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From Andrey Gura <ag...@apache.org>
Subject Re: [DISCUSSION][IEP-35] Metrics configuration
Date Tue, 06 Aug 2019 11:45:40 GMT
> What do you mean by "exponential bounds"?

Something like this if we talk about latency in ms for example: 5, 10,
25, 50, 100, 200, 500, ...

> Thanks, for the feedback, appreciate you ownesty.

Nothing personal. It is just about functionality from user's stand point.

> What is your proposal?
> How metrics configuration should work?

My proposal is simple: just drop this change. We don't need the
configuration. Metric owner (developer) defines buckets' bounds for
each particular case (it could be done uniformly or exponentially, it
depends on metric and problem definition).

On Mon, Aug 5, 2019 at 6:36 PM Nikolay Izhikov <nizhikov@apache.org> wrote:
>
> Hello, Andrey.
>
> > Not necessary if we have exponential bounds' values for histograms.
>
> What do you mean by "exponential bounds"?
>
> > Anyway, in current solution it looks ugly and not usable.
>
> Thanks, for the feedback, appreciate you ownesty.
>
> > No. But we should admit that this is bad decision and do not include this change
to the code base.
>
> What is your proposal?
> How metrics configuration should work?
>
> > Yes. But it still will not give enough accuracy.
>
> Enough for what?
>
> В Пн, 05/08/2019 в 18:29 +0300, Andrey Gura пишет:
> > > > - metric configuration is node local (not cluster wide).
> > > This issue is easy to solve on the user-side and in Ignite core.
> >
> > It's imaginary simplicity. The first, you need some additional
> > automation on user-side in order to configure all nodes of the
> > cluster. The second, new nodes can join to the cluster and
> > configuration will be different on new node and on other nodes of the
> > cluster. This leads to complication whole functionality. Anyway, I
> > don't like such simplified solution because at the moment it brings
> > more problems than value.
> >
> > > The easiest solution was implemented.
> > > Do we want to make it more complex right now :)?
> >
> > No. But we should admit that this is bad decision and do not include
> > this change to the code base.
> >
> > > The reason it exists in PR - we already have this parameter in DataStorageConfiguration#getMetricsSubIntervalCount
> >
> > I believe this method should be deprecated and removed in major release.
> >
> > > I think the user should be able to configure buckets for histogram and rateTimeInterval
for hitrate.
> >
> > Not necessary if we have exponential bounds' values for histograms.
> > Anyway, in current solution it looks ugly and not usable.
> >
> > > Ignite has dozens of use-cases and deployment modes, seems,
> > > we can't cover it all with the single predefined buckets/rateTimeInterval set.
> >
> > Yes. But it still will not give enough accuracy.
> >
> > On Mon, Aug 5, 2019 at 5:25 PM Nikolay Izhikov <nizhikov@apache.org> wrote:
> > >
> > > Hello, Andrey.
> > >
> > > > - metric configuration is node local (not cluster wide).
> > >
> > > This issue is easy to solve on the user-side and in Ignite core.
> > >
> > > > - metric configuration doesn't survive node restart.
> > >
> > > We decide to go with the simplest solution, for now.
> > > The easiest solution was implemented.
> > > Do we want to make it more complex right now :)?
> > >
> > > > - User shouldn't configure hit rate metrics at runtime in most cases.
> > >
> > > I agree with you - the size of the counters array looks odd as a configuration
parameter.
> > > The reason it exists in PR - we already have this parameter in DataStorageConfiguration#getMetricsSubIntervalCount
> > >
> > > > - May be it is enough for user to have histograms with pre-configured
buckets
> > > > So I think we should drop this change and idea about runtime histrogram
and hit rate configuration.
> > >
> > > I think the user should be able to configure buckets for histogram and rateTimeInterval
for hitrate.
> > >
> > > Ignite has dozens of use-cases and deployment modes, seems,
> > > we can't cover it all with the single predefined buckets/rateTimeInterval set.
> > >
> > > В Пн, 05/08/2019 в 16:59 +0300, Andrey Gura пишет:
> > > > Igniters,
> > > >
> > > > I've took a look to the PR and I want follow up this discussion again.
> > > >
