Hi Cassandra: On Fri, Mar 19, 2010 at 6:47 AM, Cassandra Pugh <cp...@pppl.gov> wrote:
> We may be special since we have nfs disks available to our servers, but I > simply write to the shared nfs disk from the head node, and read it from the > web server that is running the web-front of ganglia. Yes sharing RRD files via NFS is another way of de-coupling the frontend from gmetad. One issue with your current approach though is that in the long run, as you get more servers, you may hit a I/O bottleneck since gmetad is writing to a remote NFS server. Users are experiencing I/O related issue even when writing to local disks as hosts get to the 1000+ range. So you might want to take note of that. Having the web server remotely mount RRD files via NFS on the other hand should be fine, since the data it needs to render any particular Ganglia web page is limited. > I think I ran into an issue and found I needed the same version of rrdtool > and the exact same date/time across both servers. > > What are the advantages of running the system as described below? Would > there be better performance (time to load graphs on webpage?)? More/less > load? I haven't really done any performance benchmark, you may be in a better position to give some numbers since you already have a "de-coupled" setup. Basically instead of a system call to rrdtool, it opens a network socket and queries the RRD Server. Each time a call is made the socket has to be opened and closed, so there is overhead involved. One difference between this setup and the NFS approach is that you don't need to install rrdtool on the webserver, since it just relies on communicating with the RRD Server presumably installed on the gmetad server. One issue I forgot to mention with my approach is that RRD Server runs in a chroot, and therefore do not have access to any system-level libraries it may need. For RRDTool 1.2.x, you will need to copy the fonts to your ganglia RRD directory. For instance if RRDTool comes with the font /usr/share/rrdtool/fonts/DejaVuSansMono-Roman.ttf, you will need to create the same directory tree in your RRD root, eg. /var/lib/ganglia/rrds/usr/share/rrdtool/fonts/ and then copy DejaVuSansMono-Roman.ttf to that directory. For RRDTool 1.3+ which uses pango, this may get a lot more complicated since there are a lot more dependencies involved. On a related note. It looks like rrdcached will be supporting the FETCH command soon, which means you may soon be able to query rrdcached for graph generation -- so that may be another route to go. Cheers, Bernard ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Ganglia-general mailing list Ganglia-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-general
