Time Series data structure for redis
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README.md

Redis Time-Series Module

Time series data structure for redis.

CircleCI

Using with other tools metrics tools

See Tools directory. Including Integration with:

  1. StatsD, Graphite exports using graphite protocol.
  2. Grafana - using SimpleJson datasource.

Memory model

A time series is a linked list of memory chunks. Each chunk has a predefined size of samples, each sample is a tuple of the time and the value. Each sample is the size of 128bit (64bit for the timestamp and 64bit for the value).

Features

  • Quick inserts (50K samples per sec)
  • Query by start time and end-time
  • Aggregated queries (Min, Max, Avg, Sum, Range, Count, First, Last) for any time bucket
  • Configurable max retention period
  • Compactions/Roll-ups - automatically updated aggregated timeseries

Build

git submodule init
git submodule update
cd src
make all

Run

In your redis-server run: loadmodule redis-tsdb-module.so.

More infomation about modules can be found at redis offical documentation: https://redis.io/topics/modules-intro

Tests

Tests are written in python using the rmtest library.

$ cd src
$ pip install -r tests/requirements.txt # optional, use virtualenv
$ make test

Commands

TS.create - create a new time-series

TS.CREATE KEY [retentionSecs] [maxSamplesPerChunk]
  • key - key name for timeseries

Optional args:

  • retentionSecs - max age for samples compared to current time (in seconds).
    • Default: 0
    • When set to 0, the series will not be trimmed at all
  • maxSamplesPerChunk - how many samples to keep per memory chunk
    • Default: 360

TS.createrule - create a compaction rule

TS.CREATERULE SOURCE_KEY AGG_TYPE BUCKET_SIZE_SEC DEST_KEY
  • SOURCE_KEY - key name for source time series
  • AGG_TYPE - aggregation type one of the following: avg, sum, min, max, range, count, first, last
  • BUCKET_SIZE_SEC - time bucket for aggregated compaction,
  • DEST_KEY - key name for destination time series

DEST_KEY should be of a timeseries type, and should be created before TS.CREATERULE is called.

Performance Notice: if a compaction rule exits on a timeseries TS.ADD performance might be reduced, the complexity of TS.ADD is always O(M) when M is the amount of compactions rules or O(1).

TS.deleterule - delete a compaction rule

TS.DELETERULE SOURCE_KEY DEST_KEY
  • SOURCE_KEY - key name for source time series
  • DEST_KEY - key name for destination time series

TS.add - append a new value to the series

TS.ADD key TIMESTAMP value
  • TIMESTAMP - unix timestamp (in seconds) or * for automatic timestamp (using the system clock)
  • value - sample numeric data value (double)

Complexity

if a compaction rule exits on a timeseries TS.ADD performance might be reduced, the complexity of TS.ADD is always O(M) when M is the amount of compactions rules or O(1).

TS.range - ranged query

TS.RANGE key FROM_TIMESTAMP TO_TIMESTAMP [aggregationType] [bucketSizeSeconds]
1) 1) (integer) 1487426646
   2) "3.6800000000000002"
2) 1) (integer) 1487426648
   2) "3.6200000000000001"
3) 1) (integer) 1487426650
   2) "3.6200000000000001"
4) 1) (integer) 1487426652
   2) "3.6749999999999998"
5) 1) (integer) 1487426654
   2) "3.73"
  • key - key name for timeseries Optional args:
    • aggregationType - one of the following: avg, sum, min, max, range, count, first, last
    • bucketSizeSeconds - time bucket for aggregation in seconds

Complexity

TS.RANGE complexity is O(n/m+k)

n = number of data points m = chunk size (data points per chunk) k = number of data points that are in the requested range

This can be improved in the future by using binary search to find the start of the range, which will make this O(Log(n/m)+k*m), but since m is pretty small, we can neglect it and look at the operation as O(Log(n) + k).

Example for aggregated query

ts.range stats_counts.statsd.packets_received 1487527100 1487527133 avg 5
1) 1) (integer) 1487527100
   2) "284.39999999999998"
2) 1) (integer) 1487527105
   2) "281"
3) 1) (integer) 1487527110
   2) "278.80000000000001"
4) 1) (integer) 1487527115
   2) "279.60000000000002"
5) 1) (integer) 1487527120
   2) "215"
6) 1) (integer) 1487527125
   2) "266.80000000000001"
7) 1) (integer) 1487527130
   2) "310.75"
127.0.0.1:6379>

TS.INCRBY/TS.DECRBY - Increment the latest value

TS.INCRBY key [VALUE] [RESET] [TIME_BUCKET]

This command can be used as a counter/gauge that get automatic history as a time series.

  • key - key name for timeseries Optional args:
    • VALUE - one of the following: avg, sum, min, max, range, count, first, last
    • RESET - Should the current counter should be resetted when TIME_BUCKET is changes
    • TIME_BUCKET - time bucket for resetting the current counter in seconds

TS.info - query the series metadata

TS.INFO key
1) lastTimestamp
2) (integer) 1486289265
3) retentionSecs
4) (integer) 0
5) chunkCount
6) (integer) 139
7) maxSamplesPerChunk
8) (integer) 360

License

Apache 2.0 with Commons Clause - see LICENSE