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 > > >>> servers > > >>> that may be having problems :). > > >>> > > >>> Do you see these proposed changes as being sufficient for 3-4 months > of > > >>> 40hrs/week work? If you plan to really dig into these changes > (perhaps > > >>> reworking components of the monitor itself), I could perhaps see > this. > > Do > > >>> you have any ideas for more lofty goals that you could pursue as > well? > > I > > >>> don't want you/us to get one month into things and see you complete > > >>> everything we initially planned to accomplish :) > > >>> > > >>> - Josh > > >>> > > >>> > > >>> On 04/21/2013 10:37 AM, Supun Kamburugamuva wrote: > > >>> > > >>> Hi all, > > >>>> > > >>>> I would like to start writing the proposal for the GSoc. I've put > > >>>> together > > >>>> some initial high level goals of the project. Please let me know > what > > I > > >>>> can > > >>>> improve. > > >>>> > > >>>> Per table plots: Accumulo 594 > > >>>> --------------------- > > >>>> > > >>>> The goal of this is to display plots that explains the various > > >>>> activtities > > >>>> that happens per table. When we go to the tables page of the monitor > > and > > >>>> go > > >>>> to a specific table it displays some information in a table format. > We > > >>>> can > > >>>> argument this information by showing graphs for > > >>>> > > >>>> 1. Ingest entries > > >>>> 2. Ingest data size > > >>>> 3. Scan entries > > >>>> 4. Scan data size > > >>>> > > >>>> Per tablet plots > > >>>> ---------------------- > > >>>> > > >>>> Same as in the table plots we can display information regarding > tablet > > >>>> servers in the tablet server page. The plots will display the same > > >>>> information as table plots considering data per tablet server. > > >>>> > > >>>> Trace Visualization: Accumulo 1198 > > >>>> ---------------------------- > > >>>> > > >>>> Since we are displaying graphs about each tablet and each table we > can > > >>>> add > > >>>> major and minor compaction graph to each table and each tablet. > > >>>> > > >>>> Or other option is to display this in a single graph in overview > page > > >>>> with > > >>>> different graph lines for different tables and tablets. > > >>>> > > >>>> Server type information : Accumulo 807 > > >>>> ------------------------------****--- > > >>>> > > >>>> For displaying this informations we can add a new page and display > the > > >>>> information as a table. The table should specify the network address > > of > > >>>> the > > >>>> server, server type, weather it is active or in-active etc. > > >>>> > > >>>> Thanks, > > >>>> Supun... > > >>>> > > >>>> > > >>>> > > >> > > > > > >
