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ChenLin updated KAFKA-8328: --------------------------- Attachment: Kafka_smooth_expansion.patch > Kafka smooth expansion > ---------------------- > > Key: KAFKA-8328 > URL: https://issues.apache.org/jira/browse/KAFKA-8328 > Project: Kafka > Issue Type: Improvement > Components: clients, core > Affects Versions: 0.10.2.0 > Reporter: ChenLin > Priority: Major > Labels: Kafka, expansion > Fix For: 0.10.2.0 > > Attachments: DiskUtil.png, Kafka_smooth_expansion.patch, > producerP999.png > > > When expanding the kafka cluster, the new follower will read the data from > the earliest offset. This can result in a large amount of historical data > being read from the disk, putting a lot of pressure on the disk and affecting > the performance of the kafka service, for example, the producer write latency > will increase. In general, kafka's original expansion mechanism has the > following problems: > 1. The new follower will put a lot of pressure on the disk; > 2. Causes the producer write latency to increase; > 3. Causes the consumer read latency to increase; > In order to solve these problems, we have proposed a solution for > smooth expansion. The main idea of the scheme is that the newly added > follower reads data from the HW position, and when the newly added follower > reads the data to a certain time threshold or data size threshold, the > follower enters the ISR queue. . Since the new follower reads data from the > HW location, most of the data read is in the operating system's cache, so it > does not put pressure on the disk and does not affect the performance of the > kafka service, thus solving the above problems. > In order to illustrate the problems of the original expansion scheme, > we have done some tests, and there are corresponding test charts in the > attachment. > !image-2019-05-07-14-12-41-314.png! > !image-2019-05-07-14-12-03-005.png! -- This message was sent by Atlassian JIRA (v7.6.3#76005)