Category: Riak

The Database Deluge… Who’s Who

These are the top NoSQL Solutions in the market today that are open source, readily available, with a strong and active community, and actively making forward progress in development and innovations in the technology. I’ve provided them here, in no order, with basic descriptions, links to their main website presence, and with short lists of some of their top users of each database. Toward the end I’ve provided a short summary of the database and the respective history of the movement around No SQL and the direction it’s heading today.

Cassandra

http://cassandra.apache.org/

Cassandra is a distributed databases that offers high availability and scalability. Cassandra supports a host of features around replicating data across multiple datacenters, high availability, horizontal scaling for massive linear scaling, fault tolerance and a focus, like many NoSQL solutions around commodity hardware.

Cassandra is a hybrid key-value & row based database, setup on top of a configuration focused architecture. Cassandra is fairly easy to setup on a single machine or a cluster, but is intended for use on a cluster of machines. To insure the availability of features around fault tolerance, scaling, et al you will need to setup a minimal cluster, I’d suggest at least 5 nodes (5 nodes being my personal minimum clustered database setup, this always seems to be a solid and safe minimum).

Cassandra also has a query language called CQL or Cassandra Query Langauge. Cassandra also support Apache Projects Hive, Pig with Hadoop integration for map reduce.

Who uses Cassandra?

  • IBM
  • HP
  • Netflix
  • …many others…

HBase

http://hbase.apache.org/

In the book, Seven Databases in Seven Weeks, the Apache HBase Project is described as a nail gun. You would not use HBase to catalog your sales list just like you wouldn’t use a nail gun to build a dollhouse. This is an apt description of HBase.

HBase is a column-oriented database. It’s very good at scaling out. The origins of HBase are rooted in BigTable by Google. The proprietary database is described in in the 2006 white paper, “Bigtable: A Distributed Storage System for Structured Data.”

HBase stores data in buckets called tables, the tables contain cells that are at the intersection of rows and columns. Because of this HBase has a lot of similar characteristics to a relational database. However the similarities are only in name.

HBase also has several features that aren’t available in other databases, such as; versioning, compression, garbage collection and in memory tables. One other feature that is usually only available in relational databases is strong consistency guarantees.

The place where HBase really shines however is in queries against enormous datasets.

HBase is designed architecturally to be fault tolerate. It does this through write-ahead logging and distributed configuration. At the core of the architecture HBase is built on Hadoop. Hadoop is a sturdy, scalable computing platform that provides a distribute file system and mapreduce capabilities.

Who is using it?

  • Facebook uses HBase for its messaging infrastructure.
  • Stumpleupon uses it for real-time data storage and analytics.
  • Twitter uses HBase for data generation around people search & storing logging & monitoring data.
  • Meetup uses it for site data.
  • There are many others including Yahoo!, eBay, etc.

Mongo

http://www.mongodb.org/

MongoDB is built and maintained by a company called 10gen. MongoDB was released in 2009 and has been rising in popularity quickly and steadily since then. The name, contrary to the word mongo, comes from the word humongous. The key goals behind MongoDB are performance and easy data access.

The architecture of MongoDB is around document database principles. The data can be queried in an ad-hoc way, with the data persisted in a nested way. This database also, like most NoSQL databases enforces no schema, however can have specific document fields that can be queried off of.

Who is using it?

  • Foursquare
  • bit.ly
  • CERN for collecting data from the large Hadron Collider
  • …others…

Redis

http://redis.io/

Redis stands for Remote Dictionary Service. The most common capability Redis is known for, is blindingly fast speed. This speed comes from trading durability. At a base level Redis is a key-value store, however sometimes classifying it isn’t straight forward.

Redis is a key-value store, and often referred to as a data structure server with keys that can be string, hashes, lists, sets and sorted sets. Redis is also, stepping away from only being a key-value store, into the realm of being a publish-subscribe and queue stack. This makes Redis one very flexible tool in the tool chest.

Who is using it?

  • Blizzard (You know, that World of Warcraft game maker)  😉
  • Craigslist
  • flickr
  • …others…

Couch

http://couchdb.apache.org/

Another Apache Project, CouchDB is the idealized JSON and REST document database. It works as a document database full of key-value pairs with the values a set number of types including nested with other key-value objects.