> > > > Proposed solution has a couple of significant drawbacks:
> > > >
> > > > - metric configuration is node local (not cluster wide).
> > > > - metric configuration doesn't survive node restart.
> > > >
> > > > This drawbacks make configuration complex, annoying and useless in most
cases.
> > > >
> > > > Moreover, I think that:
> > > >
> > > > - User shouldn't configure hit rate metrics at runtime in most cases.
> > > > Especially HitRateMetric.size because it's just details of
> > > > implementation. Purpose of size is plots smoothing and this parameter
> > > > could be fixed (e.g. 16 is enough). HitRate metric is just LongMetric
> > > > but with additional feature.
> > > > - May be it is enough for user to have histograms with pre-configured
> > > > buckets. The trick here is properly chosen bounds. It seems that
> > > > exponentially chosen values will fit for most cases. So we can avoid
> > > > runtime configuration for histograms.
> > > > - We can also provide percentile metric for more accurate
> > > > measurements. Yes, it will bring additional performance impact and
> > > > accuracy will not be the best. But it will more clearly and will not
> > > > require configuration.
> > > >
> > > > So I think we should drop this change and idea about runtime
> > > > histrogram and hit rate configuration.
> > > >
> > > > Thoughts?
> > > >
> > > > On Tue, Jul 9, 2019 at 2:06 PM Nikolay Izhikov <nizhikov@apache.org>
wrote:
> > > > >
> > > > > Igniters,
> > > > >
> > > > > I made a PR for metrics configuration.
> > > > >
> > > > > Please, review
> > > > >
> > > > > https://github.com/apache/ignite/pull/6676/files
> > > > >
> > > > > В Вт, 09/07/2019 в 12:27 +0300, Nikolay Izhikov пишет:
> > > > > > Hello, Alex.
> > > > > >
> > > > > > OK, Let's go with the simplest solution.
> > > > > > I will provide API and JMX method for metrics configuration
shortly.
> > > > > >
> > > > > > В Пн, 08/07/2019 в 18:23 +0300, Alexey Goncharuk пишет:
> > > > > > > Nikolay,
> > > > > > >
> > > > > > > To me a separate metrics configuration file seems to be
not very
> > > > > > > user-friendly. First of all, it does not allow to configure
the system only
> > > > > > > from Java code. Second, having multiple configuration files
seem to be
> > > > > > > quite confusing for end users (judging by the logging configuration
> > > > > > > questions).
> > > > > > >
> > > > > > > Perhaps, we will still end up with the configuration file
- but for now I
> > > > > > > would put this aside for a more thorough brainstorm and
added the JMX and
> > > > > > > internal API for changing metrics configuration.
> > > > > > >
> > > > > > > пт, 5 июл. 2019 г. в 14:17, Seliverstov Igor <gvvinblade@gmail.com>:
> > > > > > >
> > > > > > > > Igniters,
> > > > > > > >
> > > > > > > > One more question on topic.
> > > > > > > >
> > > > > > > > Should we preserve metrics configuration on restart?
(I think we should)
> > > > > > > >
> > > > > > > > If so, which configuration use after restart? Defined
in config file or
> > > > > > > > saved in config storage? (I guess, saved configuration
should have a
> > > > > > > > priority)
> > > > > > > >
> > > > > > > > So, how to tell users that any changes in configuration
file have no
> > > > > > > > effect on Ignite configuration after first start?
> > > > > > > >
> > > > > > > > I think there are too many open questions and (at
least at now) we should
> > > > > > > > provide only JMX API until all of the questions are
clarified.
> > > > > > > >
> > > > > > > > Regards,
> > > > > > > > Igor
> > > > > > > >
> > > > > > > > > 4 июля 2019 г., в 19:55, Nikolay Izhikov
<nizhikov@apache.org>
> > > > > > > >
> > > > > > > > написал(а):
> > > > > > > > >
> > > > > > > > > Hello, Andrey.
> > > > > > > > >
> > > > > > > > > > 3. I can't imagine that adequate values
will be chosen on project
> > > > > > > > > > setup stage.
> > > > > > > > >
> > > > > > > > > Configuration file required in the case we adds
new node or replace
> > > > > > > >
> > > > > > > > existing to the cluster.
> > > > > > > > > Use can have parameters similar to Ignite configuration,
log
> > > > > > > >
> > > > > > > > configuration files.
> > > > > > > > >
> > > > > > > > > > My proposal is adding API for boundaries
configuration to the metrics
> > > > > > > > > > framework and expose it via JMX
> > > > > > > > >
