Discussion on removal of list and get workflows queries in Zeebe 0.18.0


#1

This is a continuation of a Slack convo (available here) related to the removal of list and get workflows queries from the Zeebe API in 0.18.0. Because we consider this an important discussion about the product, we decided to move it to the forum so that it’s easier for new users to find and easier to reference in the future.

The last comment of that conversation was:

as a developer I find it very helpful to have symmetric APIs whenever feasible. if I can create a thing, I should be able to list those things too. If zeebe doesn’t support listing workflows, then every developer has to implement their own system for tracking what’s been deployed. That seems like an impediment to adoption. Further, recovery from system failures becomes more difficult. Is it truly a binary choice that ‘all workflows were lost’ or ‘no workflows were lost’? Perhaps this doesn’t matter in this case as users could simply redeploy every workflow they think they should have… ?

First of all thank you for your feedback. It is very valuable for us and helps us to shape the future of Zeebe. Regarding the current discussion of removing query APIs from Zeebe 0.18 I want to give you some background information which might help you to understand our decision. Zeebe is not designed to be a queryable state store, instead it focuses on the execution of stateful workflows. The only existing query APIs (list/get workflow) were initially implemented as a temporary solution before the exporter API was available. We now decided to remove them before the GA as they were inconsistent with the remaining API, i.e. no query APIs for workflow instances and jobs. This doesn’t mean that we will never implement a query API, but we’re not going to offer it right now.

At the moment the architecture of Zeebe enables users to query state by exporting the event stream to their preferred data stores which already have clients and query APIs in place. This removes a lot of complexity from the initial Zeebe scope. From my perspective, a usable implementation of a query API on top of Zeebe requires handling partitioned data sets and pagination/filtering support. I don’t want to say that this will never be implemented but at the moment is out of scope for the first GA.


#2

maybe monitor should be split to two parts, one for event center and one for monitor ui
event center should be pure and independent. put it to broker is not a good choice in my opinion, it should be focus on storing/querying, it can be based on exporter.
event store should be released officially, but monitor ui maybe communal.