query_help.md 1.5 KB

Alias patterns

  • replaced with measurement name
  • $measurement = replaced with measurement name
  • $1 - $9 = replaced with part of measurement name (if you separate your measurement name with dots)
  • $col = replaced with column name
  • $tag_exampletag = replaced with the value of the exampletag tag
  • You can also use [[tag_exampletag]] pattern replacement syntax

Stacking and fill

  • When stacking is enabled it is important that points align
  • If there are missing points for one series it can cause gaps or missing bars
  • You must use fill(0), and select a group by time low limit
  • Use the group by time option below your queries and specify for example 10s if your metrics are written every 10 seconds
  • This will insert zeros for series that are missing measurements and will make stacking work properly

Group by time

  • Group by time is important, otherwise the query could return many thousands of datapoints that will slow down Grafana
  • Leave the group by time field empty for each query and it will be calculated based on time range and pixel width of the graph
  • If you use fill(0) or fill(null) set a low limit for the auto group by time interval
  • The low limit can only be set in the group by time option below your queries
  • Example: 60s if you write metrics to InfluxDB every 60 seconds

Documentation links:

Grafana's InfluxDB Documentation

Official InfluxDB Documentation