> > > > > > > > > Agree. I think we should have both:
> > > > > > > > >
> > > > > > > > > 1. Configuration file.
> > > > > > > > > 2. JMX API to change bounaries of histogram *and
HitRateMetric params*.
> > > > > > > > >
> > > > > > > > > But, if you and other community member are against
config file, let's
> > > > > > > >
> > > > > > > > have only JMX.
> > > > > > > > > Seems, JMX will provide required level of configurability
for metrics.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > В Чт, 04/07/2019 в 17:53 +0300, Andrey Gura
пишет:
> > > > > > > > > > Igniters,
> > > > > > > > > >
> > > > > > > > > > I rethought the issue and I see some problems:
> > > > > > > > > >
> > > > > > > > > > 1. It seems that in most cases bucket boundaries
configuration will be
> > > > > > > > > > problem for user. Absolute values for latency
boundaries it is very
> > > > > > > > > > odd choice.
> > > > > > > > > > 2. Also seems that latency for most caches
(if we configure cache
> > > > > > > > > > metrics fro example) will be similar.
> > > > > > > > > > 3. I can't imagine that adequate values
will be chosen on project
> > > > > > > > > > setup stage. So chosen values should be
changed in the future.
> > > > > > > > > >
> > > > > > > > > > Solution with configuration file looks unnatural
and creates more
> > > > > > > > > > problems than could solve.
> > > > > > > > > >
> > > > > > > > > > My proposal is adding API for boundaries
configuration to the metrics
> > > > > > > > > > framework and expose it via JMX (at this
step). It still provides
> > > > > > > > > > configuration possibility but don't force
user to do it.
> > > > > > > > > >
> > > > > > > > > > Also we should chose default values for
bucket boundaries. And it is
> > > > > > > > > > most complex problem at the moment :) Let's
discuss it.
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > On Wed, Jul 3, 2019 at 4:49 PM Andrey Gura
<agura@apache.org> wrote:
> > > > > > > > > > >
> > > > > > > > > > > Nikolai,
> > > > > > > > > > >
> > > > > > > > > > > Metric is disabled if it doesn't allocate
any memory and doesn't
> > > > > > > > > > > update any variable because doesn't
have any value. Ideally disabling
> > > > > > > > > > > metrics for some cache should be equal
to cache stopping.
> > > > > > > > > > >
> > > > > > > > > > > On Fri, Jun 28, 2019 at 1:02 PM Nikolay
Izhikov <nizhikov@apache.org>
> > > > > > > >
> > > > > > > > wrote:
> > > > > > > > > > > >
> > > > > > > > > > > > Hello, Alexey.
> > > > > > > > > > > >
> > > > > > > > > > > > Thanks for the feedback!
> > > > > > > > > > > >
> > > > > > > > > > > > > My only concert is that we
should have the metrics framework
> > > > > > > >
> > > > > > > > configuration
> > > > > > > > > > > > > as the first-citizen of the
framework itself
> > > > > > > > > > > >
> > > > > > > > > > > > Yes. I planned to add `void configure(String
param)` method to the
> > > > > > > >
> > > > > > > > metric API.
> > > > > > > > > > > >
> > > > > > > > > > > > > but change the metrics parameters
in
> > > > > > > > > > > > > runtime from JMX or command-line,
etc.
> > > > > > > > > > > >
> > > > > > > > > > > > I've add requirement of JMX method
to the ticket:
> > > > > > > > > > > >
> > > > > > > > > > > > https://issues.apache.org/jira/browse/IGNITE-11927
> > > > > > > > > > > >
> > > > > > > > > > > > > Another concern is to have
an
> > > > > > > > > > > > > ability to disable/enable
metrics per metrics group/prefix.
> > > > > > > > > > > >
> > > > > > > > > > > > Yes, we discusss it.
> > > > > > > > > > > > But, let's make it clear:
> > > > > > > > > > > >
> > > > > > > > > > > > *What is disabling metric?*
> > > > > > > > > > > >
> > > > > > > > > > > > Looks like exporter filter solve
this task.
> > > > > > > > > > > >
> > > > > > > > > > > > В Чт, 27/06/2019 в 16:24 +0300,
Alexey Goncharuk пишет:
> > > > > > > > > > > > > Nikolay,
> > > > > > > > > > > > >
> > > > > > > > > > > > > My only concert is that we
should have the metrics framework
> > > > > > > >
> > > > > > > > configuration
> > > > > > > > > > > > > as the first-citizen of the
framework itself. This way, we can
> > > > > > > >
> > > > > > > > configure
> > > > > > > > > > > > > the metrics not only from
file, but change the metrics parameters in
> > > > > > > > > > > > > runtime from JMX or command-line,
