Posts Tagged “centos”

Kafka Kerberos Enable and Testing.

Apache Kafka is a distributed streaming platform. Kafka 2.0 supports Kerberos authentication, Enabling Kerberos Authentication Using the Wizard on cloudera manager. Courtesy - Apache Kafka

Written on May 16, 2017
linux centos redhat cloudera kafka kerberos cluster

Cloudera Manager - Duplicate entry 'zookeeper' for key 'NAME'.

We had recently built a cluster using cloudera API’s and had all the services running on it with Kerberos enabled. Next we had a requirement to add another kafka cluster to our already exsisting cluster in cloudera manager. Since it is a quick task to get the zookeeper and kafka up and running. We decided to get this done using the cloudera manager instead of the API’s. But we faced the Duplicate entry 'zookeeper' for key 'NAME' issue as described in the bug below.

Written on May 14, 2017
linux centos redhat cloudera kafka zookeeper cluster

Parcel Not Distributing Cloudera CDH.

We were deploying one of the cluster on our lab environment which is used by everyone. So the lab has it own share of stale information on it.

Written on March 8, 2017
linux centos redhat cloudera hadoop cluster

Creating /etc/hosts file in Chef.

We had a cluster environment which we needed to update the /etc/hosts file. Which would help communicate between the server over a private network. Our servers have multiple interfaces and we need them to communicate between each other using the private network.

Written on March 3, 2017
linux centos redhat chef hadoop cluster

Encrypted Data Bags - Chef

Data Bags are a way to store information on the chef-server which all the cookbooks can access. Few more additional advantages are that we can encrypt the data-bags as well, this will help in keeping any sensitive information like user/password.

Written on September 6, 2016
chef linux ubuntu centos kitchen

knife Quick Reference

This is a quick reference for few of the commands which I use often.

Written on August 26, 2016
centos rhel nagios opensource monitoring

Remove Old Files using find Command

GNU find searches the directory tree rooted at each given file name by evaluating the given expression from left to right, according to the rules of precedence, until the outcome is known (the left hand side is false for and operations, true for or), at which point find moves on to the next file name. Remove old files which are older than a specific time using find Command.

Written on August 23, 2016
ubuntu centos linux commands

Moving RRD file from 32bit to 64bit Architecture

When we were working on a nagios monitoring system we were migrating from a 32bit nagios to a 64bit Architecture. Most of the graphs are not working as the RRD was from an older 32bit architecture.

Written on August 22, 2016
ubuntu centos linux rrd nagios

Migrating Nagios XI to a New Server on Centos6.6

Migrating an old Nagios backup to a new nagiosxi server. Migration is simple in Nagios XI, you a backup and restore it. Once that is done we need to update/add the clients with IP of the new server, so that both Nagios get alerts. After a while once we are comfortable with the new server we can decommission the old one.

Written on August 18, 2016
centos rhel nagiosxi nagios opensource monitoring

Setting up ssl https On Nagios XI Server

HTTPS is a protocol for secure communication over a computer network which is widely used on the Internet. HTTPS consists of communication over Hypertext Transfer Protocol (HTTP) within a connection encrypted by Transport Layer Security or its predecessor, Secure Sockets Layer. The main motivation for HTTPS is authentication of the visited website and protection of the privacy and integrity of the exchanged data. Intro Courtesy Wikipedia

Written on August 17, 2016
centos linux nagios nagiosxi ssl https monitoring

Standalone Chef Server / Workstation / Client Setup on CentOS 6

The standalone installation of Chef server creates a working installation on a single server. This installation is also useful when you are installing Chef server in a virtual machine, for proof-of-concept deployments, or as a part of a development or testing loop.

Written on August 16, 2016
centos linux chef chefdk

Creating Documents Using pandoc

Pandoc is an opensource utility to create documents from markdown. We can create PDF, Doc, doc, html and other formats. And can be also used to convert html to doc, html to pdf, markdown to pdf and many more.

Written on August 15, 2016
centos linux win documents

Setup/Configuration Nagios XI on Centos6.6

Nagios monitors your entire IT infrastructure to ensure systems, applications, services, and business processes are functioning properly. In the event of a failure, Nagios can alert technical staff of the problem, allowing them to begin remediation processes before outages affect business processes, end-users, or customers.

Written on August 12, 2016
centos rhel nagios nagiosxi monitoring

RPM Command Cheat Sheet

RPM (Redhat Package Manager) is the most popular package utility and is used mostly on RHEL, Centos and Fedora. RPM helps user/admins to build, install, query, verify, update, and remove/erase individual software packages.

