Install the cloud dispatcher

Note:

arvados-dispatch-cloud is only relevant for cloud installations. Skip this section if you are installing an on premises cluster that will spool jobs to Slurm or LSF.

  1. Introduction
  2. Create compute node VM image
  3. Update config.yml
  4. Install arvados-dispatch-cloud
  5. Start the service
  6. Restart the API server and controller
  7. Confirm working installation

Introduction

The cloud dispatch service is for running containers on cloud VMs. It works with Microsoft Azure and Amazon EC2; future versions will also support Google Compute Engine.

The cloud dispatch service can run on any node that can connect to the Arvados API service, the cloud provider’s API, and the SSH service on cloud VMs. It is not resource-intensive, so you can run it on the API server node.

More detail about the internal operation of the dispatcher can be found in the architecture section.

Update config.yml

Configure CloudVMs

Add or update the following portions of your cluster configuration file, config.yml. Refer to config.defaults.yml for information about additional configuration options. The DispatchPrivateKey should be the private key generated in the previous section.

    Services:
      DispatchCloud:
        InternalURLs:
          "http://localhost:9006": {}
    Containers:
      CloudVMs:
        # BootProbeCommand is a shell command that succeeds when an instance is ready for service
        BootProbeCommand: "sudo systemctl status docker"

        # --- driver-specific configuration goes here --- see Amazon and Azure examples below ---

      DispatchPrivateKey: |
        -----BEGIN RSA PRIVATE KEY-----
        MIIEpQIBAAKCAQEAqXoCzcOBkFQ7w4dvXf9B++1ctgZRqEbgRYL3SstuMV4oawks
        ttUuxJycDdsPmeYcHsKo8vsEZpN6iYsX6ZZzhkO5nEayUTU8sBjmg1ZCTo4QqKXr
        FJ+amZ7oYMDof6QEdwl6KNDfIddL+NfBCLQTVInOAaNss7GRrxLTuTV7HcRaIUUI
        jYg0Ibg8ZZTzQxCvFXXnjseTgmOcTv7CuuGdt91OVdoq8czG/w8TwOhymEb7mQlt
        lXuucwQvYgfoUgcnTgpJr7j+hafp75g2wlPozp8gJ6WQ2yBWcfqL2aw7m7Ll88Nd
        [...]
        oFyAjVoexx0RBcH6BveTfQtJKbktP1qBO4mXo2dP0cacuZEtlAqW9Eb06Pvaw/D9
        foktmqOY8MyctzFgXBpGTxPliGjqo8OkrOyQP2g+FL7v+Km31Xs61P8=
        -----END RSA PRIVATE KEY-----
    InstanceTypes:
      x1md:
        ProviderType: x1.medium
        VCPUs: 8
        RAM: 64GiB
        IncludedScratch: 64GB
        Price: 0.62
      x1lg:
        ProviderType: x1.large
        VCPUs: 16
        RAM: 128GiB
        IncludedScratch: 128GB
        Price: 1.23

NVIDIA GPU support

To specify instance types with NVIDIA GPUs, you must include an additional CUDA section:

    InstanceTypes:
      g4dn:
        ProviderType: g4dn.xlarge
        VCPUs: 4
        RAM: 16GiB
        IncludedScratch: 125GB
        Price: 0.56
        CUDA:
          DriverVersion: "11.4"
          HardwareCapability: "7.5"
          DeviceCount: 1

The DriverVersion is the version of the CUDA toolkit installed in your compute image (in X.Y format, do not include the patchlevel). The HardwareCapability is the CUDA compute capability of the GPUs available for this instance type. The DeviceCount is the number of GPU cores available for this instance type.

AWS Credentials for Local Keepstore on Compute node

When Containers/LocalKeepBlobBuffersPerVCPU is non-zero, the compute node will spin up a local Keepstore service for faster storage access. If Keep is backed by S3, the compute node will need to be able to access the S3 bucket.

If the AWS credentials for S3 access are configured in config.yml (i.e. Volumes/DriverParameters/AccessKeyID and Volumes/DriverParameters/SecretAccessKey), these credentials will be made available to the local Keepstore on the compute node to access S3 directly and no further configuration is necessary.

Alternatively, if an IAM role is configured in config.yml (i.e. Volumes/DriverParameters/IAMRole), the name of an instance profile that corresponds to this role (often identical to the name of the IAM role) must be configured in the CloudVMs/DriverParameters/IAMInstanceProfile parameter.

Finally, if config.yml does not have Volumes/DriverParameters/AccessKeyID, Volumes/DriverParameters/SecretAccessKey or Volumes/DriverParameters/IAMRole defined, Keepstore uses the IAM role attached to the node, whatever it may be called. The CloudVMs/DriverParameters/IAMInstanceProfile parameter must then still be configured with the name of a profile whose IAM role has permission to access the S3 bucket(s). That way, arvados-dispatch-cloud can attach the IAM role to the compute node as it is created.