etc. Another concern is to have an
> > > > > > > > > > > > > ability to disable/enable
metrics per metrics group/prefix.
> > > > > > > > > > > > >
> > > > > > > > > > > > > The logger-like configuration
meets these suggestions given that the
> > > > > > > > > > > > > configuration is generalized
into the metrics framework.
> > > > > > > > > > > > >
> > > > > > > > > > > > > What do you think?
> > > > > > > > > > > > >
> > > > > > > > > > > > > чт, 27 июн. 2019 г.
в 12:30, Nikolay Izhikov <nizhikov@apache.org>:
> > > > > > > > > > > > >
> > > > > > > > > > > > > > Hello, Igniters.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > As you may know, I've
contributed Phase1 [1] for IEP-35 [2].
> > > > > > > > > > > > > > Now we have metrics
subsystem and can create and export any metrics
> > > > > > > >
> > > > > > > > from
> > > > > > > > > > > > > > Ignite.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > I think user(administrator
of Ignite) should be able to configure
> > > > > > > >
> > > > > > > > some
> > > > > > > > > > > > > > metrics params in a
common way [3]
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > I propose to use the
same way from logging frameworks.
> > > > > > > > > > > > > > We should define some
file format Ignite can understand.
> > > > > > > > > > > > > > An administrator fills
configuration file to configure one or
> > > > > > > >
> > > > > > > > several
> > > > > > > > > > > > > > metrics.
> > > > > > > > > > > > > > Ignite will analyze
the file and use provided params during metrics
> > > > > > > > > > > > > > creation.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > For now, we have 2 types
of metrics that should be configured:
> > > > > > > > > > > > > >
> > > > > > > > > > > > > >        *       HistrogramMetric
[4]
> > > > > > > > > > > > > >                This
metric is a count of measurement that falls into
> > > > > > > > > > > > > > predefined intervals.
> > > > > > > > > > > > > >                An example
is "Request processing time distribution".
> > > > > > > > > > > > > >                We want
to calculate a count of requests processed
> > > > > > > >
> > > > > > > > quicker
> > > > > > > > > > > > > > then 50ms, 50-100, 100-250,
250-500 and slower.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > >        *       HitRateMetric
[5]
> > > > > > > > > > > > > >                This
metric is a count of events in the last time
> > > > > > > >
> > > > > > > > interval.
> > > > > > > > > > > > > >                An example
is the "Count of requests processed in
> > > > > > > >
> > > > > > > > the last
> > > > > > > > > > > > > > 5 seconds".
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > Example of file content:
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > ````
> > > > > > > > > > > > > > cache.my-cahe.GetLatency=50,100,250,500
#Params for the histogram
> > > > > > > >
> > > > > > > > metric
> > > > > > > > > > > > > > with the name `cache.my-cahe.get`
> > > > > > > > > > > > > > cache.my-cache.RebalancingKeysRate=60000
#Param for existing
> > > > > > > >
> > > > > > > > HitRateMetric
> > > > > > > > > > > > > > that hold "Estimated
rebalancing speed in keys".
> > > > > > > > > > > > > > ````
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > Please, share your vision.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > [1]
> > > > > > > > > > > > > >
> > > > > > > >
> > > > > > > > https://github.com/apache/ignite/commit/fdaa310430aefff07994eb35510d3416886b5bbe
> > > > > > > > > > > > > > [2]
> > > > > > > > > > > > > >
> > > > > > > >
> > > > > > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=112820392
> > > > > > > > > > > > > > [3] https://issues.apache.org/jira/browse/IGNITE-11927
> > > > > > > > > > > > > > [4]
> > > > > > > > > > > > > >
> > > > > > > >
> > > > > > > > https://github.com/apache/ignite/blob/master/modules/core/src/main/java/org/apache/ignite/internal/processors/metric/impl/HistogramMetric.java
> > > > > > > > > > > > > > [5]
> > > > > > > > > > > > > >
> > > > > > > >
> > > > > > > > https://github.com/apache/ignite/blob/master/modules/core/src/main/java/org/apache/ignite/internal/processors/metric/impl/HitRateMetric.java
> > > > > > > > > > > > > >
> > > > > > > >
> > > > > > > >

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