"Messages Behind" in kafka topic

[winnielim347]

May i know what is "Messages Behind" in kafka topic means?

Sometime i get number in this column, sometime not.
Is the desired behavior for "Messages Behind" shall be 0?

thanks in advance.

[Haarolean]

Hi,

it's also known as consumer lag. Yea, ideally it should be zero.

[winnielim347]

Hi @Haarolean
1.May i know normally what will cause consumer lag?
2.Is "Messages Behind" also means those messages haven't read by consumer yet?

[Haarolean]

1. Your consumers consume messages slower than producers produce them.
2. Yes, that's right.

[xiaomlove]

I've got a negative number here. What does that mean?

[Devarsh23]

@xiaomlove Were you able to figure out why you were seeing the negative number?
We are seeing the same negative number for some kafka-connect based consumer

[ghost]

Same here. I constantly get negative numbers in a lot of consumers. What does this mean?

[Haarolean]

This is considered normal, meaning your consumers are consuming the messages from the topic faster than they're produced into one.

[AliAhmadi99]

The problem is the message bus gets stuck because consumers can't consume a message correctly. I want to be able to skip messages if a error happened in running