Cloudera Developer Blog · General Posts

What are HBase znodes?

Apache ZooKeeper is a client/server system for distributed coordination that exposes an interface similar to a filesystem, where each node (called a znode) may contain data and a set of children. Each znode has a name and can be identified using a filesystem-like path (for example, /root-znode/sub-znode/my-znode).

In Apache HBase, ZooKeeper coordinates, communicates, and shares state between the Masters and RegionServers. HBase has a design policy of using ZooKeeper only for transient data (that is, for coordination and state communication). Thus if the HBase’s ZooKeeper data is removed, only the transient operations are affected – data can continue to be written and read to/from HBase.

Guide to Special Users in the Hadoop Environment

There are a number of special “users” with roles to play in the Apache Hadoop environment. For your reference, we have summarized them below as of CDH 4.4. Kerberos principals (used for authentication in a secure cluster) are not covered here.

The specific user IDs listed are the ones created by default on installation but they are configurable unless otherwise indicated.

Enabling SSO Authentication in Hue

There’s good news for users of Hue, the open source web UI that makes Apache Hadoop easier to use: A new SAML 2.0-compliant backend, which is scheduled to ship in the next release of the Cloudera platform, will provide a better authentication experience for users as well as IT.

With this new feature, single sign-on (SSO) authentication can be achieved instead of using Hue credentials – thus, user credentials can be managed centrally (a big benefit for IT), and users needn’t log in to Hue if they have already logged in to another Web application sharing the SSO (a big benefit for users).

What’s Next for Impala After Release 1.1

In December 2012, while Cloudera Impala was still in its beta phase, we provided a roadmap for planned functionality in the production release. In the same spirit of keeping Impala users, customers, and enthusiasts well informed, this post provides an updated roadmap for upcoming releases later this year and in early 2014.

But first, a thank-you: Since the initial beta release, we’ve received a tremendous amount of feedback and validation about Impala — copious in its quality as well as quantity. At least one person in approximately 4,500 unique organizations around the world have downloaded the Impala binary, to date. And even after only a few months of GA, we’ve seen Cloudera Enterprise customers from multiple industries deploy Impala 1.x in business-critical environments with support via a Cloudera RTQ (Real-Time Query) subscription — including leading organizations in insurance, banking, retail, healthcare, gaming, government, telecom, and advertising.

New Webinar Series Featuring Cloudera and Partner Solutions

Welcome to the Cloudera Connect Webinar Series!

Cloudera’s platform touches every part of your data management infrastructure, so it’s critical that it works well with partner technologies to create value beyond simple integration. We need to make sure that 1 + 1 > 2.

Community Meetups at Strata Conference + Hadoop World 2013

Strata Conference + Hadoop World 2013 (Oct. 28-30 in New York City) approaches (register here for an automatic 20% discount), and that means it’s time to get your meetup schedule sorted out!

There are a variety of them planned across the week (something for everyone!), onsite at the conference hotel as well as offsite. Use the links below to RSVP.

This Month in the Ecosystem (August 2013)

Welcome to our second edition of “This Month in the Ecosystem.” (See the inaugural edition here.) Although August was not as busy as July, there are some very notable highlights to report.

Hadoop 2 is Now a Beta

As announced last Sunday (Aug. 25) on the project mailing list, Apache Hadoop 2.1.0 is the first beta release for Hadoop 2. (See the Release Notes for full list of new features and fixes.) Our congratulations to the Hadoop community for reaching this important milestone in the ongoing adoption of the core Hadoop platform!

With the release of this new beta, and the follow-on GA release on the horizon, we expect to see more customers exploring Hadoop 2 for production use cases. In fact, the upcoming CDH5 beta will be based on the Hadoop 2 GA release, delivering features that we’ve thoroughly tested against enterprise requirements, including (but not limited to):

What I Learned During My Summer Internship at Cloudera

Catherine Ray, a Summer Intern at Cloudera this year, was kind enough to summarize her experiences for you below. Best of luck in your new field, Catherine!

I’m currently 16 and a rising senior at George Mason University, majoring in Computational Physics. (The full title is Computational and Data Sciences with a concentration in Physics.).

This Month in the Ecosystem

The ecosystem is evolving at a rapid pace – so rapidly, that important developments are often passing through the public attention zone too quickly. Thus, we think it might be helpful to bring you a digest (by no means complete!) of our favorite highlights on a regular basis. (This effort, by the way, has different goals than the fine Hadoop Weekly newsletter, which has a more expansive view – and which you should subscribe to immediately, as far as we’re concerned.)

Find the first installment below. Although the time period reflected here is obviously more than a month long, we have some catching up to do before we can move to a truly monthly cadence.

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