Archive for the ‘DBA’ Category

Getting JConsole working over ssh with Cassandra

I’ve been working with Cassandra recently and wanted to start using JConsole. JConsole exposes some pretty useful information about Cassandra and the Java environment in which it runs. It operates over JMX and by default it only accepts connections from the localhost. Since we don’t run GUIs on our servers and we didn’t want to open […]

Staged service restart with Ansible

I’ve been working on a small project to create a Cassandra Cluster for Development purposes. I’m using Vagrant and Ansible to deploy a 5-node Cassandra Cluster and node #5 would always fail to join the cluster. I checked /var/log/cassandra/cassandra.log and this is what I found; INFO [InternalResponseStage:1] 2017-09-09 18:49:07,673 ColumnFamilyStore.java:406 – Initializing system_auth.roles INFO [main] […]

MySQL 5.7: root password is not in mysqld.log

I came across this issue today when working on an ansible playbook with MySQL 5.7. Old habits die hard and I was still trying to use mysql_install_db to initialise my instance. It seems a few others have been doing the same. The effect of using mysql_install_db in more recent version of MySQL is that we end […]

Cassandra 3 Node Cluster Setup Notes

Install on each node ?View Code BASHwget http://www-eu.apache.org/dist/cassandra/redhat/30x/cassandra-3.0.13-1.noarch.rpm yum install jre rpm -ivh cassandra-3.0.13-1.noarch.rpm chkconfig cassandra on Configuration changes on each node vi /etc/cassandra/conf/cassandra.yaml Customise the seeds / ip address for your environment cluster_name: ‘cassandra_cluster’ seeds: “192.168.65.120,192.168.65.121,192.168.65.122” listen_address: rpc_address: Start the cassandra service on each node ?View Code BASHservice cassandra start service cassandra status If […]

A Clone of the STRING_SPLIT MSSQL 2016 Function

I have recently been developing some stuff using MSSQL 2016 and used the STRING_SPLIT function. This doesn’t exist in earlier versions and I discovered I would be required to deploy to 2008 or 2012. So here’s a my own version of the STRING_SPLIT function I have developed and tested on MSSQL 2008 (may also work […]