Rework Spring Session Redis properties to make it clearer which properties apply in which situations

[wilkinsona]

We have 6 properties at the moment:

• spring.session.redis.cleanup-cron
• spring.session.redis.configure-action
• spring.session.redis.flush-mode
• spring.session.redis.namespace
• spring.session.redis.repository-type
• spring.session.redis.save-mode

Of these, two are servlet-specific:

• spring.session.redis.cleanup-cron
• spring.session.redis.flush-mode

And two are specific to indexed repositories:

• spring.session.redis.cleanup-cron
• spring.session.redis.configure-action

We should try to rework the properties and how they're handled to make this more clear. For example, we could move the servlet-specific properties into a group of their own:

• spring.session.redis.servlet.cleanup-cron
• spring.session.redis.servlet.flush-mode

We could also fail if an indexed-specific properties is set when using the default repository type. Additionally or alternatively we could move the indexed-specific properties into their own group. This would leave us with these 6 properties:

• spring.session.redis.servlet.indexed.cleanup-cron
• spring.session.redis.indexed.configure-action
• spring.session.redis.servlet.flush-mode
• spring.session.redis.namespace
• spring.session.redis.repository-type
• spring.session.redis.save-mode

[travisriegler]

Good afternoon, is this something that I could work on? I previously helped with issue #40988 and this current issue appears to be similar, if I am not mistaken.

[philwebb]

Thanks for the offer @travisriegler, but this one is currently labeled as "pending-design-work" which means we need to give it some thought as a team before we can accept contributions.