CODEWITHSUNDEEP
phpmysqlajaxgearman
Clement
Clement

Reputation: 35

How to use gearman to perform recuring tasks

I am making an payment system in PHP which depends on a REST API.

My Business Logic:

If someone submits a request through my system, lets say "transfer money from point A to point B" that transaction is saved in my database with status: "submited", then submitted to the (Mobile Network Operator) API URL which processes it and returns back the status to my system, update my database transaction status to the new status 'eg: waiting for the confirmation' and notify the user of the incoming status.

The problem is:

My application should keep requesting with an interval of 10 seconds to check for the new status and showing the new status to the user till the last status of 'complete or declined', since statuses can range to 5 eg:"waiting, declined, approved, complete...' .

I have managed to do this using AJAX, setting time intervals in JavaScript. But it stops requesting if the user closes the browser or anything happened at their end. resulting into my app not knowing whether the money was delivered or not .

I would like to how i can run this circular tasks in the background using Gearman without involving JavaScript time intervals thanks

Upvotes: 2

Views: 300

Answers (2)

Kris Peeling
Kris Peeling

Reputation: 1025

You wouldn't use Gearman in the background for circular tasks, which is normally referred to as polling. Gearman is normally used as a job queue for doing things like video compression, resizing images, sending emails, or other tasks that you want to 'background'.

I don't recommend polling the database, either on the frontend or the backend. Polling is generally considered bad, because it doesn't scale. In your javascript example, you can see that as your application grows and is used by thousands of users, polling is going to introduce a lot of unnecessary traffic and load on your servers. On the backend, the machine doing the polling is a single point of failure.

The architecture you want to explore is a message queue. It's similar to the Listener/Observer pattern in programming, but applied at the systems level. This will allow a more robust system that can handle interruptions, from a user closing the browser all the way to a backend system going down for maintenance.

Upvotes: 0

Alex Barker
Alex Barker

Reputation: 4400

Gearman is more of a worker queue, not a scheduling system. I would probably setup some type of cron job that will query the database and submit the appropriate jobs to Gearman in an async way. With gearman, you will want to use libdrizzle or something else for persistent queues and also some type of GearmanWorker process manager to run more than one job at a time. There are a number of projects that currently do this with varying degrees of success like https://github.com/brianlmoon/GearmanManager. None of the worker managers I have evaluated have really been up to par, so I created my own that will probably be open-sourced shortly.

Upvotes: 2

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