Basic commands for memcached (installation, uninstall, startup, configuration-related)
-P Listening Port
The IP address of the-l connection, the default is native
-D Start memcached service
-D Restart Restart memcached service
-D Stop|shutdown shut down the running memcached service
-D Install installation memcached service
-d Uninstall Uninstall memcached service
-U Run as (only valid when run as root)
-m maximum memory usage, in MB. Default 64MB
-Returns an error when M memory is exhausted instead of deleting the item
-C Maximum Simultaneous connection number, default is 1024
-F Block size growth factor, default is 1.25
-N Minimum allocation space, key+value+flags default is 48
-H Display Help
memcached the basic command ( when memcached is activated for memcached Managed data and its own running state-related commands ):
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 |
Keywords for viewing information in Chinese and English tables
Pid
|
Memcache The process ID of the server
|
Uptime
|
Number of seconds the server has been running
|
Time
|
Server's current UNIX timestamp
|
Version
|
Memcache version
|
Pointer_size
|
The current operating system pointer size (32-bit system is typically 32bit)
|
Rusage_user
|
Cumulative user time for the process
|
Rusage_system
|
Cumulative system time of the process
|
Curr_items
|
The number of items currently stored by the server
|
Total_items
|
Total number of items stored since server startup
|
bytes
|
The number of bytes consumed by the current server storage items
|
Curr_connections
|
The number of connections currently open
|
Total_connections
|
Number of connections that have been opened since the server was started
|
Connection_structures
|
Number of connection constructs that the server assigns
|
Cmd_get
|
Get command (gets) the total number of requests
|
Cmd_set
|
Set command (save) number of total requests
|
Get_hits
|
Total Hit Count
|
Get_misses
|
Total missed Hits
|
Evictions
|
Number of items deleted to get free memory (the space allocated to memcache needs to be removed from the old items to get space allocated to new items)
|
Bytes_read
|
Total Read bytes (number of bytes requested)
|
Bytes_written
|
Total Bytes sent (result bytes)
|
Limit_maxbytes
|
Size of memory allocated to Memcache (bytes)
|
Threads
|
Current number of threads
|
The following is a simple test code that accesses the object data with the identifier ' MyKey ' in the code:
The code is as follows |
Copy Code |
<?php Contains memcached class files Require_once (' memcached-client.php '); Option settings $options = Array ( ' Servers ' => array (' 192.168.1.1:11211 '),//memcached service address, port, multiple array elements can be used to represent more than one memcached service ' Debug ' => true,//whether to turn on debug ' Compress_threshold ' => 10240,//compressed with more than the number of bytes of data ' Persistant ' => false//whether to use persistent connection ); Create a Memcached object instance $MC = new memcached ($options); Set the unique identifier used by this script $key = ' MyKey '; Writing objects to the memcached $MC->add ($key, ' some random strings '); $val = $MC->get ($key); echo "n". Str_pad (' $MC->add () ', 60, ' _ '). " n "; Var_dump ($val); Replace the object data value that has been written $MC->replace ($key, Array (' some ' => ' haha ', ' array ' => ' xxx ')); $val = $MC->get ($key); echo "n". Str_pad (' $MC->replace () ', 60, ' _ '). " n "; Var_dump ($val); Delete an object in memcached $MC->delete ($key); $val = $MC->get ($key); echo "n". Str_pad (' $MC->delete () ', 60, ' _ '). " n "; Var_dump ($val); ?> |
is not very simple, in practical applications, the result set of the database query is usually saved to the memcached, the next visit directly from the memcached, and no longer do the database query operations, which can greatly reduce the burden of the database. The value after the SQL statement MD5 () is typically used as the unique identifier key. Below is an example of caching a database query result set using memcached (this code fragment immediately follows the example code above):
code is as follows |
copy code |
<?php $sql = ' SELECT * from users '; $key = MD5 ($sql);//memcached object identifier if (!) ( $datas = $MC->get ($key))) { //cached data is not obtained in memcached, then a database query is used to get the recordset. echo "n". Str_pad (' Read datas from MySQL. ', 60, ' _ '). " n "; $conn = mysql_connect (' localhost ', ' test ', ' test '); mysql_select_db (' Test '); $result = mysql_query ($sql); while ($row = Mysql_fetch_object ($result)) $datas [] = $row; //Save the result set data obtained in the database to memcached for use on the next visit. $MC->add ($key, $datas); } else { echo "n". Str_pad (' Read datas from memcached. ', 60, ' _ '). " n "; } Var_dump ($datas); ? |
It can be seen that the use of memcached, you can reduce the database connection, query operations, the database load down, the speed of the script also improved.
OK, so memcached basic erection completed, if there is any problem or what I said wrong welcome to contact me