We are considering using Graylog opensouce in our product as a part of the application for monitoring functionality of the health of our application when deployed to cllients. Is there any licensing issue with using the free version given that we charge for the our product?
There may be, Graylog is licensed under SSPL, which does have some limitations on how it can be used as part of other services https://graylog.org/post/graylog-v4-0-licensing-sspl/ Server Side Public License - Wikipedia
The commercial version of Graylog however does not have this limitation, and we have several partners who use Graylog commercial in these ways, reach out to our team through the website if you want to explore that option.