This document summarizes an update on OpenTSDB, an open source time series database. It discusses OpenTSDB's ability to store trillions of data points at scale using HBase, Cassandra, or Bigtable as backends. Use cases mentioned include systems monitoring, sensor data, and financial data. The document outlines writing and querying functionality and describes the data model and table schema. It also discusses new features in OpenTSDB 2.2 and 2.3 like downsampling, expressions, and data stores. Community projects using OpenTSDB are highlighted and the future of OpenTSDB is discussed.

1. OpenTSDB Update
Distributed, Scalable Time Series Database
Chris Larsen clarsen@yahoo-inc.com

2. Who Am I? (no really, who am I?)
Chris Larsen
Current lead for OpenTSDB
Software Engineer @ Yahoo!
Monitoring Team

3. What Is OpenTSDB?
Open Source Time Series Database
Store trillions of data points
Sucks up all data and keeps going
Never lose precision
Scales using HBase, Cassandra
Or Bigtable

4. What good is it?
Systems Monitoring & Measurement
Servers
Networks
Sensor Data
The Internet of Things
SCADA
Financial Data
Scientific Experiment Results

5. Use Cases
Backing store for Argus:
Open source monitoring
and alerting system
15 HBase Servers
6 month retention
10M writes per minute
95p query latency < 30 days = 200ms
Moving to 200 node cluster writing at 100M/m

6. Use Cases
●Monitoring system, network and application
performance and statistics
110 region servers, 10M writes/s ~ 2PB
Multi-tenant and Kerberos secure HBase
~200k writes per second per TSD
Central monitoring for all Yahoo properties
Over 2 billion time series served

7. Some Other Users

8. What Are Time Series?
Time Series: data points for an identity
over time
Typical Identity:
Dotted string: web01.sys.cpu.user.0
OpenTSDB Identity:
Metric: sys.cpu.user
Tags (name/value pairs):
host=web01 cpu=0

9. What Are Time Series?
Data Point:
Metric + Tags
+ Value: 42
+ Timestamp: 1234567890
sys.cpu.user 1234567890 42 host=web01 cpu=0
^ a data point ^

10. How it Works

11. Writing Data
1) Open Telnet style socket, write:
put sys.cpu.user 1234567890 42 host=web01 cpu=0
2) ..or, post JSON to:
http://<host>:<port>/api/put
3) .. or import big files with CLI
No schema definition
No RRD file creation
Just write!

12. Querying Data
Graph with the GUI
CLI tools
HTTP API
Aggregate multiple series
Simple query language
To average all CPUs on host:
start=1h-ago
avg sys.cpu.user
host=web01

13. HBase Data Tables
tsdb - Data point table. Massive
tsdb-uid - Name to UID and UID to
name mappings
tsdb-meta - Time series index and
meta-data
tsdb-tree - Config and index for
hierarchical naming schema

14. Data Table Schema
Row key is a concatenation of UIDs and time:
metric + timestamp + tagk1 + tagv1… + tagkN + tagvN
sys.cpu.user 1234567890 42 host=web01 cpu=0
x00x00x01x49x95xFBx70x00x00x01x00x00x01x00x00x02x00x00x02
Timestamp normalized on 1 hour boundaries
All data points for an hour are stored in one row
Enables fast scans of all time series for a metric
…or pass a row key filter for specific time series with
particular tags

15. New for OpenTSDB 2.2
● Append writes (no more need for TSD
Compactions)
● Row salting and random metric IDs
● Downsampling Fill Policies
● Query filters (wildcard, regex, group by or not)
● Storage Exception plugin for retrying writes
● Released February 2016

16. New for OpenTSDB 2.3
● Graphite style expressions
● Cross-metric expressions
● Calendar based downsampling
● New data stores
● UID assignment plugin interface
● Datapoint write filter plugin interface
● RC1 released May 2016

17. Fuzzy Row Filter
How do you find a single time
series out of 1 million?
For a day?
For a month?

18. Fuzzy Row Filter
Instead of running a regex
string comparator over each
byte array formatted key…
(?s)^.{9}(?:.{8})*Qx00x00x00x02
E(?:Q)x00x0F‡x42x2BE)(?:.{8})*$
TSDB query takes 1.6 seconds
for 89,726 rows
KEY
Match -> m t1 tagk tagv1
No Match -> m t1 tagk tagv2
No Match -> m t1 tagk tagv3
No Match -> m t1 tagk tagv4
No Match -> m t1 tagk tagv5
No Match -> m t1 tagk tagv6
Match -> m t2 tagk tagv1
No Match -> m t2 tagk tagv2

