memcached

Memcache v/s redis for maintaining persistent sessions?

由 这一生的挚爱 提交于 2019-12-25 14:15:11
问题 I want to make persistent sessions on server i am using node.js with express and for that first i read about connect-redis enter link description here and connect-mongo enter link description here i read that redis is faster then mongo that's why i decided to use it but now i also find a module named memcached enter link description here i dont know which will be better for my project, also in mamcache is data stored in memory or where because if it is memory then it must be fastest. 回答1: If

数据库介绍

由 纵然是瞬间 提交于 2019-12-25 13:38:27
1、数据库是什么？ 数据库（database）就是一个存放数据的仓库，这个仓库是按照一定的数据结构（数据结构是指数据的组织形式或数据之间的联系）来组织、存储的，我们可以通过数据提供的多种方法来管理数据库里的数据。 2、数据库的种类？ 数据库通常分为层次式数据库、网络式数据库和关系式数据库三种。而不同的数据库是按不同的 数据结构 来联系和组织的。 而在当今的互联网中，最常见的数据库模型主要是两种，即 关系型数据库和非关系型数据库 。 2.1、关系型数据库介绍？ （1）、关系型数据库的由来 虽然网状数据库和层次数据库已经很好的解决了数据的集中和共享问题，但是在数据库独立性和抽象级别上扔有很大欠缺。用户在对这两种数据库进行存取时，仍然需要明确数据的存储结构，指出存取路径。而关系型数据库就可以较好的解决这些问题。 （2）、关系型数据库介绍 关系型数据库模型是把复杂的数据结构归结为简单的二元关系（即二维表格形式）。在关系型数据库中，对数据的操作几乎全部建立在一个或多个关系表格上，通过对这些关联的表格分类、合并、连接或选取等运算来实现数据库的管理。 关系型数据库诞生40多年了，从理论产生发展到现实产品，例如： Oracle和MySQL，Oracle 在数据库领域上升到霸主地位，形成每年高达数百亿美元的庞大产业市场。 （3）、常用的关系型数据库 oracle；Mysql；MariaDB

数据库分类

由 妖精的绣舞 提交于 2019-12-25 13:38:03
http://www.jianshu.com/p/763f890579f9 做了几年开发，用过几种数据库，但是也就知道数据库的名字，其他的也没学到啥，开发过程中大多数也就是写写SQL文，增删改查之类的，现在发现我的知识很模糊，基础不牢靠，需要系统的学习一下。 1.1 数据库介绍 1.1.1什么是数据库 简单的说，数据库（database）就是一个存放数据的仓库，这个仓库是按照一定的数据结构（数据结构是指数据的组织形式或数据之间的联系）来组织、存储的，我们可以通过数据提供的多种方法来管理数据库里的数据。 1.2 数据库的种类 数据库通常分为层次式数据库、网络式数据库和关系式数据库三种。而不同的数据库是按不同的 数据结构 来联系和组织的。而在当今的互联网中，最常见的数据库模型主要是两种，即关系型数据库和非关系型数据库。 1.2.1关系型数据库介绍 关系型数据库介绍 关系型数据库模型是把复杂的数据结构归结为简单的二元关系（即二维表格形式）。在关系型数据库中，对数据的操作几乎全部建立在一个或多个关系表格上，通过对这些关联的表格分类、合并、连接或选取等运算来实现数据库的管理。 关系型数据库诞生40多年了，从理论产生发展到现实产品，例如：Oracle和MySQL，Oracle在数据库领域上升到霸主地位，形成每年高达数百亿美元的庞大产业市场。 1.2.2非关系型数据库介绍 NoSQL

Transaction Error while installing memcached.x86_64 & php-pecl-memcache.x86_64

由 一笑奈何 提交于 2019-12-25 12:07:29
问题 On executing yum install memcached.x86_64 php-pecl-memcache.x86_64 I am getting this error: Transaction check error: file /usr/bin/php from install of php-cli-5.4.16-42.el7.x86_64 conflicts with file from package ea-php-cli-0.2.0-1.1.1.cpanel.x86_64 回答1: This solution finally worked for me: https://documentation.cpanel.net/display/ALD/PHP+PECL 来源： https://stackoverflow.com/questions/42348809/transaction-error-while-installing-memcached-x86-64-php-pecl-memcache-x86-64

Ignoring Server Down Error Message when using Yii CMemCache

由 给你一囗甜甜゛ 提交于 2019-12-25 07:22:24
问题 I've enabling yii memcached, How do I ignoring this error when dedicated memcached server was down. MemcachePool::get(): Server 192.168.1.200 (tcp 11211, udp 0) failed with: No connection could be made because the target machine actively refused it. (10061) Thanks, 回答1: You could: extend CMemCache as your own caching component override the getters and setters to return false if no connection is present or connection isn't active, otherwise call the parent:: equivalent method (with any

How to implement memcached with Django & APIs while underlying Database objects may change

由 こ雲淡風輕ζ 提交于 2019-12-25 07:01:58
问题 I am using Django's native Authorization/Authentication model to manage logins for my WebApp. This creates instances of the User model. I would like to write a simple class-based-APIView that can tell me if a specific email is already used (IE: Is there already a user with the given email in my database?). The first time this API is called, it should get the matching User object from the DB. But subsequent times it is called, it should return it from the Memcache (if and only if, the

How to handle code when memchache is not working(simple-spring-memcached)

由 给你一囗甜甜゛ 提交于 2019-12-25 05:07:19
问题 Thanks to the 'Getting started guide' in ‘simple-spring-memcached’ I manage to get memcached working in my project using ‘Spring 3.1’ example in in the guide , Im using ‘spymemcached’ as the provider . All working well when memcached server is up and running. However, when memcache server is not accessible (deliberately shut down for testing) underline code doesn’t work and application wont execute simply throwing runtime exception ,stating that unable to connect to memcache server and

How to handle code when memchache is not working(simple-spring-memcached)

由 浪尽此生 提交于 2019-12-25 05:07:15
问题 Thanks to the 'Getting started guide' in ‘simple-spring-memcached’ I manage to get memcached working in my project using ‘Spring 3.1’ example in in the guide , Im using ‘spymemcached’ as the provider . All working well when memcached server is up and running. However, when memcache server is not accessible (deliberately shut down for testing) underline code doesn’t work and application wont execute simply throwing runtime exception ,stating that unable to connect to memcache server and

How can we block Ruby on Rails on a Memcached read so it doesn't eat CPU?

由 China☆狼群 提交于 2019-12-25 04:07:37
问题 We have a daemon which scans a table for dirty bits and then schedules dirty rows to a delayed_job in batches. In order to avoid a constant select from data where dirty = 1 , we set up a memcached barrier, which wraps the table scan, like loop do # daemon until Rails.cache.fetch("have_dirty_rows") do end page = 1 loop do # paginate dirty rows dirty_batch = paginate(#:select => "*", :order => "id", :per_page => DIRTY_GET_BATCH_SIZE, :conditions => {:dirty => 1}, :page => page) if dirty_batch

Count active sessions

由 倖福魔咒の 提交于 2019-12-25 02:46:53
问题 I store my sessions with memcached. I am looking to detect how many active sessions there are currently. I am convinced it must be possible - But I have googled and googled but to no avail so please stackoverflowers give me some guidence :) 回答1: Memcached by nature isn't meant to be used like that (it's a fleeting cache store, it is not intended to do SQL / database like aggregate queries over), and current active sessions is usually not something I am remotely interested in (for load
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