RFR: JMC-5327: Using HdrHistograms to visualize latencies

[Elliott Baron]

Hi Marcus,

On 2019-05-24 3:13 p.m., Marcus Hirt wrote:
> Very nice Elliot! This looks great!

Glad to hear it, thanks!

> How sure are you of the Japanese and 
> Chinese translations? Would you want for someone to take a look at them?

These come from substituting the word for "percentile" (found online) 
into existing localized strings with the same sort of desired phrasing 
(e.g. File I/O Histogram Selection). If there is someone who could 
verify/improve the translations, I would appreciate it.

Thanks,
Elliott

> 
> Kind regards,
> Marcus
> 
> On Fri, May 24, 2019 at 1:06 AM Elliott Baron <ebaron at redhat.com 
> <mailto:ebaron at redhat.com>> wrote:
> 
>     Hi,
> 
>     Sorry for the delay. Thank you both for your reviews!
> 
>     On 2019-05-02 12:55 p.m., Alex Macdonald wrote:
>      > A handful of minor formatting nits:
>      >
>      > - Messages.properties (x3)
>      > - - the DurationPercentileTable_PERCENTILE_COL_NAME should come
>     after
>      > DUMP_RECORDING_* for alphabetical order I believe
> 
>     Should be fixed now. I took this into account for the new keys added in
>     this revision too.
> 
>      > - There are some cases of extra whitespace, I went through hg
>     diff and
>      > counted the following number of occurrences:
>      > - - DurationHdrHistogram (8)
>      > - - DurationPercentileTable (38)
>      > - - FileIOPage (5)
>      > - - SocketIOPage (6)
>      > - - IOPageTest (5)
>      > - - IOPageTestBase (4)
>      > - - SocketIOPageTest(5)
> 
>     This revised patch should not have any trailing whitespace.
> 
>      > I noticed that when resizing the page, the durations table stays
>     static
>      > whereas the other tables seems to adjust (gif) [3]. This only
>     seems to
>      > cause an issue when my JMC window gets resized to just under 50%
>     on my
>      > monitor width, and the chart will get hidden. In the gif my JMC
>     window
>      > is around half my monitor width (of 1920), and with the JVM
>      > Browser/Outline window open then I don't have much more room to
>     shrink
>      > the application before the chart disappears. I was just curious
>     if the
>      > table could adjust to resizing like the other tables.
> 
>     This was a bit tricky due to the table sitting side-by-side with the
>     chart. I used the (unused?) SimpleLayout class within JMC to define
>     weights to keep the percentage of the width occupied by the chart and
>     table constant, even while resizing.
> 
>      > Also not caused by this patch (but thought it'd be interesting to
>      > share), I'm seeing a bug where my chart text gets really large
>     [4] when
>      > I run JMC locally and not as an RCP application (I recall seeing
>     a JIRA
>      > bug for this before, but cannot find it), and my durations tab
>     will only
>      > show the table (and not even the whole thing) [5].
>     I am still seeing this as well.
> 
>     On 2019-05-02 3:02 p.m., Marcus Hirt wrote:
>      > This is a great start! Aside from the comments already provided
>     by Alex,
>      > here is some feedback:
>      >
>      > * It would be great to be able to select a percentile and be able
>     to do
>      > set as focused selection, and add the events for that percentile
>     to the
>      > focused selection.
> 
>     This should be working now. When setting a table row as the focused
>     selection, all events with duration at least as long as the percentile
>     values in that row will be selected.
> 
>     e.g. Setting the 99th percentile row as the focused selection, with
>     read
>     duration of 10ms and write duration of 50ms, will only show read events
>       >= 10ms and write events >= 50ms.
> 
>      > * The current UI splits read and writes in two different lanes,
>     perhaps
>      > that would make sense here too, also for selection purposes. And
>     just as
>      > with the lanes, only show when there is available data.
> 
>     With this revised patch, when there are no matching read or write
>     events, the corresponding columns will not be shown. There is a slight
>     issue when columns are hidden and then reappear, the last column is too
>     large and needs be resized manually. I can reproduce this in other
>     tables by hiding two columns, and restoring them. I'm not sure of
>     the cause.
> 
>      > * Perhaps the counts shown should be the number of events in the
>      > percentile or above, as those would be the number of events
>     selected -
>      > i.e. if you select events in the 99.9 percentile, you probably don't
>      > want all of the events up to and including the ones in the 99.9th
>      > percentile, but rather the outliers, the ones in 99.9 and above.
> 
>     Makes sense to me, the event counts now show events with duration
>     greater or equal to the value in that row.
> 
>      > * It would be cool to add a normalized backdrop in the tables to
>     get a
>      > rough visual representation of how many of the events are
>     actually in
>      > the different buckets.
> 
>     I have added this as well.
> 
>     Here is a revised webrev that should address all of the feedback
>     received so far.
> 
>     Bug: https://bugs.openjdk.java.net/browse/JMC-5327
>     Webrev: http://cr.openjdk.java.net/~ebaron/JMC-5327/webrev.0/
>     Preview: https://imgur.com/a/oqX0fai
> 
>     Thanks,
>     Elliott
>