Analysis of issues in parallel computing, especially parallelized database management. Related subjects include:
Occasionally I talk with an astute reporter — there are still a few left — and get led toward angles I hadn’t considered before, or at least hadn’t written up. A blog post may then ensue. This is one such post.
There is a group of questions going around that includes:
- Is Hadoop overhyped?
- Has Hadoop adoption stalled?
- Is Hadoop adoption being delayed by skills shortages?
- What is Hadoop really good for anyway?
- Which adoption curves for previous technologies are the best analogies for Hadoop?
To a first approximation, my responses are: Read more
|Categories: Application areas, Data warehousing, Databricks, Spark and BDAS, EAI, EII, ETL, ELT, ETLT, Hadoop, Hortonworks, MapR, MapReduce, Market share and customer counts, Open source, Pricing||6 Comments|
At the highest level:
- Presto is, roughly speaking, Facebook’s replacement for Hive, at least for queries that are supposed to run at interactive speeds.
- Teradata is announcing support for Presto with a classic open source pricing model.
- Presto will also become, roughly speaking, Teradata’s replacement for Hive.
- Teradata’s Presto efforts are being conducted by the former Hadapt.
Now let’s make that all a little more precise.
Regarding Presto (and I got most of this from Teradata)::
- To a first approximation, Presto is just another way to write SQL queries against HDFS (Hadoop Distributed File System). However …
- … Presto queries other data stores too, such as various kinds of RDBMS, and federates query results.
- Facebook at various points in time created both Hive and now Presto.
- Facebook started the Presto project in 2012 and now has 10 engineers on it.
- Teradata has named 16 engineers – all from Hadapt – who will be contributing to Presto.
- Known serious users of Presto include Facebook, Netflix, Groupon and Airbnb. Airbnb likes Presto well enough to have 1/3 of its employees using it, via an Airbnb-developed tool called Airpal.
- Facebook is known to have a cluster cited at 300 petabytes and 4000 users where Presto is presumed to be a principal part of the workload.
Daniel Abadi said that Presto satisfies what he sees as some core architectural requirements for a modern parallel analytic RDBMS project: Read more
Indexes are central to database management.
- My first-ever stock analyst report, in 1982, correctly predicted that index-based DBMS would supplant linked-list ones …
- … and to this day, if one wants to retrieve a small fraction of a database, indexes are generally the most efficient way to go.
- Recently, I’ve had numerous conversations in which indexing strategies played a central role.
Perhaps it’s time for a round-up post on indexing.
1. First, let’s review some basics. Classically:
- An index is a DBMS data structure that you probe to discover where to find the data you really want.
- Indexes make data retrieval much more selective and hence faster.
- While indexes make queries cheaper, they make writes more expensive — because when you write data, you need to update your index as well.
- Indexes also induce costs in database size and administrative efforts. (Manual index management is often the biggest hurdle for “zero-DBA” RDBMS installations.)
2. Further: Read more
|Categories: Data warehousing, Database compression, GIS and geospatial, Google, MapReduce, McObject, MemSQL, MySQL, ScaleDB, solidDB, Sybase, Text, Tokutek and TokuDB||17 Comments|
I chatted with the MariaDB folks on Tuesday. Let me start by noting:
- MariaDB, the product, is a MySQL fork.
- MariaDB, product and company alike, are essentially a reaction to Oracle’s acquisition of MySQL. A lot of the key players are previously from MySQL.
- MariaDB, the company, is the former SkySQL …
- … which acquired or is the surviving entity of a merger with The Monty Program, which originated MariaDB. According to Wikipedia, something called the MariaDB Foundation is also in the mix.
- I get the impression SkySQL mainly provided services around MySQL, especially remote DBA.
- It appears that a lot of MariaDB’s technical differentiation going forward is planned to be in a companion product called MaxScale, which was released into Version 1.0 general availability earlier this year.
The numbers around MariaDB are a little vague. I was given the figure that there were ~500 customers total, but I couldn’t figure out what they were customers for. Remote DBA services? MariaDB support subscriptions? Something else? I presume there are some customers in each category, but I don’t know the mix. Other notes on MariaDB the company are:
- ~80 people in ~15 countries.
- 20-25 engineers, which hopefully doesn’t count a few field support people.
- “Tiny” headquarters in Helsinki.
- Business leadership growing in the US and especially the SF area.
MariaDB, the company, also has an OEM business. Part of their pitch is licensing for connectors — specifically LGPL — that hopefully gets around some of the legal headaches for MySQL engine suppliers.
