Crate db metrics integration with jmx_exporter

Question

Hi I want crate db metrics like number of connections exposed via an api. I got to know that this can be done through crate/jmx_exporter(https://github.com/crate/jmx_exporter). I have very little knowledge of java agents and jmx. Its not very clear in the link I mentioned how do we get crate db metrics exposed via api. I do not have any java application/repo connected to my crate db and my crate db is up on ubuntu 16.04. Can someone help me how I can get the metrics exposed via api of the crated db hosted in my system ? Do we require a java application for this ?

Answer 1

You just need to download the jmx_exporter and set an environment variable with the respective location. However many metrics can also be collected from the sys tables. e.g. sys.nodes contains information about connections

Look at https://crate.io/docs/crate/reference/en/4.6/admin/system-information.html or run the following to get a list of all sys-tables

SELECT table_name FROM information_schema.tables
where table_schema = 'sys'
ORDER BY 1;