Cloudera Engineering Blog
Big Data best practices, how-to's, and internals from Cloudera Engineering and the community
HBaseCon 2015 is ON, people! Book Thursday, May 7, in your calendars.
If you’re a developer in Silicon Valley, you probably already know that since its debut in 2012, HBaseCon has been one of the best developer community conferences out there. If you’re not, this is a great opportunity to learn that for yourself: HBaseCon 2015 will occur on Thurs., May 7, 2015, at the Westin St. Francis on Union Square in San Francisco.
Apache Spark is making a huge impact across our industry, changing the way we think about batch processing and stream processing. However, as we progressively migrate from MapReduce toward Spark, we shouldn’t have to “give up” anything. One of those capabilities we need to retain is the ability to interact with Apache HBase.
In this post, we will share the work being done in Cloudera Labs to make integrating Spark and HBase super-easy in the form of the SparkOnHBase project. (As with everything else in Cloudera Labs, SparkOnHBase is not supported and there is no timetable for possible support in the future; it’s for experimentation only.) You’ll learn common patterns of HBase integration with Spark and see Scala and Java examples for each. (It may be helpful to have the SparkOnHBase repository open as you read along.)
HBase and Batch Processing Patterns
Our “Top 10″ list of blog posts published during a calendar year is a crowd favorite (see the 2013 version here), in particular because it serves as informal, crowdsourced research about popular interests. Page views don’t lie (although skew for publishing date—clearly, posts that publish earlier in the year have pole position—has to be taken into account).
In 2014, a strong interest in various new components that bring real time or near-real time capabilities to the Apache Hadoop ecosystem is apparent. And we’re particularly proud that the most popular post was authored by a non-employee.
- How-to: Create a Simple Hadoop Cluster with VirtualBox
by Christian Javet
Explains how t set up a CDH-based Hadoop cluster in less than an hour using VirtualBox and Cloudera Manager.
- Why Apache Spark is a Crossover Hit for Data Scientists
by Sean Owen
An explanation of why Spark is a compelling multi-purpose platform for use cases that span investigative, as well as operational, analytics.
- How-to: Run a Simple Spark App in CDH 5
by Sandy Ryza
Helps you get started with Spark using a simple example.
- New SQL Choices in the Apache Hadoop Ecosystem: Why Impala Continues to Lead
by Justin Erickson, Marcel Kornacker & Dileep Kumar
Open benchmark testing of Impala 1.3 demonstrates performance leadership compared to alternatives (by 950% or more), while providing greater query throughput and with a far smaller CPU footprint.
- Apache Kafka for Beginners
by Gwen Shapira & Jeff Holoman
When used in the right way and for the right use case, Kafka has unique attributes that make it a highly attractive option for data integration.
- Apache Hadoop YARN: Avoiding 6 Time-Consuming “Gotchas”
by Jeff Bean
Understanding some key differences between MR1 and MR2/YARN will make your migration much easier.
- Impala Performance Update: Now Reaching DBMS-Class Speed
by Justin Erickson, Greg Rahn, Marcel Kornacker & Yanpei Chen
As of release 1.1.1, Impala’s speed beat the fastest SQL-on-Hadoop alternatives–including a popular analytic DBMS running on its own proprietary data store.
- The Truth About MapReduce Performance on SSDs
by Karthik Kambatla & Yanpei Chen
It turns out that cost-per-performance, not cost-per-capacity, is the better metric for evaluating the true value of SSDs. (See the session on this topic at Strata+Hadoop World San Jose in Feb. 2015!)
- How-to: Translate from MapReduce to Spark
by Sean Owen
The key to getting the most out of Spark is to understand the differences between its RDD API and the original Mapper and Reducer API.
- How-to: Write and Run Apache Giraph Jobs on Hadoop
by Mirko Kämpf
Explains how to create a test environment for writing and testing Giraph jobs, or just for playing around with Giraph and small sample datasets.
Interested in Hive-on-Spark progress? This new AMI gives you a hands-on experience.
Nearly one year ago, the Apache Hadoop community began to embrace Apache Spark as a powerful batch-processing engine. Today, many organizations and projects are augmenting their Hadoop capabilities with Spark. As part of this shift, the Apache Hive community is working to add Spark as an execution engine for Hive. The Hive-on-Spark work is being tracked by HIVE-7292 which is one of the most popular JIRAs in the Hadoop ecosystem. Furthermore, three weeks ago, the Hive-on-Spark team offered the first demo of Hive on Spark.
Benchmarking Big Data systems is nontrivial. Avoid these traps!
Here at Cloudera, we know how hard it is to get reliable performance benchmarking results. Benchmarking matters because one of the defining characteristics of Big Data systems is the ability to process large datasets faster. “How large” and “how fast” drive technology choices, purchasing decisions, and cluster operations. Even with the best intentions, performance benchmarking is fraught with pitfalls—easy to get numbers, hard to tell if they are sound.
Bookmark this new living document to ensure use of current and proper configuration, sizing, management, and measurement practices.
Impala, the open source MPP analytic database for Apache Hadoop, is now firmly entrenched in the Big Data mainstream. How do we know this? For one, Impala is now the standard against which alternatives measure themselves, based on a proliferation of new benchmark testing. Furthermore, Impala has been adopted by multiple vendors as their solution for letting customers do exploratory analysis on Big Data, natively and in place (without the need for redundant architecture or ETL). Also significant, we’re seeing the emergence of best practices and patterns out of customer experiences.
Community contributions to Parquet are increasing in parallel with its adoption. Here are some of the highlights.
Apache Parquet (incubating), the open source, general-purpose columnar storage format for Apache Hadoop, was co-founded only 18 months ago by Cloudera and Twitter. Since that time, its rapid adoption by multiple platform vendors and communities has made it a de facto standard for this purpose.
These new Apache HBase features in CDH 5.2 make multi-tenant environments easier to manage.
Historically, Apache HBase treats all tables, users, and workloads with equal weight. This approach is sufficient for a single workload, but when multiple users and multiple workloads were applied on the same cluster or table, conflicts can arise. Fortunately, starting with HBase in CDH 5.2 (HBase 0.98 + backports), workloads and users can now be prioritized.
November was busy, even accounting for the US Thanksgiving holiday:
A significant vulnerability affecting the entire Apache Hadoop ecosystem has now been patched. What was involved?
By now, you may have heard about the POODLE (Padding Oracle On Downgraded Legacy Encryption) attack on TLS (Transport Layer Security). This attack combines a cryptographic flaw in the obsolete SSLv3 protocol with the ability of an attacker to downgrade TLS connections to use that protocol. The result is that an active attacker on the same network as the victim can potentially decrypt parts of an otherwise encrypted channel. The only immediately workable fix has been to disable the SSLv3 protocol entirely.