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Note: All the posts are based on practical approach avoiding lengthy theory. All have been tested on some development servers. Please don’t test any post on production servers until you are sure.

Thursday, November 09, 2017

Diagnostics: Hive CLI is hanging On HDP


On our HDP, some time Hive CLI shell just hangs.




Diagnostics: Fix Under replicated blocks [Ambari Dashboard]


I see below in Ambari dashboard under HSDS Summary.

Wednesday, November 08, 2017

Using HDP Zeppelin



Apache Zeppelin is a web-based notebook that enables interactive data analytics. With Zeppelin, you can make beautiful data-driven, interactive and collaborative documents with a rich set of pre-built language backends (or interpreters, An interpreter is a plugin that enables you to access processing engines and data sources from the Zeppelin UI.) such as Scala (with Apache Spark), Python (with Apache Spark), SparkSQL, Hive, Markdown, Angular, and Shell. 

Tuesday, November 07, 2017

Using Apache Phoenix on HDP



Apache Phoenix is an open source, massively parallel, relational database engine supporting OLTP for Hadoop using Apache HBase as its backing store. It is a SQL abstraction layer for interacting with HBase. Phoenix translates SQL to native HBase API calls. Phoenix provide JDBC/ODBC and Python drivers. 

Monday, November 06, 2017

Working with HBase on HDP

Introduction
Apache HBase is a No-SQL database that runs on a Hadoop cluster. It is ideal for storing unstructured or semi-structured data. It was designed to scale due to the fact that data that is accessed together is stored together which allows to build big data applications for scaling and eliminating limitations of relational databases. 

Thursday, August 10, 2017

Working with Talend for Big Data (TOSBD)


Introduction                                                                               

Talend (eclipse based) provides unified development and management tools to integrate and process all of your data with an easy to use, visual designer. It helps companies become data driven by making data more accessible, improving its quality and quickly moving it where it’s needed for real-time decision making.
Talend for Big Data is built on top of Talend's data integration solution that enables users to access, transform, move and synchronize big data by leveraging the Apache Hadoop Big Data Platform and makes the Hadoop platform ever so easy to use.

Tuesday, August 08, 2017

Analyzing/Parsing syslogs using Hive and Presto


Scenario


My company asked me to provide the solution for syslog aggregation for all the environments so that they may be able to analyze and get insights. Logs should be captured first, then retained and finally processed by the analyst team in a way they already use to query/process with database. The requirements are not much clearer as well as volume of data can't be determined at the stage.

Wednesday, August 02, 2017

Working with Apache Cassandra (RHEL 7)


Introduction
Cassandra (created at Facebook for inbox search) like HBase is a NoSQL database, generally, it means you cannot manipulate the database with SQL. However, Cassandra has implemented CQL (Cassandra Query Language), the syntax of which is obviously modeled after SQL and designed to manage extremely large data sets with manipulation capabilities. It is a distributed database, clients can connect to any node in the cluster and access any data.

Tuesday, August 01, 2017

Hortonworks - Using HDP Spark SQL



Using SQLContext, Apache Spark SQL can read data directly from the file system. This is useful when the data you are trying to analyze does not reside in Apache Hive (for example, JSON files stored in HDFS).

Monday, July 31, 2017

Installing/Configuring Hortonworks Data Platform [HDP]

Ambari is  completely open source management platform for provisioning, managing, monitoring and securing Apache Hadoop clusters. Apache Ambari takes the guesswork out of operating Hadoop. As part of the Hortonworks Data Platform, allows enterprises to plan, install and securely configure HDP making it easier to provide ongoing cluster maintenance and management, no matter the size of the cluster.


Monday, July 10, 2017

Working with Apache Spark SQL


What is Spark?
Apache Spark is a lightning-fast cluster (in-memory cluster )computing technology, designed for fast computation. Spark does not depend upon Hadoop because it has its own cluster management, Hadoop is just one of the ways to implement Spark, it uses Hadoop for storage purpose. It extends the MapReduce model to efficiently use it for more types of computations, which includes interactive queries and stream processing.



