tsbs

README

Time Series Benchmark Suite (TSBS)

This repo contains code for benchmarking several time series databases, including TimescaleDB, MongoDB, InfluxDB, and Cassandra. This code is based on a fork of work initially made public by InfluxDB at https://github.com/influxdata/influxdb-comparisons.

Current databases supported:

• TimescaleDB (supplemental docs)
• MongoDB (supplemental docs)
• InfluxDB (supplemental docs)
• Cassandra (supplemental docs)

Overview

The Time Series Benchmark Suite (TSBS) is a collection of Go programs that are used to generate datasets and then benchmark read and write performance of various databases. The intent is to make the TSBS extensible so that a variety of use cases (e.g., devops, finance, etc.), query types, and databases can be included and benchmarked. To this end we hope to help prospective database administrators find the best database for their needs and their workloads. Further, if you are the developer of a time series database and want to include your database in the TSBS, feel free to open a pull request to add it!

Current use cases

Currently, TSBS supports one use case -- dev ops -- in two forms. The full form is used to generate, insert, and measure data from 9 'systems' that could be monitored in a real world dev ops scenario (e.g., CPU, memory, disk, etc). Together, these 9 systems generate 100 metrics per reading interval. The alternate form focuses solely on CPU metrics for a simpler, more streamlined use case. This use case generates 10 CPU metrics per reading.

In addition to metric readings, 'tags' (including the location of the host, its operating system, etc) are generated for each host with readings in the dataset. Each unique set of tags identifies one host in the dataset and the number of different hosts generated is defined by the scale-var flag (see below).

What the TSBS tests

TSBS is used to benchmark bulk load performance and query execution performance. (It currently does not measure concurrent insert and query performance, which is a future priority.) To accomplish this in a fair way, the data to be inserted and the queries to run are pre-generated and native Go clients are used wherever possible to connect to each database (e.g., mgo for MongoDB).

Although the data is randomly generated, TSBS data and queries are entirely deterministic. By supplying the same PRNG (pseudo-random number generator) seed to the generation programs, each database is loaded with identical data and queried using identical queries.

Installation

TSBS is a collection of Go programs (with some auxiliary bash and Python scripts). The easiest way to get and install the Go programs is to use go get and then go install:

# Fetch TSBS and its dependencies
$ go get github.com/timescale/tsbs
$ cd $GOPATH/src/github.com/timescale/tsbs/cmd
$ go get ./...

# Install desired binaries. At a minimum this includes tsbs_generate_data,
# tsbs_generate_queries, one tsbs_load_* binary, and one tsbs_run_queries_*
# binary:
$ cd $GOPATH/src/github.com/timescale/tsbs/cmd
$ cd tsbs_generate_data && go install
$ cd ../tsbs_generate_queries && go install
$ cd ../tsbs_load_timescaledb && go install
$ cd ../tsbs_run_queries_timescaledb && go install

# Optionally, install all binaries:
$ cd $GOPATH/src/github.com/timescale/tsbs/cmd
$ go install ./...

How to use TSBS

Using TSBS for benchmarking involves 3 phases: data and query generation, data loading/insertion, and query execution.

Data and query generation

So that benchmarking results are not affected by generating data or queries on-the-fly, with TSBS you generate the data and queries you want to benchmark first, and then you can (re-)use it as input to the benchmarking phases.

Data generation

Variables needed:

1. a use case. E.g., cpu-only (choose from cpu-only or devops)
2. a PRNG seed for deterministic generation. E.g., 123
3. the number of devices to generate for. E.g., 4000
4. a start time for the data's timestamps. E.g., 2016-01-01T00:00:00Z
5. an end time. E.g., 2016-01-04T00:00:00Z
6. how much time should be between each reading per device, in seconds. E.g., 10s
7. and which database(s) you want to generate for. E.g., timescaledb (choose from cassandra, influx, mongo, or timescaledb)

Given the above steps you can now generate a dataset (or multiple datasets, if you chose to generate for multiple databases) that can be used to benchmark data loading of the database(s) chosen using the tsbs_generate_data tool:

$ tsbs_generate_data -use-case="cpu-only" -seed=123 -scale-var=4000 \
    -timestamp-start="2016-01-01T00:00:00Z" \
    -timestamp-end="2016-01-04T00:00:00Z" \
    -log-interval="10s" -format="timescaledb" \
    | gzip > /tmp/timescaledb-data.gz

# Each additional database would be a separate call.

Note: We pipe the output to gzip to reduce on-disk space.

