Hi Anjana,

Even for a bar graph, it is OK to randomly sample if it is bigger than some
size  (e.g. 10000) with a warning that data has  been sampled. That is the
best we can do, and it is much better than going OOM.

Thanks
Srinath

On Sat, Aug 29, 2015 at 10:31 AM, Anjana Fernando <[email protected]> wrote:

> Hi,
>
> On Fri, Aug 28, 2015 at 9:18 PM, Srinath Perera <[email protected]> wrote:
>
>> Correct approch (for Viz) would be to sample it down rather than taking
>> first 1000 ( but not for DAL data retrival case). Any chance we can do that?
>>
>
> That also, should be done case by case for graph types I guess, for
> example, it doesn't make sense to sample data for a bar graphs, like some
> bars won't be visible! ..
>
> Cheers,
> Anjana.
>
>
>>
>> On Fri, Aug 28, 2015 at 7:12 PM, Dunith Dhanushka <[email protected]>
>> wrote:
>>
>>> Hi Anjana,
>>>
>>> I'll work on the above change.
>>>
>>> Regards,
>>> Dunith
>>>
>>> On Fri, Aug 28, 2015 at 8:22 AM, Anjana Fernando <[email protected]>
>>> wrote:
>>>
>>>> Hi Srinath,
>>>>
>>>> I was checking on this, and it seems, the issue is, if you've a large
>>>> result set, and for the gadget, if you select this large result set as its
>>>> source data, it will go and read everything. For example, if you use the
>>>> smart home sample and just put all the raw records as the X axis of a bar
>>>> chart, it will try to read all thousands of data records and try to render
>>>> it. But this operation takes a bit of time, to do the JSON serialization
>>>> and send it to the front end. And what makes this far more worse is, the
>>>> dashboard automatically refreshes the data, and this happens in an
>>>> asynchronous manner, and it doesn't wait for the earlier cycle to be
>>>> finished. So these requests effectively builds up and eats up the CPU in
>>>> the backend and can end up going OOM.
>>>>
>>>> So I guess, first, we have to fix the refreshing of the gadgets
>>>> somehow, so it will wait for the earlier request to finish, before making
>>>> new ones. Then after that, we should also provide a sensible upper limit to
>>>> the data records queries, so people won't mistakenly query millions of
>>>> records from a raw data table. We have to do this carefully, because for a
>>>> thing like a scatter plot, we may need to read thousands of records to
>>>> render the image. So for things like that, it maybe easier for it to be
>>>> rendered in the backend and sent to the front end. And also, Maninda also
>>>> pointed out, since we have a natural refresh interval for a dashboard, we
>>>> should also cache the data in the end backend, with a cache validity period
>>>> similar to the dashboard interval, so we don't have to read data from the
>>>> physical databases all the time.
>>>>
>>>> So as an immediate fix, shall we try to change the dashboard refresh
>>>> logic and also put a upper limit to the backend data retrieval to about
>>>> 1000 (by changing "LAST_INDEX" variable from -1 to 100 in analytics.jag at
>>>> carbon-dashboards). @Dunith, will you be able to do these changes.
>>>>
>>>> Cheers,
>>>> Anjana.
>>>>
>>>>
>>>> On Fri, Aug 28, 2015 at 3:07 PM, Anjana Fernando <[email protected]>
>>>> wrote:
>>>>
>>>>> Hi Srinath,
>>>>>
>>>>> Yeah, I also could reproduce the issue. Will check it out.
>>>>>
>>>>> Cheers,
>>>>> Anjana.
>>>>>
>>>>> On Fri, Aug 28, 2015 at 2:38 PM, Srinath Perera <[email protected]>
>>>>> wrote:
>>>>>
>>>>>> This was a batch chart.
>>>>>>
>>>>>> On Fri, Aug 28, 2015 at 2:32 PM, Damith Wickramasinghe <
>>>>>> [email protected]> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> AFAIK That message "Data is not available for plotting. The chart
