How do I get rid of Kafka lag?

How do I get rid of Kafka lag?

3 Answers

1. Monitor how much lag is getting reduced in unit time (per minute, let’s assume) by each consumer.
2. If the rate of lag reduction is still too low, and you’d like to increase it, then add appropriate number of consumers.
3. Make sure all your consumers are in the same consumer group.

What is Kafka offset lag?

An offset is a simple integer that Kafka uses to identify a position in the log. Lag is simply the delta between the last produced message and the last consumer’s committed offset. Today, offsets are stored in a special topic called __consumer_offsets .

What causes Kafka consumer lag?

Consumer lag indicates the lag between Kafka producers and consumers. If the rate of production of data far exceeds the rate at which it is getting consumed, consumer groups will exhibit lag. As the broker writes data – it keeps track of the last offset and records it as the log end offset.

How do you reset Kafka topic offset?

Consumer offset reset options

1. –shift-by Use shift-by to move the offset ahead or behind.
2. –to-datetime Reset offsets to offset from datetime.
3. –to-earliest. Reset offsets to earliest (oldest) offset available in the topic.
4. –to-latest.

Can Kafka offset be negative?

Currently, the per partition level lag metric can be negative since the last committed offset can be smaller than the follower’s offset.

How can I speed up Kafka consumer?

In short, for Kafka Consumer Optimization be sure to use rebalance delay, process messages with exactly_once processing, ensure good network connections, set consumers to a multiple of the number of partitions, and keep messages below 1 MB in size.

What is an offset in Kafka?

The offset is a simple integer number that is used by Kafka to maintain the current position of a consumer. That’s it. The current offset is a pointer to the last record that Kafka has already sent to a consumer in the most recent poll. So, the consumer doesn’t get the same record twice because of the current offset.

What is negative lag in Kafka?

Consumer offset is read from the offset topic for Kafka based consumers. This means the reported lag may be negative since we are consuming offset from the offset topic faster then polling the producer offset. This is normal and not a problem.” Taken from github.com/yahoo/CMAK.

How is Kafka consumer lag calculated?

Kafka Lag Exporter estimates time lag by either interpolation or extrapolation of the timestamp of when the last consumed offset was first produced. The Kafka Consumer Group coordinator will return the last produced offsets for all the partitions we are subscribed to (the set of all partitions of all consumer groups).

Does Kafka offset ever reset?

“CURRENT-OFFSET” is the offset where this consumer group is currently at in each of the partitions. This will print the expected result of the reset, but not actually run it. This will execute the reset and reset the consumer group offset for the specified topic back to 0.

Does Kafka offset reset?

offset. reset to define the behavior of the consumer when there is no committed position (which would be the case when the group is first initialized) or when an offset is out of range. You can choose either to reset the position to the “earliest” offset or the “latest” offset (the default).

How does Kafka handle offset?