memcached

UPSTREAM 语法: upstream name { ... } 默认值: — 上下文: http Defines a group of servers. Servers can listen on different ports. In addition, servers listening on TCP and UNIX-domain sockets can be mixed. 定义一组服务器。 这些服务器可以监听不同的端口。 而且，监听TCP和UNIX域套接字的服务器可以混用。 Example: upstream backend { server backend1.example.com weight=5; server 127.0.0.1:8080 max_fails=3 fail_timeout=30s; server unix:/tmp/backend3; server backup1.example.com backup; } By default, requests are distributed between the servers using a weighted round-robin balancing method. In the above example, each 7 requests will be distributed as

常见问题： 1、为什么使用redis （一）性能 我们在碰到需要执行耗时特别久，且结果不频繁变动的SQL，就特别适合将运行结果放入缓存。这样，后面的请求就去缓存中读取，使得请求能够迅速响应。 （二）并发 在大并发的情况下，所有的请求直接访问数据库，数据库会出现连接异常。这个时候，就需要使用redis做一个缓冲操作，让请求先访问到redis，而不是直接访问数据库。 2.使用redis有什么缺点 (一)缓存和数据库双写一致性问题 (二)缓存雪崩问题 (三)缓存击穿问题 (四)缓存的并发竞争问题 3、单线程的redis为什么这么快 (一)纯内存操作 (二)单线程操作，避免了频繁的上下文切换 (三)采用了非阻塞I/O多路复用机制     参照上图，简单来说，就是。我们的redis-client在操作的时候，会产生具有不同事件类型的socket。在服务端，有一段I/0多路复用程序，将其置入队列之中。然后，文件事件分派器，依次去队列中取，转发到不同的事件处理器中。 4、redis的数据类型，以及每种数据类型的使用场景 回答：一共五种 (一)String 这个其实没啥好说的，最常规的set/get操作，value可以是String也可以是数字。一般做一些复杂的计数功能的缓存。 (二)hash 这里value存放的是结构化的对象，比较方便的就是操作其中的某个字段。博主在做单点登录的时候

I want to use cache-money but I don't want to start automatically caching everything (I'm working with a large production app, terabytes of data etc). How do I use it for only the models that I specify? Right now I've got: # initializers/cache_money.rb require 'cache_money' config = (cfg = YAML.load(IO.read(File.join(RAILS_ROOT, "config", "memcached.yml"))))[RAILS_ENV] || cfg["defaults"] $memcache = MemCache.new(config) $memcache.servers = config['servers'] $local = Cash::Local.new($memcache) $lock = Cash::Lock.new($memcache) $cache = Cash::Transactional.new($local, $lock) and then in the

When I try : $mc= new Memcached(); I get Fatal error: Class 'Memcached' not found in /my/path phpinfo says that /etc/php5/apache2/conf.d/20-memcached.ini is loaded as an additional .ini file. The content of this file is this one : ; uncomment the next line to enable the module extension=memcached.so dpkg --get-selections | grep memcached libmemcached6 install memcached install php5-memcached install Kubuntu Apache 2.0 php 5.4.4-1 Why do I have this fatal error ? Based on your comment I don't think you have it installed properly. Make sure you see a see a section in phpinfo() such as: memcached

I have a database that won't grow much in size. It's current size is about 1 GB. Achieving the fastest performance is desired. Question : When should I use Memcache vs simply using MySQL Innodb ability to store all my content within RAM (innodb_buffer_pool_size)? I would only resort to memcached if you require more than one server to hold everything in RAM. Otherwise, you're adding complexity for not much functionality. mysql is more performance degradated on much threads then memcached. so when you will get much simultaneous requests - memcached will respond almost in the same constant time,

一、yum安装 1、Linux系统安装memcached，首先要先安装libevent库。 yum install libevent libevent-devel 2、安装memcached yum install memcached 二、手动安装 1.下载libevent库。 wget https://github.com/downloads/libevent/libevent/libevent-2.0.21-stable.tar.gz 2.安装 tar -zxvf libevent-2.0.21-stable.tar.gz cd ibevent-2.0.21-stable ./configure --prefix=/usr/local/libevent-2.0.21-stable make make install 3.检查是否安装成功 ls -al /usr/local/libevent-2.0.21-stable/lib | grep libevent 4.下载memcached wget http://memcached.org/files/memcached-1.5.9.tar.gz 5.安装 tar -zxvf memcached-1.5.9.tar.gz cd memcached-1.5.9 ./configure -with-libevent=/usr/local

Consider the following. From my heroku console: >> Rails.cache.stats => {"server_id"=>{"evictions"=>"0", "curr_items"=>"2064", "total_items"=>"18793", "bytes"=>"7674501", ... >> Rails.cache.clear => [true] >> Rails.cache.stats => {"server_id"=>{"evictions"=>"0", "curr_items"=>"2064", "total_items"=>"18793", "bytes"=>"7674501", Super weird -- how can I clear my cache!! Similar Issue ? : https://stackoverflow.com/q/7122513/192791 If you connect directly to the Dalli/memcahced client through the console and flush_all the cache clears. i.e. dc = Dalli::Client.new('localhost:11211') dc.flush_all