Spring boot 2 Redis cache default client

I am using Spring Boot 2 and this dependency to use redis cache:

implementation 'org.springframework.boot:spring-boot-starter-data-redis'

As I read before Letucce is a default client for Redis. But, when I started to configure it with properties (even default) it become failed.

spring: redis:  lettuce:    pool:      max-active: 8      max-idle: 8      max-wait: -1      min-idle: 0

To recover service I can add common-pool2:

implementation group: 'org.apache.commons', name: 'commons-pool2', version: '2.8.1'

It looks like spring boot starts to use this pool only after setting properties.

So, the question is what exact redis client is used by Spring Boot by default and what properties are set by default?