Six instructions of Memcache based caching mechanism

Memcached Is a high-performance Distributed Memory object caching system , For dynamic Web Application to reduce database load . It reduces the number of database reads by caching data and objects in memory , To improve dynamics 、 Speed of database driven websites .Memcached Based on a storage key / Value pairs hashmap. Its daemons （daemon ） Yes, it is C Written , But the client can be written in any language , And pass memcached Protocol communication with Daemons .　　

The main function ：

• The server Parameter monitoring ：STATS、SETTINGS、ITEMS、SLABS、SIZES Real time refresh
• The server Performance monitoring ：GET、DELETE、INCR、DECR、CAS Real time monitoring of hit rate of common operations
• Support data traversal , Easy to monitor the stored content
• Support condition query , Screen out the KEY or VALUE
• Array 、JSON And so on
• compatible memcache Other services of the agreement , Such as Tokyo Tyrant ( Except for traversal function )
• Support The server Connection pool , many The server Management switching is convenient and simple

stay Nginx Server standards HTTP One of the modules ngx_http_memcached_module modular , Dedicated to handling and memcached Related configuration and function realization ,

　　1, memcached_pass

　　　　 Used for configuration memcached The address of the server

　　　　memcached_pass  adress;

　　　　 among address by memcached The address of the server , Support IP+ Port or domain name address , You can also use upstream The instruction configures a memcacched Server groups , And then configure it to upstream The name of

　　 2, memcached_connect_timeout

　　　　 Used to configure connections memcached Server timeout time ,

　　　　memcached_connect_timeout time;

　　　　time Unset timeout , The default is 60, It is recommended not to exceed 75;

　　 3, memcached_read_timeout

　　　　 To configure Nginx Server to the memcached The server sends two read Wait timeout between requests , If the event does not wake up the data transmission , The connection will close

　　　　memcached_read_timeout time;

　　　　 Default time 60

　　  4 memcached_send_timeout

　　　　 Used for configuration Nginx Server to the memcached The server sends two write Wait timeout between requests , If the event does not wake up the data transmission , The connection will close

　　　5　memcached_buffer_size

　　　　 Used for configuration Nginx The server is used to receive memcached Cache size of server response data

　　　　memcached_buffer_size size

　　　　size Cache size set for , Generally, the memory size of the platform is also different

　　　　memcached_buffer_size 4K|8K

　　　6, memcached_next_upstream Instructions

　　　　 Used to configure a group memcached Server , In the server group memcached The access rules of the server follow upstream Polling rules for command configuration , At the same time, you can use this instruction to configure when those exceptions occur , The request will be refueled in sequence to the next group and processed by the server

　　　　memcached_next_uptream status ...

　　　　 among , status Not set memcached The server returns status , It can be more than one

　　　　　　error Establishing connection at , towards memcached The server encountered an error while sending the request or reading the response header

　　　　　　timeout Establishing connection at , towards memcached When the server sends a request or reads the corresponding header, the server has a connection timeout

　　　　　　incalid_header, memcached The response header returned by the server is empty or invalid

　　　　　　not_found, memcached The server did not find the right key / It's worth it

　　　　　　off  Unable to send request to memcache Short service