Use a Dedicated Headnode Instance for Management Services
In dedicated headnode mode, any management services (for example, the job manager or the file server) run on a separate instance called the headnode. The headnode does not host any workers. This approach is useful when workers run computations that use many system resources, such as memory, processor, network, or local storage. Using many system resources can negatively impact the performance of the job manager. In that case, if the job manager becomes unresponsive, then the MATLAB client can lose communication with the cluster.
In dedicated headnode mode, the job manager is optimized for the instance types that Cloud Center allows you to choose. A dedicated headnode adds an additional instance to your cluster, and so adds to your overall cost.
In dedicated headnode mode, the cluster machines are in the same availability zone, which improves the communication speed between the headnode and the workers. For instructions on enabling or disabling the dedicated headnode, see Create a Cloud Cluster.
The following Cloud Center functionality requires using a dedicated headnode:
Personal Clusters with access to MATLAB® Drive™.
You can still have a Personal cluster (homogeneous cluster node) with Auto-Manage Cluster Access and not use a dedicated headnode, but in this setup, you would not have access to MATLAB Drive.
Limitation with S3 File Upload
The current S3 files upload works only if the headnode is an ephemeral storage instance type, such as C3. Otherwise, the S3 files are not visible in the worker nodes. For details, see Headnode Limitation on S3 Uploads.
Use a Shared Instance for Management Services
If you disable the dedicated headnode mode, any management services (for example, the job manager) run on one instance in your cluster, along with workers. Use this mode if you want to reduce the number of machines in your cluster by one. This mode uses the same machine type for the headnode and the workers.
For instructions on enabling or disabling the dedicated headnode, see Create a Cloud Cluster.