Exim Mailqueue Monitoring Script

This script will count number of mails in queue and validate with threshold value. If it is more than it will send an email using thirdparty tool called SendEmail. One important point to note, that is we need to use SMTP hosted on other server. Thats why we are using SendEmail perl script. We need…

Configure Mail Notification with icinga2

Configuring Mail Notification in Icinga2 is very easy. We will use third party SMTP to send email notifications using thirdparty tool “sendEmail.pl”. sendEmail.pl is Perl script which send email to mailserver to send email. /etc/icinga2/scripts/mail-service-notification.sh : This script actually does work of sending emails. By default it uses inbuild “mail” utility. /etc/icinga2/users.conf: This conf file has user…

Steps to Install and Configure VerticaDB on Cloud

  Steps to Install and Configure VerticaDB on CentOS 6.x on Cloud: Vertica require Swap space. So if you dont have Swap on your cloud, you can still create by using below steps: It also require transparent_hugepage to be disabled and tuning of few more system parameters. It is better to add them in /etc/rc.local…

Monitoring Kafka, Storm, Zookeeper with Icinga2

Steps to monitor Kafka & Storm: – open JMX port for kafka and storm – To open JMX port in Kafka : a. Add below line to $KAFKA_HOME/bin/kafka-run-class.sh b. Add below line to $KAFKA_HOME/bin/kafka-server-start.sh c. Restart kafka – To open JMX port in Storm: a. Add below lines $STORM_HOME/conf/storm.yaml b. Restart Storm – Check ports…

Bare Metal Provisioning of Linux (Proxmox) using FAI

By Neelesh Gurjar What is Remote unattended installation? Remote unattended installation means installation of remote server without any human interference. This process is very useful for bare metal provisioning, automated installation on multiple servers, etc. What is Proxmox? Proxmox is debian based OS, which provides Virtualization Platform like VMware. https://www.proxmox.com/en/ What is FAI? FAI is…

Migrate Linux VMs from XEN (SolusVM) to KVM (Proxmox)

Migrating CentOS Linux installed Xen instance to KVM is really tricky. This note contains one of the way to migrate. Here I have used SolusVM for Xen based instances and Proxmox for KVM based instances. PS: This will work with Linux Only. For eg. I have used CentOS6 linux Here are the steps to migrate:…

Setting up Self Healing Tomcat

System Administrator has to configure Critical services regularly. He/She also needs to monitor that services and if services stop then needs to start them. We can automate starting of service after failure using Daemontools/supervise. We can also use monit for same. In this note we will configure Daemontools to monitor Tomcat service and if Tomcat crashes, Daemontools…

Configuring SSL in Tomcat & AWS Elastic Load Balancer (ELB)

Steps to configure SSL in Tomcat & integrate it with AWS Elastic Load Balancer (ELB) 1. Create Keystore using keytool.2. Generate Certificate Signing Request (CSR)3. Get RootCertificate, Intermidiate Certificate & Public Certificate. 4. Import above certificates in keystore 5. Configure keystore in tomcat 6. Integrate SSL certificate with AWS ELB – – Generate RSA Private…

Configure Elastic IP Failover between EC2 instances in AWS

Configuring Failover cluster between 2 EC2 instances is bit tricky. We can achieve Failover between 2 EC2 by configuring Elastic IP Failover. In AWS we can associate Elastic IP to an EC2 instance. Using this Elastic IP we can connect to the associated instance using terminal. We can configure basic Failover of EIP using below…