>>>>>>> will be loaded once the dashboard receives events" normally comes for 
>>>>>>> real
>>>>>>> time flow gadgets.
>>>>>>>
>>>>>>> Regards,
>>>>>>> Damith.
>>>>>>>
>>>>>>> On Fri, Aug 28, 2015 at 2:22 PM, Srinath Perera <[email protected]>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> Yes, I could see the preview ok.
>>>>>>>>
>>>>>>>> --Srinath
>>>>>>>>
>>>>>>>> On Fri, Aug 28, 2015 at 2:19 PM, Anjana Fernando <[email protected]>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> Hi Srinath,
>>>>>>>>>
>>>>>>>>> Did you have data in that table before you created the gadget? ..
>>>>>>>>>
>>>>>>>>> Cheers,
>>>>>>>>> Anjana.
>>>>>>>>>
>>>>>>>>> On Fri, Aug 28, 2015 at 2:16 PM, Srinath Perera <[email protected]>
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>> It is fixed with new pack.
>>>>>>>>>>
>>>>>>>>>>  However, when I create a Gadget ( based on beatch data) and add
>>>>>>>>>> teh Gadget, it says "Data is not available for plotting. The chart 
>>>>>>>>>> will be
>>>>>>>>>> loaded once the dashboard receives events".
>>>>>>>>>>
>>>>>>>>>> Thanks
>>>>>>>>>> Srinath
>>>>>>>>>>
>>>>>>>>>> On Fri, Aug 28, 2015 at 8:58 AM, Srinath Perera <[email protected]
>>>>>>>>>> > wrote:
>>>>>>>>>>
>>>>>>>>>>> Yesterday packs had the same problem
>>>>>>>>>>>
>>>>>>>>>>> On Thu, Aug 27, 2015 at 4:20 PM, Maninda Edirisooriya <
>>>>>>>>>>> [email protected]> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> This was fixed in https://wso2.org/jira/browse/DAS-84 on
>>>>>>>>>>>> yesterday by Dunith. Now the fix should be there in latest jenkins 
>>>>>>>>>>>> built
>>>>>>>>>>>> packs.
>>>>>>>>>>>> Thanks.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> *Maninda Edirisooriya*
>>>>>>>>>>>> Senior Software Engineer
>>>>>>>>>>>>
>>>>>>>>>>>> *WSO2, Inc.*lean.enterprise.middleware.
>>>>>>>>>>>>
>>>>>>>>>>>> *Blog* : http://maninda.blogspot.com/
>>>>>>>>>>>> *E-mail* : [email protected]
>>>>>>>>>>>> *Skype* : @manindae
>>>>>>>>>>>> *Twitter* : @maninda
>>>>>>>>>>>>
>>>>>>>>>>>> On Thu, Aug 27, 2015 at 4:16 PM, Srinath Perera <
>>>>>>>>>>>> [email protected]> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> is this fixed?
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Tue, Aug 25, 2015 at 4:41 PM, Maninda Edirisooriya <
>>>>>>>>>>>>> [email protected]> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On Tue, Aug 25, 2015 at 3:28 PM, Srinath Perera <
>>>>>>>>>>>>>> [email protected]> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Using yesterday's pack
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> 1. Can we make creating a receiver part of the creating/
>>>>>>>>>>>>>>> editing new streams flow? e.g. by asking what transports to 
>>>>>>>>>>>>>>> expose and
>>>>>>>>>>>>>>> automatically creating it.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> 2. In the gadget generation wizard, x, y axis drop downs are
>>>>>>>>>>>>>>> now not be populated.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Yes this issue was observed in latest packs. I am looking at
>>>>>>>>>>>>>> it.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> [image: Inline image 1]
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> 3. When you go into Gadget design view, there is no button
>>>>>>>>>>>>>>> to come back.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> [image: Inline image 2]
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks
>>>>>>>>>>>>>>> Srinath
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>> ============================
>>>>>>>>>>>>>>> Blog: http://srinathsview.blogspot.com
>>>>>>>>>>>>>>>  twitter:@srinath_perera
