[SAMZA-1331] Optimize Snapshot class constructor

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.13.0
• Assignee: Maxim Logvinenko
• Reporter: Maxim Logvinenko
• Created: 09/Jun/17 11:19
• Updated: 23/Jun/17 19:11
• Resolved: 09/Jun/17 17:35

Description

In some of our workloads (where we need to gather samza metrics five times per minute) `SlidingTimeWindowReservoir.getSnapshot()` method takes up to 10% of processor time.

Almost all of `getSnapshot` time is taken by Collections.sort method. So, the complexity of Snapshot constructor is O(NlogN) + iteration through passed values.

This ticket asks to improve the performance of Snapshot constructor but keep the performance of all other methods at least on the same level.

Issue Links

• links to: GitHub Pull Request #221