Trying to reach Signals on a table whose records are constantly changing (deleted as well)

Vefa Gulecyuz shared this question 38 days ago
Answered

Hi guys, I have a question. I have Signals running on a view. The table behind this view is a buffer table and whose records are deleted once we are done with the process.

I see some cases that Signals are detected at some point, but when I try to open Signals, I receive some errors, I can not see the Signals.

An example error: Error retrieving results

An error occurred retrieving the results from the database. Please check the SQL syntax and try again.
I remember that Signals are only stored as definitions (like query of a Signal etc) and whenever we try to open a Signal, that query is executed and all related charts etc are generated from scratch. Do I remember correctly?

My theory, is that I got a Signal, but when I try to reach that Signal, the relevant data is deleted from the table and my query is not returning any results since data is gone.

Can this be the case here?


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System InformationApplication Version:8.0.4Build:20191216Java Version:1.8.0_252Operating System:Linux 4.19.112+ (amd64)

Comments (9)

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Hi Vefa,

Thanks for reaching out. I believe the answer to your question may be found in the logs, actually. I recommend getting back to the 'An error occurred...' message, taking note of the timestamp for when you saw the error message, then take a look at the corresponding time in the yellowfin.log file. There may or may not be an indication of what's going on and/or the specific query being attempted. If it does not, then I recommend taking the same steps for replication, but this time with DEBUG logging enabled, which you can read how to enable here. Please let me know what you find.

Regards,

Mike

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Hi Vefa,

I just wanted to check in and see how things are going with this.

Regards,

Mike

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Hi Mike, after some trials, I have a new problem :)

The Outlier type of Signals are detected in my data, but when I click on a Signal, I do not see the chart in the Signal. Here is the error message:


 WARN (ChartCreator:create) - Error generating chart: org.jfree.data.general.SeriesException: You are attempting to add an observation for the time period Fri Sep 25 00:00:00 CEST 2020 but the series already contains an observation for that time period. Duplicates are not permitted.  Try using the addOrUpdate() method.
org.jfree.data.general.SeriesException: You are attempting to add an observation for the time period Fri Sep 25 00:00:00 CEST 2020 but the series already contains an observation for that time period. Duplicates are not permitted.  Try using the addOrUpdate() method.
My date field is timestamp with milisecond granularity and my Signal date granularity is seconds.

I tried many combinations here, using another date field (which has hour granularity) and hour or days as date granularity field.

I still have this error.

How can I get rid of this one and I see my Signal?

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Hi Vefa,

I'm going to have to perform additional research and discuss with Consulting team to determine exactly what this means and where to look.

I hope to have an update for you soon.

Regards,

Mike

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Hi Vefa,

This looks to be an aggregation issue. The issue might be with the millisecond granularity as it seems YF doesn't always handle that granularity so well. As a test, can you perhaps try configuring this Signal by rounding up to the nearest second instead? You can do this by either using a date field with a second aggregation or casting on it via Freehand SQL to round up to nearest second. Please give this a try and let me know how goes.

Regards,

Mike

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I will let you know Mike, thanks! Currently I am busy with other stuff, might take some time to come back to you.

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Hi Vefa,

No problem. Thanks for getting back to me. Please do let me know how goes once you get the chance and I'll check back in later in the week.

Regards,

Mike

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Hi Vefa,

I just wanted to check in and see how things are going with this.

Regards,

Mike

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Hi Vefa,

I'm going to go ahead and mark this one as Answered since I haven't heard back from you, but if you have further questions or concerns on this, if you respond, it will re-open the case and put it back in my queue and I'll be happy to help.

Regards,

Mike