>>>>>>>>>>>>>>> Site: http://people.apache.org/~hemapani/
>>>>>>>>>>>>>>> Photos: http://www.flickr.com/photos/hemapani/
>>>>>>>>>>>>>>> Phone: 0772360902
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>> Dev mailing list
>>>>>>>>>>>>>>> [email protected]
>>>>>>>>>>>>>>> http://wso2.org/cgi-bin/mailman/listinfo/dev
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> --
>>>>>>>>>>>>> ============================
>>>>>>>>>>>>> Blog: http://srinathsview.blogspot.com twitter:@srinath_perera
>>>>>>>>>>>>> Site: http://people.apache.org/~hemapani/
>>>>>>>>>>>>> Photos: http://www.flickr.com/photos/hemapani/
>>>>>>>>>>>>> Phone: 0772360902
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> --
>>>>>>>>>>> ============================
>>>>>>>>>>> Blog: http://srinathsview.blogspot.com twitter:@srinath_perera
>>>>>>>>>>> Site: http://people.apache.org/~hemapani/
>>>>>>>>>>> Photos: http://www.flickr.com/photos/hemapani/
>>>>>>>>>>> Phone: 0772360902
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> ============================
>>>>>>>>>> Blog: http://srinathsview.blogspot.com twitter:@srinath_perera
>>>>>>>>>> Site: http://people.apache.org/~hemapani/
>>>>>>>>>> Photos: http://www.flickr.com/photos/hemapani/
>>>>>>>>>> Phone: 0772360902
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> *Anjana Fernando*
>>>>>>>>> Senior Technical Lead
>>>>>>>>> WSO2 Inc. | http://wso2.com
>>>>>>>>> lean . enterprise . middleware
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> ============================
>>>>>>>> Blog: http://srinathsview.blogspot.com twitter:@srinath_perera
>>>>>>>> Site: http://people.apache.org/~hemapani/
>>>>>>>> Photos: http://www.flickr.com/photos/hemapani/
>>>>>>>> Phone: 0772360902
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> Dev mailing list
>>>>>>>> [email protected]
>>>>>>>> http://wso2.org/cgi-bin/mailman/listinfo/dev
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Software Engineer
>>>>>>> WSO2 Inc.; http://wso2.com
>>>>>>> <http://www.google.com/url?q=http%3A%2F%2Fwso2.com&sa=D&sntz=1&usg=AFQjCNEZvyc0uMD1HhBaEGCBxs6e9fBObg>
>>>>>>> lean.enterprise.middleware
>>>>>>>
>>>>>>> mobile: *+94728671315 <%2B94728671315>*
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> ============================
>>>>>> Blog: http://srinathsview.blogspot.com twitter:@srinath_perera
>>>>>> Site: http://people.apache.org/~hemapani/
>>>>>> Photos: http://www.flickr.com/photos/hemapani/
>>>>>> Phone: 0772360902
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> *Anjana Fernando*
>>>>> Senior Technical Lead
>>>>> WSO2 Inc. | http://wso2.com
>>>>> lean . enterprise . middleware
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> *Anjana Fernando*
>>>> Senior Technical Lead
>>>> WSO2 Inc. | http://wso2.com
>>>> lean . enterprise . middleware
>>>>
>>>
>>>
>>>
>>> --
>>> Regards,
>>>
>>> Dunith Dhanushka,
>>> Senior Software Engineer
>>> WSO2 Inc,
>>>
>>> Mobile - +94 71 8615744
>>> Blog - dunithd.wordpress.com <http://blog.dunith.com>
>>> Twitter - @dunithd <http://twitter.com/dunithd>
>>>
>>
>>
>>
>> --
>> ============================
>> Blog: http://srinathsview.blogspot.com twitter:@srinath_perera
>> Site: http://people.apache.org/~hemapani/
>> Photos: http://www.flickr.com/photos/hemapani/
>> Phone: 0772360902
>>
>
>
>
> --
> *Anjana Fernando*
> Senior Technical Lead
> WSO2 Inc. | http://wso2.com
> lean . enterprise . middleware
>



-- 
============================
Blog: http://srinathsview.blogspot.com twitter:@srinath_perera
Site: http://people.apache.org/~hemapani/
Photos: http://www.flickr.com/photos/hemapani/
Phone: 0772360902
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