single object size limit

Antony Dovgal antony at zend.com
Sat Dec 10 23:26:47 UTC 2005


Brad, could you please comment this?
I can reproduce it easily increasing the size of the item.
And memcached's reply "SERVER_ERROR out of memory" doesn't look like something expected in this case.
Or is it?

Thanks.

On 08.12.2005 16:18, Reinis Rozitis wrote:
> Hello,
> is there in memcache a hardcoded limit to single object data size?
> 
> The situation is such, we try to set in memcache quite a large
> multidimensional array and after some point it fails:
> 
> The reproducable code is such:
> <?
> $mc = new Memcache;
> $mc->connect('127.0.0.1', 11211) or die ("Could not connect");
> 
> $in = array();
> for($i=1;$i<5001;$i++) {
> $in[$i] = array("sadfasdf"=>"aaaaa asdfo asdopifa sopdif asdjf klasdhfja
> hskldfjh alksjdfh lkadhlkjasdfhoiuq oweiuf oasiudf oiasud foi",
> 4534=>"asdfjh askljd fhklasjdhf oiasudy foiuas dfoiuasdoif");
> }
> $mc->set("zzz",$in);
> print_r($mc->get("zzz"));
> ?>
> This works fine.
> But if we increase the for() cycle from 5001 to lets say 6001 or just add
> few data to the array values nothing is set/returned I can't tell the
> precise amount of data after which the issue occurs (on 6001
> strlen(serialize($in)) is 1246902)
> Just seems that the connection is dropped cause I can't get any output also
> after the $mc->set from $mc->getStats(); function).
> 
> memcached (1.1.12) server is started with: -c 1000 -u root -d -m 500 -p
> 11211
> 
> I have contacted the author of PHP memached pecl extension Antony Dovgal (
> http://tony2001.phpclub.net/ ) and he denied that this is problem of the
> extension and after looking into my code his reply was:
> "With your code server responses "SERVER_ERROR out of memory", so it looks
> like some memcached limitation I don't know of..."
> 
> How could that be if memcached has free 500Mb?
> 
> [pid] => 9170
> [uptime] => 54
> [time] => 1134044963
> [version] => 1.1.12
> [rusage_user] => 0.000999
> [rusage_system] => 0.009998
> [curr_items] => 0
> [total_items] => 0
> [bytes] => 0
> [curr_connections] => 1
> [total_connections] => 4
> [connection_structures] => 2
> [cmd_get] => 0
> [cmd_set] => 0
> [get_hits] => 0
> [get_misses] => 0
> [bytes_read] => 2493857
> [bytes_written] => 56
> [limit_maxbytes] => 524288000
> 
> 
> with best regards,
> Reinis Rozitis
> 
> 
> 


-- 
Wbr, 
Antony Dovgal


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