[COUCHDB-3304] Rollback default value of config global_change:max_write_delay to 500

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Component/s: Database Core
• Assignee: Unassigned
• Reporter: Bala Kolla
• Created: 20/Feb/17 14:54
• Updated: 26/Feb/17 23:47
• Resolved: 26/Feb/17 23:47

Description

This config default value has changed from 500 to 25 and it's causing a noticeable impact on the performance. We executed a performance test benchmark to simulate the load test of put_insert (create) scenario. The summary of the results is shown below.

As evident in the performance test results shown below, when the max_write_delay was set to 500 then there is an improvement across all the metrics.

• Throughput improved by around 10%
• p99 is improved by around 20%
• And similar gains in other latency metrics.

A0 ==> Default config of 25
A1 ==> 500.0

global_changes-max_write_delay	bench_result	p90	p99	p999

A0	363874	83485.6	115756	176128
A1	403827	63356.4	84457.6	102221