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Introduction

Vast is introducing support for several features (local VPNs for client instances [in beta], network volumes [in alpha]) that depend on the host’s LAN configuration. Hosts can now register a set of machines they own sharing a LAN as a cluster to allow clients renting their machines to access local network resources. This will allow their machines to support use cases such as multi-node training via NCCL; as well, this will be a prerequisite to listing network volumes when they are released. A registered cluster is associated with:
  • A machine that acts as the manager node and is responsible for dispatching cluster management commands from the Vast server.
  • An IP subnet that machines in the cluster use to identify which network interface / which IP addresses for communication with other machines in the cluster.
  • A set of member machines.
The requirements for a set of machines to be registered as a cluster are that every member machine has a (non-NATed) IP address in the cluster’s subnet to which any other machine in the cluster can communicate with on all ports.

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Cluster registration guide

  • Update to the newest version of the CLI: go to (https://cloud.vast.ai/cli/)[https://cloud.vast.ai/cli/] and copy+run the command starting with wget.
  • Identify and test the subnet to register:
    • On the manager node ---
      • Run ip addr or ifconfig (the ip utility is part of the iproute2 package).
      • Identify which interface correspond’s to their LAN. For most hosts this will be an ethernet interface, which have the naming format enp$BUSs$SLOT[f$FUNCTION]] in modern Ubuntu.
        • Hosts using Mellanox devices for their main ethernet connection may instead see their interface show up as bond0
      • Find the IPv4 subnet corresponding to that network interface —
        • In ip addr output, the third line for each interface usually starts with inet IPv4SUBNET where IPv4SUBNET has the format IPv4ADDRESS/MASK where MASK is a non-negative integer < 32.
    • Test that the other machines to be added to the cluster can reach the manager node on that subnet/address.
      • On the manager node:
        • run nc -l IPv4ADDRESS 2337 where IPv4ADDRESS is the IPv4 address component of the chosen subnet.
      • On each other node:
        • run nc IPv4ADDRESS 2337
        • Type in some test text (i.e., “hello”) and press enter
        • Check that nc received and outputed the test text on the manager node.
  • Run ./vast.py create cluster IPv4SUBNET MACHINE_ID_OF_MANAGER_NODE
  • Run ./vast.py show clusters to check the ID of the cluster you just created.
  • Run ./vast.py join cluster MACHINE_IDS where MACHINE_IDS is a space seperated list of the remaining machines to add to your cluster.

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Cluster Management Commands Reference

  • ./vast create cluster SUBNET MANAGER_ID
    • Initializes a cluster containing the machine with ID MANAGER_ID as its manager node and using the network interface corresponding to SUBNET
  • ./vast show clusters
    • Shows clusters, for each cluster showing its CLUSTER_ID, associated SUBNET, manager node machine_id, and list of member machines.
  • ./vast join cluster CLUSTER_ID MACHINE_IDS
    • Takes MACHINE_IDS as a space seperated list, and adds them to the cluster specified by CLUSTER_ID
  • ./vast remove-machine-from-cluster CLUSTER_ID MACHINE_ID [NEW_MANAGER_ID]
    • Removes machine MACHINE_ID from cluster CLUSTER_ID. If the machine is the only manager, another machine in the cluster NEW_MANAGER_ID must be specified so that the cluster still has a manager.
  • ./vast delete cluster CLUSTER_ID
    • Deletes cluster CLUSTER_ID. Fails if cluster resources are currently in use by client instances.