FE: Fix 'Online Partitions' column

[bachmanity1]

• Breaking change? (if so, please describe the impact and migration path for existing application instances)

What changes did you make? (Give an overview)

Resolves #526.

The value shown in the Online Partitions column of the brokers list table was modified in #137. This PR restores the original logic used to render Online Partitions prior to #137.

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• No need to
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• I have performed a self-review of my own code
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• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged

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[Haarolean]

This PR restores the original logic

@bachmanity1 hi, could you please elaborate here? The changes previously introduced were done so with a purpose (even if introducing incorrect behavior), so reverting these changes you're probably introducing another faulty behavior that was present before #137 (#26)?

[kapybro]

Further user feedback is requested. Please reply within 7 days or we might close the issue.

[bachmanity1]

This PR restores the original logic

@bachmanity1 hi, could you please elaborate here? The changes previously introduced were done so with a purpose (even if introducing incorrect behavior), so reverting these changes you're probably introducing another faulty behavior that was present before #137 (#26)?

Hi @Haarolean, thanks for review!

You're right. We can't simply revert the changes made in #137 because that would bring back the original faulty behavior. While the changes in #137 fixed the issue with the Online Partitions column's color, they also caused every row in the brokers table to show the same value in that column. From looking at the backend code, it seems that Online Partitions refers to partitions where the describeTopics API doesn't return null for the partition leader. While it's possible to compute this for the whole cluster, I don't think it's possible (or needed?) to do so for each individual broker.

So, how about renaming the Online Partitions column to just Partitions and showing the actual number of partitions (replicas) located on each broker by using partitions field from the broker info? If possible, I'd even suggest renaming Online Partitions to Replicas and Partitions Skew to Replicas Skew. I think this would make more sense, since in Kafka terminology, partitions stored on brokers are referred to as replicas.

[kapybro]

Thanks for the additional feedback! We'll get back to your issue soon.

[bachmanity1]

Hi @Haarolean,

Following my last comment, I've made slight changes to the brokers table by rearranging the order and renaming columns. Here is a sample screenshot: