Key Size

Renato Silveira renatosilveira at
Sun Jan 7 14:04:33 UTC 2007

Thank you all for the answers!
First of all I´ll try to increase the key size as Steve said. Because, the
application that I´m working is perfomance oriented, so I think that we
would have some problems with the overhead of Sha or MD5.
I´m using java api of memcached as the client. The problem of whitespace in
the url is solved because the client api use a URLEncoder in the key before
the store the objects.
Well, as I´ll try this first approach and I tell you if it works!

tks again!


On 1/5/07, Marc <Marc at> wrote:
>  I misspoke about whitespace...the server will drop it, not the client.
> On 1/5/07 11:25 AM, "Marc" <Marc at> wrote:
> I see two possible problems.  First – as you note – the client needs to
> deal with the increase too.  I'm not sure which one you're using but for
> most implementations, the default read -buf  size for GET results is 250+1
> so, if memcached is returning results like:
>     VALUE very<250>long_key 0 3\r\nxxx\r\nEND
> It very well may be the case that the client punts after scanning "VALUE
> very<250>" without seeing either space (\b) or CRLF (\r\n)
> Second, if you have spaces in your URL this will cause similar problems.
>  The client will take the following:
>     VALUE http://url/key/with white space 0 3\r\nxxx\r\nEND
> as the value for key "http://url/key/with" <http://url/key/with%C2%B2> and
> not finding a corresponding client request for that key will  most likely
> discard it.
> On 1/5/07 11:08 AM, "Renato Silveira" <renatosilveira at> wrote:
> Hi,
> I´m using memcached as a URL keyword cache. The url is the key and the
> cached object is a string with relevant keywords of the site. Well, it´s
> working fine for my purpose. The only problem is the limit of key size to
> 250 bytes(because there can be url bigger than 250 bytes). Well, I tried to
> increase the value of the constant KEY_MAX_LENGTH to 2048 bytes. I recompile
> memcached and it´s not working. Should I have to make any modification on
> the client API? Does anyone can helpme with this issue?
> tks!
> Renato
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