Visualization and Query issues
The most common problems are related to the query and response from you data source. Even if it looks like a bug or visualization issue in Grafana it is 99% of time a problem with the data source query or the data source response.
To check this you should use Query Inspector (new in Grafana v4.5). The query Inspector shows query requests and responses.
If you encounter an error or problem it is a good idea to check the grafana server log. Usually located at
/var/log/grafana/grafana.log on Unix systems or in
<grafana_install_dir>/data/log on other platforms and manual installs.
You can enable more logging by changing log level in you grafana configuration file.
Checkout the FAQ section on our community page for frequently asked questions.