The example above will generate a psuedo-CSV file that can be used to bulk load data into TimescaleDB. Each database has it's own format of how it stores the data to make it easiest for its corresponding loader to write data. The above configuration will generate just over 100M rows (1B metrics), which is usually a good starting point. Increasing the time period by a day will add an additional ~33M rows so that, e.g., 30 days would yield a billion rows (10B metrics)

Query generation

Variables needed:

1. the same use case, seed, # of devices, and start time as used in data generation
2. an end time that is one second after the end time from data generation. E.g., for 2016-01-04T00:00:00Z use 2016-01-04T00:00:01Z
3. the number of queries to generate. E.g., 1000
4. and the type of query you'd like to generate. E.g., single-groupby-1-1-1

For the last step there are numerous queries to choose from, which are listed in Appendix I. Additionally, the file scripts/generate_queries.sh contains a list of all of them as the default value for the environmental variable queryTypes. If you are generating more than one type of query, we recommend you use that helper script.

For generating just one set of queries for a given type:

$ tsbs_generate_queries -use-case="cpu-only" -seed=123 -scale-var=4000 \
    -timestamp-start="2016-01-01T00:00:00Z" \
    -timestamp-end="2016-01-04T00:00:01Z" \
    -queries=1000 -query-type="single-groupby-1-1-1" -format="timescaledb" \
    | gzip > /tmp/timescaledb-queries-single-groupby-1-1-1.gz

For generating sets of queries for multiple types:

$ formats="timescaledb" scaleVar=4000 seed=123 \
    tsStart="2016-01-01T00:00:00Z" \
    tsEnd="2016-01-04T00:00:01Z" \
    queries=1000 queryTypes="single-groupby-1-1-1 single-groupby-1-1-12 double-groupby-1" \
    dataDir="/tmp" scripts/generate_queries.sh

A full list of query types can be found in Appendix I at the end of this README.

Benchmarking insert/write performance

TSBS measures insert/write performance by taking the data generated in the previous step and using it as input to a database-specific command line program. To the extent that insert programs can be shared, we have made an effort to do that (e.g., the TimescaleDB loader can be used with a regular PostgreSQL database if desired). Each loader does share some common flags -- e.g., batch size (number of readings inserted together), workers (number of concurrently inserting clients), connection details (host & ports), etc -- but they also have database-specific tuning flags. To find the flags for a particular database, use the -help flag (e.g., tsbs_load_timescaledb -help).

Instead of calling these binaries directly, we also supply scripts/load_<database>.sh for convenience with many of the flags set to a reasonable default for some of the databases. So for loading into TimescaleDB, ensure that TimescaleDB is running and then use:

# Will insert using 2 clients, batch sizes of 10k, from a file
# named `timescaledb-data.gz` in directory `/tmp`
$ NUM_WORKERS=2 BATCH_SIZE=10000 BULK_DATA_DIR=/tmp \       
    scripts/load_timescaledb.sh

This will create a new database called benchmark where the data is stored. It will overwrite the database if it exists; if you don't want that to happen, supply a different DATABASE_NAME to the above command.

---

By default, statistics about the load performance are printed every 10s, and when the full dataset is loaded the looks like this:

time,per. metric/s,metric total,overall metric/s,per. row/s,row total,overall row/s
# ...
1518741528,914996.143291,9.652000E+08,1096817.886674,91499.614329,9.652000E+07,109681.788667
1518741548,1345006.018902,9.921000E+08,1102333.152918,134500.601890,9.921000E+07,110233.315292
1518741568,1149999.844750,1.015100E+09,1103369.385320,114999.984475,1.015100E+08,110336.938532

Summary:
loaded 1036800000 metrics in 936.525765sec with 8 workers (mean rate 1107070.449780/sec)
loaded 103680000 rows in 936.525765sec with 8 workers (mean rate 110707.044978/sec)

All but the last two lines contain the data in CSV format, with column names in the header. Those column names correspond to:

• timestamp,
• metrics per second in the period,
• total metrics inserted,
• overall metrics per second,
• rows per second in the period,
• total number of rows,
• overall rows per second.

For databases, like Cassandra, that do not use rows when inserting, the last three values are always empty (indicated with a -).

The last two lines are a summary of how many metrics (and rows where applicable) were inserted, the wall time it took, and the average rate of insertion.