Minimal configuration example for Amazon EC2

The ImageID value is the compute node image that was built in the previous section.

    Containers:
      CloudVMs:
        ImageID: ami-01234567890abcdef
        Driver: ec2
        DriverParameters:
          # If you are not using an IAM role for authentication, specify access
          # credentials here. Otherwise, omit or set AccessKeyID and
          # SecretAccessKey to an empty value.
          AccessKeyID: XXXXXXXXXXXXXXXXXXXX
          SecretAccessKey: YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

          SecurityGroupIDs:
          - sg-0123abcd
          SubnetID: subnet-0123abcd
          Region: us-east-1
          EBSVolumeType: gp2
          AdminUsername: arvados

Example policy for the IAM role used by the cloud dispatcher:

{
    "Version": "2012-10-17",
    "Id": "arvados-dispatch-cloud policy",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "iam:PassRole",
                "ec2:DescribeKeyPairs",
                "ec2:ImportKeyPair",
                "ec2:RunInstances",
                "ec2:DescribeInstances",
                "ec2:CreateTags",
                "ec2:TerminateInstances"
            ],
            "Resource": "*"
        }
    ]
}

Minimal configuration example for Azure

Using managed disks:

The ImageID value is the compute node image that was built in the previous section.

    Containers:
      CloudVMs:
        ImageID: "zzzzz-compute-v1597349873"
        Driver: azure
        # (azure) managed disks: set MaxConcurrentInstanceCreateOps to 20 to avoid timeouts, cf
        # https://docs.microsoft.com/en-us/azure/virtual-machines/linux/capture-image
        MaxConcurrentInstanceCreateOps: 20
        DriverParameters:
          # Credentials.
          SubscriptionID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientSecret: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
          TenantID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

          # Data center where VMs will be allocated
          Location: centralus

          # The resource group where the VM and virtual NIC will be
          # created.
          ResourceGroup: zzzzz
          NetworkResourceGroup: yyyyy   # only if different from ResourceGroup
          Network: xxxxx
          Subnet: xxxxx-subnet-private

          # The resource group where the disk image is stored, only needs to
          # be specified if it is different from ResourceGroup
          ImageResourceGroup: aaaaa

Azure recommends using managed images. If you plan to start more than 20 VMs simultaneously, Azure recommends using a shared image gallery instead to avoid slowdowns and timeouts during the creation of the VMs.

Using an image from a shared image gallery:

    Containers:
      CloudVMs:
        ImageID: "shared_image_gallery_image_definition_name"
        Driver: azure
        DriverParameters:
          # Credentials.
          SubscriptionID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientSecret: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
          TenantID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

          # Data center where VMs will be allocated
          Location: centralus

          # The resource group where the VM and virtual NIC will be
          # created.
          ResourceGroup: zzzzz
          NetworkResourceGroup: yyyyy   # only if different from ResourceGroup
          Network: xxxxx
          Subnet: xxxxx-subnet-private

          # The resource group where the disk image is stored, only needs to
          # be specified if it is different from ResourceGroup
          ImageResourceGroup: aaaaa

          # (azure) shared image gallery: the name of the gallery
          SharedImageGalleryName: "shared_image_gallery_1"
          # (azure) shared image gallery: the version of the image definition
          SharedImageGalleryImageVersion: "0.0.1"

Using unmanaged disks (deprecated):

The ImageID value is the compute node image that was built in the previous section.

    Containers:
      CloudVMs:
        ImageID: "https://zzzzzzzz.blob.core.windows.net/system/Microsoft.Compute/Images/images/zzzzz-compute-osDisk.55555555-5555-5555-5555-555555555555.vhd"
        Driver: azure
        DriverParameters:
          # Credentials.
          SubscriptionID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientSecret: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
          TenantID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

          # Data center where VMs will be allocated
          Location: centralus

          # The resource group where the VM and virtual NIC will be
          # created.
          ResourceGroup: zzzzz
          NetworkResourceGroup: yyyyy   # only if different from ResourceGroup
          Network: xxxxx
          Subnet: xxxxx-subnet-private

          # Where to store the VM VHD blobs
          StorageAccount: example
          BlobContainer: vhds

Get the SubscriptionID and TenantID:

$ az account list
[
  {
    "cloudName": "AzureCloud",
    "id": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXX",
    "isDefault": true,
    "name": "Your Subscription",
    "state": "Enabled",
    "tenantId": "YYYYYYYY-YYYY-YYYY-YYYYYYYY",
    "user": {
      "name": "you@example.com",
      "type": "user"
    }
  }
]

You will need to create a “service principal” to use as a delegated authority for API access.