Written on August 11, 2016
centos rhel rpms

Creating a large file in Windows / Linux

Was working on a monitoring project, need to create a large file to test notifications. Here is how we can do that.

Written on August 11, 2016
centos windows

Cloudera Manager Setup Using Chef [CentOS 6.6]

This cookbook [currently as of now] can be used to setup a Cloudera Manager Server (Management Server) running on MySQL database. But the intended use for this cookbook [rather a wishlist] is to do more. Simply put Auto Deployment of a Cloudera Hadoop Cluster using Chef, Python and Cloudera API. This will help create cluster for a development/test/preproduction/production environment on a click of a button.

Written on June 24, 2016
centos chef chefdk cloudera-manager cdh

Check Port on Remote Server CentOS 6.6/RHEL 6

Checking port available on a remote machine using nc command instead of telnet. Same command can be used to check on a remote server as well, change the with IP address of the server.

Written on April 1, 2016
centos linux nc

LUKS Disk encryption for CentOS 6.6/RHEL 6

Linux Unified Key Setup-on-disk-format (or LUKS) allows you to encrypt partitions on your Linux computer. This is particularly important when it comes to mobile computers and removable media. LUKS allows multiple user keys to decrypt a master key, which is used for the bulk encryption of the partition.

Written on February 23, 2016
centos linux luks disk encryption

Mysql Database Moving Data Directory to New Location.

How to move an existing data directory in mysql to a new location. We were running out of space and had to move the existing data directory to a new drive. Below are the steps to move the data directory to new location.

Written on February 4, 2016
mysql centos linux

Mysql Database Disk Usage.

We were running out of disk space on one of the databases server, we need to get information on what the current table/database usage was. Below are few commands for mysql server tables usages.

Written on February 4, 2016
mysql centos linux

Installing `python 2.7.x` on Centos 6.5/6.6

By default centos comes with python 2.6. In most of the cases we might need python 2.7 or later to be installed. Below are few ways to install python 2.7 on centos 6.x.

Written on February 3, 2016
python centos linux install

Zabbix Installation Script on Centos/Redhat 6.x

Installation on zabbix is quit simple and straight forward, but when you are install multiple servers and want to automate installation it is better to use a script. I would have preferred an ansible setup, but we have non of that on the server, so had to make do with good old shell script.

Written on January 6, 2016
zabbix snmp trap centos linux install online nagios monitoring

Zabbix Database Backup Script for `postgres` and `mysql`.

After the zabbix setup is done, we would like to take backup of the database. Here we are doing a complete backup. But if we are looking for only configuration backup then we can ignore the history* tables from the database, but for now we are taking complete backup. Backups are taken everyday and last 3 days backups are stored and rest for removed.

Written on January 6, 2016
zabbix snmp trap centos linux backup mysql postgres nagios monitoring

Installing Zabbix Version 2.4 Offline (Zabbix Server without Internet).

There might be situations where you have a remote/zabbix server which does not have internet connectivity, due to security or other reasons. So we create a custom repo on the remote/zabbix server so that we can install zabbix using rpms

Written on December 29, 2015
zabbix snmp trap centos linux offline nagios monitoring

Zabbix Template Creation using CSV file.

In zabbix we dont have a better way to capture snmptraps. we have to manually create an item and corresponfding trigger to handle a trap arriving from the device.

Written on December 10, 2015
zabbix snmp trap centos linux offline nagios monitoring

Installing SNMP Builder using `zabbix-extra` on Zabbix Version 2.4.

SNMP Builder/Extra is an add-in for Zabbix. It provides new web interface components to browse MIB trees and values. SNMP OIDs can then be automatically converted into Zabbix items and inserted into a template. The underlying snmpbuilder script uses calls to NetSNMP in order to communicate with devices on the network.

Written on December 9, 2015
zabbix snmp trap centos linux nagios monitoring

Setting up SNMP Trapper for Zabbix.

Receiving SNMP traps is the opposite to querying SNMP-enabled devices. In this case the information is sent from a SNMP-enabled device and is collected or “trapped” by Zabbix. Usually traps are sent upon some condition change and the agent connects to the server on port 162 (as opposed to port 161 on the agent side that is used for queries). Using traps may detect some short problems that occur amidst the query interval and may be missed by the query data.

Written on December 3, 2015
zabbix snmp trap centos linux

YUM Repository Creation on HTTPD Web Server.

Setting up yum repos on RHEL using httpd. We will be setting up httpd and yum repo on top of it. So that we can access yum over http.