MaxScale is a proxy, which starts out by intercepting and parsing MariaDB queries. Read more
|Categories: Database compression, Hadoop, IBM and DB2, Market share and customer counts, Mid-range, MySQL, Open source, Tokutek and TokuDB, Transparent sharding||1 Comment|
I talked with a couple of Cloudera folks about HBase last week. Let me frame things by saying:
- The closest thing to an HBase company, ala MongoDB/MongoDB or DataStax/Cassandra, is Cloudera.
- Cloudera still uses a figure of 20% of its customers being HBase-centric.
- HBaseCon and so on notwithstanding, that figure isn’t really reflected in Cloudera’s marketing efforts. Cloudera’s marketing commitment to HBase has never risen to nearly the level of MongoDB’s or DataStax’s push behind their respective core products.
- With Cloudera’s move to “zero/one/many” pricing, Cloudera salespeople have little incentive to push HBase hard to accounts other than HBase-first buyers.
- Cloudera no longer dominates HBase development, if it ever did.
- Cloudera is the single biggest contributor to HBase, by its count, but doesn’t make a majority of the contributions on its own.
- Cloudera sees Hortonworks as having become a strong HBase contributor.
- Intel is also a strong contributor, as are end user organizations such as Chinese telcos. Not coincidentally, Intel was a major Hadoop provider in China before the Intel/Cloudera deal.
- As far as Cloudera is concerned, HBase is just one data storage technology of several, focused on high-volume, high-concurrency, low-latency short-request processing. Cloudera thinks this is OK because of HBase’s strong integration with the rest of the Hadoop stack.
- Others who may be inclined to disagree are in several cases doing projects on top of HBase to extend its reach. (In particular, please see the discussion below about Apache Phoenix and Trafodion, both of which want to offer relational-like functionality.)
|Categories: Cloudera, Clustering, Data models and architecture, Database diversity, Hadoop, HBase, Hortonworks, HP and Neoview, Intel, Market share and customer counts, NoSQL, Open source||4 Comments|
I’m on record as believing that:
- Hadoop needs a memory-centric storage grid.
- Tachyon is a strong candidate to fill the role.
- It’s an open secret that there will be a Tachyon company. However, …
- … no details have been publicized. Indeed, the open secret itself is still officially secret.
- Tachyon technology, which just hit 0.6 a couple of days ago, still lacks many features I regard as essential.
- As a practical matter, most Tachyon interest to date has been associated with Spark. This makes perfect sense given Tachyon’s origin and initial technical focus.
- Tachyon was in 50 or more sites last year. Most of these sites were probably just experimenting with it. However …
- … there are production Tachyon clusters with >100 nodes.
As a reminder of Tachyon basics: Read more
|Categories: Clustering, Databricks, Spark and BDAS, Hadoop, Memory-centric data management||3 Comments|
I chatted last night with Ion Stoica, CEO of my client Databricks, for an update both on his company and Spark. Databricks’ actual business is Databricks Cloud, about which I can say:
- Databricks Cloud is:
- Currently running on Amazon only.
- Not dependent on Hadoop.
- Databricks Cloud, despite having a 1.0 version number, is not actually in general availability.
- Even so, there are a non-trivial number of paying customers for Databricks Cloud. (Ion gave me an approximate number, but is keeping it NDA until Spark Summit East.)
- Databricks Cloud gets at data from S3 (most commonly), Redshift, Elastic MapReduce, and perhaps other sources I’m forgetting.
- Databricks Cloud was initially focused on ad-hoc use. A few days ago the capability was added to schedule jobs and so on.
- Unsurprisingly, therefore, Databricks Cloud has been used to date mainly for data exploration/visualization and ETL (Extract/Transform/Load). Visualizations tend to be scripted/programmatic, but there’s also an ODBC driver used for Tableau access and so on.
- Databricks Cloud customers are concentrated (but not unanimously so) in the usual-suspect internet-centric business sectors.
- The low end of the amount of data Databricks Cloud customers are working with is 100s of gigabytes. This isn’t surprising.
- The high end of the amount of data Databricks Cloud customers are working with is petabytes. That did surprise me, and in retrospect I should have pressed for details.
I do not expect all of the above to remain true as Databricks Cloud matures.
