PHP 7.1.0 Released

Memcached::getServerByKey

(PECL memcached >= 0.1.0)

Memcached::getServerByKeyMap a key to a server

Descrizione

public array Memcached::getServerByKey ( string $server_key )

Memcached::getServerByKey() returns the server that would be selected by a particular server_key in all the Memcached::*ByKey() operations.

Elenco dei parametri

server_key

La chiave che identifica il server su cui salvare il valore. Invece di effettuare li'hashing sulla chiave dell'elemento, si effettua l'hashing della chiave del server al momento di decidere con quale server memcached comunicare. Questo permette di raggruppare gli elementi correlati ad un singolo server ottenendo maggiore efficienza nelle operazioni multiple.

Valori restituiti

Returns an array containing three keys of host, port, and weight on success or FALSE on failure. Utilizzare Memcached:getResultCode() se necessario.

Esempi

Example #1 Memcached::getServerByKey() example

<?php
$m 
= new Memcached();
$m->addServers(array(
    array(
'mem1.domain.com'1121140),
    array(
'mem2.domain.com'1121140),
    array(
'mem3.domain.com'1121120),
));

$m->setOption(Memcached::OPT_LIBKETAMA_COMPATIBLEtrue);

var_dump($m->getServerByKey('user'));
var_dump($m->getServerByKey('log'));
var_dump($m->getServerByKey('ip'));
?>

Il precedente esempio visualizzerĂ  qualcosa simile a:

array(3) {
  ["host"]=>
  string(15) "mem3.domain.com"
  ["port"]=>
  int(11211)
  ["weight"]=>
  int(20)
}
array(3) {
  ["host"]=>
  string(15) "mem2.domain.com"
  ["port"]=>
  int(11211)
  ["weight"]=>
  int(40)
}
array(3) {
  ["host"]=>
  string(15) "mem2.domain.com"
  ["port"]=>
  int(11211)
  ["weight"]=>
  int(40)
}

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User Contributed Notes 2 notes

up
4
zhaoyong dot lc at gmail dot com
3 years ago
The parameter server_key is very confusing, it's not a server key for MemCached Server, but it's key,in key-value pair which you stored in server.

<?php
$m
= new Memcached;
$m->addServers(array(
    array(
'127.0.0.1',11212),
    array(
'127.0.0.1',11211)
));
for(
$i=0;$i<10;$i++){
   
$key = 'key_'.$i;
   
$m->add($key, 1);
}
for(
$i=0;$i<10;$i++) {
   
$key = 'key_'.$i;
   
$arr = $m->getServerByKey($key);
    echo (
$key.":\t".$arr['port']."\n");
}
?>

key_0:  11212
key_1:  11211
key_2:  11212
key_3:  11212
key_4:  11212
key_5:  11211
key_6:  11211
key_7:  11212
key_8:  11212
key_9:  11211
up
0
morphles
8 months ago
Just to clarify (as documentation of memcached, even for C lib, frankly is quite lacking), $server_key is hashed using same method as regular keys for values (I checked C source, as again docs......). So you should be able to see where set($key, $value) goes by using getServerByKey($key) with same key. This can be useful if one does not wish to bother with using/has no need to use *ByKey functions, but still want to know which servers are/should be used with regular keys, for implementing fallback or failure reporting.
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