I have to run a pretty heavy task on PHP once a week (script that curls to various locations (websites, API's), gathers, sorts data and inserts it into a db). The whole script takes about 10 to 15 mintues to run on my mac (localhost) - guessing it'll run a bit faster on a server. Nevertheless - I'm currently looping through with AJAX, so when each task is finished, next one is launched. Now I need to run it weekly, automatically. So I think I can't do it with AJAX Anymore.
Do I have to just set the php.ini to let a script run for 30 mintues or there is a better way to do it ?
The maximum execution time of the PHP script is determined by the amount of time in which no output has been generated. So writing data into STDOUT (e.g. to a logfile) will keep the script running.
However, if you're running the script from command line, the max-execution-time will be defaulted to zero anyway and as already suggested, I'd start the script with a cronjob instead of an AJAX-Request or similar methods. I actually do that for most of my php-scripts performing administrative tasks like synchronizing data across several databases or similar purposes.
php.ini has nothing to do with scheduling jobs. It's simply definining PHP's startup settings. What you want is a cron job, as your title says.
For OSX cron setup, see http://hintsforums.macworld.com/showthread.php?s=&threadid=39005
Related
I have some limitations with my host and my scripts can't run longer than 2 or 3 seconds. But the time it will take to finish will certainly increase as the database gets larger.
So I thought about making the script stop what it is doing and call itself after 2 seconds, for example.
Firstly I tried using cURL and then I made some attempts with wget. But there is always a problem with waiting for the response and timeouts (with cURL, for example, I just need to ping the script, not wait for a response) or permissions with the server (functions that we use to run wget such as exec seems to be disabled on my server, or something like that).
What do you think is the best idea to make a PHP script ping/call itself?
On Unix/LInux systems I would personally recommend to schedule CRON JOBS to keep running the scripts at certain intervals
May be this SO Link will help you
Php scripts generally don't call other php scripts. It is possible to spawn a background process as illustrated here, but I don't think that's what you're after. If, so you'd be better off using cron as was discussed above.
Calling a function every X amount of seconds with the same script is certainly possible, but this does the opposite of what you want since it would only extend the run time of the script in question.
What you seem to be asking is, contrary to your comment, somewhat paradoxical. A process that calls method() every so often is still a long running process and is subject to the same restrictions as any other process on the server, regardless of the fact that it may be sitting idle for short intervals.
As far as I can see your options are:
Extend the php max_execution_time directive, or have your sysadmin do so if they are willing
Revise your script so that it completes within the time limit
Move to a new server
I have a PHP script that pulls down a bunch of RSS feeds. To prevent overloading the publishers' servers, I use the PHP Sleep function to slow things down.
The entire script could last for a couple of hours.
If I run this from a Cron job on GoDaddy, it will happily work for 5 - 10 minutes and then return a server error. I checked and the PHP maximum execution time is 30 seconds, so I'm not sure if this is the cause of the problem.
If I run the job on my Mac, my local PHP also has a default maximum execution time of 30 seconds, but this script does work if I run it from the terminal, but I don't understand why.
How do I loop a script that will exceed 30 seconds without running into unreliability problems?
Help appreciated.
Short answer is use set_time_limit(0) to allow for a long-running script. Your terminal (CLI) PHP probably has it set to 0. You could also be running out of memory, especially on PHP 5.2 or older. Log all errors to a file, and inspect it.
You could rewrite your program to be able to work on a subset of the data during one run. The benefit of that approach is you could use it to run 24/7 or to run every five minutes, depending on what the PHP environment supports. You could also run multiple instances at a time, each working on their own data.
I have a database in MySQL which have entries of time. There are more than 1000 entries of time. I want to extract time and run a PHP script exactly at that time..
I have tried to run a PHP script continuously which check the time, but my server does not allow to run the script for more than 60 seconds.
EDIT. I have to check the database every second. Is there any alternative?
