# Slurm On Azure

# Overview

This workflow demonstrates the creation of a multinode Slurm cluster on Microsoft Azure which utilises Flight Solo.

It is assumed that you have a flight solo image on azure, if not see the documentation here.

# Make a login node

1. Click on your image

2. Click create VM

3. On the Basics page:

   • Set Subscription to your subscription type.
   • Set Resource Group to your desired resource group (where the vm will be kept after creation). Alternatively, create a new resource group.
   • Set Virtual machine name to any suitable name. (- does not work in a name)
   • Image should be set to your Flight Solo Image.
   • Set Size to your choice of size.
   • Set Authentication type to SSH public key
   • Set Username to flight.
   • Set SSH public key source to the most suitable option, but remember what key was used if creating compute nodes later.
   • Fill in the Key pair name/Stored key/Use existing key as appropriate to the chosen public key source.
   • Set the most appropriate license type.

4. Go to the networking tab and fill out the necessary options.

   • Set Virtual Network or create a new one by pressing "Create new" and setting a name. Remember what this is for if you create compute nodes.
   • Set Subnet to one of the options in the dropdown menu, if it isn't already set. Remember what this is for if you create compute nodes.
   • Set Public IP to an existing public IP or create a new one by pressing "Create new" and setting a name.
   • Set NIC network security group to "Advanced", and press "Create new" to create a new security group.
     • Click on "Add an inbound rule" to open the inbound rule creator
     • Create rules to allow HTTP, HTTPS and SSH traffic from your IP address to the security group. Add a rule to allow traffic to port 8888 from your ip address with any protocol. ??? any ip address to hunter?
     • When complete, press "OK" at the bottom left of the screen to return to image creation.

5. Go to the Advanced tab and find the custom data box.

   • Copy in the following:

   #cloud-config
   write_files:
     - content: |
         AUTH_KEY=example
         PREFIX=login1
       path: /opt/flight/cloudinit.in
       permissions: '0644'
       owner: root:root

6. Skip to the final tab Review + create

7. Azure will take some time to review your settings. If there are no issues click "Create" to finish creation.

# Get information for Compute node setup

Login to the login node, then become the root user and get the contents of ~/.ssh/id_alcescluster.pub.

# Create Compute node

Create another VM, filling it out with the same information as the login node but with these changes:

• Instead of creating a security group, use the security group created with the login node.
• Use this custom data:

  #cloud-config
  write_files:
  - content: |
      SERVER=<LOGIN_SERVER_IPV4_PRIVATE_ADDRESS>
      AUTH_KEY=example
      PREFIX=node0
    path: /opt/flight/cloudinit.in
    permissions: '0644'
    owner: root:root
  users:
  - default    
  - name: root
    ssh_authorized_keys:
      - <Content of ~/.ssh/id_alcescluster.pub from root user on login node>

# Parse Nodes

Login to the login node.

Parse the nodes.

• Run the command flight hunter parse.
• Select a node with space.
• The prefix name will show up.
• Press enter to leave node editing.
• Repeat for each node in the list that is in your cluster
• Press enter from the list to finish.

# Configure Slurm

Login to the login node.

Run flight profile configure and Select OpenFlight Slurm Multinode

• Cluster Name: slurmcluster1
• NFS server (hostname or flight-hunter label): login1
• SLURM server (hostname or flight-hunter label): login1
• Default user: flight
• Set user password to:
• IP or FQDN for Web Access:
• IP Range of Compute Nodes: 10.10.0.0/16
• IP Range of Kubernetes Pods (must not overlap with Compute Node IP Range): 192.168.0.0/16

Apply the login identity to login1 with flight profile apply login1 login

Wait for flight profile list to show the status of login1 as completed.

Apply the compute identity to your other node with flight profile apply node0 compute

Repeat the above to create more compute nodes.

# Checking it Works

Congratulations! You now have a Slurm cluster!

What you can do next is:

• Seamlessly access the cluster via the Flight Web Suite in a web browser by visiting the Public IPv4 DNS for the login node.
• Run some batch jobs.
• Add more nodes as described in the Create a Compute Node section.
• Remove unused nodes from the cluster before deleting them from azure.