Parameter Groups are a collection of parameters which control the behaviour of the ElastiCache cluster. They are automatically created as part of creating the cluster. But many times, we need our own list of parameters to be grouped together for some specific configuration needs. In such case we can create our own custom parameter groups.
In the custom parameter group, we create, we can edit the values of the parameters from the default value to a desired value.
We login to the AWS console and go to the ElastiCache dashboard. From the dashboard in the left we choose Parameter Groups. Then we see the name of the parameter group along with the family to which the parameter group belongs. The family of the group indicates the type of cache whether Redis or Memcached along with the version of the engine.
The below screen shows the result of selecting the parameter group form the left tab.
Next, we click on the button Create Parameter Group to create a parameter group. It prompts for the family of the cluster, which is the type of the cluster like Redis or Memcached along with the Engine version of the cluster. We also mention the name and description of parameter group in the input screen.
We can edit the parameters in a parameter group by selecting the check box to the left of it and then clicking on the button edit parameters as shown below.
On clicking the edit parameters button, we get the window where we can put our custom values in the various parameters listed. After changing them we can click Save Changes to make the new values effective.
Please note, we also have option to restore the parameter values to default values in case we have a need. That safeguards us against any incorrect parameter configuration we do by allowing us to go back to the original configuration.