We are adding hetrogeneous hardware to our cluster. So we should be usign ambari config groups. how should it be done. should we need to create the config groups in advance and then add the machines or should we need to add the machines and then create the config groups. By doing either way will it affect the existing cluster( can jobs run or a downtime is required) or will there be a need of restart of some services.
@ARUN the best way I found to make use of config groups is to click on the "Override" icon (green circle) of the parameter you want to override, put your new parameter value and add it to your new config group.
Once you want to do the changes, you'll just have to "Manage Config Groups", get the machines out of the default group and put it in the new one.
You'll have to restart components since Ambari will have to deploy the new config files to the corresponding hosts, but this may vary : for example, a HDFS modification will lead to a restart of HDFS and YARN since Yarn makes use of the hdfs config files too.
Hi @ARUN You can add the new hardware first, but not add any services to it. Applying config groups do not require downtime, though of course when you change configs you will need to restart the respective services. Depending on how many nodes, and which services you may be able to restart them in batches.
Hope that helps.
The process is outlined in the docs here: http://docs.hortonworks.com/HDPDocuments/Ambari-126.96.36.199/bk_ambari-user-guide/content/using_host_conf...
You can either create the group first (by clicking on any service > Configs > "Manage Config Groups" link), or just click override button next to the property in question: it will bring up the same config group dialog.
It has the same effect of changing a config property for a service: the change will not take effect until the relevant service is restarted