= Periodic tasks =

'''Periodic tasks''' are programs that are run periodically. They are executed by the [StartTool bin/start --cron] program, which you should run from cron. To do this, run '''crontab -e''' and add a line of the form
{{{
0,5,10,15,20,25,30,35,40,45,50,55 * * * * HOME/projects/PROJECT/bin/start --cron
}}}

Periodic tasks are short-running, but in case they aren't, the 'start' script detect when an instance is still running and won't start another instance.

Your project's periodic tasks are described in its [ProjectConfigFile config.xml] file, with elements of the following form:

{{{
    <task>
      <cmd> get_load </cmd>
      <output> get_load.out </output>
      <period> 5 min </period>
      [ <host> host.ip </host>       ]
      [ <disabled>  0|1 </disabled>   ]
      [ <always_run> 0|1  </always_run> ]
    </task>
    <task>
      <cmd> run_in_ops update_forum_activities.php </cmd>
      <output> update_form_activities.out </output>
      <period> 1 day </period>
    </task>
    <task>
    ...
    </task>
}}}

 cmd::
	The command used to perform the task. Must be a program in the project's /bin directory.

 You can run PHP scripts as periodic tasks. These scripts must be in the html/ops/ directory, and can be run with a command of the form
{{{
run_in_ops scriptname
}}}
 The script should be executable, and should have the form
{{{
#! /usr/bin/env php
<?php
...
?>
}}}
 You must specify the output file for such tasks (otherwise it will go to run_in_ops.out).
 host::
	Specifies where the daemon should run. The default is the project's main host, as specified in config.xml.
 period::
	The interval between executions, expressed as a single number (in units of minutes) or a number followed by 'seconds', 'minutes', 'hours', or 'days' (may be abbreviated to unique initial string).
 output::
	Specifies the output file to output; and by default it is COMMAND_BASE_NAME.out. Output files are in log_X/, where X is the host.
 disabled::
	Ignore this entry
 always_run::
	Run this task regardless of whether or not the project is enabled (for example, a script that logs the current CPU load of the host machine).

A project newly created by [MakeProject make_project] has periodic tasks that run the following:

 db_dump::
	Write statistics data to XML files for export. Details are [DbDump here]. Recommended period: 1 day.
 update_profile_pages.php::
	Generate HTML files with lists of links to user profiles, organized alphabetically and by country. Recommended period: a few days.
 update_stats::
	Update the recent average credit fields of users, teams, and hosts. This is important if you use send personalized [VolunteerRecruit mass emails] or [http://boinc.berkeley.edu/reminder_email.php reminder emails], or use recent credit to enable message-board posting. Recommended period: every few days.
 update_uotd.php::
	Select a new User of the Day. Period: 1 day.
 update_forum_activities.php::
	Recompute 'popularity' estimages for threads and posts in the Questions and Answers message boards. Recommended period: 1 hour.