROM s3_monitor s3 
                INNER JOIN tbl_server s
                ON s3.flag = 'UPLOAD STARTED'
                AND s3.server_id = s.id
                $this->_sqlWhereCondition";
        if ($result = $this->_dbCron->executeQuery($sql)) {
            while ($row = mysqli_fetch_assoc($result)) {
                if (!file_exists("/proc/{$row['process_id']}")) { // if process not exists
                    $notExistProcessesStatusIdArr[] = $row['monitorId'];
                }
            } // end while
            if (!empty ($notExistProcessesStatusIdArr)) {
                echo "updated " . count($notExistProcessesStatusIdArr) . " classes cron status as cron updated\n";
                $sqlUpdateStatus = "UPDATE s3_monitor 
                                    SET flag = 'CRON UPDATED' 
                                    WHERE id IN (". implode(',', $notExistProcessesStatusIdArr) .")";
                $this->_dbCron->executeNonQuery($sqlUpdateStatus);
            } // end if
        } // end if
    }
    
    /**
     * DeliveryScheduler runScheduler
     * Schedules the active rets server classes which is ready to run
     * @author  Sanjay <incubator228@hotmail.com>
     * @date    06-AUG-2014
     */
    public function runScheduler()
    {
        $showMsg = true;
        $iterator = 1;
        $firstTime = true;
        while (true) { // inifinite loop
            if (true === $this->isWaitingTimeExeededLimit()) {
                Common::logger("\tDate:". gmdate('Y-m-d H:i:s') . "none of the scripts ran", 'scheduler_log.txt');
                exit;
            }
            if ($this->getAvailableFreeMemory() > $this->_minRam) {  //starting time checks for the available RAM
                Common::displayMessages(" + Free Memory: {$this->getAvailableFreeMemory()} KB");
                if ($resultScheduleServerClasses = $this->getServerClassesForScheduling()) {
                    $firstTime = false;
                    Common::logger("Date:". gmdate('Y-m-d H:i:s') . "scheduler classes count: ".mysqli_num_rows($resultScheduleServerClasses), 'scheduler_log.txt');
                    while ($rowServerClass = mysqli_fetch_assoc($resultScheduleServerClasses)) {
                        if ($rowServerClass['server_name'] && $rowServerClass['class_name']) {
                            $showMsg = true;
                            while ($this->getPhpProcessesCount() >= $this->_maxNoOfProcesses || $this->getAvailableFreeMemory() < $this->_minRam) {
                                // first time shows the message
                                if (true === $showMsg) {
                                    $this->showWaitingMsg();
                                    $showMsg = false;
                                }
                                // if serverScheduler is taking more than the specified limit, exit
                                if (true === $this->isWaitingTimeExeededLimit()) { 
                                    Common::logger("\tDate:". gmdate('Y-m-d H:i:s') . "processed crons count: ". count($this->_ranServerClasses), 'scheduler_log.txt');
                                    Common::displayMessages(" + Scheduler is taking more than {$this->_waitimeTimeLimitMinutes}Mins 30Sec...");
                                    exit;
                                }
                                Common::displayMessages("\t + Waiting for 10s");
                                sleep(10); // 10 sec delay
                            }
                            if ($this->getPhpProcessesCount() < $this->_maxNoOfProcesses) {
                                $command = "php Scripts/iCanDeliveryLive_new.php '{$rowServerClass['server_name']}' '{$rowServerClass['class_name']}' '{$rowServerClass['provider_name']}' '{$rowServerClass['customer_name']}'";
                                //Log data extraction details and errors
                                $logFile = __DIR__."/log/delivery_logs/{$rowServerClass['server_name']}/{$rowServerClass['class_name']}/{$rowServerClass['customer_name']}/". str_replace(' ', 'T', $this->_schedulerStartedgmtTime) ."_log.txt";
                                mkdir(dirname($logFile), "0777", true);
                                chmod(dirname($logFile), 0777);
                                Common::displayMessages("\t + $command \n\t $logFile");
                                dirname($logFile) ? exec("$command > $logFile &") : exec("$command");
                                Common::displayMessages(" + ".$iterator++ . ". {$rowServerClass['server_name']} => {$rowServerClass['class_name']} ({$rowServerClass['provider_name']}) - {$rowServerClass['cronId']}", 'bold_purple');
                                //$this->_ranServerCrons[] = $rowServerClass['cronId'];
                                $this->_ranServerClasses[] = $rowServerClass['class_id'];
                            }
                        } // end if
                    } // end while
                } else {
                    if ($firstTime) {
                        Common::displayMessages(" + No classes to schedule", 'bold_red');
                    } else {
                        Common::displayMessages(" + All active server classes scheduled for extraction", 'bold_cyan');
                    }
                    Common::freeUserDefinedVariablesSpace();
                    exit;
                } // end if else
            } else {
                if (true === $showMsg) {
                    $this->showWaitingMsg();
                    $showMsg = false;
                }
            } // end if else
        } // end while       
        