Saturday, June 24, 2017

Installing/Configuring and working with Apache Kafka


Introduction

Apache Kafka is an open source, distributed publish-subscribe messaging system,
mainly designed to persistent messaging, high throughput, support multiple clients and providing real time message visibility to consumers.

Kafka is a solution to the real-time problems of any software solution, that is, to deal with real-time volumes of information and route it to multiple consumers quickly. Kafka provides seamless integration between information of producers and consumers without blocking the producers of the information, and without letting producers know who the final consumers are. It supports parallel data loading in the Hadoop systems.


Friday, June 23, 2017

Forward syslog to Flume with rsyslog


Introduction


Syslog  


In computing, syslog is a standard for message logging. It allows separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them. Each message is labeled with a facility code, indicating the software type generating the message, and assigned a severity label.

Computer system designers may use syslog for system management and security auditing as well as general informational, analysis, and debugging messages. A wide variety of devices, such as printers, routers, and message receivers across many platforms use the syslog standard. This permits the consolidation of logging data from different types of systems in a central repository. Implementations of syslog exist for many operating systems.

Streaming Twitter Data by Flume using Cloudera Twitter Source

In my previous post Streaming Twitter Data using Apache Flume which fetches tweets using Flume and twitter streaming for data analysis.Twitter streaming converts tweets to Avro format and send Avro events to downsteam HDFS sinks, when Hive table backed by Avro load the data, I got the error message said "Avro block size is invalid or too large". In order to overcome this issue, I used Cloudera TwitterSource rather than apache TwitterSource.

Streaming Twitter Data using Apache Flume


Introduction                                                                           

Flume is a distributed service for efficiently collecting, aggregating, and moving large amounts of streaming event data. It is a highly reliable, distributed, and configurable tool. It is principally designed to copy streaming data (event/log data) from various web servers and services like Facebook and Twitter to HDFS.


Building Teradata Presto Cluster


Prerequisites:
Before working on this post you should review below posts.



Installing/Configuring PrestoDB
Working with PrestoDB Connectors

In this post , I'll be covering below

1- Installing and configuring Presto Admin
2- Installing Presto Cluster on a single node
3- Using Presto ODBC Driver
4- Installing and configuring Presto Cluster with one coordinator and three workers

Working with PrestoDB Connectors



Prerequisite:
Complete my previous post Installing/Configuring PrestoDB


Presto enables you to connect to other databases using some connector, in order to perform queries and joins over several sources providing metadata and data for queries. In this post we will work with some connectors. A coordinator (a master daemon) uses connectors to get metadata (such as table schema) that is needed to build a query plan. Workers use connectors to get actual data that will be processed by them.


Installing and Configuring PrestoDB

Introduction

Presto (invented at Facebook) is an open source distributed SQL query engine for running interactive analytic queries against data sources of all sizes ranging from gigabytes to petabytes. It allows querying data where it lives, including Hive, Cassandra, relational databases or even proprietary data stores. Unlike Hive, Presto doesn’t use the map reduce framework for its execution. Instead, Presto directly accesses the data through a specialized distributed query engine that is very similar to those found in commercial parallel RDBMSs. A single Presto query can combine data (through pluggable connectors) from multiple sources, allowing for analytics across your entire organization. It is targeted at analysts who expect response times ranging from sub-second to minutes.

Managing HDFS Quotas


The Hadoop Distributed File System (HDFS) allows the administrator to set quotas for the number of names used and the amount of space used for individual directories. Name quotas and space quotas operate independently, but the administration and implementation of the two types of quotas are closely parallel.

Hadoop DFSAdmin Commands

The dfsadmin tools are a specific set of tools designed to help you root out information about your Hadoop Distributed File system (HDFS). As an added bonus, you can use them to perform some administration operations on HDFS as well.