The primary mode of querying CouchDB is to use incremental mapreduce to produce indexed views.

One other interesting characteristic about CouchDB is that it’s built with the idea of a multitude of deployment scenarios. CouchDB might be deployed to some big servers or may be a mere service running on your Android Phone or Mac OS-X Desktop.

Like many NoSQL options CouchDB is RESTful in operation and uses JSON to send data to and from clients.

The Node.js Community also has an affinity for Couch since NPM and a lot of the capabilities of Couch seem like they’re just native to JavaScript. From the server aspect of the database to the JSON format usage to other capabilities.

Who uses it?

  • NPM – Node Package Manager site and NPM uses CouchDB for storing and providing the packages for Node.js.

Couchbase (UPDATED January 18th)

Ok, I realized I’d neglected to add Couchbase (thus the Jan 18th update), which is an open source and interesting solution built off of Membase and Couch. Membase isn’t particularly a distributed database, or database, but between it and couch joining to form Couchbase they’ve turned it into a distributed database like couch except with some specific feature set differences.

A lot of the core architecture features of Couch are available, but the combination now adds auto-sharding clusters, live/hot swappable upgrades and changes, memchaced APIs, and built in data caching.

Who uses it?

  • Linkedin
  • Orbitz
  • Concur
  • …and others…

Neo4j

http://www.neo4j.org/

Neo4j steps away from many of the existing NoSQL databases with its use of a graph database model. It stored data as a graph, mathematically speaking, that relates to the other data in the database. This database, of all the databases among the NoSQL and SQL world, is very whiteboard friendly.

Neo4j also has a varied deployment model, being able to deploy to a small or large device or system. It has the ability to store dozens of billions of edges and nodes.

Who is using it?

  • Accenture
  • Adobe
  • Lufthansa
  • Mozilla
  • …others…

Riak

Riak is a key-value, distributed, fault tolerant, resilient database written in Erlang.  It uses the Riak Core project as a codebase for the distributed core of the system. I further explained Riak, since yes, I work for Basho who are the makers of Riak, in a separate blog entry “Riak is… A Big List of Things“. So for a description of the features around Riak check that out.

Who is using Riak?

In Summary

One of the things you’ll notice with a lot of these databases and the NoSQL movement in general is that it originated from companies needing to go “web scale” and RDBMSs just couldn’t handle or didn’t meet the specific requirements these companies had for the data. NoSQL is in no way a replacement to relational or SQL databases except in these specific cases where need is outside of the capability or scope of SQL & Relational Databases and RDBMSs.

Almost every NoSQL database has origins that go pretty far back, but the real impetus and push forward with the technology came about with key efforts at Google and Amazon Web Services. At Google it was with BigTable Paper and at Amazon Web Services it was with the Dynamo Paper. As time moved forward with the open source community taking over as the main innovator and development model around big data and the NoSQL database movement. Today the Apache Project has many of the projects under its guidance along with other companies like Basho and 10gen.

In the last few years, many of the larger mainstays of the existing database industry have leapt onto the bandwagon. Companies like Microsoft, Dell, HP and Oracle have made many strategic and tactical moves to stay relevant with this move toward big data and nosql databases solutions. However, the leadership is still outside of these stalwarts and in the hands of the open source community. The related companies and organizations that are focused on that community such as 10gen, Basho and the Apache Organization still hold much of the future of this technology in the strategic and tactical actions that they take since they’re born from and significant parts of the community itself.

For an even larger list of almost every known NoSQL Database in existence check out NoSQL Database .org.

Riak is… A Whole Big List of Things

What is Riak? Who builds it? Who maintains it? Can I download it? How does it work? What are the features?

Here’s the start of answers to these questions and more.

First, the basic high level description:

“Riak is an open source, highly scalable, fault-tolerant distributed database.”

That’s the first line you’ll read when checking out the product via the Basho product link. It provides good information, but here I’m going to add more to the definition without the need to dig around yourself. Maybe I can save you some time & provide some links directly to solid information in the docs. Kind of a “Cliff Notes” of Riak. Let’s take this feature by feature which will in turn get us to a definitive definition of what exactly Riak is.

Riak is Open Source.

