InfluxDB 101

Connect to our instance

Curl

> curl -G 'https://scala-ci.typesafe.com/influx/query?pretty=true' --data-urlencode "u=scala" --data-urlencode "p=<>" --data-urlencode "db=scala_benchmark" --data-urlencode "q=SELECT * FROM result WHERE time > now() - 1d"
...

SSH and CLI

> ssh [email protected]
> influx -username scala -password <>
> use scala_benchmark
> SELECT * FROM result WHERE time > now() - 1d
...

Web UI

> ssh [email protected] -L 8086:localhost:8086 -N &
> ssh [email protected] -L 8083:localhost:8083 -N &

Open http://localhost:8083. Host: localhost, port: 8086, no SSL.

In principle, it should work without the first tunnel (host: scala-ci.typesafe.com/influx, port: 443, with SSL), but I couldn't get it to work.

Try with query SELECT * FROM result WHERE time > now() - 1d.

InfluxDB schema

Measurement

• Similar to an sql table
• Examples in scala_benchmark: result, commit
• Query: SHOW MEASUREMENTS

Tags:

• Similar to an indexed column in sql
• Examples: benchmark, branch, source, ...
• Queries: SHOW TAG KEYS FROM result, SHOW TAG VALUES FROM result WITH KEY = benchmark

Fields:

• Similar to non-indexed columns in sql
• Data and metadata
• Examples: javaVersion, score, ...
• Query: SHOW FIELD KEYS FROM result

Point:

• A data entry, similar to a row in sql
• Contains a timestamp, values for all tag keys, values for some field keys (sparse)

Series

• A measurement with a unique list of tag key-value pairs
• Example: result,benchmark=HotScalacBenchmark.compile,branch=2.12.x,source=better-files

Writing the same (measurement,timestamp,tagKeyValues) twice overwrites the existing point. We can exploit this to re-run a benchmark.

Querying

• A query requires at least one field key in the SELECT clause to return data
• Tag and field keys can be quoted in double quotes (if necessary)
• String literals need to be in single quotes
  • Example: SELECT * FROM result WHERE "benchmark" = 'HotScalacBenchmark.compile' LIMIT 5
• Regex matching: WHERE tagName =~ /regex/
• Query by time: SELECT * FROM result WHERE time > now() - 7d