Introduction, installation, and command of memcached

1. memcached Overview

Memcache (memory, cache): a high-performance distributed memory object cache system. Maintain a large hash table in the memory. (Key = value)

 

Hash table

Key)	Value)
Var1	"123456"
Var2	Array ('AB', 'cd ')
Var3	Object Value

 

 

Ii. Install memcached (Windows)

1. Download The memcached software. Click to download>

2. Copy the memcached software to a directory, which is better to be stored in the PHP development environment directory for ease of management.

3. log on to the Windows command console, go to the directory, and install memcached.exe-D install [uninstall memcached.exe-D uninstall]

Note: After you add the directory where memcached is located to the path, you can directly use the memcached command in the command console. For more information, see the following procedure.

4. start/stop the memcached service, memcached-d start [stop]

If the startup is successful, you can see in the service:

5. The default port used by memcached is: 11211.

Note: by default, memcached has a maximum memory of 64 MB. If the memory of memcached is larger than 64 MB, it should be started like this

 

[Plain]View plaincopy

1. Memcached-M 256 m-d start

 

III. Basic memcached commands

Installation, uninstallation, startup, and Configuration

-P listening port
-L connected IP address. The default value is local
-D start: Start the memcached service.
-D restart: restart the memcached service.
-D stop | Shutdown the running memcached Service
-D install the memcached Service
-D uninstall memcached Service
-U runs as the identity (only valid when running as root)
-MB maximum memory usage, in MB. The default value is 64 MB.
-An error is returned when M memory is used up, instead of deleting items.
-C: Maximum number of simultaneous connections. The default value is 1024.
-F block size growth factor, default value: 1.25
-N: minimum allocation space. The default value of key + value + flags is 48.
-H Show Help

4. Operate memcached

Telnet localhost 11211 -- Telnet memcached

 

Command	Description	Example
Get	Reads a value	Get mykey
Set	Set a key unconditionally	Set mykey 0 60 5
Add	Add a new key	Add newkey 0 60 5
Replace	Overwrite existing key	Replace Key 0 60 5
Append	Append data to existing key	Append Key 0 60 15
Prepend	Prepend data to existing key	Prepend Key 0 60 15
Incr	Increments numerical key value by given number	Incr mykey 2
Decr	Decrements numerical key value by given number	Decr mykey 5
Delete	Deletes an existing key	Delete mykey
Flush_all	Invalidate specific items immediately	Flush_all
	Invalidate all items in n seconds	Flush_all 900
Stats	Prints General Statistics	Stats
	Prints memory statistics	Stats Slabs
	Prints memory statistics	Stats malloc
	Print higher level allocation statistics	Stats items
		Stats detail
		Stats sizes
	Resets statistics	Stats Reset
Version	Prints server version.	Version
Verbosity	Increases Log Level	Verbosity
Quit	Terminate Telnet session	Quit