jobs

Computing in the NuNet Network

Table of Contents

• Computing in the NuNet Network
  • Ensemble Orchestration
    • Compute Ensembles
    • Ensemble Specification
    • Ensemble Constraints
    • Ensemble Deployment
    • Ensemble Supervision
  • Deploying in the NuNet Network
    • Behaviors and Capabilities
    • Deploying in a Private Network
    • Deploying in a Restricted Network
    • Authorizing a Third Party to Vet Users
    • Distributing and Revoking Capability Tokens
    • Public Deployment

Ensemble Orchestration

In NuNet, compute workloads are structured as compute ensembles. Here, we discuss how an ensemble can be created, deployed, and supervised in the NuNet network.

Compute Ensembles

An ensemble is a collection of logical nodes and allocations. Nodes represent the hardware where the compute workloads run. Allocations are the individual compute jobs that comprise the workload. Each allocation is assigned to a node, and a node can have multiple allocations assigned to it.

All allocations in the ensemble are assigned a private IP address in the 10/8 range and are connected with a virtual private network, implemented using IP over libp2p. All allocations can reach each other through the VPN. Allocation IP addresses can be discovered internally in the ensemble using DNS: each allocation has a name and a DNS name, which by default is just the allocation name in the .internal domain.

Allocation and Node names within an ensemble must be unique. The ensemble as a whole has a globally unique ID (a randomn UUID).

Ensemble Specification

In order to deploy an ensemble, the user must specify its structure and constraints; this is done with a YAML file encoding the ensemble configuration data structure; the fields of the configuration structure are described in detail in this reference.

Fundamentally the ensemble configuration has the following structure:

• A map of allocations, mapping allocation names to configuration for individual allocations.
• A map of nodes, mapping node names to configuration for individual nodes.
• A list of edges between nodes, encoding specific logical edge constraints.
• There are additional fields in the data structure which allows us to include ssh keys and scripts in the configuration, as well as supervision strategies policies.

An allocation's configuration has the following structure:

• The name of the allocation executor; this is the environment in which the actual compute job is executed. We currently support docker and firecracker VMs, but we plan to also support WASM and generally any sandbox/VM that makes sense for users.
• The resources required to run the allocation, such as memory, cpu cores, gpus, and so on.
• The execution details, which encodes the executor specific configuration of the allocation.
• The DNS name for internal name resolution of the allocation. This can be omitted, in which case the allocation's name becomes the DNS name.
• The list of ssh keys ton drop in the allocation, so that administrators can ssh into the allocation.
• The list of scripts to execute during provisioning, in execution order.
• Finally, the user can also specify the application specific health check to be performede by the supervisor, so that the health of the application can be ascertained and failures detected.

A node's configuration has the following structure:

• The list of allocations that are assigned to the node
• The configuration of mapping public ports to ports in allocations
• The Location constraints for the node
• An optional field for explicitly specifying the peer on which the node should be assigned, allowing users and organizations to bring their own nodes into the mix, for instance for hosting sensitive data.

In the near future, we also plan to support directly parsing kubernetes job description files. We also plan to provide a declarative format for specifying large ensembles so that it is possible to succinctly describe a 10k GPU ensemble for training an LLM and so on.

Ensemble Constraints

It is worth reiterating that ensembles carry with the constraints, as specified by the user. This allows the user to have finegrained control of their ensemble deployment and ensure that certain requirements are met.

In DMS v0.5 we support the following constraints:

• Resources for an allocation, such as memory, core count, gpu details, and so on.
• Location for nodes; the user can specify the region, city, etc all the way to choosing a particular ISP. Location constraints can also be negative, so that a node will not be deployed in certain locations e.g. because of regulatory considerations such as GPDR.
• Edge Constraints, which specify the relationship between nodes in the allocation in terms of available bandwidth and round trip time.

In subsequent releases we plan to add additional constraints (e.g. existence of a contract, price range, explicit datacenter placement, energy sources and so on) and generalize the constraint expression language as graphs.

Ensemble Deployment

Given an ensemble specification, the core functionality of the NuNet network is to find and assign peers to nodes that satisfies the constraints of the ensemble. The system treats the deployment as a constraint satisfaction problem over permutations of available peers (compute nodes) on which the user is authorized to deploy. The process of deploying an ensemble is called orchestration. In the following we summarize how deployment orchestration is performed.

Ensemble deployment is initiated with a user invoking the /dms/node/deployment/new behavior on the node which is willing to run an orchestrator for them; this can be just the user's private DMS running on his laptop. The node accepting the invocation creates the orchestrator actor inside its process space, initiates the deployment orchestration, and return to the user the ensemble identifier. The user can use this identifier to poll the status of the deployment and control of the ensemble through the orchestrator actor. The user also specifies a timeout on how long the deployment process should take before declaring failure. This is simply the expiration on the message that invokes /dms/node/deployment/new.

The orchestrator then proceeds to request bids for each node in the ensemble. This is accomplished by broadcasting a message to the /dms/deployment/request behavior in the /nunet/deployment broadcast topic. The deployment request contains a mapping of node names in the ensemble, together with their aggregate (for all allocations to be assigned in the node) resource constraints, together with location and other constraints that can restrict the search space.

In order for this to proceed, the orchestrator must have the appropriate capabilities; only provider nodes that accept the user's capabilities will respond to the broadcast message. The response to the bid request is a bid for a node in the ensemble, by sending a message to the /dms/deployment/bid behavior in the orchestrator. This also implies that the nodes that submit such bids must have appropriate capabilities accepted by the orchestrator.

