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Accumulo >> mail # dev >> GSOC: Monitor Improvements


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Re: GSOC: Monitor Improvements
Great.. we could certainly introduce the graph Mike and Keith have
mentioned.

Supun..
On Mon, Apr 22, 2013 at 12:02 PM, Keith Turner <[EMAIL PROTECTED]> wrote:

> On Mon, Apr 22, 2013 at 11:42 AM, Mike Drob <[EMAIL PROTECTED]> wrote:
>
> > Adding on to the comment about summaries, averages, and outliers. If, for
> > some reason, you end up with a two-hump population, then simply showing
> > averages will mask the split and lose a lot of valuable information. It
> is
> > often valuable to know that a particular set of users or servers are
> > experiencing degraded performance while the rest of the ecosystem is
> > healthy.
> >
> > This isn't something that shows up in a regular time series because the
> > secondary population is usually very small compared to the total
> > population. There was a graph for request latency of a service that I saw
> > once that I really wish I could find again, maybe somebody on the list
> will
> > be able to chime in - It had timestamps on the x-axis, latency on the y,
> > and each (x,y) point was colored on a gradient representing how many
> > requests were fulfilled at time x with latency y. This chart make it
> > immediately easy to see that most data points fit a normal distribution
> > with a low mean, but there was also a cluster at the top for some reason.
> >
>
>
> That sounds really cool.  Maybe the y-axis/latency could be log scale.
> Inevitably a 3004 second operation will finish and obscure the
> smaller latencies.
>
> Sometimes its more useful to sample this type of info from the clients
> rather than tablet servers.   A tablet server may report low latencies, but
> all clients using may experience high latencies because of a network issue.
>   We could certainly consider making the client code report this info.
>
>
> >
> > I'd love to see that type of chart show up for tablet servers (probably
> not
> > as useful for tables).
> >
> > Mike
> >
> >
> > On Mon, Apr 22, 2013 at 9:05 AM, Eric Newton <[EMAIL PROTECTED]>
> > wrote:
> >
> > > Another thing to consider is scale.  On large clusters (many hundreds
> of
> > > nodes), more data is not helpful for visualization.  Instead,
> summaries,
> > > averages and outliers are important.
> > >
> > > For example, if one node is consistently slow, it is better to know
> that
> > > than to see one graph with low numbers in a sea of graphs.
> > >
> > > If the monitor collects information using JMX, collection time for each
> > > node would be a good thing to know, too.
> > >
> > > -Eric
> > >
> > >
> > > On Sun, Apr 21, 2013 at 10:00 PM, Josh Elser <[EMAIL PROTECTED]>
> > wrote:
> > >
> > > > Supun,
> > > >
> > > > Yup, very much so. Having a way to consume any and all metrics via
> JMX
> > > > would simplify things for any consumers (internal or external).
> > > >
> > > >
> > > >
> > > > On 04/21/2013 02:15 PM, Supun Kamburugamuva wrote:
> > > >
> > > >> Hi Josh,
> > > >>
> > > >> Thanks for the suggestions. I'll incorporate these to the proposal.
> > > >>
> > > >> Another area I would like to work is on JMX. There is a Jira that
> says
> > > to
> > > >> replace the Monitor calls from Thrift to JMX (Accumulo 694). Do you
> > > think
> > > >> this is a good addition to the Monitor?
> > > >>
> > > >> Thanks,
> > > >> Supun..
> > > >>
> > > >>
> > > >> On Sun, Apr 21, 2013 at 1:45 PM, Josh Elser <[EMAIL PROTECTED]>
> > > wrote:
> > > >>
> > > >>  Supun,
> > > >>>
> > > >>> Looks good! Can I make some suggestions/comments?
> > > >>>
> > > >>> For: "Per table plots: ACCUMULO-594", I'd also like to see minor
> > > >>> compactions, major compactions, index cache hit rate, and data
> cache
> > > hit
> > > >>> rate per table (same graphs that are displayed system-wide when you
> > > visit
> > > >>> http://${MONITOR_HOST}:50095/.
> > > >>>
> > > >>> For "Per tablet [server] plots", it would be neat if you could also
> > > >>> extract some general statistics like top N least performing, top N
> > > >>> highest
> > > >>> performing, etc. tablet servers. Ideally, this could correlate with

Supun Kamburugamuva
Member, Apache Software Foundation; http://www.apache.org
E-mail: [EMAIL PROTECTED];  Mobile: +1 812 369 6762
Blog: http://supunk.blogspot.com