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dataloopio

27 karma · joined October 21, 2013

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dataloopio··on A Comparison of Time Series Databases and Netsil’s Use of Druid
DalmatinerDB, InfluxDB, Prometheus and Graphite each claim their numbers based on similar benchmark methods. The results range from 500k/sec to a couple of million metrics /sec. Druid comparatively, for the same benchmark would be closer to 30k/sec. If that's factually wrong please post some details and we can update the spreadsheet.

Expanding the benchmark to cover cardinality and other aspects would indeed be comparing apples to oranges.

In terms of benchmarking DalmatinerDB with billions of unique combinations indexed in Postgres.. I think we know what will happen there :) That's what it's designed for. We can also shard in the query engine, or use any of the multi master Postgres options, but I doubt that would even be necessary.

dataloopio··on A Comparison of Time Series Databases and Netsil’s Use of Druid
Those sources contain literally no technical detail. At 1.1 million metrics per second is that a 40 node druid cluster?
dataloopio··on A Comparison of Time Series Databases and Netsil’s Use of Druid
Most benchmarks are given a colour for reliability and link to repeatability.
dataloopio··on A Comparison of Time Series Databases and Netsil’s Use of Druid
No bias there then
dataloopio··on A Comparison of Time Series Databases and Netsil’s Use of Druid
Can you point me to a source for 'routinely stream millions of events per second into druid'?

While it is true that druid is great at querying billions of rows per second it's not very good at ingress. Here is a mailing list discussion for some background.

https://groups.google.com/forum/#!searchin/druid-user/benchm...

dataloopio··on A Comparison of Time Series Databases and Netsil’s Use of Druid
Broader comparison of the facts:

https://docs.google.com/spreadsheets/d/1sMQe9oOKhMhIVw9WmuCE...

Also a blog comparison:

https://blog.dataloop.io/top10-open-source-time-series-datab...

From reading benchmarks and various articles on how to setup druid for real-time analytics it isn't great. Druid was designed for batch workloads. Feeding the database slowly and then once complete performing analytics over a large data set. Real-time streaming analytics are dreadful to setup and use.

dataloopio··on A Review of Time Series Databases
It's in the spreadsheet. I've not tried it and there wasn't much info available at the time of writing the blog.
dataloopio··on A Review of Time Series Databases
Hi, I'm the original author. I think that GCE instance has 2Gb per core but I'd need to check. It wasn't bottlenecked on network bandwidth though.

The other benchmarks are linked in the spreadsheet to their respective details. It's not an absolute, direct, fair comparison. However, we wanted to start somewhere with information available right now and try to collect better results over time as the respective interested parties benchmarked and blogged about their databases.

I'd like to spend more time benchmarking every database in the spreadsheet but it feels like something the project owners should do themselves. I'd probably only get the setup wrong.

dataloopio··on Building a Scalable Postgres Metrics Backend Using the Citus Extension
I had a look at Citus when evaluating time series databases and the documents said that work was still under way on masterless setup for faster ingestion (up to 500k metrics /sec).

https://docs.citusdata.com/en/v5.2/performance/scaling_data_...

If that has changed I'd add it to my table.

https://docs.google.com/spreadsheets/d/1sMQe9oOKhMhIVw9WmuCE...

dataloopio··on Comparison of opensource time series db's
The raw data in the spreadsheet, which I have continued to update and is now up to 15 databases with 30 characteristics each, is indeed applicable to both people who want to pick up a database and use it in their monitoring stack, or who want to use a time series database for another purpose.

Some of the newer additions like Warp10 and Akumuli for example have comments about being great choices for sensor applications and those who need highly performant local time series storage written in C++.

That's a good point about the compression. I bundled that all in the row 'bytes per point after compression' which gives the end result for each database but I haven't noted which ones actually compress. However, there is 1 database that uses lossy compression so that is noted. That's all in row 11 currently.

Someone else also raised the clustering question and I added a row for 'dynamic cluster management' to address the question of whether you could just horizontally scale by adding a node without bringing the system down.

The performance numbers are a big problem regardless of how they are calculated. Firstly, I'd like to address the issue of whether having them or not is important. I believe it's incredibly important to have some kind of idea up front before investing time trying out a database. If we agree that performance numbers are essential, especially considering the database list is up to 15 and growing and we need some kind of method to reduce the number to trial, then we're onto the next problem. Benchmarking 15 databases in a uniform way as a science experiment is about 7 master thesis worth of work (there are actually several on the topic of benchmarking a few of those databases together that are interesting reads). To put it plainly such a benchmark won't ever happen and if if ever does someone would find a way to undermine it for their use case and setup. Therefore the usefulness of the numbers in the list is more a practical ballpark estimate as outlined in the blog.

We did however benchmark DalmatinerDB and released easy to re-create results, the exact box hardware, test method, code and a little graph. I used the same mechanism to benchmark InfluxDB and got reasonably close to the figures they released.

The version of each database is in row 29. It probably wasn't when you first saw the sheet but I added it soon after along with a maturity field.

Dataloop is a SaaS company of which I'm a co-founder and we needed a database a few years ago to build our SaaS monitoring product. None of the things that existed at the time were all that appealing so we picked up an already open sourced project (DalmatinerDB) and have put about 5 people working for a year improving it under the direction of Heinz (the original author) and contributed it all back.

The reason to contribute it back wasn't completely altruistic. I'm personally interested in time series databases, as a co-founder I need to go on the road and talk at conferences, and chatting about DalmatinerDB seemed like a good way to get my slides up and a big 'we are hiring' one at the end. Also, hiring Erlang devs is hard. The more community contributors we have the bigger the potential hiring pool of known good people.

