This is a good resource page: Splunk Cloud Platform Service Details - Splunk Documentation
- Is there a message informing the license is about to expire?
You can view information about your license entitlements. Here's the docs that explain that for Splunk Cloud.
- After the expiration date, is there any grace period provided?
Assume no, but open a support ticket and work with your account manager on this situation.
- In case I decide to not renew the license, are we able somehow to download the company data before its total removal? Or after my license is expired I lose all indexed data?
Per the page under Data Handling, retrieving your data is suggested to be a Splunk Professional Services engagement, which often can mean "this is kinda hard if you're new to Splunk."
If you require your ingested data to be moved into your control before the termination of your subscription, this is accomplished through a Splunk Professional Services engagement. Some data can be moved into your control by enabling Dynamic Data Self-Storage to export your aged data to your Amazon S3 or Google Cloud Storage account in the same region
There are data egress notes on that page, too, and this page details getting your data out of your Splunk Cloud envirnment using Dynamic Data Self Storage (DDSS). You could technically "age out" your data to your own S3 buckets, for example.
This also could be a good discussion for the #splunk_cloud channel on the splunk-usergroups.slack.com workspace.
