There is a new tool to link Synapse Evaluation queues to a workflow engine at Sage-Bionetworks/SynapseWorkflowOrchestrator. This has the option of linking the queue through a Workflow Execution Service implementation. If you aren't currently using the SynapseWorkflowHook please consider using the new implementation. Thanks!

Synapse Workflow Hook Build

Toil Image Build

Synapse Workflow Hook

Links one or more Synapse Evaluation queues to a workflow engine. Each Evaluation queue is associated with a workflow template. Each submission is a workflow job, an instance of the workflow template. Upon submission to the Evaluation queue the Workflow Hook initiates and tracks the workflow job, sending progress notifications and uploading log files.

Features:

• Services one or more Synapse submission queues.
• Enforces time quota (signaled by separate process).
• Reconciles running submissions listed in Synapse with those listed by the workflow engine. Notifies admin' if there is a workflow job without a running submission listed in Synapse.
• Respects keyboard interrupt and ensures Workflow Hook stops at the end of a monitoring cycle.
• Implements submission cancellation.
• Tracks in Synapse when the job was started and ended (last updated).
• Notifies submitter about invalid submissions, notifies queue administrator about problems with the queue itself.
• Uploads logs to Synapse periodically and when done.
• Populates a status dashboard in Synapse with the following fields:
  • job status
  • start timestamp
  • last updated timestamp
  • location where log file is uploaded
  • failure reason (if workflow job failed to complete)
  • progress (0->100%), if provided by the Workflow engine

Setting up Amazon linux environment

1. Install docker sudo yum install docker
2. Must start the docker service: sudo service docker start or you will get this error: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
3. Allow for non-root user to manage docker: https://docs.docker.com/install/linux/linux-postinstall/#manage-docker-as-a-non-root-user
4. Log out and back into the instance to be able to do docker images as current user
5. Install docker-compose https://docs.docker.com/compose/install/#install-compose.

To use:

Create a project, submission queue, workflow template and dashboard

To run:

docker run --rm -it -e SYNAPSE_USERNAME=xxxxx -e SYNAPSE_PASSWORD=xxxxx \
-e WORKFLOW_TEMPLATE_URL=http://xxxxxx -e ROOT_TEMPLATE=xxxxx sagebionetworks/synapseworkflowhook /set_up.sh

where WORKFLOW_TEMPLATE_URL is a link to a zip file and ROOT_TEMPLATE is a path within the zip where a workflow file can be found. To use a workflow in Dockstore:

docker run --rm -it -e SYNAPSE_USERNAME=xxxxx -e SYNAPSE_PASSWORD=xxxxx \
-e WORKFLOW_TEMPLATE_URL=https://dockstore.org:8443/api/ga4gh/v2/tools/{id}/versions/{version_id}/CWL \
-e ROOT_TEMPLATE=xxxxx sagebionetworks/synapseworkflowhook /set_up.sh

TODO: Automatically lookup ROOT_TEMPLATE in Dockstore

Will print out created Project ID and the value for the EVALUATION_TEMPLATES in the following step.

Linking your workflow with evaluation queue manually

If you already have an existing project and do not want to follow the Create a project, submission queue, workflow template and dashboard instructions above, here are instructions on how to link your workflow with an Evaluation queue.

1. Create an Evaluation queue in a Synapse Project and retrieve the Evaluation id. View instructions here to learn more. For this example, lets say the Evaluation id is 1234.

2. Obtain the link of your github repo as a zipped file. (eg. https://github.com/Sage-Bionetworks/SynapseWorkflowExample/archive/master.zip)

3. Upload this URL into your project and set the annotation ROOT_TEMPLATE to be the path of your workflow. So for the example, the value would be SynapseWorkflowExample-master/workflow-entrypoint.cwl. For this example, lets say the Synapse id of this File is syn2345

4. EVALUATION_TEMPLATES will be: {"1234":"syn2345"}

Start the workflow service

Set the following as properties in a .env file to use with Docker Compose. Please carefully read through these properties and fill out the .envTemplate, but make sure you rename the template to .env.

• DOCKER_ENGINE_URL - address of the Docker engine. Along with DOCKER_CERT_PATH_HOST this is needed since the Workflow Hook will manage containers. Examples:

DOCKER_ENGINE_URL=unix:///var/run/docker.sock

or

DOCKER_ENGINE_URL=tcp://192.168.0.1:2376

• DOCKER_CERT_PATH_HOST - (optional) path to credentials files allowing networked access to Docker engine. Required if connecting over the network (DOCKER_ENGINE_URL starts with http, https or tcp, but not with unix). Example:

DOCKER_CERT_PATH_HOST=/my/home/dir/.docker/machine/certs

When using DOCKER_CERT_PATH_HOST you must also add the following under volumes: in docker-compose.yaml:

    - ${DOCKER_CERT_PATH_HOST}:/certs:ro

• SYNAPSE_USERNAME - Synapse credentials under which the Workflow Hook will run. Must have access to evaluation queue(s) being serviced
• SYNAPSE_PASSWORD - password for SYNAPSE_USERNAME
• WORKFLOW_OUTPUT_ROOT_ENTITY_ID - root (Project or Folder) for uploaded doc's, like log files. Hierarchy is root/submitterId/submissionId/files. May be the ID of the project generated in the set-up step, above.
• EVALUATION_TEMPLATES - JSON mapping evaluation ID(s) to URL(s) for workflow template archive. Returned by the set up step, above. Example:

{"9614045":"syn16799953"}

• TOIL_CLI_OPTIONS - (optional, but highly recommended) Space separated list of options. (Without the toil parameters, you may run into errors when a new workflow job is started). See https://toil.readthedocs.io/en/3.15.0/running/cliOptions.html. Example:

TOIL_CLI_OPTIONS=--defaultMemory 100M --retryCount 0 --defaultDisk 1000000

• NOTIFICATION_PRINCIPAL_ID - (optional) Synapse ID of user or team to be notified of system issues. If omitted then notification are sent to the Synapse account under which the workflow pipeline is run.
• SUBMITTER_NOTIFICATION_MASK - controls for which events notifications are sent to the submitter. The integer value is a union of these masks:

 1: send message when job has started;
 2: send message when job has completed;
 4: send message when job has failed;
 8: send message when job has been stopped by user;
16: send message when job has timed out;

Default is 31, i.e. send notifications for every event.

