Transparent sharding

Discussion of transparent sharding vendors and products.

May 2, 2014

Introduction to CitusDB

One of my lesser-known clients is Citus Data, a largely Turkish company that is however headquartered in San Francisco. They make CitusDB, which puts a scale-out layer over a collection of fully-functional PostgreSQL nodes, much like Greenplum and Aster Data before it. However, in contrast to those and other Postgres-based analytic MPP (Massively Parallel Processing) DBMS:

*One benefit to this strategy, besides the usual elasticity and recovery stuff, is that while PostgreSQL may be single-core for any given query, a CitusDB query can use multiple cores by virtue of hitting multiple PostgreSQL tables on each node.

Citus has thrown a few things against the wall; for example, there are two versions of its product, one which involves HDFS (Hadoop Distributed File System) and one of which doesn’t. But I think Citus’ focus will be scale-out PostgreSQL for at least the medium-term future. Citus does have actual customers, and they weren’t all PostgreSQL users previously. Still, the main hope — at least until the product is more built-out — is that existing PostgreSQL users will find CitusDB easy to adopt, in technology and price alike.

Read more

April 23, 2013

MemSQL scales out

The third of my three MySQL-oriented clients I alluded to yesterday is MemSQL. When I wrote about MemSQL last June, the product was an in-memory single-server MySQL workalike. Now scale-out has been added, with general availability today.

MemSQL’s flagship reference is Zynga, across 100s of servers. Beyond that, the company claims (to quote a late draft of the press release):

Enterprises are already using distributed MemSQL in production for operational analytics, network security, real-time recommendations, and risk management.

All four of those use cases fit MemSQL’s positioning in “real-time analytics”. Besides Zynga, MemSQL cites penetration into traditional low-latency markets — financial services (various subsectors) and ad-tech.

Highlights of MemSQL’s new distributed architecture start: Read more

April 14, 2013

Introduction to Deep Information Sciences and DeepDB

I talked Friday with Deep Information Sciences, makers of DeepDB. Much like TokuDB — albeit with different technical strategies — DeepDB is a single-server DBMS in the form of a MySQL engine, whose technology is concentrated around writing indexes quickly. That said:

*For reasons that do not seem closely related to product reality, DeepDB is marketed as if it supports “unstructured” data today.

Other NewSQL DBMS seem “designed for big data and the cloud” to at least the same extent DeepDB is. However, if we’re interpreting “big data” to include multi-structured data support — well, only half or so of the NewSQL products and companies I know of share Deep’s interest in branching out. In particular:

Edit: MySQL has some sort of an optional NoSQL interface, and hence so presumably do MySQL-compatible TokuDB, GenieDB, Clustrix, and MemSQL.

Also, some of those products do not today have the transparent scale-out that Deep plans to offer in the future.

Read more

January 5, 2013

NewSQL thoughts

I plan to write about several NewSQL vendors soon, but first here’s an overview post. Like “NoSQL”, the term “NewSQL” has an identifiable, recent coiner — Matt Aslett in 2011 — yet a somewhat fluid meaning. Wikipedia suggests that NewSQL comprises three things:

I think that’s a pretty good working definition, and will likely remain one unless or until:

To date, NewSQL adoption has been limited.

That said, the problem may lie more on the supply side than in demand. Developing a competitive SQL DBMS turns out to be harder than developing something in the NoSQL state of the art.

Read more

January 5, 2013

Data(base) virtualization — a terminological mess

Data/database virtualization seems to be a hot subject right now, and vendors of a broad variety of different technologies are all claiming to be in the space. A terminological mess has ensued, as Monash’s First and Third Laws of Commercial Semantics are borne out in spades.

If something is like “virtualization”, then it should resemble hypervisors such as VMware. To me:

Anything that claims to be “like virtualization” should be viewed in that light. Read more

March 26, 2012

CodeFutures/dbShards update

I’ve been talking a fair bit with Cory Isaacson, CEO of my client CodeFutures, which makes dbShards. Business notes include:

Apparently, the figure of 6 dbShards customers in July, 2010 is more comparable to today’s 20ish contracts than to today’s 7-8 production users. About 4 of the original 6 are in production now.

