I wanted to make a suggestion, that the metrics functions be changed to g_val_t (*fn)(time_t) so that the time system call could be made once and passed to each of the metric functions. System calls tend to be a bit expensive.
Also, I was considering adding linux metrics for bytes read/written and sectors read/written. This would require a bit of finesse, since those statistics exist for partitions which are e.g. part of a raid array, and ganglia would have to find a sum without double counting, but it seems like a worthwhile addition none the less. I had a few questions about this: Firstly, I notice that solaris has: #ifdef SOLARIS g_val_t bread_sec_func(void); g_val_t bwrite_sec_func(void); g_val_t lread_sec_func(void); g_val_t lwrite_sec_func(void); g_val_t phread_sec_func(void); g_val_t phwrite_sec_func(void); g_val_t rcache_func(void); g_val_t wcache_func(void); #endif I would think that the names should be reused, if the semantics are the same, but not if they differ. I'm not sure, however, whether they're a match. Secondly, the Linux version shows the total number of bytes/sectors read/written since boot, which would be a good fit for the rrdtool COUNTER type (or the similar one whose name and purpose I can't remember), or I could cache the old values and send the delta divided by the elapsed time as a whatever/second value. I'm not sure if ganglia supports any type of rrd except METER, however. Lastly, I'm curious as to whether there's a conceptual problem with what I'm thinking. I am suspicious of the idea because it seems that were it not problematic, somebody probably would have done it by now. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
