RE: Global Lock When Getting Stats?

[Tim Sneed]

Actually sorry I should've been more descriptive. I plan on using a java
client to get the stats from memcached so that we can eventually pipe the
stats to our monitoring software. What would be the best java client?
Spymemcached?

Also, is there any consideration in the future to provide stats via JMX?

-ts

-Original Message-
From: memcached@googlegroups.com [mailto:memcac...@googlegroups.com] On
Behalf Of dormando
Sent: Tuesday, May 18, 2010 1:58 AM
To: memcached@googlegroups.com
Subject: RE: Global Lock When Getting Stats?

memcached.org/wiki

also inside the source tarball there's a protocol.txt that explains the
raw stats thoroughly. You seem to be referring to the php api's stats
call.

On Mon, 17 May 2010, Tim Sneed wrote:

 Great thanks for the information! Is there any documentation available
from
 the project team that explains the monitoring aspects of memcached? Such
as
 the methods of receiving stats (if there are any aside from getStats())?


 -Original Message-
 From: memcached@googlegroups.com [mailto:memcac...@googlegroups.com] On
 Behalf Of dormando
 Sent: Thursday, May 13, 2010 4:57 PM
 To: memcached
 Subject: Re: Global Lock When Getting Stats?

  I was watching a Memcached video spoken by John Adams when I heard
  something that made me curious.  When one gets stats from memcached,
  does it really perform a global lock? Does anyone have any good test
  cases on what sort of impact there is with an increasing node size
  with respect to performance degradation?

 'stats sizes' grabs a global lock and iterates the whole cache. we don't
 recommend you run that one. All other stats commands are extremely fast.

  I am looking to do some research on expanding our product to support
  real-time monitoring, management, and analysis of memcached. But I'm a
  little concerned that this lock occurs during every stat collection,
  so much to the point that John Adams mentions that it can noticeably
  degrade the performance of memcached. I tried to do some research on
  my own but am finding very little performance analysis or any
  benchmark info with respect to constant polling (minimally 30 sec
  interval) of a enterprise-level memcached distributed system. Has
  anyone seen bad performance with respect to a large cluster and
  gathering stats? Any info would be great, thanks!

 There is no major lock every stat collection. There's a minor lock and
 reading the values is very fast.

 A while ago twitter was running an extremely old version of memcached and
 they took a long time to upgrade. That particular version had a bug in
 stats collection that was *missing* a mutex lock, and would thus crash
 sometimes. So they were afraid of running stats commands. That bug hasn't
 existed for three years at least.

 -Dormando

Re: Tools : phpMemCacheAdmin

[c.mahi...@of2m.fr]

Hello everyone
I've released version 1.1.3 today to fix a bad slabs display, some
minor fixes and code improvements.
You can download it from Google Code : 
http://code.google.com/p/phpmemcacheadmin/


Hope you'll find it useful,

Cordially
Cyrille

RE: Global Lock When Getting Stats?

[dormando]

 Actually sorry I should've been more descriptive. I plan on using a java
 client to get the stats from memcached so that we can eventually pipe the
 stats to our monitoring software. What would be the best java client?
 Spymemcached?

Probably,  yes.

 Also, is there any consideration in the future to provide stats via JMX?

Unless you're getting it from a client, no.

Again, please take a look at those protocol documents. Parsing the stats
is incredibly trivial and you probably don't have to pull in a whole
client library as a dependency just for that. Also, again, it the document
describes the stats in detail.

Memcached as web page cache

[Sun-N-Fun]

I am considering Memcached as a web page cache, so that I can expire/
delete certain web pages as content changes on the backend.  Is there
a provision to use Memcached in this way, or is it stricktly for
populating using the add method in the API?

Re: Tools : phpMemCacheAdmin

[Artur Ejsmont]

hi, if you want you can have a look at the memcache stats scripts i have
modified some time ago and published here

http://artur.ejsmont.org/blog/content/first-version-of-memcache-stats-script-based-on-memcachephp

probably same thing, i just added some slabs stats, maybe you will find
something missing in your new admin. I guess would be cool to have one tool
that does everything and you dont have to use 10 different things to get all
features covered.

will check out your scripts soon, they look very nice, thanks.

art

On 18 May 2010 19:44, c.mahi...@of2m.fr eli...@free.fr wrote:

 Hello everyone
 I've released version 1.1.3 today to fix a bad slabs display, some
 minor fixes and code improvements.
 You can download it from Google Code :
 http://code.google.com/p/phpmemcacheadmin/


 Hope you'll find it useful,

 Cordially
 Cyrille

Re: Memcached as web page cache

[Joseph Engo]

You might be better off with http://varnish-cache.org/

Sent from my über iPad

On May 18, 2010, at 6:04 PM, Sun-N-Fun bayaread...@yahoo.com wrote:

 I am considering Memcached as a web page cache, so that I can expire/
 delete certain web pages as content changes on the backend.  Is there
 a provision to use Memcached in this way, or is it stricktly for
 populating using the add method in the API?