NDA stuff aside, the main technical subject we talked about is something Cory calls “relational sharding”. The point is that dbShards’ transparent sharding can be done in such a way as to make many joins be single-server. Specifically:

dbShards can’t do cross-shard joins, but it can do distributed transactions comprising multiple updates. Cory argues persuasively that in almost all cases this is enough; but I see cross-shard joins as a feature that should someday be added to dbShards even so.

The real issue with dbShards’ transparent sharding is ensuring it’s really transparent. Cory regards as typical a customer with a couple thousand tables, who had to change a dozen or so SQL statements to implement dbShards. But there are near-term plans to automate the number of SQL changes needed down to 0. The essence of that change is this: Read more

October 23, 2011

Transparent relational OLTP scale-out

There’s a perception that, if you want (relatively) worry-free database scale-out, you need a non-relational/NoSQL strategy. That perception is false. In the analytic case it’s completely ridiculous, as has been demonstrated by Teradata, Vertica, Netezza, and various other MPP (Massively Parallel Processing) analytic DBMS vendors. And now it’s false for short-request/OLTP (OnLine Transaction Processing) use cases as well.

My favorite relational OLTP scale-out choice these days is the SchoonerSQL/dbShards partnership. Schooner Information Technology (SchoonerSQL) and Code Futures (dbShards) are young, small companies, but I’m not too concerned about that, because the APIs they want you to write to are just MySQL’s. The main scenarios in which I can see them failing are ones in which they are competitively leapfrogged, either by other small competitors – e.g. ScaleBase, Akiban, TokuDB, or ScaleDB — or by Oracle/MySQL itself. While that could suck for my clients Schooner and Code Futures, it would still provide users relying on MySQL scale-out with one or more good product alternatives.

Relying on non-MySQL NewSQL startups, by way of contrast, would leave me somewhat more concerned. (However, if their code is open sourced. you have at least some vendor-failure protection.) And big-vendor scale-out offerings, such as Oracle RAC or DB2 pureScale, may be more complex to deploy and administer than the MySQL and NewSQL alternatives.

February 24, 2011

Terminology: Transparent sharding

When databases are too big to manage via a single server, responsibility for them is spread among multiple servers. There are numerous names for this strategy, or versions of it — all of them at least somewhat problematic. The most common terms include:

I plan to start using the term transparent sharding to denote a data management strategy in which data is assigned to multiple servers (or CPUs, cores, etc.), yet looks to programmers and applications as if it were managed by just one. Thus,

Read more

February 9, 2011

Clarification on dbShards’ shard replication

After I posted recently about dbShards, a Very Smart Commenter emailed me with the challenge “but each individual shard is still replicated via two-phase commit, and everybody knows two-phase commit is fundamentally slow.” I replied that no, it wasn’t exactly two-phase commit, but fumbled the explanation of why — so I decided to escalate straight to dbShards honcho Cory Isaacson. Read more

January 25, 2011

ScaleBase, another MPP OLTP quasi-DBMS

Liran Zelkha of ScaleBase raised his hand on Twitter. It turns out ScaleBase has a story rather similar to that of CodeFutures/dbShards. That is:

Our talk didn’t get deeply technical, and I don’t know exactly how ScaleBase’s replication works. But a website reference to a small transaction log in a distributed cache does sound, while not identical to the dbShards approach, at least directionally similar.

ScaleBase is a year or so old, with about 6 people, based in the Boston area despite strong Israeli roots. ScaleBase has raised a round of venture capital; I didn’t ask for details.

Liran says that ScaleBase is in closed beta, with some production users, at least one of whom has over 100 database servers.

Next Page →

Feed: DBMS (database management system), DW (data warehousing), BI (business intelligence), and analytics technology Subscribe to the Monash Research feed via RSS or email:

Login

Search our blogs and white papers

Monash Research blogs

User consulting

Building a short list? Refining your strategic plan? We can help.

Vendor advisory

We tell vendors what's happening -- and, more important, what they should do about it.

Monash Research highlights

Learn about white papers, webcasts, and blog highlights, by RSS or email.