Install Kudu in Cloudera CDH 5.16

Reference: https://blog.clairvoyantsoft.com/installing-apache-kudu-on-clouderas-quickstart-vm-3bdc202ce142 Apache Kudu is a relational database in the Hadoop ecosystem which provides CRUD update/delete capabilities in Impala tables. It stores data outside of hdfs in tablet files in the hadoop datanodes. It is useful for fast IOT data storage and querying as soon as data is inserted into the table unlike HDFS hive … Continue reading Install Kudu in Cloudera CDH 5.16

Use pyodbc with Cloudera Impala ODBC and Kerberos

Initially tried the python impyla package to connect to Cloudera Impala but ran into various errors and dependency issues. Also 2 of 3 queries would hang or give errors. So next tried pyodbc to connect to Impala. Linux System Requirements: The Cloudera ODBC Driver for Impala is recommended for Impala versions 2.8 through 3.3, and … Continue reading Use pyodbc with Cloudera Impala ODBC and Kerberos

Python code examples

JSON PARSING EXAMPLE-1: import json # some JSON: x = '{  "name": "John", "devlist": [ {"name":"kiny", "age":30,"city":"New York"}]}' # parse x: y = json.loads(x) # the result is a Python dictionary: print(y["name"]) print(y["devlist"][0]["name"]) -----------------------RESULT----------------------------- john kiny JSON PARSING EXAMPLE-2: import json # some JSON: loradevice    = \ '[{"devtype":"dlab","deviceeui": ["eui1", "eui2"]}, \   {"devtype":"adenu","deviceeui": ["eui3", "eui4"]}]' # … Continue reading Python code examples

WordPress vs Drupal vs Joomla: Are you kidding???

It is funny to see now almost 2020 that some people are still discussing which CMS is better WordPress or Drupal or Joomla. This question was probably valid 10 or more years back but not anymore. The website creators have voted and overwhelmingly WordPress is the winner. Just check the market share stats below in … Continue reading WordPress vs Drupal vs Joomla: Are you kidding???

Use Windows VScode to edit Linux files.

VScode is one of the best code editors with lots of add-on packages. Although you can install VScode in linux and use X windows to edit in linux, most people run VScode in Windows and would like to edit Linux files from Windows within VScode. There is a simple way to do this using the … Continue reading Use Windows VScode to edit Linux files.

Install Python pip on RHEL/Centos 7

When you initially try to install pip you may get an error as below: # python --version Python 2.7.5 [root]# yum install python-pip No package python-pip available. Error: Nothing to do We need to install epel-release first: [root] # yum install epel-release Installed: epel-release.noarch 0:7-11 Next install pip: [root]# yum install python-pip Installed: python2-pip.noarch 0:8.1.2-10.el7 … Continue reading Install Python pip on RHEL/Centos 7

Useful SQL query examples

Example SQL queries which may be helpful: This works in IMPALA SQL to convert a unix epoch time to 30min intervals time for example time 19:15, 19:25 will show as 19:00 and 19:31, 19:50 will show as 19:30 etc. SELECT from_timestamp (cast((epochtime div 1800000)*1800 as timestamp) + interval (epochtime % 1000) milliseconds, 'yyyy-MM-dd-HH:mm') as timeat30mininterval, … Continue reading Useful SQL query examples