Add an option to use on demand Dynamodb

[stijndehaes]

Is your feature request related to a problem? Please describe.
I want to be able to use loki without running prometheus for autoscaling the DynamoDB. By using on the Demand DynamoDB options I can be sure my grafana loki keeps on working without me worying about write and read capacity.
Also the application-autoscaling for DynamoDB is hard to configure and is becoming unsupported in cortex: #1267 (comment).

Describe the solution you'd like
I would like the options to provision the DynamoDB tables with on Demand instead of using provisioned read/write capacity.

Describe alternatives you've considered
Application autoscaling

Additional context
None

I am ok with implementing this myself by the way. Just want to make sure that you would accept this PR.

[patrickjahns]

@stijndehaes
This is already working - here is a config I am using with with loki 1.4.1

table_manager:
  creation_grace_period: 3h
  retention_deletes_enabled: false
  retention_period: 0
  chunk_tables_provisioning:
    provisioned_throughput_on_demand_mode: true
    inactive_throughput_on_demand_mode: true
    provisioned_write_throughput: 0
    provisioned_read_throughput: 0
    inactive_write_throughput: 0
    inactive_read_throughput: 0
  index_tables_provisioning:
    provisioned_throughput_on_demand_mode: true
    inactive_throughput_on_demand_mode: true
    provisioned_write_throughput: 0
    provisioned_read_throughput: 0
    inactive_write_throughput: 0
    inactive_read_throughput: 0

The flags here are taken from cortex 0.7 https://github.com/cortexproject/cortex/blob/v0.7.0/docs/configuration/config-file-reference.md

With the next version of loki the config values will change, as cortex has renamed quite a few parameters in 1.0.0

[stijndehaes]

@putrasattvika I completely missed that, Thank you for the info. Will close this ticket

[stale]

This issue has been automatically marked as stale because it has not had any activity in the past 30 days. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.