(PECL memcached >= 2.0.0)
Memcached::getAllKeys — Gets the keys stored on all the servers
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.
Note:
This method is intended for debugging purposes and should not be used at scale!
This function has no parameters.
Returns the keys stored on all the servers on success or false on failure.
// 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);
}
}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.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 $allKeys;
}/**
* Get all memcached keys. Special function because getAllKeys() is broken since memcached 1.4.23. Should only be needed on php 5.6
*
* cleaned up version of code found on Stackoverflow.com by Maduka Jayalath
*
* @return array|int - all retrieved keys (or negative number on error)
*/
public function getMemcachedKeys($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;
}