Rust Client for KairosDB  

Description

A simple rust language client for the time series database KairosDB.

Documentation

Full documentation for rust-kairosdb.

Usage

Put this in your Cargo.toml:

[dependencies]
kairosdb = "0.2"

Then add this in your crate root:

extern crate kairosdb;

Overview

The Client itself is used as the central access point, from which numerous operations are defined implementing each of the specific KairosDB APIs.

use kairosdb::Client;
let client = Client::new("localhost", 8080);

A main job of a time series database is collecting and querying data. To add data to KairosDB we have to create a Datapoints struct and add the data to the object. //!

use kairosdb::datapoints::Datapoints;
let mut datapoints = Datapoints::new("myMetric", 0);
datapoints.add_ms(1000, 11.0);
datapoints.add_ms(2000, 12.0);
datapoints.add_ms(3000, 13.0);
datapoints.add_tag("test", "first");
let result = client.add(&datapoints);
assert!(result.is_ok());

To query data we have to create a Query Object with the start and end of the query. The start and the end can be a relative time. Check the 'Time' structure for more information.

use std::collections::HashMap;
use kairosdb::query::{Query, Time, Metric, Tags};
let mut query = Query::new(
   Time::Nanoseconds(1000),
   Time::Nanoseconds(2000));
let metric = Metric::new("myMetric", Tags::new(), vec![]);
query.add(metric);
let result = client.query(&query).unwrap();
assert!(result.contains_key("myMetric"));
assert_eq!(result["myMetric"].len(), 2);
assert_eq!(result["myMetric"][0].time, 1000);
assert_eq!(result["myMetric"][0].value, 11.0);
assert_eq!(result["myMetric"][1].time, 2000);
assert_eq!(result["myMetric"][1].value, 12.0);

Optionally you can specify aggregators. Aggregators perform an operation on data points. For example, you can sum all data points that exist in 5 minute periods. Aggregators can be combined together. E.g you could sum all data points in 5 minute periods then calculate the average of them for a week period. Aggregators are processed in the order they are specified in the vector for the metric constructor.

use kairosdb::query::*;
use kairosdb::datapoints::Datapoints;
for i in 0..10 {
   let mut datapoints = Datapoints::new("myMetric", 0);
   datapoints.add_ms(i * 500, i as f64);
   datapoints.add_tag("test", "first");
   let result = client.add(&datapoints);
   assert!(result.is_ok());
}

let mut query = Query::new(
   Time::Nanoseconds(0),
   Time::Nanoseconds(10*500));

let aggregator = Aggregator::new(
    AggregatorType::AVG,
    RelativeTime::new(1, TimeUnit::SECONDS));
let metric = Metric::new("myMetric", Tags::new(), vec![aggregator]);
query.add(metric);

let result = client.query(&query).unwrap();
assert!(result.contains_key("myMetric"));
assert_eq!(result["myMetric"].len(), 5);
assert_eq!(result["myMetric"][0].time, 0);
assert_eq!(result["myMetric"][0].value, 0.5);

Deleting data is like querying data.

use kairosdb::query::{Query, Time, Metric, Tags};

let mut query = Query::new(
   Time::Nanoseconds(1000),
   Time::Nanoseconds(2000));

let mut tags = Tags::new();
tags.insert("test".to_string(), vec!["first".to_string()]);
let metric = Metric::new("myMetric", tags, vec![]);
query.add(metric);

let result = client.delete(&query);
assert!(result.is_ok());

Getting the current set of metric names is a simple function call.

let result = client.list_metrics();
assert!(result.unwrap().contains(&"myMetric".to_string()));

To get information about the current tags and tag values you can use the tagsnames and tagvalues method.

let tagnames = client.tagnames();
let tagvalues = client.tagvalues();
assert!(tagnames.unwrap().contains(&"test".to_string()));
assert!(tagvalues.unwrap().contains(&"first".to_string()));

Delete a metric by name

let result = client.delete_metric(&"myMetric");
assert!(result.is_ok());

Server status

To get the health status of the KairosDB Server

let response = client.health();
let result = response.unwrap();
assert_eq!(result[0], "JVM-Thread-Deadlock: OK");
assert_eq!(result[1], "Datastore-Query: OK");

Get the version of the KairosDB Server

let client = Client::new("localhost", 8080);
assert!(client.version().unwrap().starts_with("KairosDB"));

Limitations

The rust client is currently not supporting the roll-up features.

Licence

   Copyright 2016-2020 Kai Strempel

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.