Error 131 Transaction rolled back by lock wait timeout

[Former Member]

Hello all,

I was trying to run apriori, and then HANA writer in my database.

Apriori executes directly, and then I configure and try to execute HANA Writer. But it keeps executing for more than half an hour, and then gives the following error: Error 131 Transaction rolled back by lock wait timeout. Lock timeout occurs while waiting TABLE_LOCK of mode EXCLUSIVE.

Bimal suggested me to reduce the data to be analysed, so then I reduced it to a pretty small part and executed again.

It gave me the same error after more than 30 minutes waiting executing.

after having this error, I tried just execute apriori, but with a filter of 5 transactions and than it worked. After that I tried to visualize the results, and got the following error:

It means that my HANA memory is full?

I got the view from HANA:

Regards!

Error 131 Transaction rolled back by lock wait timeout

[Former Member]

Did anyone get the same problem already?

Even I'm trying to work with Predictive Analysis, I've posted this message in HANA Forum because the error occurs in a HANA Component,and not in an algorithm from Preditive. (the algorithm worked fine).

And when I try to execute Apriori, and than the HANA Writer, I get the following error:

[former_member181931]

Thread moved to the Predictive Analysis space. Hopefully it will get more attention there.

Laure

[Former Member]

Thank you!

[Former Member]

Hi Jurgen,

I'm a developper for PAL from Shanghai team.

Could you please provide some details information about this case:

-          How many records did you use ?

-          What’s the value of “MIN_SUPPORT” and “MIN_CONFIDENCE” did you use ?

The algorithm of apriori will consume much memory when the input data is very large and min_support is low.

So I suggest you set “MIN_SUPPORT” and “MIN_CONFIDENCE” as 0.9 firstly, check if it can output result.

Thanks,

Peng

[Former Member]

Hi Peng, thank you so much for your suggestion.

I talked with some people from SAP Brazil and they suggested me to change my HANA to the last version (because the one I was using have some bugs in the memory) : SPS7 Rev73, so then I'm asking to the responsable to do this changes for me.

I was using the confidence and Support as the one it cames originally: 0.9 and 0.1

I also tried to analyse only a small sample data (about 200k lines) and it also didn't work.

I noticed that after trying to visualize the results from any execution, the resident memory didn't reduced, and after each time I execute, the memory gets more fully. Did you know what I mean?

So now I'll wait to see if they upgrade it for me, and after that I'll try the steps you suggested me!

In back to you with my feedback.

Regards

[Former Member]

Hi Jurgen,

If the number of output rules is very large, I think the resident memory will not reduced.

Because these rules are stored in output tables (which means saved in memory).

Thanks,

Peng