19. Fuzzy Row Filter
Use a byte mask!
● Use the bloom filter to skip-scan
to the next candidate row.
● Combine with regex (after fuzzy
filter) to filter further.
FuzzyFilter{[FuzzyFilterPair{row_key=[18, 68,
-3, -82, 120, 87, 56, -15, 96, 0, 0, 0, 1, 0,
0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0],
mask=[0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0,
1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]}]}
Now it takes 0.239 seconds
KEY
Match -> m t1 tagk tagv1
Skip -> m t1 tagk tagv2
m t1 tagk tagv3
m t1 tagk tagv4
m t1 tagk tagv5
m t1 tagk tagv6
Match -> m t2 tagk tagv1
Skip -> m t2 tagk tagv2

20. Fuzzy Row Filter
Pros:
● Can improve scan latency by orders of magnitude
● Combines nicely with other filters
Cons:
● All row keys for the match have to be a fixed length
● Doesn’t help much when matching the majority of a set
● Doesn’t support bitmasks, only byte masks

21. AsyncHBase
AsyncHBase is a fully asynchronous, multi-
threaded HBase client
Supports HBase 0.90 to 1.x
Faster and less resource intensive than the
native HBase client
Support for scanner filters, META prefetch,
“fail-fast” RPCs

22. AsyncHBase in YCSB

23. AsyncHBase in YCSB

24. Upcoming in 1.8
●Reverse Scanning
●New Yahoo! Cloud Serving Benchmark
(YCSB) module for testing
●Lots of bug fixes

25. OpenTSDB on Bigtable
● Bigtable
○Hosted Google Service
○Client uses HTTP2 and GRPC for communication
● OpenTSDB heads home
○Based on a time series store on Bigtable at Google
○Identical schema as HBase
○Same filter support (fuzzy filters are coming)

26. OpenTSDB on Bigtable
● AsyncBigtable
○Implementation of AsyncHBase’s API for drop-in use
○https://github.com/OpenTSDB/asyncbigtable
○Uses HTable API
○Moving to native Bigtable API
● Thanks to Christos of Pythian, Solomon, Carter, Misha,
and the rest of the Google Bigtable team
● https://www.pythian.com/blog/run-opentsdb-google-
bigtable/#

27. OpenTSDB on Cassandra
● AsyncCassandra - Implementation of AsyncHBase’s
API for drop-in use
● Wraps Netflix’s Astyanax for asynchronous calls
● Requires the ByteOrderedPartitioner and legacy
API
● Same schema as HBase/Bigtable
● Scan filtering performed client side
● May not work with future Cassandra versions
if they drop the API

28. Community
Salesforce Argus
●Time series monitoring
and alerting
●Multi-series annotations
●Dashboards
Thanks to Tom Valine and the Salesforce engineers
https://medium.com/salesforce-open-source/argus-time-series-monitoring-and-
alerting-d2941f67864#.ez7mbo3ek
https://github.com/SalesforceEng/Argus

29. Community
Turn Splicer
●API to shard TSDB queries
●Locality advantage hosting
TSDs on region servers
●Query caching
Thanks to Jonathan Creasy and the Turn engineers
https://github.com/turn/splicer

30. The Future of OpenTSDB

31. The Future
Reworked query pipeline for selective ordering
of operations
Histogram support
Flexible query caching framework
Distributed queries
Greater data store abstraction

32. More Information
Thank you to everyone who has helped test, debug and add to OpenTSDB
2.3 including, but not limited to:
TODO
Contribute at github.com/OpenTSDB/opentsdb
Website: opentsdb.net
Documentation: opentsdb.net/docs/build/html
Mailing List: groups.google.com/group/opentsdb
Images
http://photos.jdhancock.com/photo/2013-06-04-212438-the-lonely-vacuum-of-space.html
http://en.wikipedia.org/wiki/File:Semi-automated-external-monitor-defibrillator.jpg
http://upload.wikimedia.org/wikipedia/commons/1/17/Dining_table_for_two.jpg
http://upload.wikimedia.org/wikipedia/commons/9/92/Easy_button.JPG
https://www.flickr.com/photos/verbeeldingskr8/15563333617
http://www.flickr.com/photos/ladydragonflyherworld/4845314274/
http://lego.cuusoo.com/ideas/view/96