• SHARE_RESULTS_IMMEDIATELY - (optional) if omitted or set to 'true', uploaded results are immediately accessible by submitter. If false then a separate process must 'unlock' files. This is useful when workflows run on sensitive data and administration needs to control the volume of results returned to the workflow submitter.
• DATA_UNLOCK_SYNAPSE_PRINCIPAL_ID - (optional) Synapse ID of user authorized to share (unlock) workflow output files (only required if SHARE_RESULTS_IMMEDIATELY is false).
• WORKFLOW_ENGINE_DOCKER_IMAGE - (optional) defaults to sagebionetworks/synapseworkflowhook-toil, produced from this Dockerfile. When overriding the default, you must ensure that the existing dependencies are preserved. One way to do this is to start your own Dockerfile with

FROM sagebionetworks/synapseworkflowhook-toil

and then to add additional dependencies.

• MAX_CONCURRENT_WORKFLOWS - (optional) the maximum number of workflows that will be allowed to run at any time. Default is 10.
• RUN_WORKFLOW_CONTAINER_IN_PRIVILEGED_MODE - (optional) if true then when the containerized workflow is initiated, the container it's running in will be run in 'privileged mode'. In some environments this is required for workflows which themselves run containers.
• ACCEPT_NEW_SUBMISSIONS - (optional) if omitted then new submissions will be started. If present, then should be boolean (true or false). If false then no new submissions will be started, only existing ones will be finished up. This is an important feature for smoothly decommissioning one machine to switch to another.

Now run:

docker-compose --verbose up

Submit a job to the queue

docker run --rm -it -e SYNAPSE_USERNAME=xxxxx -e SYNAPSE_PASSWORD=xxxxx -e EVALUATION_ID=xxxxx \
-v /path/to/workflow/job:/workflowjob sagebionetworks/synapseworkflowhook /submit.sh

where EVALUATION_ID is one of the keys in the EVALUATION_TEMPLATES map returned from the set-up step

See results

In the Synapse web browser, visit the Project created in the first step. You will see a dashboard of submissions.

Tear down

Stop the service:

docker-compose down

Now, in Synapse, simply delete the root level project

Workflow creation guidelines

See this example for a working example of a Synapse-linked workflow. It includes reusable steps for downloading submissions and files, uploading files and annotating submissions. Some notes:

• The workflow inputs are non-negotiable and must be as shown in the sample workflow entry point.

• If the submission is a .cwl input file then it can be download by this script and parsed by a step customized from this example.

• The workflow should not change the 'status' field of the submission status, which is reserved for the use of the Workflow Hook.

• The workflow must have no output. Any results should be written to Synapse along the way, e.g., as shown in in this example.

Other details

Uploading results

The workflow hook uses this folder hierarchy for uploading results:

< WORKFLOW_OUTPUT_ROOT_ENTITY_ID> / <SUBMITTER_ID> / <SUBMISSION_ID> / 

and

< WORKFLOW_OUTPUT_ROOT_ENTITY_ID> / <SUBMITTER_ID>_LOCKED / <SUBMISSION_ID> / 

where

• <WORKFLOW_OUTPUT_ROOT_ENTITY_ID> is a parameter passed to the hook at startup;

• <SUBMITTER_ID> is the user or team responsible for the submission;

• <SUBMISSION_ID> is the ID of the submission;

When SHARE_RESULTS_IMMEDIATELY is omitted or set to true then logs are uploaded into the unlocked folder. When SHARE_RESULTS_IMMEDIATELY is set to false then logs are uploaded into the locked folder. To share the log file (or anything else uploaded to the _LOCKED folder) with the submitter, a process separate from the workflow should move the item(s) to the unlocked folder, rather than by creating an ACL on the lowest level folder. Such a process can run under a separate Synapse account, if desired. If so, set DATA_UNLOCK_SYNAPSE_PRINCIPAL_ID to be the Synapse principal ID of the account used to run that process.

The workflow is passed the IDs of both the locked and unlocked submission folders so it can choose whether the submitter can see the results it uploads by choosing which folder to upload to.

Timing out

The workflow hook checks each submission for an integer (long) annotation named org.sagebionetworks.SynapseWorkflowHook.TimeRemaining. If the value is present and not greater than zero then the submission will be stopped and a "timed out" notification sent. If the annotation is not present then no action will be taken. Through this mechanism a custom application can determine which submissions have exceeded their alloted time and stop them. Such an application is communicating with the workflow hook via the submissions' annotations. This architecture allows each submission queue administrator to customize the time-out logic rather than having some particular algorithm hard-coded into the workflow hook.

Decommissioning a Machine

If there is a need to decommission a machine while workflows are pending, then do the following:

Stop the service,

docker-compose down

Set the environment variable, ACCEPT_NEW_SUBMISSIONS to false. Now restart,

docker-compose up

The currently running submissions will finish up but no new jobs will be started. When all running jobs have finished,

docker-compose down

The machine may now be decommissioned.