Setting RABBITMQ_BASE on Windows vs. setting

[rubin55]

The documentation here: https://www.rabbitmq.com/relocate.html

Suggests that you can set RABBITMQ_MNESIA_BASE and RABBITMQ_LOG_BASE instead of setting the (windows-only) RABBITMQ_BASE:

"Note: Windows only. This base directory contains sub-directories for the RabbitMQ server's database and log files. Alternatively, set RABBITMQ_MNESIA_BASE and RABBITMQ_LOG_BASE individually."

However, if you don't set RABBITMQ_BASE, it will default to APPDATA/Roaming/RabbitMQ and specifically write the db directory and enabled_plugins file there, whilst honoring whatever you set RABBITMQ_MNESIA_BASE and RABBITMQ_LOG_BASE to.

This needs to be clarified better (i.e., indicate it not as "Alternatively" but as additionally).

[michaelklishin]

Both RABBITMQ_MNESIA_BASE and RABBITMQ_LOG_BASE are computed based on the value of RABBITMQ_BASE.

This docs do state the intended behavior: setting either RABBITMQ_BASE or the two more specific variables should be enough (assuming you want to override just data directory and log directory locations).

If that's not the case, we need a specific set of steps to reproduce.

Here are the relevant batch files that use those environment variables:

• https://github.com/rabbitmq/rabbitmq-server/blob/a3344e2ea595c3e2d7e5dc8d73d79ef2f257c668/deps/rabbit_common/src/rabbit_env.erl#L617-L620
• https://github.com/rabbitmq/rabbitmq-server/blob/v3.11.x/deps/rabbit/scripts/rabbitmq-defaults.bat
• https://github.com/rabbitmq/rabbitmq-server/blob/v3.11.x/deps/rabbit/scripts/rabbitmq-env.bat
• https://github.com/rabbitmq/rabbitmq-server/blob/v3.11.x/deps/rabbit/scripts/rabbitmq-server.bat
• https://github.com/rabbitmq/rabbitmq-server/blob/v3.11.x/deps/rabbit/scripts/rabbitmq-service.bat

[michaelklishin]

I have pushed a doc update. It's not clear to me whether the docs have to be updated or this is a node startup behavior issue that has to be addressed.

The docs now say that overriding RABBITMQ_BASE is the optimal option for many.