There are various reasons for which you will need to modify an existing cluster. For example, you have a increase in demand for larger data sets to be put into the cache. In that case you will need to change the node type to a higher configuration. Below are the steps through which we can modify the configuration of an existing cluster.
In this method we login to the aws console and go to the ElastiCache dashboard. From the dashboard we choose the name of the cluster whose details we need. In the below diagram we see the name of the cluster as a hyperlink after visiting the ElastiCache dashboard.
Clicking on the name of the cluster above takes us to the page which shows two tabs, one describing the node details and another tab giving the description of the cluster. Next, we click on the description tab and get the details shown below. As you can find, the complete details of the cluster mentioning the Endpoint, Availability zone, security group and parameter group etc is listed down here.
The above cluster can be modified by clicking on the modify button. The below screen pops up, which has the fields with the drop downs to change the value in that field. One important point during modification is the option to apply the changes immediately to the cluster. The Apply Immediately box applies only to node type and engine version modifications. To apply changes immediately, choose the Apply Immediately check box. Other modifications, such as changing the maintenance window, are applied immediately.