**The core parameter of Redis memory configuration is maxmemory, which limits the amount of memory that Redis can use. When this limit is exceeded, Redis executes an elimination strategy based on maxmemory-policy, including: noeviction (directly reject write), allkeys-lru/volatile-lru (eliminated by LRU), allkeys-random/volatile-random (eliminated by random elimination), and volatile-ttl (eliminated by expiration time). Other related parameters include maxmemory-samples (LRU sample quantity), rdb-compression
Redis memory configuration? This is a cliché, but often troublesome problem. Do you think that simply increasing maxmemory
will make everything go well? Naive! This article will look at the Redis memory configuration, so that you no longer scratch your head for memory rush. After reading it, you can easily control Redis's memory configuration like an experienced driver, so that your Redis can run fast and steadily.
Don't rush to see the parameters first, let's talk about Redis's memory model first. Redis is a memory-based database where all data is stored in memory. This determines the importance of memory configuration. If the memory is insufficient, the performance will be degraded at the least, and the operation will be down. Only by understanding this can you better understand the role of various memory configuration parameters.
The core memory parameter of Redis is undoubtedly maxmemory
. It limits the maximum amount of memory that Redis can use. If this limit is exceeded, Redis will execute different elimination strategies based on maxmemory-policy
you set. There are many strategies, such as noeviction
, allkeys-lru
, allkeys-random
, volatile-lru
, volatile-random
, volatile-ttl
, each with its own characteristics. noeviction
is the simplest and most crude, and it directly refuses to write new data, which can easily lead to application blockage; allkeys-lru
and volatile-lru
will eliminate the longest-lasting keys according to the LRU algorithm, which is relatively gentle; while the random
strategy is more casual, suitable for scenarios with low requirements for data accuracy. Which strategy to choose depends on your application scenario. Don't use noeviction
to save trouble, it's a time bomb.
In addition to maxmemory
and maxmemory-policy
, there are other memory-related parameters, such as maxmemory-samples
that controls the number of samples of LRU algorithms, affecting the accuracy of the elimination strategy; rdb-compression
controls the compression level of RDB persistent files, affecting disk space and persistence speed; and aof-rewrite-incremental-fsync
affects memory usage during AOF rewrite, etc. The settings of these parameters need to be comprehensively considered based on your Redis version, hardware resources, and application characteristics.
Let’s take a look at an example and experience the differences between different strategies:
<code class="python"># 模擬數(shù)據(jù)import random import time data = {f"key_{i}": f"value_{i}" for i in range(1000)} # 連接Redis (假設(shè)你已經(jīng)安裝了redis-py) import redis r = redis.Redis(host='localhost', port=6379, db=0) # 設(shè)置不同的maxmemory-policy policies = ["noeviction", "allkeys-lru", "volatile-lru"] for policy in policies: print(f"Testing policy: {policy}") r.config_set('maxmemory', '10mb') # 設(shè)置最大內(nèi)存為10MB r.config_set('maxmemory-policy', policy) start_time = time.time() try: for key, value in data.items(): r.set(key, value) except redis.exceptions.RedisError as e: print(f"Error: {e}") end_time = time.time() print(f"Time taken: {end_time - start_time:.2f} seconds") print("-" * 20) r.flushall() # 清理數(shù)據(jù)</code>
This code simulates writing large amounts of data to Redis and tests three different maxmemory-policy
. You will find that noeviction
will directly report an error when there is insufficient memory, while the lru
strategy will consume more time because data elimination is required. In practical applications, you need to choose the appropriate strategy based on your data characteristics and performance requirements.
Finally, let me remind you not to forget to monitor your Redis memory usage. You can use Redis's own monitoring tools or some third-party monitoring tools to discover problems in a timely manner and avoid accidents. Memory configuration is not a one-time thing, and needs to be continuously adjusted according to actual conditions. This requires accumulation of experience and continuous learning and practice. I wish you to play with Redis memory configuration!
The above is the detailed content of What are the Redis memory configuration parameters?. 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









The stablecoin trading process includes the steps of registering an exchange, completing certification, buying or selling. First, choose a trusted exchange such as Binance, OKX, etc., and then complete KYC identity authentication, and then buy stablecoins through fiat currency recharge or OTC transactions. You can also transfer the stablecoins to the fund account and sell them through P2P transactions and withdraw them to the bank card or Alipay. When operating, you need to pay attention to choosing a regulated platform, confirm transaction security and handling fees.

In Python, the following points should be noted when merging strings using the join() method: 1. Use the str.join() method, the previous string is used as a linker when calling, and the iterable object in the brackets contains the string to be connected; 2. Make sure that the elements in the list are all strings, and if they contain non-string types, they need to be converted first; 3. When processing nested lists, you must flatten the structure before connecting.

To master Python web crawlers, you need to grasp three core steps: 1. Use requests to initiate a request, obtain web page content through get method, pay attention to setting headers, handling exceptions, and complying with robots.txt; 2. Use BeautifulSoup or XPath to extract data. The former is suitable for simple parsing, while the latter is more flexible and suitable for complex structures; 3. Use Selenium to simulate browser operations for dynamic loading content. Although the speed is slow, it can cope with complex pages. You can also try to find a website API interface to improve efficiency.

There are three common methods for deduplication in Python. 1. Use set deduplication: It is suitable for situations where you don’t care about the order, and is implemented through list(set(my_list)). The advantage is that it is simple and fast, and the disadvantage is to disrupt the order; 2. Manually judge the deduplication: By traversing the original list and determining whether the elements already exist in the new list, the elements that appear for the first time are retained, which is suitable for scenarios where order needs to be maintained; 3. dict.fromkeys() deduplication: supported by Python 3.7, implemented through list(dict.fromkeys(my_list)), which maintains both the order and the writing method is concise. It is recommended to use modern Python. Notes include first converting the structure when dealing with non-hashable elements. It is recommended to use large data sets.

To get started with quantum machine learning (QML), the preferred tool is Python, and libraries such as PennyLane, Qiskit, TensorFlowQuantum or PyTorchQuantum need to be installed; then familiarize yourself with the process by running examples, such as using PennyLane to build a quantum neural network; then implement the model according to the steps of data set preparation, data encoding, building parametric quantum circuits, classic optimizer training, etc.; in actual combat, you should avoid pursuing complex models from the beginning, paying attention to hardware limitations, adopting hybrid model structures, and continuously referring to the latest documents and official documents to follow up on development.

To get a list of members based on scores from a ordered set of Redis, the ZRANGEBYSCORE command should be used. 1) The basic syntax is ZRANGEBYSCOREkeyminmax, which is used to obtain members within the specified score range; 2) Pagination query can be implemented by adding LIMIToffsetcount; 3) The boundary value can be excluded by adding (symbols before min or max; 4) The WITHSCORES flag can be added to return members and their scores at the same time.

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.

Blockchain browser is a must-have on-chain query tool for Web3 users. 1. It serves as a "search engine" in the decentralized world, allowing users to openly and transparently verify all records on the blockchain; 2. The core functions include querying transaction details, viewing account information, exploring block data and tracking smart contracts; 3. When tracking transactions, you need to obtain the transaction hash, select the browser corresponding to the public chain, and enter the hash to view the status, address, amount and fee details; 4. Confirm whether the transaction is successful through the browser is a key step to ensure the security of digital assets. Proficient use can help users better understand and participate in the blockchain ecosystem, thereby operating more safely and stably in the decentralized world.