Use the pear package, System_Daemon
http://pear.php.net/package/System_Daemon/
Try Unix's cron.
You'll need some external service to execute the script. On a Unix box, that would be cron. On a Windows box, use Task Scheduler.
Have you thought about writing your process as a server daemon. It would start up and run in a while loop forever. Every few minutes or however often you'd like it could check the next x minutes of run times. You queue up your requests and whenever that time comes around you kick off the script you need to run. I don't think cron is what you'd want since you are trying to schedule future events at arbitrary times... And I'm sure it's what you are currently using to try and check the db every second.
Write a PHP script to read from the database and add entries to your crontab to make the script run at the desired time
Keeping a process running is not a very good solution, not least because you'll need to ensure it does keep running. Presumably you know when the next occurrence is going to happen - so use the 'atd' to schedule it - when triggered the script should also work when and how to schedule the next job.
This does mean that jobs are chained - and failure of one breaks the chain, also the granularity of most implementations of atd can be rather high.
You might want to look at using a more sophisticated scheduling tool like Nagios or a process monitoring type approach like DJB's daemontools or Oracle's OPMN.
C.
You must use the sleep(arg) function that pauses the PHP script for a given time and then continues.
sleep(50); //Pauses
myFunction(); //Runs after the pause
For example, this pauses the script for 50 seconds.
DJB's DAEMONTOOLS is great. So, apparently, is systemd and/or Upstart, though Remnant plays a true wanker.
The recommended Pear package - system_daemon looks great. However, the author now recommends to use new functionality that's readily available in Ubuntu: upstart
See his article on his own blog from 2012
I am using MYSQL as my database and PHP as my programming language.I wanted to run a cron job which would run until the current system date matches the "deadline(date)" column in my database table called "PROJECT".Once the dates are same an update query has to run which would change the status(field of project table) from "open" to "close".
I am not really sure if cron jobs are the best way or I could use triggers or may be something else.Also I am using Apache as my web server and my OS is windows vista.
Also which is the best way to do it? PHP scheduler or cron jobs or any other method? can anybody enlighten me?
I think your concept needs to change.
PHP cannot schedule a job, neither can MySQL. Triggers in MySQL execute when a mysql query occurs, not at a specific time. Neither
This limitation usually isn't a problem in web development. The reason is because your PHP application should control all data going in and out. Usually, this means just the HTML that displays that data, or other formats to users, or other programs.
In your case you can think about it this way. The deadline is a set date. You can treat it as data, and save it to your database. When the deadline occurs is not important, it is that the data you have sent in your database is viewed correctly.
When a request is made to your application, check if the date of the deadline is in the past, if it is, then display that the project is closed - or update that the project is closed, just before display.
There really is no reason to update data independantly of your PHP application.
Usually, the only things you want to schedule are jobs that would affect your application in terms of load, or that need to be done only once, or where concurrency or time is an issue.
In your case none of those apply.
PS: I haven't tried PHPscheduler but I can guess it isn't a true scheduler. Cron is a deamon that sleeps until a given task is due in its queue, executes the task, then sleeps till the next one is due (at least thats what it does in the current algorithm). PHP cannot do that without the sockets and fork extensions, as special setup. So PHPscheduler is most likely just checking if a date for a task has expired, on each load of a webpage (whenever PHP executes a page). This is no different then you just checking if the date on the project has expired, without the overhead of PHPScheduler.
I would always go for a cron job for anything scheduling related.
The big bonus point is that you can echo info out as well and it get's emailed to you.
You'll find once you start using cronjobs, it's hard to stop.
cron does not exist, per se, in vista, but what does exist is the standard windows scheduling manager which you can run with a command line like "php -q -f myfile.php" which will execute the php file at the given time.
you can also use a port of the cron program, there are many out there.
if it is not critical to the second, any windows scheduling application will do, just be sure to have you PHP bin path in your PATH variable for simplicity.
For Windows CRON jobs I cannot recommend PyCron enough.