For the ZFS question there's the choice of SmartOS (which is what Heinz built it on) or Linux. Ubuntu 16.04 has been out for several months and supports native ZFS. Dataloop runs DalmatinerDB on ZFS on Ubuntu. Heinz and several of his customers running Project Fifo (which DalmatinerDB came out of) usually run it on SmartOS. I'm guessing far more people would be interested in running it on Linux than SmartOS. The database is intrinsically linked to the filesystem for proper running. It relies on the way the compression works to achieve 1 byte per data point storage volume. As well as the way the filesystem makes atomic writes. You can run DalmatinerDB without ZFS but you'd quickly run out of disk space and your data integrity wouldn't be as well known.

The bit I do agree with fully is the marketing sizing questions.. it's all a gamble based on opinion. We can probably agree it's a huge area for growth right now with more people moving to cloud and spinning up far more infrastructure than ever before. All I personally know, being a SysAdmin most of my career, is that things are getting more complex and open source isn't scaling very well, or when it does you still need a team to manage it. If you had asked big companies 10 years ago who would want to outsource their email hosting I think you'd get a much different answer to today. The trend long term is towards SaaS and I believe the 90% of companies who today are using open source will see the same shift. Will I get the amateurs? Probably never, but then the 90% market numbers come from our own research:

https://blog.dataloop.io/2014/01/30/what-we-learnt-talking-t...

And then validated time and time again by others:

https://kartar.net/2015/08/monitoring-survey-2015---tools/

I honestly don't think that even if the mega combo of Prometheus / DalmatinerDB / Grafana was polished today it would eat into either Dataloops or Datadogs business. Some people want to run their own, others want to buy SaaS. Over time we're going to see the shift to SaaS that has happened with most other products and by having a foot in the door with DalmatinerDB, Dataloop should hopefully create some good-will and credibility from the people who want to run a monitoring stack themselves. At least then if they move on into an environment where they do want to buy SaaS hosted monitoring we're going in warm with a good reputation.

dataloopio··on Comparison of opensource time series db's
Hi, the wording could probably use some tidying up around that part and I'm open to suggestions. However, I do think it's a big problem with columnar based time series databases.

When somebody wants to query for a few points matching certain dimensions in Cassandra there's no getting around the fact that you have to do a scan across potentially billions of data points.

Whereas if the index lives outside in something relational like Postgres the lookup becomes insanely cheap and you're not having to scan over a bunch of data.

There are quite a few databases that don't have an efficient external index. For those, running 10 times the number of nodes would certainly speed things up, but it's probably just a good idea to avoid databases like that if you want fast queries.

dataloopio··on Comparison of opensource time series db's
Hi, that is a good point. It was all written yesterday so is pretty up to date :) I've added some dates to the top of the blog post. Thanks!
dataloopio··on Comparison of opensource time series db's
The blog discusses storage sizes with very similar maths examples. DalmatinerDB uses 1 byte of storage per point compared to at the top end Elasticsearch using 22 bytes per point.

Build vs buy is an age old discussion. You won't convince anyone to switch from one side to the other. There will continue to be people like you and me who would prefer to buy, and others who want to build and run it themselves. As you have found out I don't need to be convinced as I started a company to address the issue of there being no good options to buy at the time. In most cases, for monitoring micro services, I'd buy a SaaS solution. I founded Dataloop 3 years ago so not really a new startup any more. We're past Series A and starting to grow.

It's true that we compete with Datadog and SignalFX in that area although our real competition is open source with 90% of the addressable market using older tools like Nagios etc. As the shift to the cloud and micro services happens I'm sure it won't be a winner takes all market. Dataloop tends to focus on the enterprise end of the scale whereas Signalfx is more developer focussed and Datadog is more operations and SME.

When you say best I'd argue that's subjective. Signalfx charges by the metric and that gets very expensive. Datadog limits you to 100 metrics per node with an agent based pricing model. Dataloop uses per node pricing that's much cheaper with unlimited metric volume. We're aiming to keep the costs extremely low by investing in highly efficient backend storage.

The reason people are moving away from Graphite to InfluxDB and Prometheus is the dimensional data model. Graphite simply isn't as powerful. Similarly, StatsD aggregates down to the service and doesn't help pinpoint the outlier. Prometheus collects all metrics in their raw format far more efficiently and will let you instantly drill down into what is causing the issue.

To answer your question about what's next after you outgrow open source solutions that don't scale.. well that was kind of the point of the blog! DalmatinerDB scales to millions of metrics per second on a single node and linearly as you add additional nodes. It isn't exactly hard to maintain either as it's based on Riak Core.

I guess the final thing to say was that this wasn't really an advert for Dataloop. Our business model doesn't depend on selling database features. Unlike other SaaS companies we're happy to release the work done on our time series database for free and available as open source.

Why would we do that? Mostly because it's fun to do open source stuff. Also because hiring Erlang developers is pretty hard and this gives me an excuse to talk at conferences where they hang out.

We've had a team of people working on this stuff now for over a year and as you've mentioned no open source time series databases really scale. It's a problem we've solved and are giving away for free. I must be really bad at conveying that message in the blog.

dataloopio··on A discussion about Time Series databases
Spreadsheet link:

https://docs.google.com/spreadsheets/d/1sMQe9oOKhMhIVw9WmuCE...

Blog Link:

https://blog.dataloop.io/top11-open-source-time-series-datab...

dataloopio··on DalmatinerDB: A fast, distributed metric store
I know quite a few companies running ZFSOL in production. In terms of our own experiences I blogged about them here: https://dataloopio.wordpress.com/2016/03/07/zfs-on-linux/
dataloopio··on DalmatinerDB: A fast, distributed metric store
Sorry, blog corrected.
dataloopio··on DalmatinerDB: A fast, distributed metric store
Some more info here:

https://dataloopio.wordpress.com/2016/03/21/playing-with-dal...