Command line stats

[Steven Grimm]

The problem here is not that echo sends the command early (after all, it 
will just sit in nc's input buffer until nc is ready to read it) or a 
bug in memcached, but rather that nc exits as soon as it gets 
end-of-file on its standard input, before it has had a chance to read 
memcached's response.

echo -e "stats\nquit" | nc -w1 memcached-host 11211

works fine. That tells nc to wait (1 second) for input before exiting.

-Steve


Brad Fitzpatrick wrote:
> Hmm... I'd thought this was fixed awhile back.  I at least remember seeing
> a patch for it?  Steven?
>
> Garth, what version is this?
>
>
> On Sun, 4 Feb 2007, Garth Webb wrote:
>
>   
>> I've noticed a few people on the list pulling stats from memcached by
>> telneting to the memcached port.  The problem that you've probably found
>> (and what I found) was that something like this
>>
>>   echo stats | nc memd-host 11211
>>
>> doesn't work because the 'echo' sends "stats" a split second before the
>> connection is actually established.  So you have to cook thing up like:
>>
>>   (sleep 1; echo stats) | nc memd-host 11211
>>
>>   echo stats | nc -i1 memd-host 11211
>>
>> This isn't ideal since you have to wait a full second to get any
>> information.  This isn't too bad with one memcached server, but with
>> several, the time to get a full report can be pretty long.
>>
>> So, just as an FYI, here's some linux command line foo that we cooked up
>> that will return stats as quickly as memcached can be contacted and
>> return them:
>>
>>   exec 9<>/dev/tcp/memd-host/11211 ; echo -e "stats\nquit" >&9; cat <&9
>>
>> Obviously Perl/Python/Java will be able to do this for you, but this is
>> good for quick and dirty command line tools and simple monitoring
>> scripts.
>>
>> Garth
>>
>>
>>