After a pretty positive experience with influxdb I wanted to create a super simple telemetry producer (this one in Node.js) to spotlight a few types of time series data query in influxdb. To get us some live data, the included mock.js generate second-resolution metric data for CPU Utilization and Free Memory on your local machine.
First the database, in the db directory execute: ./setup.sh to start the influxdb instance and redirect logging to stdout. Once running follow with: ./init.sh to create the DB (test) and DB User (test/test). You should be able to access the influxdb UI at where you can see the created DB and its user.
At this point you can fire up the mock script in the node directory: node mock (golang sample coming soon) which will start sending data and output a few sample queries to play with.
Select of values based on arbitrary time window.
select sample_value from cpu_series where time > '2013-08-12 23:32:01.232' and time < 2013-08-12 23:22:055.134
On the fly 90th percentile of value in 5 second intervals. No windowing or period tables required.
select percentile(sample_value, 90) from mem_series group by time(5s);
Standard deviation of value in 5 second intervals. Again, all ad-hoc, downsampling with no priori declarations.
select stddev(sample_value) from cpu_series group by time(1m);
Having done a few time series systems in Cassandra, HBase and yes, even Mongo, I was looking for something that would be already optimized for that specific data type. Furthermore, I wanted clean API as well as support for many of common telemetry aggregate functions:
count(), min(), max(), mean(), mode(), median(), distinct(), percentile(), histogram(), derivative(), sum(), stddev(), first(), last()
Additionally:
- Open source (MIT), hosted on GitHub
- No external dependancies (nope, no zookeeper)
- SQL-like query and built-in UI
- On the fly, downsample aggregate (no need to define windows, just record it and query by ad-hoc period: e.g. 1s, 4s, 2m etc.)
- Clustering support (there is currently a limit of 2M writes per second in 0.9 release, which suppose to be removed in 1.0)
- Pure Golang since 0.9 (plus for me, may not be for others)