    }
    
    /**
     * DeliveryScheduler showWaitingMsg
     * Shows the message why the scheduler is waiting
     * @author  Sanjay <incubator228@hotmail.com>
     * @date    15-SEP-2014
     */
    private function showWaitingMsg()
    {
        $phpProcessCount = $this->getPhpProcessesCount();
        $ramAvailable    = $this->getAvailableFreeMemory();
        if ($phpProcessCount >= $this->_maxNoOfProcesses) {
            $warningsArr[] = "Max number of processes ($phpProcessCount/$this->_maxNoOfProcesses) reached";
            $warningsArr[] = "Waiting for processor to finish any of the currently running processes";
        }
        if ($ramAvailable < $this->_minRam) {
            $warningsArr[] = "Not enough memory (Min RAM needed: $this->_minRam KB, RAM Avialble: $ramAvailable KB)";
            $warningsArr[] = "Waiting to get the required amount of RAM";
        }
        if (!empty($warningsArr)) {
            Common::displayMessages($warningsArr, 'bold_red', '', '-');
        }
    }
    
    /**
     * DeliveryScheduler isWaitingTimeExeededLimit
     * Returns wheather the scheduler script waiting time is exeeded
     * @return  Boolean wheather the scheduler script waiting time is exeeded a particluar limit
     * @author  Sanjay <incubator228@hotmail.com>
     * @date    26-AUG-2014
     */
    private function isWaitingTimeExeededLimit()
    {
        $currentTime = new DateTime(gmdate("Y-m-d H:i:s"));
        $interval    = $this->_schedulerStartedgmtTimeObj->diff($currentTime);
        if ($interval->i >= $this->_waitimeTimeLimitMinutes) {
           return true;
        }
        return false;
    }

    /**
     * DeliveryScheduler getAvailableFreeMemory
     * Returns the free memory available in the machine
     * @return  Int freeMem free memory available (KB) in the machine
     * @author  Sanjay <incubator228@hotmail.com>
     * @date    06-AUG-2014
     */
    private function getAvailableFreeMemory()
    {
        $freeMem = shell_exec("cat /proc/meminfo");
        $freeMem = explode('MemFree:', $freeMem);
        $freeMem = explode('kB', $freeMem[1]);
        $freeMem = trim($freeMem[0]); 
        return $freeMem;
    }

    /**
     * DeliveryScheduler getServerClassesForScheduling
     * Returns the object which contains the servers which is active and 
     * corresponding classes
     *      whose upload script is not still running 
     *      whose upload not done yet by checking(falg IN ('STDZN_COMPLETED','CRON UPDATED'))
     * @return  Object  Database object contains the servers and classes which are ready to run
     * @author  Amrutha Viswanath <incubator319@hotmail.com>
     * @date    22-NOV-2016
     */
    private function getServerClassesForScheduling()
    {
        $sql = "SELECT s.server_name, s.customer_id, c.class_name, c.id as class_id, p.provider_name, cu.customer_name
                FROM tbl_server s
                INNER JOIN tbl_server_class c
                ON (s.server_status = 'Active' 
                $this->_sqlWhereCondition
                AND s.is_delivery_enabled = 'Enable') 
                AND c.tbl_server_id = s.id
                INNER JOIN  tbl_customer cu
                ON cu.id = s.customer_id
                INNER JOIN tbl_server_providers p
                ON p.id = s.tbl_server_providers_id
                AND (SELECT s3.class_id FROM s3_monitor s3
                WHERE s3.server_id = s.id
                AND s3.class_id = c.id
                AND s3.flag IN ('STDZN_COMPLETED','CRON UPDATED') 
                AND s3.class_id NOT IN (". implode(',', $this->_ranServerClasses) .")
                limit 1)";
        
        return $this->_dbCron->executeQuery($sql);
    }
    
     /**
     * DeliveryScheduler getPhpProcessesCount
     * Returns the number of currently running php delivery scripts
     * @return  Int the number of currently running php delivery scripts
     * @author  Sanjay <incubator228@hotmail.com>
     * @date    07-AUG-2014
     */
    private function getPhpProcessesCount()
    {
        return substr_count(shell_exec("ps aux | grep php"), 'php index.php');
    }
    
}


chdir(__DIR__.'/');    // Setting the project root directory
//require_once("config/config.php");
include 'Modules/General/GeneralArrays.php';
include 'Modules/General/Common.php';
include '../SiFrameworks/Db.php';
$scheduler = new DeliveryScheduler($argv[1]);