Domain_event_entry_seq

Axon Framework
1

Dear Axon Team,

my team and myself have a question regarding the domain_event_entry_seq.

What is it used for?
Why is it set to 50?

Thanks for the answer.

2

Hi Gheorghe,

It not really framework, but generated by hibernate for the domain sequence, it is 50 by default.

3

Hi Gerard,
thank you for the quick answer.
So we can set it the incrementBy = 1, because for us it seems weird that it is set to 50.

And also would it be a problem if the sequence is not ongoing because we have the problem that in a cluster we can only set to incrementBy = 0 which would mean it is shared with other instances and it can be like: 1, 3, 5, 10. Or we have to switch from mariaDB to postgresql.

Thank you
Your help is much appreciated.

4

If you set it to 1, it’s likely a little more load on the database. It’s not my expertise, and the default of 50 is likely a good tradeoff.

5

Actually, setting it to 1 is the best thing to do. Unfortunately, Hibernate chooses 50 as a default for performance reasons, but that generates a lot of gaps in the sequences, which Axon doesn’t know are permanent gaps or not. So it will have to keep track of them. Yes, there will be a little performance impact setting it to 1, but it will be much less than the impact of having to track all the gaps.

Best is of course to use a proper event store solution. Relational databases just aren’t great at it. That’s why we built Axon Server.

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