PHP queue processing: PHP message queue implementation principle (picture and text)

What does php queue mean? How is it achieved? What are the application scenarios? The following explains the implementation principle of PHP message queue in detail through the use of mysql to achieve decoupling and the use of redis to reduce traffic.

The concept of queue:

1. It is the middleware of the queue structure

2. After the message is put in, it does not need to be processed immediately

3,

Processed by subscribers / consumers in order

Queue principle:

is also the principle of decoupling: the business system and the queue processing system have nothing to do

One writes (business system) and one reads ( queue management system).

Just writeto the queueWrite, don’t worry about anything else, it doesn’t matter whether you can finish reading or not

Similarly ,

Just read from the queue out , do the work when it comes, and rest when there is no work

Application scenarios:

Redundancy:

Permanently stored in the queue

, and subsequently obtained by the order processing program. After the processing is completed, the record is deleted Decoupling: yes decoupling These two systems (business and queue processing) are what we usually do. There is no direct relationship between the systems that enter the queue and the systems that exit the queue.

If one system fails, the other system will not be affected

because there is a queue in the middleThe traffic is reduced. Edge: Flash sales and rush sales. The traffic increased sharply, Use the message queue with the cache

(It is under the limit, for example, only 10 are allowed, and after 10 are stored in the queue, they will no longer be stored, and the flash sale will be prompted when it comes)

Asynchronous communication: Because the message itself can cause the queued system to

return directly, it is said that the asynchronous operation of the program is realized

Scenario scalability: such as

Now there are only order system and financial system. I want to add a distribution system in the future. Just let the distribution system subscribe to this queue directlySorting guarantee: some scenarios For example,

the processing order of bank data is very important, because the queue itself can be made into a single-threaded, single-input, single-out systemImplementation medium:

1. Using mysql: high reliability, easy to implement, slow speed2. Using redis: fast speed, single large message package Low efficiency

3. Use a more professional third-party class library: highly professional, reliable, and high learning cost.

Message processing triggering mechanism:

1. Infinite loop reading: easy to implement, unable to reply in time in case of failure (Suitable for short periods such as flash sales )

2. Scheduled tasks: pressure is evenly distributed and has a processing upper limit (no matter how unstable the peak value of the system in front of your queue is, the system behind the queue will still execute it regularly )

Note: Timing time is the key: do not start the next scheduled task before the previous scheduled task is completed

Case: Order system, place an order After writing the order information into the queue, it immediately returns that the order was placed successfully. The distribution system reads the queue every few minutesregularly, and summarizes the orders

3. Daemon process: similar to php-fpm and cgi, requires shell basics (use this process to Check whether there is content in the queue. If there is content, start the dequeuing system for processing)

Use mysql to implement decoupling case:

Why decoupling: If the architecture is together. The order system is under great pressure, and logistics information does not need to be returned immediately. When orders collapse, logistics also collapses, so we need to decouple

Table design:

The order system writes the code to the queue:

The distribution system reads the queue code:

Execute scheduled tasksCrontab -e

Note: This log file must be created by yourself

1. Access through the browser order.phpAdd order

2. Go to the database to see the results, and see the results in the log in shell ( The execution was not successful, maybe this sh file needs to be placed in a certain directory, and I will run it after the review is completed)

Using redis for traffic cutting case

Idea:

1. The flash sale program requests writing to redis

2. Check the length of the data stored in redis. If it exceeds the upper limit, it will be discarded directly (return to the end of the flash sale)

3. Infinite loop processing and storage in redis The data is merged into the database

Table design:

Flash sale code:

Storage code:

Browser direct access to user.php

atshell Use php -f savetodb.php

Go to the database to view

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PHP message queue service

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