Ion also said that Databricks is over 50 people, and has moved its office from Berkeley to San Francisco. He also offered some Spark numbers, such as: Read more
|Categories: Amazon and its cloud, Cloud computing, Databricks, Spark and BDAS, EAI, EII, ETL, ELT, ETLT, Parallelization, Petabyte-scale data management, Predictive modeling and advanced analytics, Software as a Service (SaaS)||5 Comments|
I hoped to write a reasonable overview of current- to medium-term future IT innovation. Yeah, right. But if we abandon any hope that this post could be comprehensive, I can at least say:
1. Back in 2011, I ranted against the term Big Data, but expressed more fondness for the V words — Volume, Velocity, Variety and Variability. That said, when it comes to data management and movement, solutions to the V problems have generally been sketched out.
- Volume has been solved. There are Hadoop installations with 100s of petabytes of data, analytic RDBMS with 10s of petabytes, general-purpose Exadata sites with petabytes, and 10s/100s of petabytes of analytic Accumulo at the NSA. Further examples abound.
- Velocity is being solved. My recent post on Hadoop-based streaming suggests how. In other use cases, velocity is addressed via memory-centric RDBMS.
- Variety and Variability have been solved. MongoDB, Cassandra and perhaps others are strong NoSQL choices. Schema-on-need is in earlier days, but may help too.
2. Even so, there’s much room for innovation around data movement and management. I’d start with:
- Product maturity is a huge issue for all the above, and will remain one for years.
- Hadoop and Spark show that application execution engines:
- Have a lot of innovation ahead of them.
- Are tightly entwined with data management, and with data movement as well.
- Hadoop is due for another refactoring, focused on both in-memory and persistent storage.
- There are many issues in storage that can affect data technologies as well, including but not limited to:
- Solid-state (flash or post-flash) vs. spinning disk.
- Networked vs. direct-attached.
- Virtualized vs. identifiable-physical.
- Graph analytics and data management are still confused.
I believe in all of the following trends:
- Hadoop is a Big Deal, and here to stay.
- Spark, for most practical purposes, is becoming a big part of Hadoop.
- Most servers will be operated away from user premises, whether via SaaS (Software as a Service), co-location, or “true” cloud computing.
Trickier is the meme that Hadoop is “the new OS”. My thoughts on that start:
- People would like this to be true, although in most cases only as one of several cluster computing platforms.
- Hadoop, when viewed as an operating system, is extremely primitive.
- Even so, the greatest awkwardness I’m seeing when different software shares a Hadoop cluster isn’t actually in scheduling, but rather in data interchange.
There is also a minor issue that if you distribute your Hadoop work among extra nodes you might have to pay a bit more to your Hadoop distro support vendor. Fortunately, the software industry routinely solves more difficult pricing problems than that.
|Categories: Cloud computing, Databricks, Spark and BDAS, Hadoop, MapReduce, MemSQL, Software as a Service (SaaS)||15 Comments|
I’m taking a few weeks defocused from work, as a kind of grandpaternity leave. That said, the venue for my Dances of Infant Calming is a small-but-nice apartment in San Francisco, so a certain amount of thinking about tech industries is inevitable. I even found time last Tuesday to meet or speak with my clients at WibiData, MemSQL, Cloudera, Citus Data, and MongoDB. And thus:
1. I’ve been sloppy in my terminology around “geo-distribution”, in that I don’t always make it easy to distinguish between:
- Storing different parts of a database in different geographies, often for reasons of data privacy regulatory compliance.
- Replicating an entire database into different geographies, often for reasons of latency and/or availability/ disaster recovery,
The latter case can be subdivided further depending on whether multiple copies of the data can accept first writes (aka active-active, multi-master, or multi-active), or whether there’s a clear single master for each part of the database.
What made me think of this was a phone call with MongoDB in which I learned that the limit on number of replicas had been raised from 12 to 50, to support the full-replication/latency-reduction use case.
2. Three years ago I posted about agile (predictive) analytics. One of the points was:
… if you change your offers, prices, ad placement, ad text, ad appearance, call center scripts, or anything else, you immediately gain new information that isn’t well-reflected in your previous models.
Subsequently I’ve been hearing more about predictive experimentation such as bandit testing. WibiData, whose views are influenced by a couple of Very Famous Department Store clients (one of which is Macy’s), thinks experimentation is quite important. And it could be argued that experimentation is one of the simplest and most direct ways to increase the value of your data.
3. I’d further say that a number of developments, trends or possibilities I’m seeing are or could be connected. These include agile and experimental predictive analytics in general, as noted in the previous point, along with: Read more