While CRON and Windows Scheduled Tasks are the tried and true ways of scheduling jobs/tasks to run on a regular basis, there are use cases where having a different scheduled task in CRON/Windows can become tedious. Namely when you want to let users schedule things to run, or for instances where you prefer simplicity/maintainability/portability/etc or all of the above.
In cases where I prefer to not use CRON/Windows for scheduled tasks, I build into the application a task scheduling system. This still requires 1 CRON job or Windows Task to be scheduled. The idea is to store Job details in the database (job name, job properties, last run time, run interval, anything else that is important for your implementation). You then schedule a "Master" job in CRON or Windows which handles running all of your other jobs for you. You'll need this master job to run at least as often as your shortest interval; if you want to be able to schedule jobs that run every minute the master job needs to run every minute.
You can then launch each scheduled job in the background from PHP with minimal effort (if you want). In memory constrained systems you can monitor memory usage or keep track of the PIDs (various methods) and limit to N jobs running at a given time.
I've had a great deal of success with this method, YMMV however based on your needs and your implementation.
how about PHPscheduler..R they not better than cronjobs? I think crons would be independent of the application hence would be difficult if one has to change the host..i am not really sure though..It would be great if anyone can comment on this!! Thanks!
I have a PHP script that needs to be run at certain times every weekday. Is cron or Windows task scheduler the only way to do this?
Is there a way to set this up from within another PHP script?
Depends how exact the timing needs to be. A technique I've seen used (dubbed "poor man's cron") is to have a frequently accessed script (a site's home page, for example) fire off a task on the first page load after a certain time (kept track of in the database).
If you need any sort of guaranteed accuracy, though, cron or a Windows scheduled task is really the best option. If your host doesn't support them, it's time to get a better one.
Apart from cron or Scheduled Tasks, you can have your PHP script to always run it. The process should sleep (within a loop) until the time has reached. Then, the process could execute the remaining functions/methods. Or, you can set up another script (which will act as a daemon) to check for the time and execute the other script.
Well since the web is a pull mechanism you have to have some sort of action that will trigger a PHP script to execute. cron is an option on *nix and task scheduler on windows. You could also write your own service that has a timer but only if needed, this is common on windows services for updaters, jobs etc.
One way you could do it is in the cron task just call a php script for each action needed. Or one php script that executes other tasks. The problem with web based tasks though such as PHP is timeouts. Make sure your tasks are under 60-90 seconds. If not you might look at using python , perl or ruby or even bash scripts to do the work rather than the PHP script.
cron seems like the best option for you though. You will have to call your script with wget. There are examples here: http://www.thesitewizard.com/general/set-cron-job.shtml
For instance this runs the script everyday at 11:
30 11 * * * /usr/bin/wget http://www.example.com/cron.php
Cron, of course, is by far the best way to schedule anything on *nix.
If this is in a remote server you do not have cron access to, you can setup cron/windows scheduler on your computer, to open a web browser to the page that contains the script you wish to run
You probably want to use cron (or windows scheduled tasks).
If you really wanted, you could set up another php script to run continuously with an infinite loop (with a sleep command inside the loop, say for 30 seconds or so) and then when you reach your desired day/time execute the other script via a shell command call. While possible, I can't think if a single good reason to use this method rather than cron/scheduled tasks
You can write a long running script that runs your main script in predefined times but it will be very unnecessary, error prone, and it will basically be a "cron rewrite in phph".
Using the real cron itself will be easier and a more robust solution. If you are packaging an application, you can put a file in /etc/cron.d which contains a single cron line running your application.
You'll need to use a cron job (under Linux/Unix) or a scheduled task under Windows. You could have another script running on a continuous basis which checks the time and executes a script at a specified interval, but using the OS-supplied mechanism is easier to manage and resilient to restarts, etc.
The Uniform Server project has some good suggestions on mimicking cron in environments where cron is unacceptable. Still though, if cron is at all an option, use it.