Written on November 3, 2015
linux hadoop webserver http httpd yum rhel centos

Access Filter Setup with SSSD

If using access_provider = ldap, this option is mandatory. It specifies an LDAP search filter criteria that must be met for the user to be granted access on this host. If access_provider = ldap and this option is not set, it will result in all users being denied access. Use access_provider = allow to change this default behaviour.

Written on October 23, 2015
linux hadoop sssd access-filter rhel centos security

Redhat Intergration with Active Directory using SSSD.

There are inherent structural differences between how Windows and Linux handle system users. The user schemas used in Active Directory and standard LDAPv3 directory services also differ significantly. When using an Active Directory identity provider with SSSD to manage system users, it is necessary to reconcile Active Directory-style users to the new SSSD users. There are two ways to achieve it:

Written on October 6, 2015
linux hadoop sssd active-directory ad ldap rhel centos security

Simple Steps to Intergrate RHEL with Active Directory using SSSD.

There are inherent structural differences between how Windows and Linux handle system users. The user schemas used in Active Directory and standard LDAPv3 directory services also differ significantly. When using an Active Directory identity provider with SSSD to manage system users, it is necessary to reconcile Active Directory-style users to the new SSSD users. There are two ways to achieve it:

Written on October 6, 2015
linux hadoop sssd ad active-directory rhel centos security

Installing `ansible` on RHEL 6.6.

Ansible is a radically simple IT automation engine that automates cloud provisioning, configuration management, application deployment, intra-service orchestration, and many other IT needs. For more detail, hop over to

Written on October 6, 2015
linux ansible hadoop rhel centos

Creating a passwordless entry on Centos 6.5.

You can enter a linux system without entring a password using below steps. We will be creating a ssh jey which will be share between the servers, which will be used to authenticate. This is also a secure way of connecting to server, as the private key is inside the user home directory and can only be accessed by the user.

Written on March 19, 2015
linux centos rhel

Creating a Multi-node Cassandra Cluster on Centos 6.5.

The Apache Cassandra database is the right choice when you need scalability and high availability without compromising performance. Linear scalability and proven fault-tolerance on commodity hardware or cloud infrastructure make it the perfect platform for mission-critical data. Cassandra’s support for replicating across multiple datacenters is best-in-class, providing lower latency for your users and the peace of mind of knowing that you can survive regional outages.

Written on March 19, 2015
hadoop linux cassandra centos rhel

Installing SpagoBI 5.1 on Centos 6.5 -Tomcat 7 with MySQL 5.6.

The SpagoBI project is a free software/open source initiative by the SpagoBI Labs of Engineering Group. It aims to realize the most complete 100% open source business intelligence suite, aggregating developers, integrators, companies, users and passionate people in an open community.

Written on March 4, 2015
linux spagobi bi spago centos tomcat mysql

KVM Installation on CentOS 6.x.

KVM is a kernel-based Virutal Machine which grows quickly in maturity and popularity in the Linux server market. Red Hat officially dropped Xen in favor of KVM since RHEL 6. With KVM being officially supported by Red Hat, installing KVM on RedHat-based systems should be a breeze.

Written on February 18, 2015
linux kvm centos rhel virtual-machine vmware

Installing `zabbix-java-gateway` on Centos 6.5

Zabbix 2.0 adds native support for monitoring JMX applications by introducing a new Zabbix daemon called Zabbix Java gateway. Zabbix Java gateway is a daemon written in Java. When Zabbix server wants to know the value of a particular JMX counter on a host, it asks Zabbix Java gateway, which uses the JMX management API to query the application of interest remotely. The application does not need any additional software installed, it just has to be started with option on the command line.

Written on February 9, 2015
zabbix linux java zabbix-java-gateway centos rhel nagios monitoring

Installing NodeJS on Centos 6.6.

Node.js is an open-source, cross-platform runtime environment for developing server-side web applications. Node.js applications are written in JavaScript and can be run within the Node.js runtime on OS X, Microsoft Windows, Linux, FreeBSD, IBM AIX, IBM System z and IBM i.

Written on February 6, 2015
linux webserver nodejs centos rhel

Simple Script to create a user on centos 6.5

Default passwd is set as username@123 As we are setting the chage, user needs to change the passwd on first login.

Written on January 27, 2015
linux create user centos rhel

Zabbix Installation 2.4 - CentOS 6.5

Zabbix is the ultimate enterprise-level software designed for monitoring availability and performance of IT infrastructure components. Zabbix is open source and comes at no cost.

Written on December 31, 2014
zabbix centos nagios monitoring