How to deal with Redis memory fragmentation?
Apr 10, 2025 pm 02:24 PM
Redis memory fragmentation refers to the existence of small free areas in the allocated memory that cannot be reassigned. Coping strategies include: Restart Redis: completely clear the memory, but interrupt service. Optimize data structures: Use a structure that is more suitable for Redis to reduce the number of memory allocations and releases. Adjust configuration parameters: Use the policy to eliminate the least recently used key-value pairs. Use persistence mechanism: Back up data regularly and restart Redis to clean up fragments. Monitor memory usage: Discover problems in a timely manner and take measures.
Redis memory fragments, this thing has troubled many people, and so do I. Simply put, some places are used in the memory allocated by Redis, and some are empty, but these empty areas are too small to be allocated to new data structures, wasting space. It's like your refrigerator, stuffed with all kinds of leftover pieces. Although the refrigerator has a lot of space, there is no place to put a big watermelon in it.
In this article, let’s talk about how to deal with this annoying memory fragment. After reading it, you will understand the causes of Redis memory fragmentation and several coping strategies to avoid falling into the pits I have stepped on.
First, you have to figure out how Redis manages memory. It uses jemalloc, a very efficient memory allocator. jemalloc will divide memory into different blocks with different sizes to meet the needs of different data structures. But no matter how awesome jemalloc is, it cannot avoid the creation of fragments. Frequent memory allocation and release, especially frequent operations of small objects, are most likely to cause fragmentation. Think about it, you keep stuffing snacks into the refrigerator, take out some, and then stuff them in, and finally the refrigerator is full of fragments.
So, how to solve it? The most direct way is to restart Redis. It's like completely emptying the refrigerator and reorganizing it. But this is certainly not the best solution, because restarting will interrupt services and cause the risk of data loss.
Another idea is to optimize your data structure and usage. If your data structure is relatively small, frequent additions, deletions, modifications and checks will lead to a large number of small fragments. At this time, you can consider using some data structures that are more suitable for Redis, such as Hash instead of List, to reduce the number of memory allocation and release times. It's like you switch to some more reasonable storage boxes to organize the pieces in the refrigerator.
Another method is to adjust the configuration parameters of Redis. maxmemory-policy parameter controls Redis's policy when there is insufficient memory. You can choose different strategies, such as allkeys-lru , to let Redis eliminate some of the least recently used key-value pairs. This is equivalent to cleaning the refrigerator regularly, throwing away some of the near-expiration food, and making room. But it should be noted that choosing the right strategy requires decisions based on your actual application scenario. Choosing the wrong one may lead to the loss of important data.
Going further, you can consider using Redis's persistence mechanism, such as RDB or AOF. Back up data regularly, then restart Redis to clean up memory fragmentation. It's like taking out everything in the refrigerator regularly, wiping the refrigerator clean, and putting the important things back. While this can solve the problem, the backup and recovery process can be time and resources.
Finally, I would like to remind you that monitoring Redis's memory usage is very important. You can use Redis's own monitoring commands or some third-party monitoring tools to promptly discover memory fragmentation problems and take corresponding measures. It's like you often check the refrigerator to see if it's too messy and clean it up in time.
In short, there is no one-time solution to deal with Redis memory fragmentation, and you need to choose the appropriate strategy based on the actual situation. Remember that prevention is better than treatment. Only by having good programming habits and reasonable configuration parameters can we fundamentally reduce the generation of memory fragmentation. Don't forget that the code should be written elegantly and the annotations should be written clearly, so that it will be easier for you to find solutions when facing problems. My code style is more concise and efficient. Here is a simple example showing how to use Lua scripts to perform batch deletion operations to reduce fragmentation:
<code class="lua">local keys = redis.call('KEYS', 'myprefix:*') for i, key in ipairs(keys) do redis.call('DEL', key) end</code>
This is just a simple example, and more complex logic may be required in practical applications. Remember, choosing the right tools and methods can better meet challenges.
The above is the detailed content of How to deal with Redis memory fragmentation?. 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)
Hot Topics
How to use PHP to build social sharing functions PHP sharing interface integration practice
Jul 25, 2025 pm 08:51 PM
The core method of building social sharing functions in PHP is to dynamically generate sharing links that meet the requirements of each platform. 1. First get the current page or specified URL and article information; 2. Use urlencode to encode the parameters; 3. Splice and generate sharing links according to the protocols of each platform; 4. Display links on the front end for users to click and share; 5. Dynamically generate OG tags on the page to optimize sharing content display; 6. Be sure to escape user input to prevent XSS attacks. This method does not require complex authentication, has low maintenance costs, and is suitable for most content sharing needs.