Benchmarking query execution performance

To measure query execution performance in TSBS, you first need to load the data using the previous section and generate the queries as described earlier. Once the data is loaded and the queries are generated, just use the corresponding tsbs_run_queries_ binary for the database being tested:

$ cat /tmp/queries/timescaledb-cpu-max-all-eight-hosts-queries.gz | \
    gunzip | tsbs_run_queries_timescaledb --workers=8 \    
        --postgres="host=localhost user=postgres sslmode=disable"

You can change the value of the --workers flag to control the level of parallel queries run at the same time. The resulting output will look similar to this:

run complete after 1000 queries with 8 workers:
TimescaleDB max cpu all fields, rand    8 hosts, rand 12hr by 1h:
min:    51.97ms, med:   757.55, mean:  2527.98ms, max: 28188.20ms, stddev:  2843.35ms, sum: 5056.0sec, count: 2000
all queries                                                     :
min:    51.97ms, med:   757.55, mean:  2527.98ms, max: 28188.20ms, stddev:  2843.35ms, sum: 5056.0sec, count: 2000
wall clock time: 633.936415sec

The output gives you the description of the query and multiple groupings of measurements (which may vary depending on the database).

---

For easier testing of multiple queries, we provide scripts/generate_run_script.py which creates a bash script with commands to run multiple query types in a row. The queries it generates should be put in a file with one query per line and the path given to the script. For example, if you had a file named queries.txt that looked like this:

high-cpu-1
cpu-max-all-8
groupby-orderby-limit
double-groupby-1

You could generate a run script named query_test.sh:

# Generate run script for TimescaleDB, using queries in `queries.txt`
# with the generated query files in /tmp/queries for 8 workers
$ python generate_run_script.py -d timescaledb -o /tmp/queries \
    -w 8 -f queries.txt > query_test.sh

And the resulting script file would look like:

#!/bin/bash
# Queries
cat /tmp/queries/timescaledb-high-cpu-1-queries.gz | gunzip | query_benchmarker_timescaledb --workers=8 --limit=1000 --hosts="localhost" --postgres="user=postgres sslmode=disable"  | tee query_timescaledb_timescaledb-high-cpu-1-queries.out

cat /tmp/queries/timescaledb-cpu-max-all-8-queries.gz | gunzip | query_benchmarker_timescaledb --workers=8 --limit=1000 --hosts="localhost" --postgres="user=postgres sslmode=disable"  | tee query_timescaledb_timescaledb-cpu-max-all-8-queries.out

cat /tmp/queries/timescaledb-groupby-orderby-limit-queries.gz | gunzip | query_benchmarker_timescaledb --workers=8 --limit=1000 --hosts="localhost" --postgres="user=postgres sslmode=disable"  | tee query_timescaledb_timescaledb-groupby-orderby-limit-queries.out

cat /tmp/queries/timescaledb-double-groupby-1-queries.gz | gunzip | query_benchmarker_timescaledb --workers=8 --limit=1000 --hosts="localhost" --postgres="user=postgres sslmode=disable"  | tee query_timescaledb_timescaledb-double-groupby-1-queries.out

Query validation (optional)

Additionally each tsbs_run_queries_ binary allows you print the actual query results so that you can compare across databases that the results are the same. Using the flag -print-responses will return the results.

Appendix I: Query types

Devops / cpu-only

Query type	Description
single-groupby-1-1-1	Simple aggregrate (MAX) on one metric for 1 host, every 5 mins for 1 hour
single-groupby-1-1-12	Simple aggregrate (MAX) on one metric for 1 host, every 5 mins for 12 hours
single-groupby-1-8-1	Simple aggregrate (MAX) on one metric for 8 hosts, every 5 mins for 1 hour
single-groupby-5-1-1	Simple aggregrate (MAX) on 5 metrics for 1 host, every 5 mins for 1 hour
single-groupby-5-1-12	Simple aggregrate (MAX) on 5 metrics for 1 host, every 5 mins for 12 hours
single-groupby-5-8-1	Simple aggregrate (MAX) on 5 metrics for 8 hosts, every 5 mins for 1 hour
cpu-max-all-1	Aggregate across all CPU metrics per hour over 1 hour for a single host
cpu-max-all-8	Aggregate across all CPU metrics per hour over 1 hour for eight hosts
double-groupby-1	Aggregate on across both time and host, giving the average of 1 CPU metric per host per hour for 24 hours
double-groupby-5	Aggregate on across both time and host, giving the average of 5 CPU metrics per host per hour for 24 hours
double-groupby-all	Aggregate on across both time and host, giving the average of all (10) CPU metrics per host per hour for 24 hours
high-cpu-all	All the readings where one metric is above a threshold across all hosts
high-cpu-1	All the readings where one metric is above a threshold for a particular host
lastpoint	The last reading for each host
groupby-orderby-limit	The last 5 aggregate readings (across time) before a randomly chosen endpoint