PHP Conference Nagoya 2025

Memcached::getAllKeys

(PECL memcached >= 2.0.0)

Memcached::getAllKeysGets the keys stored on all the servers

Beschreibung

public Memcached::getAllKeys(): array|false

Memcached::getAllKeys() queries each memcache server and retrieves an array of all keys stored on them at that point in time. This is not an atomic operation, so it isn't a truly consistent snapshot of the keys at point in time. As memcache doesn't guarantee to return all keys you also cannot assume that all keys have been returned.

Hinweis:

This method is intended for debugging purposes and should not be used at scale!

Parameter-Liste

Diese Funktion besitzt keine Parameter.

Rückgabewerte

Returns the keys stored on all the servers on successBei einem Fehler wird false zurückgegeben..

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User Contributed Notes 4 notes

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6
flaviu dot chelaru at gmail dot com
7 years ago
// initiate the memcached instance
$cache = new \Memcached();
$cache->addServer('localhost', '11211');

// get all stored memcached items

$keys = $cache->getAllKeys();
$cache->getDelayed($keys);

$store = $cache->fetchAll();

// delete by regex keys

$keys = $cache->getAllKeys();
$regex = 'product_.*';
foreach($keys as $item) {
if(preg_match('/'.$regex.'/', $item)) {
$cache->delete($item);
}
}
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3
xiangku7890 at gmail dot com
8 years ago
First I use the lastest memcached version 1.4.25, but unfortunately I found memcached::getAllkeys do not work with it, though i follow the others suggestion to disable Memcached::OPT_BINARY_PROTOCOL. So i try to use history versions, when i use memcached version 1.4.17, it works.
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1
danb1974 at gmail dot com
4 years ago
The right way to dump slab keys seems to be by using lru_crawler metadump instead of stats cachedump, see https://github.com/memcached/memcached/issues/405

<?php

function getAllKeys(string $host, int $port): array
{
$sock = fsockopen($host, $port, $errno, $errstr);
if (
$sock === false) {
throw new
Exception("Error connection to server {$host} on port {$port}: ({$errno}) {$errstr}");
}

if (
fwrite($sock, "stats items\n") === false) {
throw new
Exception("Error writing to socket");
}

$slabCounts = [];
while ((
$line = fgets($sock)) !== false) {
$line = trim($line);
if (
$line === 'END') {
break;
}

// STAT items:8:number 3
if (preg_match('!^STAT items:(\d+):number (\d+)$!', $line, $matches)) {
$slabCounts[$matches[1]] = (int)$matches[2];
}
}

foreach (
$slabCounts as $slabNr => $slabCount) {
if (
fwrite($sock, "lru_crawler metadump {$slabNr}\n") === false) {
throw new
Exception('Error writing to socket');
}

$count = 0;
while ((
$line = fgets($sock)) !== false) {
$line = trim($line);
if (
$line === 'END') {
break;
}

// key=foobar exp=1596440293 la=1596439293 cas=8492 fetch=no cls=24 size=14908
if (preg_match('!^key=(\S+)!', $line, $matches)) {
$allKeys[] = $matches[1];
$count++;
}
}

// if ($count !== $slabCount) {
// throw new Exception("Surprise, got {$count} keys instead of {$slabCount} keys");
// }
}

if (
fclose($sock) === false) {
throw new
Exception('Error closing socket');
}

return
$allKeys;
}
up
1
harold at snel dot me
5 years ago
/**
* Get all memcached keys. Special function because getAllKeys() is broken since memcached 1.4.23. Should only be needed on php 5.6
*
* cleaned up version of code found on Stackoverflow.com by Maduka Jayalath
*
* @return array|int - all retrieved keys (or negative number on error)
*/
public function getMemcachedKeys($host = '127.0.0.1', $port = 11211)
{
$mem = @fsockopen($host, $port);
if ($mem === false)
{
return -1;
}

// retrieve distinct slab
$r = @fwrite($mem, 'stats items' . chr(10));
if ($r === false)
{
return -2;
}

$slab = [];
while (($l = @fgets($mem, 1024)) !== false)
{
// finished?
$l = trim($l);
if ($l == 'END')
{
break;
}

$m = [];
// <STAT items:22:evicted_nonzero 0>
$r = preg_match('/^STAT\sitems\:(\d+)\:/', $l, $m);
if ($r != 1)
{
return -3;
}
$a_slab = $m[1];

if (!array_key_exists($a_slab, $slab))
{
$slab[$a_slab] = [];
}
}

reset($slab);
foreach ($slab as $a_slab_key => &$a_slab)
{
$r = @fwrite($mem, 'stats cachedump ' . $a_slab_key . ' 100' . chr(10));
if ($r === false)
{
return -4;
}

while (($l = @fgets($mem, 1024)) !== false)
{
// finished?
$l = trim($l);
if ($l == 'END')
{
break;
}

$m = [];
// ITEM 42 [118 b; 1354717302 s]
$r = preg_match('/^ITEM\s([^\s]+)\s/', $l, $m);
if ($r != 1)
{
return -5;
}
$a_key = $m[1];

$a_slab[] = $a_key;
}
}

// close the connection
@fclose($mem);
unset($mem);

$keys = [];
reset($slab);
foreach ($slab AS &$a_slab)
{
reset($a_slab);
foreach ($a_slab AS &$a_key)
{
$keys[] = $a_key;
}
}
unset($slab);

return $keys;
}
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