


How to troubleshoot abnormal memory increase in MySQL production database
Modify performance_schema
Because the company's production environment uses Alibaba Cloud RDS, it is relatively convenient to modify parameters. The default performance_schema is 0, and this time it is modified to 1. After modifying the parameters and submitting them, the database will be restarted. It is recommended to do this during low business peaks.
Turn on memory monitoring
Log in to the MySQL database, execute the following SQL, and turn on memory monitoring.
update performance_schema.setup_instruments set enabled = 'yes' where name like 'memory%';
Verify it after opening it.
select * from performance_schema.setup_instruments where name like 'memory%innodb%' limit 5;
**Note: **This command is to open memory statistics online, so only newly added memory objects after opening will be counted. Memory objects before opening will not be counted. It is recommended that you wait for a while after opening. Perform the next steps to identify threads with high memory usage.
Find memory consumption
Statistical event memory consumption
select event_name, SUM_NUMBER_OF_BYTES_ALLOC from performance_schema.memory_summary_global_by_event_name order by SUM_NUMBER_OF_BYTES_ALLOC desc LIMIT 10; +---------------------------------------+-------------------------------------+ | event_name | SUM_NUMBER_OF_BYTES_ALLOC | +---------------------------------------+-------------------------------------+ | memory/sql/Filesort_buffer::sort_keys | 763523904056 | | memory/memory/HP_PTRS | 118017336096 | | memory/sql/thd::main_mem_root | 114026214600 | | memory/mysys/IO_CACHE | 59723548888 | | memory/sql/QUICK_RANGE_SELECT::alloc | 14381459680 | | memory/sql/test_quick_select | 12859304736 | | memory/innodb/mem0mem | 7607681148 | | memory/sql/String::value | 1405409537 | | memory/sql/TABLE | 1117918354 | | memory/innodb/btr0sea | 984013872 | +---------------------------------------+-------------------------------------+
You can see that the event with the highest memory consumption is Filesort_buffer. According to experience, this should be related to sorting.
Statistical thread consumption of memory
select thread_id, event_name, SUM_NUMBER_OF_BYTES_ALLOC from performance_schema.memory_summary_by_thread_by_event_name order by SUM_NUMBER_OF_BYTES_ALLOC desc limit 10; +---------------------+---------------------------------------+-------------------------------------+ | thread_id | event_name | SUM_NUMBER_OF_BYTES_ALLOC | +---------------------+---------------------------------------+-------------------------------------+ | 105 | memory/memory/HP_PTRS | 69680198792 | | 183 | memory/sql/Filesort_buffer::sort_keys | 49210098808 | | 154 | memory/sql/Filesort_buffer::sort_keys | 43304339072 | | 217 | memory/sql/Filesort_buffer::sort_keys | 37752275360 | | 2773 | memory/sql/Filesort_buffer::sort_keys | 31460644712 | | 218 | memory/sql/Filesort_buffer::sort_keys | 31128994280 | | 2331 | memory/sql/Filesort_buffer::sort_keys | 28763981248 | | 106 | memory/memory/HP_PTRS | 27938197584 | | 191 | memory/sql/Filesort_buffer::sort_keys | 27701610224 | | 179 | memory/sql/Filesort_buffer::sort_keys | 25624723968 | +---------------------+---------------------------------------+-------------------------------------+
It can be seen that threads that consume a lot of memory are related to Filesort_buffer
.
Locate the specific SQL
According to the thread_id
we found earlier, search the log for the corresponding SQL. The Alibaba Cloud RDS audit log is relatively powerful. We retrieve directly based on thread_id.
We saw a large number of such SQLs in the logs, and the number of scanned rows ranged from thousands to tens of thousands. Although the time of each query is not long, usually between tens and hundreds of milliseconds, the number of concurrent requests is large.
The above is the detailed content of How to troubleshoot abnormal memory increase in MySQL production database. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

1. The first choice for the Laravel MySQL Vue/React combination in the PHP development question and answer community is the first choice for Laravel MySQL Vue/React combination, due to its maturity in the ecosystem and high development efficiency; 2. High performance requires dependence on cache (Redis), database optimization, CDN and asynchronous queues; 3. Security must be done with input filtering, CSRF protection, HTTPS, password encryption and permission control; 4. Money optional advertising, member subscription, rewards, commissions, knowledge payment and other models, the core is to match community tone and user needs.