$ az ad app create --display-name "Arvados Dispatch Cloud (ClusterID)" --homepage "https://arvados.org" --identifier-uris "https://ClusterID.example.com" --end-date 2299-12-31 --password Your_Password
$ az ad sp create "appId"
(appId is part of the response of the previous command)
$ az role assignment create --assignee "objectId" --role Owner --scope /subscriptions/{subscriptionId}/
(objectId is part of the response of the previous command)

Now update your config.yml file:

ClientID is the ‘appId’ value.

ClientSecret is what was provided as Your_Password.

Test your configuration

Run the cloudtest tool to verify that your configuration works. This creates a new cloud VM, confirms that it boots correctly and accepts your configured SSH private key, and shuts it down.

~$ arvados-server cloudtest && echo "OK!"

Refer to the cloudtest tool documentation for more information.

Install arvados-dispatch-cloud

Red Hat and Centos

# yum install arvados-dispatch-cloud

Debian and Ubuntu

# apt-get install arvados-dispatch-cloud

Start the service

# systemctl enable --now arvados-dispatch-cloud
# systemctl status arvados-dispatch-cloud
[...]

If systemctl status indicates it is not running, use journalctl to check logs for errors:

# journalctl -n12 --unit arvados-dispatch-cloud

Restart the API server and controller

Make sure the cluster config file is up to date on the API server host then restart the API server and controller processes to ensure the configuration changes are visible to the whole cluster.

# systemctl restart nginx arvados-controller
# arvados-server check

Confirm working installation

On the dispatch node, start monitoring the arvados-dispatch-cloud logs:

~$ sudo journalctl -o cat -fu arvados-dispatch-cloud.service

Make sure to install the arvados/jobs image.

Submit a simple container request:

shell:~$ arv container_request create --container-request '{
  "name":            "test",
  "state":           "Committed",
  "priority":        1,
  "container_image": "arvados/jobs:latest",
  "command":         ["echo", "Hello, Crunch!"],
  "output_path":     "/out",
  "mounts": {
    "/out": {
      "kind":        "tmp",
      "capacity":    1000
    }
  },
  "runtime_constraints": {
    "vcpus": 1,
    "ram": 1048576
  }
}'

This command should return a record with a container_uuid field. Once arvados-dispatch-cloud polls the API server for new containers to run, you should see it dispatch that same container.

The arvados-dispatch-cloud API provides a list of queued and running jobs and cloud instances. Use your ManagementToken to test the dispatcher’s endpoint. For example, when one container is running:

~$ curl -sH "Authorization: Bearer $token" http://localhost:9006/arvados/v1/dispatch/containers
{
  "items": [
    {
      "container": {
        "uuid": "zzzzz-dz642-hdp2vpu9nq14tx0",
        ...
        "state": "Running",
        "scheduling_parameters": {
          "partitions": null,
          "preemptible": false,
          "max_run_time": 0
        },
        "exit_code": 0,
        "runtime_status": null,
        "started_at": null,
        "finished_at": null
      },
      "instance_type": {
        "Name": "Standard_D2s_v3",
        "ProviderType": "Standard_D2s_v3",
        "VCPUs": 2,
        "RAM": 8589934592,
        "Scratch": 16000000000,
        "IncludedScratch": 16000000000,
        "AddedScratch": 0,
        "Price": 0.11,
        "Preemptible": false
      }
    }
  ]
}

A similar request can be made to the http://localhost:9006/arvados/v1/dispatch/instances endpoint.

When the container finishes, the dispatcher will log it.

After the container finishes, you can get the container record by UUID from a shell server to see its results:

shell:~$ arv get zzzzz-dz642-hdp2vpu9nq14tx0
{
 ...
 "exit_code":0,
 "log":"a01df2f7e5bc1c2ad59c60a837e90dc6+166",
 "output":"d41d8cd98f00b204e9800998ecf8427e+0",
 "state":"Complete",
 ...
}

You can use standard Keep tools to view the container’s output and logs from their corresponding fields. For example, to see the logs from the collection referenced in the log field:

~$ arv keep ls a01df2f7e5bc1c2ad59c60a837e90dc6+166
./crunch-run.txt
./stderr.txt
./stdout.txt
~$ arv-get a01df2f7e5bc1c2ad59c60a837e90dc6+166/stdout.txt
2016-08-05T13:53:06.201011Z Hello, Crunch!

If the container does not dispatch successfully, refer to the arvados-dispatch-cloud logs for information about why it failed.


Previous: Build a cloud compute node image Next: Set up a compute node with Docker

The content of this documentation is licensed under the Creative Commons Attribution-Share Alike 3.0 United States licence.
Code samples in this documentation are licensed under the Apache License, Version 2.0.