Stepper 1.5.0: Running chains with a mix of commit_sequence and max_conflict

[Nitesh Patel]

Hi,

I have a chain with a step that uses commit_sequence, and another step
with commit_obj. The latter requires retries on conflicts, but the
flag doesn't work with commit_sequence.

The steps belong in the same logical chain, but I don't think the
software allows this combination (when the retry/commit_sequence combo
is used an exception is raised).

I would have thought perhaps having the retry/max_conficts option as
part of the step config (i.e. in the same way as commit_obj/
commit_sequence is defined) could get around this. Alternatively, to
continue with a logged warning rather than raising an exception.

Does it make sense to make these changes? If no more releases are
planned to stepper then I'll just make the changes to our local
version, or submit a patch.

What do you think?

Cheers,

Nitesh

[Chris Withers]

Nitesh Patel wrote:
> I have a chain with a step that uses commit_sequence, and another step
> with commit_obj. The latter requires retries on conflicts, but the
> flag doesn't work with commit_sequence.

Indeed, retry and commit_sequence are incompatible. Bad things will
happen if you try and mix.

> The steps belong in the same logical chain, but I don't think the
> software allows this combination

Don't think, try and provide examples of behaviour.

> (when the retry/commit_sequence combo
> is used an exception is raised).

More detail...

> I would have thought perhaps having the retry/max_conficts option as
> part of the step config (i.e. in the same way as commit_obj/
> commit_sequence is defined) could get around this.

Sure, making this an option would be a good idea. Patches accepted.

> Alternatively, to
> continue with a logged warning rather than raising an exception.

No, this is wrong and may lead to bad things happening to your database...

> Does it make sense to make these changes? If no more releases are
> planned to stepper then I'll just make the changes to our local
> version, or submit a patch.

Patches appreciated...

Chris

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