Memcached::getAllKeys

(PECL memcached >= 2.0.0)

Memcached::getAllKeys — Gets the keys stored on all the servers

Descrizione

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.

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

Elenco dei parametri

Questa funzione non contiene parametri.

Valori restituiti

Returns the keys stored on all the servers on success o false in caso di fallimento.

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User Contributed Notes 6 notes

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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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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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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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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;
}

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-8

Cuchac ¶

9 years ago


This command returns always FALSE when binary protocol in use (Memcached::OPT_BINARY_PROTOCOL = true). Without binary protocol it works.

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-7

fykknd at 163 dot com ¶

8 years ago


I got this answer..
My libmemcached version is 1.0.18. php-memcached version is 2.2.0
In Libmemcached at memcache.h line 84:
 #define MAX_NUMBER_OF_SLAB_CLASSES (63 + 1)
Modify it to 201, compile again. It's ok.
主要还是版本不兼容造成的。libmemchaed里的一个bug，
memcached_return_t这个方法里的for循环，最大数是200，和上面的常量64定义不一致造成的。

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