Notes on Spark and Databricks — technology
During my recent visit to Databricks, I of course talked a lot about technology — largely with Reynold Xin, but a bit with Ion Stoica as well. Spark 2.0 is just coming out now, and of course has a lot of enhancements. At a high level:
- Using the new terminology, Spark originally assumed users had data engineering skills, but Spark 2.0 is designed to be friendly to data scientists.
- A lot of this is via a focus on simplified APIs, based on
- Unlike similarly named APIs in R and Python, Spark DataFrames work with nested data.
- Machine learning and Spark Streaming both work with Spark DataFrames.
- There are lots of performance improvements as well, some substantial. Spark is still young enough that Bottleneck Whack-A-Mole yields huge benefits, especially in the SparkSQL area.
- SQL coverage is of course improved. For example, SparkSQL can now perform all TPC-S queries.
The majority of Databricks’ development efforts, however, are specific to its cloud service, rather than being donated to Apache for the Spark project. Some of the details are NDA, but it seems fair to mention at least:
- Databricks’ notebooks feature for organizing and launching machine learning processes and so on is a biggie. Jupyter is an open source analog.
- Databricks has been working on security, and even on the associated certifications.
Two of the technical initiatives Reynold told me about seemed particularly cool. Read more
| Categories: Benchmarks and POCs, Cloud computing, Databricks, Spark and BDAS, Predictive modeling and advanced analytics, Streaming and complex event processing (CEP) | 3 Comments |
Notes on Spark and Databricks — generalities
I visited Databricks in early July to chat with Ion Stoica and Reynold Xin. Spark also comes up in a large fraction of the conversations I have. So let’s do some catch-up on Databricks and Spark. In a nutshell:
- Spark is indeed the replacement for Hadoop MapReduce.
- Spark is becoming the default platform for machine learning.
- SparkSQL (nee’ Shark) is puttering along predictably.
- Databricks reports good success in its core business of cloud-based machine learning support.
- Spark Streaming has strong adoption, but its position is at risk.
- Databricks, the original authority on Spark, is not keeping a tight grip on that role.
I shall explain below. I also am posting separately about Spark evolution, especially Spark 2.0. I’ll also talk a bit in that post about Databricks’ proprietary/closed-source technology.
Spark is the replacement for Hadoop MapReduce.
This point is so obvious that I don’t know what to say in its support. The trend is happening, as originally decreed by Cloudera (and me), among others. People are rightly fed up with the limitations of MapReduce, and — niches perhaps aside — there are no serious alternatives other than Spark.
The greatest use for Spark seems to be the same as the canonical first use for MapReduce: data transformation. Also in line with the Spark/MapReduce analogy: Read more
| Categories: Cloudera, Databricks, Spark and BDAS, EAI, EII, ETL, ELT, ETLT, Hadoop, MapReduce, Market share and customer counts, Predictive modeling and advanced analytics | 6 Comments |
Terminology: Data scientists vs. data engineers
I learned some newish terms on my recent trip. They’re meant to solve the problem that “data scientists” used to be folks with remarkably broad skill sets, few of whom actually existed in ideal form. So instead now it is increasingly said that:
- “Data engineers” can code, run clusters, and so on, in support of what’s always been called “data science”. Their knowledge of the math of machine learning/predictive modeling and so on may, however, be limited.
- “Data scientists” can write and run scripts on single nodes; anything more on the engineering side might strain them. But they have no-apologies skills in the areas of modeling/machine learning.
Related link
- I raised concerns about the “data science” term 4 years ago.
| Categories: Predictive modeling and advanced analytics | 1 Comment |
Notes on vendor lock-in
Vendor lock-in is an important subject. Everybody knows that. But few of us realize just how complicated the subject is, nor how riddled it is with paradoxes. Truth be told, I wasn’t fully aware either. But when I set out to write this post, I found that it just kept growing longer.
1. The most basic form of lock-in is:
- You do application development for a target set of platform technologies.
- Your applications can’t run without those platforms underneath.
- Hence, you’re locked into those platforms.
2. Enterprise vendor standardization is closely associated with lock-in. The core idea is that you have a mandate or strong bias toward having different apps run over the same platforms, because:
- That simplifies your environment, requiring less integration and interoperability.
- That simplifies your staffing; the same skill sets apply to multiple needs and projects.
- That simplifies your vendor support relationships; there’s “one throat to choke”.
- That simplifies your price negotiation.
3. That last point is double-edged; you have more power over suppliers to whom you give more business, but they also have more power over you. The upshot is often an ELA (Enterprise License Agreement), which commonly works:
- For a fixed period of time, the enterprise may use as much of a given product set as they want, with costs fixed in advance.
- A few years later, the price is renegotiated, based on then-current levels of usage.
| Categories: Amazon and its cloud, Buying processes, Cassandra, Exadata, Facebook, IBM and DB2, Microsoft and SQL*Server, MongoDB, Neo Technology and Neo4j, Open source, Oracle, SAP AG | 12 Comments |
Notes from a long trip, July 19, 2016
For starters:
- I spent three weeks in California on a hybrid personal/business trip. I had a bunch of meetings, but not three weeks’ worth.
