[KAFKA-2882] Add constructor cache for Snappy and LZ4 Output/Input stream in Compressor.java

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.2.1
• Fix Version/s: 0.9.0.1
• Component/s: consumer, producer
• Assignee: Maxim Logvinenko
• Reporter: Maxim Logvinenko
• Created: 24/Nov/15 13:26
• Updated: 27/Nov/15 06:20
• Resolved: 27/Nov/15 06:18

Description

In `wrapForOutput` and `wrapForInput` methods of `org.apache.kafka.common.record.Compressor`, `Class.forName("[compression codec]")` and `getConstructor` methods are invoked for each `wrapForOutput` / `wrapForInput` call. Reflection calls are expensive and impact performance at high volumes. This patch adds a cache for `Constructor` to reduce the reflection overhead.

In our production deployments, this has reduced producer CPU usage by about 20%