memcache 的限制内存用光了以后,新的项加入会把旧的未过期项删除吗?
memcache 的限制内存用光了以后,新的项加入会把旧的未过期项删除吗? 还是怎样处理的?
比如大家都是未过期的,即都是有效缓存时间内, 超过最大使用内存后,比如100m, 加入的项,是不是先进先出这样的 ?
------解决方案--------------------
lru 自动清除最近比较少用的，然后将新的覆盖。
------解决方案--------------------
memcache的内存是按页分配的, 分配一页之后再分成更多的小块, 这样做的后果时, 回收也是按页回收, 所以往往会把不一定是"旧"的东西也给回收了, 所以会存在命中率问题, 如果你服务器可用内存很小, 还是不要使用memcache了, 可以考虑使用文件式的hash缓存类
------解决方案--------------------
http://hi.baidu.com/joysoftfan/blog/item/e6deaae459d7ae3ab9382035.html
google了一下，然后自己也写了个脚本测试了下，的确如2L所说
What is the difference between absolute and idle session timeouts?May 03, 2025 am 12:21 AMAbsolute session timeout starts at the time of session creation, while an idle session timeout starts at the time of user's no operation. Absolute session timeout is suitable for scenarios where strict control of the session life cycle is required, such as financial applications; idle session timeout is suitable for applications that want users to keep their session active for a long time, such as social media.
What steps would you take if sessions aren't working on your server?May 03, 2025 am 12:19 AMThe server session failure can be solved through the following steps: 1. Check the server configuration to ensure that the session is set correctly. 2. Verify client cookies, confirm that the browser supports it and send it correctly. 3. Check session storage services, such as Redis, to ensure that they are running normally. 4. Review the application code to ensure the correct session logic. Through these steps, conversation problems can be effectively diagnosed and repaired and user experience can be improved.
What is the significance of the session_start() function?May 03, 2025 am 12:18 AMsession_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.
What is the importance of setting the httponly flag for session cookies?May 03, 2025 am 12:10 AMSetting the httponly flag is crucial for session cookies because it can effectively prevent XSS attacks and protect user session information. Specifically, 1) the httponly flag prevents JavaScript from accessing cookies, 2) the flag can be set through setcookies and make_response in PHP and Flask, 3) Although it cannot be prevented from all attacks, it should be part of the overall security policy.
What problem do PHP sessions solve in web development?May 03, 2025 am 12:02 AMPHPsessionssolvetheproblemofmaintainingstateacrossmultipleHTTPrequestsbystoringdataontheserverandassociatingitwithauniquesessionID.1)Theystoredataserver-side,typicallyinfilesordatabases,anduseasessionIDstoredinacookietoretrievedata.2)Sessionsenhances
What data can be stored in a PHP session?May 02, 2025 am 12:17 AMPHPsessionscanstorestrings,numbers,arrays,andobjects.1.Strings:textdatalikeusernames.2.Numbers:integersorfloatsforcounters.3.Arrays:listslikeshoppingcarts.4.Objects:complexstructuresthatareserialized.
How do you start a PHP session?May 02, 2025 am 12:16 AMTostartaPHPsession,usesession_start()atthescript'sbeginning.1)Placeitbeforeanyoutputtosetthesessioncookie.2)Usesessionsforuserdatalikeloginstatusorshoppingcarts.3)RegeneratesessionIDstopreventfixationattacks.4)Considerusingadatabaseforsessionstoragei
What is session regeneration, and how does it improve security?May 02, 2025 am 12:15 AMSession regeneration refers to generating a new session ID and invalidating the old ID when the user performs sensitive operations in case of session fixed attacks. The implementation steps include: 1. Detect sensitive operations, 2. Generate new session ID, 3. Destroy old session ID, 4. Update user-side session information.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
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
WebStorm Mac version
Useful JavaScript development tools
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software
EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