Given the appropriate capabilities, the orchestrator collects bids until it has a sufficient number of bids or a timeout that ensures prompt progress in the deployment. If the orchestrator doesn't have bids for all nodes, then it rebroadcasts its bid request, excluding peers that have already submitted a bid. This continues until there are bids for all nodes or the deployment times out, at which point a deployment failure is declared.

Note that in the case of node pinning, where a specific peer is assigned to an ensemble node in advance (ie when a user brings their own nodes into the ensemble), bid requests are not broadcast but rather directly invoked on the peer.

Next, the orchestrator generates permutations of assignments of peers to nodes and evaluates the constraints. Some constraints can be directly rejected without measurement, for instance round trip latency constraints can be rejected by using speed of light calculations that provide a lower bound on physically realizable latency. We plan to do the same with bandwidth constraints, given the node measured link capacity and the throughput bound equation that governs TCP's behavior given bottleneck bandwidth and RTT.

Once a candidate assignment is deemed viable, the orchestrator proceeds to measure specific constraints for satisfiability. This involves measuring round trip time and bandwidth between node pairs, and is accomplished by invoking the /dms/deployment/constraint/edge behavior.

If a candidate assignment satisfies the constraints, the orchestrator proceeds with committing and provisioning the deployment. This is done with a two phase commit process: first the orchestrator sends a commit message to all peers to ensure that the resources are still available (nodes don't lock resources when submitting a bid), by invoking the /dms/deployment/commit behavior. If any node fails to commit, the candidate deployment is reverted and the orchestrator starts anew; revert happens with the /dms/deployment/revert behavior.

If all nodes successfully commit, the orchestrator proceeds to provision the deployment by sending allocation details to the relevant nodes and creating the VPN. This is initiated by invoking the /dms/deployment/allocate behavior on the provider nodes, which creates a new allocation actor. Subsequently, the orchestrator assigns IP addresses to allocations and creates the VPN (what we call the subnet) by invoking the appropriate behaviors on the allocation actors, and then starts the allocations. Once all nodes provision, the deployment is now considered running and enters supervision.

The deployment will keep running until the user shuts it down, as long as the user's agreement with the provider is active; in the near future we will also support explicitly specifying durations for running ensembles, and the ability to modify running ensembles in order to support mechanisms like auto scaling.

Ensemble Supervision

TODO

Deploying in the NuNet Network

In order to discuss authorization flow for deployment in the NuNet network, we need to distinguish certain actors in the system in the course of an ensembles lifetime.

Specifically, we introduce the following notation:

• Let's call U, the user as an actor.
• Let's call O the orchestrator, which is an actor living inside a DMS instance (node) for which the user is authorized to initiate a deployment. We call the node where the orchestrator runs N_o. Note that the DID of the orchestrator actor will be the same as the DID of the node on which it runs, but it will have an ephemeral actor ID.
• Let's call P_i the set of compute providers that are willing to accept deployment requests from U.
• Let's call N_{P_i,j} the DMS nodes controlled by the providers that are willing to accept deployments from users.
• And finally let's call A_i the allocation actor for each running allocation. The DID of each allocation actor will be the same as the DID of the node on which the allocation is running, but it will have an ephemeral actor ID.

Also note that we have certain identifiers pertaining to these actors; let's define the following notation:

• DID(x) is the DID of actor x; in general this is the DID that identifies the node on which the actor is running.
• ID(x) is the ID of actor x; this is generally ephemeral, except for node root actors which have persistent identities matching their DID.
• Peer(x) is the peer ID of a node/actor x.
• Root(x) is the DID of the root anchor of trust for the node/actor x.

Behaviors and Capabilities

Using the notation above we can enumerate the behavior namespaces and requisite capabilities for deployment of an ensemble:

• Invocations from U to N_o are in the /dms/node/deployment namespace
• Invocations from O to N_{P_i,j} for deployment bids:
  • broadcast /dms/deployment/request via the /nunet/deployment topic
  • unicast /dms/deployment/request for pinned ensemble nodes
• Messages from N_{P_i,j} to O:
  • /dms/deployment/bid as the reply to a bid request
• Invocations from O to N_{P_i,j} for deployment control are in the /dms/deployment namespace.
• Invocations from O to A_i are in the /dms/allocation namespace and are dynamically granted programmatically.
• Invocations from O to N_{P_i,j} for allocation control are in the dynamic /dms/ensemble/<ensemble-id> namespace and are dynamically granted programatically.

This creates the following structure:

• U must be authorized with /dms/node/deployment capability in N_o
• N_o must be authorized with /dms/deployment capability in N_{P_i,j} so that the orchestrator can make the appropriate invocations.
• N_{P_i,j} must be authorized with /dms/deployment/bid capability on N_o so that it can submit bids to the orchestrator.

Note that the decentralized structure and fine grained capability model of the NuActor system allows for very tight access control. This ensures that:

• Orchestrators can only run on DMS instances where the user is authorized to initiate deployment.
• Bid requests will only be accepted by provider DMS instances where the user is authorized to deploy.
• Bids will only be accepted by provider DMS instances whom the user has authorized.

In the following we examine common functional scenarios on how to set up the system so that deployments are properly authorized.

Deploying in a Private Network

TODO

Deploying in a Restricted Network

TODO

Authorizing a Third Party to Vet Users

TODO

Distributing and Revoking Capability Tokens

TODO

Public Deployment

TODO