Hi Martin, I am still gathering data ... but it seems all to come down to
* file system cache pollution through other processes * and the time you give the system to deal with dirty bufffers * the block queuse size may also play a role. * I think we could gain quite a lot by using fadvise in rrdtool to only keep the header portion of the file in cache. will try this later today ... cheers tobi Today Martin Sperl wrote: > Hi Toby! > > Do you know which parameters you are talking about exactly? > > We have experience that for some reason we are able to update 40k rrd files > every 5 minutes on an Intel RH7.2 system, but when we tried to migrate to > RHES4 the system would no longer perform and we reach a limit of 20k RRD files > updated every 5 minutes and then the updates to all those files fall apart. > > It seems as if the 2.6 Kernel is doing some more agressive prefetching of > blocks when opening each RRD file... > > I remember having looked for tweaking, but I have never found a conclusive > answer... That is why I initially started the libdbi patch... > > Ciao, > Martin > > Tobias Oetiker wrote: > > Hi Robert, > > > > you may want to look at your sytem configuration ... especially > > blocksized and cache handling ... how often to you want to update > > these 100k rrd files per minute ? > > > > cheers > > tobi > > > > > > > > > I while ago I noticed a topic that let rrdtool use a database backend. > > > What > > > is the status with this project? Also, has this turned out to be a viable > > > solution when updating large amounts of rrd files? We're currently > > > exploring other storage media to help our writes become faster. We are > > > currently writing just under 100K rrd files and have distributed writing. > > > We were thinking of modifying rrdtool to use a MySql database and would > > > like > > > to modify the database beackend I saw on the list (if needed) accordingly > > > so > > > that we don't have to re-invent the wheel. > > > > > > I tried to look through the archives, but was only seeing patches to the > > > library file. Is there a place to get the whole thing at? I couldn't see > > > it in the /lib or /contrib download directories of the main site. > > > > > > > > > > > > > > > -- Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten http://it.oetiker.ch [EMAIL PROTECTED] ++41 62 213 9902 _______________________________________________ rrd-developers mailing list rrd-developers@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-developers