How to use PHP combined with AI to achieve text error correction PHP syntax detection and optimization
Jul 25, 2025 pm 08:57 PM
To realize text error correction and syntax optimization with AI, you need to follow the following steps: 1. Select a suitable AI model or API, such as Baidu, Tencent API or open source NLP library; 2. Call the API through PHP's curl or Guzzle and process the return results; 3. Display error correction information in the application and allow users to choose whether to adopt it; 4. Use php-l and PHP_CodeSniffer for syntax detection and code optimization; 5. Continuously collect feedback and update the model or rules to improve the effect. When choosing AIAPI, focus on evaluating accuracy, response speed, price and support for PHP. Code optimization should follow PSR specifications, use cache reasonably, avoid circular queries, review code regularly, and use X
PHP calls AI intelligent voice assistant PHP voice interaction system construction
Jul 25, 2025 pm 08:45 PM
User voice input is captured and sent to the PHP backend through the MediaRecorder API of the front-end JavaScript; 2. PHP saves the audio as a temporary file and calls STTAPI (such as Google or Baidu voice recognition) to convert it into text; 3. PHP sends the text to an AI service (such as OpenAIGPT) to obtain intelligent reply; 4. PHP then calls TTSAPI (such as Baidu or Google voice synthesis) to convert the reply to a voice file; 5. PHP streams the voice file back to the front-end to play, completing interaction. The entire process is dominated by PHP to ensure seamless connection between all links.
PHP realizes commodity inventory management and monetization PHP inventory synchronization and alarm mechanism
Jul 25, 2025 pm 08:30 PM
PHP ensures inventory deduction atomicity through database transactions and FORUPDATE row locks to prevent high concurrent overselling; 2. Multi-platform inventory consistency depends on centralized management and event-driven synchronization, combining API/Webhook notifications and message queues to ensure reliable data transmission; 3. The alarm mechanism should set low inventory, zero/negative inventory, unsalable sales, replenishment cycles and abnormal fluctuations strategies in different scenarios, and select DingTalk, SMS or Email Responsible Persons according to the urgency, and the alarm information must be complete and clear to achieve business adaptation and rapid response.
How to use PHP to combine AI to generate image. PHP automatically generates art works
Jul 25, 2025 pm 07:21 PM
PHP does not directly perform AI image processing, but integrates through APIs, because it is good at web development rather than computing-intensive tasks. API integration can achieve professional division of labor, reduce costs, and improve efficiency; 2. Integrating key technologies include using Guzzle or cURL to send HTTP requests, JSON data encoding and decoding, API key security authentication, asynchronous queue processing time-consuming tasks, robust error handling and retry mechanism, image storage and display; 3. Common challenges include API cost out of control, uncontrollable generation results, poor user experience, security risks and difficult data management. The response strategies are setting user quotas and caches, providing propt guidance and multi-picture selection, asynchronous notifications and progress prompts, key environment variable storage and content audit, and cloud storage.
How to use PHP to call AI writing auxiliary tools PHP improves content output efficiency
Jul 25, 2025 pm 08:18 PM
When choosing an AI writing API, you need to examine stability, price, function matching and whether there is a free trial; 2. PHP uses Guzzle to send POST requests and uses json_decode to process the returned JSON data, pay attention to capturing exceptions and error codes; 3. Integrating AI content into the project requires an audit mechanism and supporting personalized customization; 4. Cache, asynchronous queue and current limiting technology can be used to optimize performance to avoid bottlenecks due to high concurrency.
The top 10 most authoritative cryptocurrency market websites in the world (the latest version of 2025)
Jul 29, 2025 pm 12:48 PM
The top ten authoritative cryptocurrency market and data analysis platforms in 2025 are: 1. CoinMarketCap, providing comprehensive market capitalization rankings and basic market data; 2. CoinGecko, providing multi-dimensional project evaluation with independence and trust scores; 3. TradingView, having the most professional K-line charts and technical analysis tools; 4. Binance market, providing the most direct real-time data as the largest exchange; 5. Ouyi market, highlighting key derivative indicators such as position volume and capital rate; 6. Glassnode, focusing on on-chain data such as active addresses and giant whale trends; 7. Messari, providing institutional-level research reports and strict standardized data; 8. CryptoCompa
Twilio call keeping and recovery: Meeting mode with independent call leg processing
Jul 25, 2025 pm 08:42 PM
This article elaborates on two main methods to realize call hold and unhold in Twilio. The preferred option is to leverage Twilio's Conference feature to easily enable call retention and recovery by updating the conference participant resources, and to customize music retention. Another approach is to deal with independent call legs, which requires more complex TwiML logic, passed, and arrived management, but is more cumbersome than meeting mode. The article provides specific code examples and operation steps to help developers efficiently implement Twilio call control.
