[KAFKA-5236] Regression in on-disk log size when using Snappy compression with 0.8.2 log message format

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.10.2.1
• Fix Version/s: 0.11.0.0
• Component/s: core
• Labels: regression
• Assignee: Ismael Juma
• Reporter: Nick Travers
• Created: 14/May/17 21:21
• Updated: 02/Jun/17 21:15
• Resolved: 02/Jun/17 21:15

Description

We recently upgraded our brokers in our production environments from 0.10.1.1 to 0.10.2.1 and we've noticed a sizable regression in the on-disk .log file size. For some deployments the increase was as much as 50%.

We run our brokers with the 0.8.2 log message format version. The majority of our message volume comes from 0.10.x Java clients sending messages encoded with the Snappy codec.

Some initial testing only shows a regression between the two versions when using Snappy compression with a log message format of 0.8.2.

I also tested 0.10.x log message formats as well as Gzip compression. The log sizes do not differ in this case, so the issue seems confined to 0.8.2 message format and Snappy compression.

A git-bisect lead me to this commit, which modified the server-side implementation of `Record`:
https://github.com/apache/kafka/commit/67f1e5b91bf073151ff57d5d656693e385726697

Here's the PR, which has more context:
https://github.com/apache/kafka/pull/2140

Here is a link to the test I used to re-producer this issue:
https://github.com/nicktrav/kafka/commit/68e8db4fa525e173651ac740edb270b0d90b8818

cc: hachikuji junrao ijuma guozhang (tagged on original PR)

Issue Links

• is related to: KAFKA-3565 Producer's throughput lower with compressed data after KIP-31/32
• is related to: KAFKA-5148 Add configurable compression block size to the broker
• links to: GitHub Pull Request #3205