Record the processing process of a certain PHP background system where images cannot be uploaded-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

Record the processing process of a certain PHP background system where images cannot be uploaded

藏色散人

Dec 13, 2021 pm 03:03 PM

php

Problem

The business department reported that a certain background system cannot upload pictures.

Background situation

There is no operation and maintenance post, the pagoda panel used by the server is unified

Processing process

Get ready to go to the server (Pagoda panel background) and look at the error log. Enter your account number and password and press Enter. It will prompt that the login is successful and jump to the login page. I have changed several browsers (I have a browser that only Used to look at the production server) This is the case
ssh successfully logged in to the server, df -h At first glance, my dear, the system disk is 100% (the system disk is only 20G), the problem has been found
I am going to empty the recycle bin first, but there is nothing in the /www/Recycle_bin/ directory
Execute the du -h --max-depth=1 command in the root directory to see which folder takes up more space, the one in the /www/wwwlogs/ directory The nginx log occupies about 13G
I found several log files exceeding 1G and deleted them with rm -rf xxx.log. The login panel background is still the same as before. Same situation. df -h Found that the system disk is still 100% occupied, the file was deleted, and the space was not recovered
The reason is that when Linux deletes files, it only deletes the files in the system A pointer to the file. If there are still processes using the file, the file will always exist. You can use lsof | grep delete to find the corresponding process and then kill, or you can directly restart the corresponding service.
Execute the /etc/init.d/nginx reload command to reload the nginx service and find that the remaining space is normal and the test upload function is normal.
I did two things later, one was to clean up part of the request log, and the other was to create a task for regular log cleaning

Better way to delete

A better way to delete large files is echo '' > file.ext, which directly overwrites and writes. #

The above is the detailed content of Record the processing process of a certain PHP background system where images cannot be uploaded. For more information, please follow other related articles on the PHP Chinese website!

Statement

This article is reproduced at:learnku. If there is any infringement, please contact admin@php.cn delete

How do you modify data stored in a PHP session?Apr 27, 2025 am 12:23 AM

TomodifydatainaPHPsession,startthesessionwithsession_start(),thenuse$_SESSIONtoset,modify,orremovevariables.1)Startthesession.2)Setormodifysessionvariablesusing$_SESSION.3)Removevariableswithunset().4)Clearallvariableswithsession_unset().5)Destroythe

Give an example of storing an array in a PHP session.Apr 27, 2025 am 12:20 AM

Arrays can be stored in PHP sessions. 1. Start the session and use session_start(). 2. Create an array and store it in $_SESSION. 3. Retrieve the array through $_SESSION. 4. Optimize session data to improve performance.

How does garbage collection work for PHP sessions?Apr 27, 2025 am 12:19 AM

PHP session garbage collection is triggered through a probability mechanism to clean up expired session data. 1) Set the trigger probability and session life cycle in the configuration file; 2) You can use cron tasks to optimize high-load applications; 3) You need to balance the garbage collection frequency and performance to avoid data loss.

How can you trace session activity in PHP?Apr 27, 2025 am 12:10 AM

Tracking user session activities in PHP is implemented through session management. 1) Use session_start() to start the session. 2) Store and access data through the $_SESSION array. 3) Call session_destroy() to end the session. Session tracking is used for user behavior analysis, security monitoring, and performance optimization.

How can you use a database to store PHP session data?Apr 27, 2025 am 12:02 AM

Using databases to store PHP session data can improve performance and scalability. 1) Configure MySQL to store session data: Set up the session processor in php.ini or PHP code. 2) Implement custom session processor: define open, close, read, write and other functions to interact with the database. 3) Optimization and best practices: Use indexing, caching, data compression and distributed storage to improve performance.

Explain the concept of a PHP session in simple terms.Apr 26, 2025 am 12:09 AM

PHPsessionstrackuserdataacrossmultiplepagerequestsusingauniqueIDstoredinacookie.Here'showtomanagethemeffectively:1)Startasessionwithsession_start()andstoredatain$_SESSION.2)RegeneratethesessionIDafterloginwithsession_regenerate_id(true)topreventsessi

How do you loop through all the values stored in a PHP session?Apr 26, 2025 am 12:06 AM

In PHP, iterating through session data can be achieved through the following steps: 1. Start the session using session_start(). 2. Iterate through foreach loop through all key-value pairs in the $_SESSION array. 3. When processing complex data structures, use is_array() or is_object() functions and use print_r() to output detailed information. 4. When optimizing traversal, paging can be used to avoid processing large amounts of data at one time. This will help you manage and use PHP session data more efficiently in your actual project.

Explain how to use sessions for user authentication.Apr 26, 2025 am 12:04 AM

The session realizes user authentication through the server-side state management mechanism. 1) Session creation and generation of unique IDs, 2) IDs are passed through cookies, 3) Server stores and accesses session data through IDs, 4) User authentication and status management are realized, improving application security and user experience.

See all articles