Connections are reused in LRU order and therefore not idle

[patriknw]

Bug Report

Versions

• Driver: r2dbc-postgres
• Database: Postgres
• Java: 11
• OS:

Current Behavior

Idle connections are not evicted after maxIdleTime.

Steps to reproduce

• Set maxIdleTime and backgroundEvictionInterval.
• Acquire up to the max number of connections.
• Acquire and close one connection at a time with a low frequency (like 1 per second).
• The number of connections in the pool will not shrink.

Expected behavior/code

Evict idle (unused) connections when low demand of connections.

Possible Solution

Reactor pool is using LRU reuse by default. That means that all connections in the pool are touched and never become idle.

Change to MRU.