Quick Notes

Things that came on the way

Restart of a Service Which Is Dependent on Multiple Services Through Chef

In a node there can be services that are dependent on other services. For e.g. a monitoring service is dependent on services which it monitors and collects data. So when a service being monitored is restarted, the service monitoring may have to be restarted to establish back the connections. This was the case with older version of JMXTrans which required a restart when any of the services it is monitoring got restarted. Assuming that the older version of JMXTrans is used to monitor various services running on a node how do we restart JMXTrans when any of the process is restarted while using Chef to manage the environment.

Dynamically Requesting a Common Service in a Chef Managed Environment

In a cluster environment there can be a common service running on all the nodes in the cluster which may be requested by an application using the cluster. For e.g. in a distributed computing environment logs can be created on each node in the cluster and a common service on each cluster node can be a service which regularly copies log entries into a common location. Copying of logs can be a requirement for some of the applications/services running on the cluster nodes so that users can go to one location to view the log data from all the nodes instead of looking at each node. This can also help with managing the security of the cluster by providing access to this common location instead of providing access to all the nodes in the cluster.

Design Optimal HBase Based Applications

Leveraging the architecture of any data management system used in an application will yield the best performance and is the case with HBase. So before listing the key points to remember while designing HBase based applications, lets briefly look at the relevant architecture of HBase which will provide the required context.

Build Your Hadoop Cluster Unattended (Almost!!)

If you are a developer who would like to have a Hadoop cluster or a dev lead who would like everyone in your team a cluster of their own without going through the hassle of creating machines, networking them, install the required software components, chef-bach is an option you want to try.