5.0-Nano: Portable Cron

5.0-Nano Portable Cron

Uniform Server’s portable Cron has been integrated into 5.0-Nano. The script has been pre-configured to run three scripts Drupal Cron, Moodle Cron and DtDNS auto IP updater. These are effectively one to two line templates that require enabling to run the appropriate applications Cron script.

Portable Cron is binary mapped into UniServer’s control space; value assigned is 16 this method makes it easier to integrate with existing control blocks.

Starting Cron periodically runs scripts that are listed in file run_cron.php, period being defined by a sleep function default is every ten minuets. This simple approach is effective however if you wish to add more flexibility this page provides additional information.

First I explain basic operation and use.

Note: This script has been rewritten now includes a configuration file refer to supplementary section (5.2-Nano and 5.3-Nano) for details.

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Cron

Cron originated from a Unix environment it is a job scheduler allowing scripts to be run automatically at a certain time or date.

Cron (chronograph) has become a more general term referring to a periodic tick.

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Portable Cron

For a permanent installation of UniServer running as a service you can set-up Windows to schedule a task similar to Unix Cron check out How To Schedule Tasks in Windows XP for details?

This is not practical when running UniServer from a USB memory stick. UniServer 5.0-Nano resolves this with a small script scheduler referred to as portable Cron.

It’s fully integrated into UniServers’s control architecture allowing it to be run from either batch files or UniTray.

To run a script or scripts a small amount of configuration is required as explained below.

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Configuration

Each script that requires running is added to the Cron script run_cron.php located in folder UniServer\unicon\main

There are three examples two for server scripts (Drupal and Moodle) and one for CLI script (DtDNS updater.

Consider the three as templates allowing to to add other scripts.

Server Scripts

These are generally single pages that require running.

Enable a line by removing the two forward slashes. Insert a script’s full url (effectively this is what you would type into a browser to run an applications Cron script).

The two enabled example lines as follows:

 $dummy = file("http://localhost/moodle/admin/cron.php"); // Uncomment to enable 
 $dummy = file("http://localhost/drupal/cron.php");       // Uncomment to enable 

The variable $dummy is just that and is never used.

Note 1: If you have installed the above applications to different folders use the appropriate folder names.

Note 2: If you have moved the servers remember to add a port number to the url.

For example moving the servers once, Apache port becomes 81 and the above two lines need to change as follows:

      
 $dummy = file("http://localhost:81/moodle/admin/cron.php"); // Uncomment to enable 
 $dummy = file("http://localhost:81/drupal/cron.php");       // Uncomment to enable

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CLI Scripts

CLI scripts may require more than a single line to run. The DtDNS script for example uses two lines.

The DtDNS automatic updater has been pre-configured and is disabled by default.

These two lines in section List of scripts to be run

  // $cmd = 'start ..\..\usr\local\php\php-win.exe ..\..\plugins\dtdns_updater\dtdns_updater.php';
  // pclose(popen($cmd,'r'));             // Start detatched process  

Need to be un-commented as shown below

  $cmd = 'start ..\..\usr\local\php\php-win.exe ..\..\plugins\dtdns_updater\dtdns_updater.php';
  pclose(popen($cmd,'r'));             // Start detatched process  

First line defines a command (script) to be run. If you wish this can expanded into several lines depends on complexity. Last line is required to detached the process and must be included otherwise the Cron script is killed.

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Configurable section

For completeness I have included the configurable section below:

   //###################################################################################
   //###                       List of scripts to be run                               #
   //###################################################################################

   // To enable Moodle Cron uncomment the next line   
   // $dummy = file("http://localhost/moodle/admin/cron.php"); // Uncomment to enable 

   // To enable Drupal Cron uncomment the next line 
   // $dummy = file("http://localhost/drupal/cron.php");       // Uncomment to enable 

   // To enable DtDNS updater uncomment the next two lines
   // $cmd = 'start ..\..\usr\local\php\php-win.exe ..\..\plugins\dtdns_updater\dtdns_updater.php';
   // pclose(popen($cmd,'r'));             // Start detatched process 


   //###################################################################################
   //###                                END List                                       #
   //###################################################################################

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Periodic tick

Starting Cron immediately runs all scripts defined in the list. After this, scripts will run periodically defined by variable $cron_time currently set to 10 minuets.

This is a reasonable value and should be adequate for most applications. Consider this to be a minimum value, ideally increase it to a higher value to reduce processor overhead.

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Running Cron

Start the servers and run cron from either the batch files or UniTray

UniTray

• Start: Left click tray icon > Advanced > click Run Portable Cron
• Stop: Left click tray icon > Advanced > click Stop Portable Cron

Batch files

Navigate to folder UniServer\alternative_control

• Start: Double click Start_Cron.bat
• Stop: Double click Stop_Cron.bat

Note: There can be a delay of up to one second before cron stops.

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General Notes

Binary coded

Control architecture, to specifically target Cron it has been binary coded with a value of 16. This caters for impendent or combined control.

Example of use

If you wish to start and stop Cron when starting and stopping both servers from UniTray

edit file UniServer\unicon\tray_menu\UniTray1.ini

Change these two lines (Note lines are split so as not to break Wiki formatting):

From:

 Type: item; Caption: "Start UniServer (Apache MySQL)"; Action: shellexecute;
 FileName: "%PHP%\php.exe"; Parameters: " -n %ServerConMain%\start_servers.php 7";
 ShowCmd: hidden; Glyph: 9

 Type: item; Caption: "Stop  UniServer (Apache MySQL)"; Action: shellexecute;
 FileName: "%PHP%\php.exe"; Parameters: " -n %ServerConMain%\stop_servers.php 7";
 ShowCmd: hidden; Glyph: 11

To:

 Type: item; Caption: "Start UniServer (Apache MySQL)"; Action: shellexecute;
 FileName: "%PHP%\php.exe"; Parameters: " -n %ServerConMain%\start_servers.php 23";
 ShowCmd: hidden; Glyph: 9

 Type: item; Caption: "Stop  UniServer (Apache MySQL)"; Action: shellexecute;
 FileName: "%PHP%\php.exe"; Parameters: " -n %ServerConMain%\stop_servers.php 23";
 ShowCmd: hidden; Glyph: 11

Only change required is the parameter value passed to a script. Although I have shown UniTray it also applies to batch files contained in folder UniServer\alternative_control

Note: Binary 1+2+4+16 = 23

1	- Run Apache server
2	- Run MySQL server
4	- Start Index page
16	- Run cron

Portable Cron and Service

Portable Cron may be run when servers are installed as a service.

However will not restart after restarting PC, you need to manually run Portable Cron again.

Note:

Reason for the above is logical, it assumes you have installed the services and are running Uniform Server as a production server. Hence you require finer control and are using Windows to schedule tasks see How To Schedule Tasks in Windows XP for details?

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Summary

If you are reading this sequentially Cron is optional. However security is a must read, a default Uniform Server installation is to lock it down to local access only.

Before allowing external access change the MySQL server password covered on the next page.

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