memcache and php server optimization

[Steven Grimm]

Memcached already supports batched "get" requests. Look for a function 
called "get_multi" or similar in your client.

As for batching "set" and "delete" requests, what *is* supported by the 
server (though not by all clients) is for the client to send a bunch of 
requests without waiting for a response from each one before sending the 
next, i.e., sending the commands asynchronously then gathering up all 
the responses at the end. The "libmemcache" C client, for example, 
supports that. As noted in another thread yesterday, handling rapidfire 
asynchronous writes is not *quite* as optimized as it could be on the 
server side, but it does work fine, and unless you're doing truly 
massive numbers of sets you're unlikely to ever notice the difference.

-Steve


Roberto Spadim wrote:
> i'm new to memcache, but i see some usefull thinks that could be 
> implemented
> see my php code:
> <?php
>    $memcache= new Memcache;
>    $memcache->connect('172.16.0.1',11211);   // only one server
>    $st=microtime(1);
>    $memcache->get('value');
>    echo (microtime(1)-$st)."\n";   // ~0.0013 seconds (maybe 1 packet 
> to and 1 packet from memcache)
>    $st=microtime(1);
>    $memcache->get(array('value','value2'));    echo 
> (microtime(1)-$st)."\n";   // ~0.0026 seconds (maybe 2 packets to and 
> 2 packets from memcache)
> ?>
> only if we are sending two packets (i don't know memcache protocol):
>    i think that sending only one packet with get two keys could be 
> faster than two packets (i don't know if memcache server implements it)
>
> now for set, add and replace:
> $memcache->set( array($key1,$key2,$key3),'1');   // set all keys to 1 
> (can make with only one packet?)
> $memcache->set( 
> array($key1,$key2,$key3),array($value1,$value2,$value3));   // set 
> each key for each value (i don't know if we could use only one packet, 
> values can be very big... but keys don't!)
>
> now for delete, allow arrays like:
>    $memcache->delete( array($key1,$key2,$key3));   // could be done 
> with only one packet too
> today only this work:
>    $memcache->delete($key1);
>    $memcache->delete($key2);
>    $memcache->delete($key3);
>
> now some feature requests, these functions should be only for one 
> server!:
>    $memcache->getkeyscount($host,$port);   // return keys count
>    $memcache->getallkeys($host,$port);   // get ALL keys
>    $memcache->getallkeys($host,$port,0,15);   // get keys from 0 to 15,
>    // i don't know if we have an index of variables but  getallkeys 
> with parameters could work with for:
>    for ($i=0;$i<$memcache->getkeyscount();$i++){
>       $memcache->getallkeys($i*15,15);
>    }
>
> i don't know memcache protocol very well but seeing time for 
> one(0.0013) and two gets(0.0026) i think that we are sending many(2) 
> packets, sending only one packet could be an optimization when we are 
> connected with one server, many servers could allow too, but i don't 
> know if cpu utilization or network utilization could be too high on 
> each memcache server
> thankx guys,
> Roberto Spadim