- The timing was awkward for most companies I wanted to see. No blame accrues to those who didn’t make themselves available.
- I came back with a nasty cough. Follow-up phone calls aren’t an option until next week.
- I’m impatient to start writing. Hence tonight’s posts. But it’s difficult for a man and his cough to be productive at the same time.
A running list of recent posts is:
- As a companion to this post, I’m publishing a very long one on vendor lock-in.
- Spark and Databricks are both prospering, and of course enhancing their technology as well.
- Ditto DataStax.
- Flink is interesting as the streaming technology it’s now positioned to be, rather than the overall Spark alternative it used to be positioned as but which the world didn’t need.
Subjects I’d like to add to that list include:
- MemSQL, Zoomdata, and Neo Technology (also prospering).
- Cloudera (multiple topics, as usual).
- Analytic SQL engines (“traditional” analytic RDBMS aren’t doing well).
- Microsoft’s reinvention (it feels real).
- Metadata (it’s ever more of a thing).
- Machine learning (it’s going to be a big portion of my research going forward).
- Transitions to the cloud — this subject affects almost everything else.
Challenges in anomaly management
As I observed yet again last week, much of analytics is concerned with anomaly detection, analysis and response. I don’t think anybody understands the full consequences of that fact,* but let’s start with some basics.
*me included
An anomaly, for our purposes, is a data point or more likely a data aggregate that is notably different from the trend or norm. If I may oversimplify, there are three kinds of anomalies:
- Important signals. Something is going on, and it matters. Somebody — or perhaps just an automated system — needs to know about it. Time may be of the essence.
- Unimportant signals. Something is going on, but so what?
- Pure noise. Even a fair coin flip can have long streaks of coming up “heads”.
Two major considerations are:
- Whether the recipient of a signal can do something valuable with the information.
- How “costly” it is for the recipient to receive an unimportant signal or other false positive.
What I mean by the latter point is:
- Something that sets a cell phone buzzing had better be important, to the phone’s owner personally.
- But it may be OK if something unimportant changes one small part of a busy screen display.
Anyhow, the Holy Grail* of anomaly management is a system that sends the right alerts to the right people, and never sends them wrong ones. And the quest seems about as hard as that for the Holy Grail, although this one uses more venture capital and fewer horses. Read more
Adversarial analytics and other topics
Five years ago, in a taxonomy of analytic business benefits, I wrote:
A large fraction of all analytic efforts ultimately serve one or more of three purposes:
- Marketing
- Problem and anomaly detection and diagnosis
- Planning and optimization
That continues to be true today. Now let’s add a bit of spin.
1. A large fraction of analytics is adversarial. In particular: Read more
| Categories: Business intelligence, Investment research and trading, Log analysis, Predictive modeling and advanced analytics, RDF and graphs, Surveillance and privacy, Web analytics | 4 Comments |
Surveillance data in ordinary law enforcement
One of the most important issues in privacy and surveillance is also one of the least-discussed — the use of new surveillance technologies in ordinary law enforcement. Reasons for this neglect surely include:
- Governments, including in the US, lie about this subject a lot. Indeed, most of the reporting we do have is exposure of the lies.
- There’s no obvious technology industry ox being gored. What I wrote in another post about Apple, Microsoft et al. upholding their customers’ rights doesn’t have a close analogue here.
One major thread in the United States is: Read more
| Categories: Surveillance and privacy | 5 Comments |
Governments vs. tech companies — it’s complicated
Numerous tussles fit the template:
- A government wants access to data contained in one or more devices (mobile/personal or server as the case may be).
- The computer’s manufacturer or operator doesn’t want to provide it, for reasons including:
- That’s what customers prefer.
- That’s what other governments require.
- Being pro-liberty is the right and moral choice. (Yes, right and wrong do sometimes actually come into play. 🙂 )
As a general rule, what’s best for any kind of company is — pricing and so on aside — whatever is best or most pleasing for their customers or users. This would suggest that it is in tech companies’ best interest to favor privacy, but there are two important quasi-exceptions: Read more
| Categories: Amazon and its cloud, Google, Microsoft and SQL*Server, Surveillance and privacy, Web analytics | 2 Comments |
Privacy and surveillance require our attention
This year, privacy and surveillance issues have been all over the news. The most important, in my opinion, deal with the tension among:
- Personal privacy.
- Anti-terrorism.
- General law enforcement.
More precisely, I’d say that those are the most important in Western democracies. The biggest deal worldwide may be China’s movement towards an ever-more-Orwellian surveillance state.
The main examples on my mind — each covered in a companion post — are:
- The Apple/FBI conflict(s) about locked iPhones.
- The NSA’s propensity to share data with civilian law enforcement.
Legislators’ thinking about these issues, at least in the US, seems to be confused but relatively nonpartisan. Support for these assertions includes:
- The recent unanimous passage in the US House of Representatives of a law restricting police access to email.
- An absurd anti-encryption bill proposed in the US Senate.
- The infrequent mention of privacy/surveillance issues in the current election campaign.
I do think we are in for a spate of law- and rule-making, especially in the US. Bounds on the possible outcomes likely include: Read more
| Categories: Surveillance and privacy | Leave a Comment |