Riak is built and contributed to by the community, with Basho being the steward and an active member that extends, builds and provides support for additional products. The avenues to reach the Riak Open Source Community members is pretty straight forward, following known avenues of communication. Hit us up on the email list, especially feel free to contribute & ask questions via the Github Basho organization, there is the Basho Riak Blog, the weekly recap and jump into the IRC chat room #riak on freenode. Oh, and there’s a twitter feed @basho.

So what exactly does this get you, when you become a user or contributor of Riak? The entire community is behind you, will help you get started using Riak and provide help whenever you run into problems. If you want SLAs or 24 hour support Basho can provide this for you. But for bugs, issues, queries, searching and all sorts of other related development questions there is the community. An open source community like this is passionate, which means you’ll have support like no closed source company will ever provide you, and absolutely no closed source product’s community will provide you. We’re talking about a different level of interest, passion and levels of personal involvement.

Riak is a key value based database store.

Riak is a key value store. What exactly is a key value store? It’s pretty simple and you’re probably already familiar with what a key value store is. A key value is made up of two pieces of data, the first is the identifier for the second element within the data structure. This gives a system or developer using key value storage a schema-less way of working with data.

Riak is designed for highly distributed environments.

This type of distributed isn’t the “we put one database over here and one database over here and you gotta figure out how they work together” type of distribution. So this isn’t some of that oddball pretend stuff Oracle keeps hoisting on people. This is the honest to goodness distribution of the sort, when one node goes down you don’t blink, you don’t stop eating dinner, you don’t sweat it. You just continue onward with life knowing full well that you’ll just spool up another node when you need to.

Riak is master-less, with no single point of failure.

This is one of self explanatory features. But what does a master-less system provide us? One thing is no single point of failure. Being that all nodes can act autonomously to work around the loss of one or more nodes it also helps add to the high availability of the system.

Riak is fault tolerant, like a disk drive you wish was real.

Ever have a backup disk drive? What? You don’t have one of those? Ugh. Ok, so imagine you had a backup disk drive that had an unfortunately high failure rate. Well, why, because you know, they have an oddly high failure rate. If you do backups like good practices dictate, eventually you’ll end up with some dead drives.

RAID, both software and hardware, are built specifically to deal with this type of failure. With a distributed system like Riak, it bumps the level of abstraction above software or hardware RAID, enabling another level of even greater fault tolerance. Not to remove the relevance of RAID capabilities, but with a multi-node system like Riak, you can easily remove nodes and swap them out as needed, keeping costs down by using simple drives in simple machines. If you want to, you could indeed get higher I/O machines and faster drives, but it isn’t necessary to insure fault tolerance in a Riak Database System.

Riak scales, with hot swappable nodes enabling zero downtime.

The ability to commit hot swappable changes while in the midst of operating starts at a very low level for Riak. The language used to build Riak, Erlang has the ability to change pieces of an application system in realtime built into the precepts of the language. This provides, at the core, the inherent capability to change out systems, and by proxy of architectural design, the ability for nodes in Riak to be changed out simply by removing them from a cluster ring. Once that is done it is just as simple to add another node or nodes back into the cluster ring, enabling a number of additional practices around upgrades, hot swaps for failures, or even version changes.

Riak can be used as a building block for distributed (aka cloud) infrastructure.

The concepts and contractual components that Riak Database is built on are available for use via the Riak Core Project. If you’re looking into starting a project around distributed systems this is a great place to get start. Also be sure to do a general web engine (re: google) search for “riak core” and you’ll find lots of material around the project, and projects people have started with the project as a base. I’m currently in the process of putting together one of these projects myself.

Riak is eventually consistent.

The term eventually consistent is becoming more and more common place. Riak is one of the many systems, that inherently often apply to distributed systems, that use the concepts of eventual consistency. The idea, is that even though all nodes may not immediately receive a new piece of data, or updated piece of data, they eventually will receive that update and by synchronized with the cluster ring of nodes. This goes back to the equality of nodes and removal of the master-less concepts, providing the availability and other capabilities, with some trade off in the synchronization of data through eventual consistency.

In Summary

That’s round one for the many features of Riak. I’ll be adding more in the future, but for now this is a good starting point in knowing about and knowing what Riak is, what it can be used for, and how it might help you extend, maintain or invent the next great piece of technology.