There are three main ways to set environment variables in PHP: 1. Global configuration through php.ini; 2. Passed through a web server (such as SetEnv of Apache or fastcgi_param of Nginx); 3. Use putenv() function in PHP scripts. Among them, php.ini is suitable for global and infrequently changing configurations, web server configuration is suitable for scenarios that need to be isolated, and putenv() is suitable for temporary variables. Persistence policies include configuration files (such as php.ini or web server configuration), .env files are loaded with dotenv library, and dynamic injection of variables in CI/CD processes. Security management sensitive information should be avoided hard-coded, and it is recommended to use.en

To achieve MySQL deployment automation, the key is to use Terraform to define resources, Ansible management configuration, Git for version control, and strengthen security and permission management. 1. Use Terraform to define MySQL instances, such as the version, type, access control and other resource attributes of AWSRDS; 2. Use AnsiblePlaybook to realize detailed configurations such as database user creation, permission settings, etc.; 3. All configuration files are included in Git management, support change tracking and collaborative development; 4. Avoid hard-coded sensitive information, use Vault or AnsibleVault to manage passwords, and set access control and minimum permission principles.

Why do I need SSL/TLS encryption MySQL connection? Because unencrypted connections may cause sensitive data to be intercepted, enabling SSL/TLS can prevent man-in-the-middle attacks and meet compliance requirements; 2. How to configure SSL/TLS for MySQL? You need to generate a certificate and a private key, modify the configuration file to specify the ssl-ca, ssl-cert and ssl-key paths and restart the service; 3. How to force SSL when the client connects? Implemented by specifying REQUIRESSL or REQUIREX509 when creating a user; 4. Details that are easily overlooked in SSL configuration include certificate path permissions, certificate expiration issues, and client configuration requirements.

To collect user behavior data, you need to record browsing, search, purchase and other information into the database through PHP, and clean and analyze it to explore interest preferences; 2. The selection of recommendation algorithms should be determined based on data characteristics: based on content, collaborative filtering, rules or mixed recommendations; 3. Collaborative filtering can be implemented in PHP to calculate user cosine similarity, select K nearest neighbors, weighted prediction scores and recommend high-scoring products; 4. Performance evaluation uses accuracy, recall, F1 value and CTR, conversion rate and verify the effect through A/B tests; 5. Cold start problems can be alleviated through product attributes, user registration information, popular recommendations and expert evaluations; 6. Performance optimization methods include cached recommendation results, asynchronous processing, distributed computing and SQL query optimization, thereby improving recommendation efficiency and user experience.

When choosing a suitable PHP framework, you need to consider comprehensively according to project needs: Laravel is suitable for rapid development and provides EloquentORM and Blade template engines, which are convenient for database operation and dynamic form rendering; Symfony is more flexible and suitable for complex systems; CodeIgniter is lightweight and suitable for simple applications with high performance requirements. 2. To ensure the accuracy of AI models, we need to start with high-quality data training, reasonable selection of evaluation indicators (such as accuracy, recall, F1 value), regular performance evaluation and model tuning, and ensure code quality through unit testing and integration testing, while continuously monitoring the input data to prevent data drift. 3. Many measures are required to protect user privacy: encrypt and store sensitive data (such as AES

PHP plays the role of connector and brain center in intelligent customer service, responsible for connecting front-end input, database storage and external AI services; 2. When implementing it, it is necessary to build a multi-layer architecture: the front-end receives user messages, the PHP back-end preprocesses and routes requests, first matches the local knowledge base, and misses, call external AI services such as OpenAI or Dialogflow to obtain intelligent reply; 3. Session management is written to MySQL and other databases by PHP to ensure context continuity; 4. Integrated AI services need to use Guzzle to send HTTP requests, safely store APIKeys, and do a good job of error handling and response analysis; 5. Database design must include sessions, messages, knowledge bases, and user tables, reasonably build indexes, ensure security and performance, and support robot memory

To enable PHP containers to support automatic construction, the core lies in configuring the continuous integration (CI) process. 1. Use Dockerfile to define the PHP environment, including basic image, extension installation, dependency management and permission settings; 2. Configure CI/CD tools such as GitLabCI, and define the build, test and deployment stages through the .gitlab-ci.yml file to achieve automatic construction, testing and deployment; 3. Integrate test frameworks such as PHPUnit to ensure that tests are automatically run after code changes; 4. Use automated deployment strategies such as Kubernetes to define deployment configuration through the deployment.yaml file; 5. Optimize Dockerfile and adopt multi-stage construction
