>>> On 11/8/2007 at 12:37 PM, in message <[EMAIL PROTECTED]>, Paul Millar <[EMAIL PROTECTED]> wrote: > Hi Brad, > > On Thursday 08 November 2007 02:25:21 Brad Nicholes wrote: >> [...] Briefly I have been trying to add some additional data to the >> gmond XDR packets so that we can communicate attributes such as an >> alternate TITLE for the metric or which GROUP(s) the metric belongs to (or >> anything else that we dream up in the future). What I have done to solve >> this issue is the following [...] > > From a quick skim, this all looks pretty good. > > Although it's early days, are you planning on supporting "metric packing" > (for > want of a better name) with several metrics will end up in a single UDP > packet? >
Not at this point. I think that we can try to tackle metric packing in a later patch. > So, if I've understood correctly, the potential attributes are now: > > 1. name: unique(*) short string for metric (potential use: create a > suitable filename for RRD storage) > > 2. host: the FQDN of the host from which the metric proports to come. > > 3. type: what kind of data is collected. > > 4. value: a (current/recent) measured value of this metric > > 5. title: short name (potential use: a title of an RRD graph) > > 6. description: a longer string, giving more information (potential use: > pop-up box in web-interface) > > 7. group: some indication of how this metric can be grouped with others. > > 8. units: a suffix to each number (potential use: label in y-axis, suffix > after static values) > > 9. slope: an indication of whether the data is a counter-, gauge- or > static- metric. > > 10. tmax: indicate how regularly the metric should be updated. > > 11. dmax: how quickly a metric should be dropped when no further > measurements are received. > > (*) The (name,host) ordered pairs must be unique for any one metric. > > Data packet contains 1.--4. > Metadata packet contains 1.--3. and 5.--11. > Correct. > Do we also want to have a timestamp when the metric was measured, or do we > assume it was sufficiently close to "now"? > I haven't thought about this. Not sure if it is necessary, but could be added later. > If we're going to record metrics in base-units (bytes rather than megabytes) > > and let RRDTool do the scaling, then we should also include a flag about > whether the SI scaling prefix should be in powers of 10 (kilo, Mega, ...) or > > powers of 2 (kibi, Mebi, ...). IIRC, RRDTool supports both. > > Perhaps we could add a bit-wise set of attributes one bit could be wither > the > metric should be scaled by powers-of-10 or powers-of-2. The current slope > value could be folded in with this attribute, or left separate. > > Did we come to any conclusion about the semantics of the group field? > Something like a space separated list of groups. Would membership of a > group > imply plotting together on the same graph, or somehow close together on a > webpage? > I don't know what the answer to this question is as far as the web-frontend goes. But for gmond and the xml output the answer is pretty basic. The built-in metrics do not have any group designation assigned to them. This is mainly because there isn't a convenient way to add a group designation to the hardcoded array. This will be resolved when the builtin metrics are ported to modules. For modular metrics I have added a macro that allows the C code to easily designate one or more groups for a metric. For the python interface a comma delimited list should be provided in the metric definition with the keyword GROUPS. In the XML data, groups are represented by one or more <GROUP> tags within the <METRIC>. The only thing that I don't like about this is that I have implemented a flexible way for a metric module to include any additional metadata for a metric. However, the XML output of both gmond and gmetad aren't as flexible. I'm not sure how to resolve that issue at th is point. Brad ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Ganglia-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ganglia-developers
