What is the usage of 3 s3 buckets(chunks,ruler,admin) in LOKI?

Hi,

I have a doubt regarding the buckets specified in the simple-scalable helm chart .Version: loki-simple-scalable-1.8.11

There are three buckets as below:

  storage:
    bucketNames:
      chunks: chunks
      ruler: ruler
      admin: admin

When i try to use the helm chart , i am able to see the data in the chunks bucket but, the ruler and admin bucket is always empty.
what is the use of ruler and admin bucket?
In case these buckets(admin and Chunks) are not mandatory , how will i be able to remove the bucket from the helm chart?

Thanks in Advance.