[rrd-developers] [Ganglia-developers] Integrating rrdcached with Ganglia

[Daniel.Pocock at barclayscapital.com]

> -----Original Message-----
> From: Pocock, Daniel: IT (LDN) 
> Sent: 29 September 2008 13:28
> To: bernard at vanhpc.org; rrd-developers at lists.oetiker.ch; 
> ganglia-developers at lists.sourceforge.net
> Subject: Re: [Ganglia-developers] Integrating rrdcached with Ganglia
> 
> 
>  
> 
> > http://ganglia.wiki.sourceforge.net/rrdcached_integration
> > 
> > Comments/feedbacks welcome.
> 
> 
> Thanks for this - I decided to try it:
> 
> - RHEL5
> - 64 bit
> - APR 1.2.7
> - rrdtool 1.3.2 + rrdcached patch from here:
>     http://dist.rufus.net/~kbrint/rrdcached/rrdcache.patch
> - Ganglia 3.1.0
> 
> gmetad stores the data and IO levels are definitely better.
> 
> However, when I display the web page with graphs for every 
> farm, rrdcached crashes, SEGV:
> 
> (gdb) bt
> #0  0x0000003312077b60 in memcpy () from /lib64/libc.so.6
> #1  0x00002aaaaaae1633 in rrd_write () from /usr/lib64/librrd.so.4
> #2  0x00002aaaaaae5e10 in rrd_lock () from /usr/lib64/librrd.so.4
> #3  0x00002aaaaaae69e2 in rrd_lock () from /usr/lib64/librrd.so.4
> #4  0x00002aaaaaae7cfb in rrd_lock () from /usr/lib64/librrd.so.4
> #5  0x0000000000405113 in ?? ()
> #6  0x00000033134062f7 in start_thread () from /lib64/libpthread.so.0
> #7  0x00000033120ce85d in clone () from /lib64/libc.so.6
> 
> The problem is reproducable every time I refresh 
> http://my-server/ganglia/




I've upgraded to 1.3.3 (the patch applies with 1 reject, which is only
the copyright message) and installed the debug symbols and found that
each time this error occurs, rrd_update is trying to update an RRD file
that is smaller than the expected size (i.e. smaller than the other RRD
files in the same directory)

I haven't yet established whether the RRD files were created earlier
with the wrong size, or if they have somehow been truncated during the
crash.

The whole directory tree was empty before I started doing these tests,
so the RRD files have definitely been created with rrdtool 1.3.
_______________________________________________

This e-mail may contain information that is confidential, privileged or otherwise protected from disclosure. If you are not an intended recipient of this e-mail, do not duplicate or redistribute it by any means. Please delete it and any attachments and notify the sender that you have received it in error. Unless specifically indicated, this e-mail is not an offer to buy or sell or a solicitation to buy or sell any securities, investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Barclays. Any views or opinions presented are solely those of the author and do not necessarily represent those of Barclays. This e-mail is subject to terms available at the following link: www.barcap.com/emaildisclaimer. By messaging with Barclays you consent to the foregoing.  Barclays Capital is the investment banking division of Barclays Bank PLC, a company registered in England (number 1026167) with its registered office at 1 Churchill Place, London, E14 5HP.  This email may relate to or be sent from other members of the Barclays Group.
_______________________________________________