Task API

7.1 Task

7.1.1 List all async tasks in graph

Params

• status: the status of asyncTasks, one of NEW, SCHEDULING, SCHEDULED, QUEUED, RESTORING, RUNNING, SUCCESS, CANCELLING, CANCELLED, FAILED, HANGING, DELETING, case-insensitive
• ids: task ids to query, can be repeated. It can not be combined with status or page, and it ignores limit.
• limit: the max number of tasks to return, default is 100
• page: page token for pagination. When it is passed, the response carries a page field with the token of the next page.

Method & Url

GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks?status=success

Response Status

200

Response Body

{
	"tasks": [{
		"task_name": "hugegraph.traversal().V()",
		"task_progress": 0,
		"task_create": 1532943976585,
		"task_status": "success",
		"task_update": 1532943976736,
		"task_result": "0",
		"task_retries": 0,
		"id": 2,
		"task_type": "gremlin",
		"task_callable": "org.apache.hugegraph.api.job.GremlinAPI$GremlinJob",
		"task_input": "{\"gremlin\":\"hugegraph.traversal().V()\",\"bindings\":{},\"language\":\"gremlin-groovy\",\"aliases\":{\"hugegraph\":\"graph\"}}"
	}]
}

7.1.2 View the details of an async task

Params

• with_result: whether to load the result of the task, default is true

Method & Url

GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/2

Response Status

200

Response Body

{
	"task_name": "hugegraph.traversal().V()",
	"task_progress": 0,
	"task_create": 1532943976585,
	"task_status": "success",
	"task_update": 1532943976736,
	"task_result": "0",
	"task_retries": 0,
	"id": 2,
	"task_type": "gremlin",
	"task_callable": "org.apache.hugegraph.api.job.GremlinAPI$GremlinJob",
	"task_input": "{\"gremlin\":\"hugegraph.traversal().V()\",\"bindings\":{},\"language\":\"gremlin-groovy\",\"aliases\":{\"hugegraph\":\"graph\"}}"
}

7.1.3 Delete task information of an async task,won’t delete the task itself

Params

• force: whether to delete the task even when it is still running, default is false

Method & Url

DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/2

Response Status

204

7.1.4 Cancel an async task, the task should be able to be canceled

If you already created an async task via Gremlin API as follows:

"for (int i = 0; i < 10; i++) {" +
    "hugegraph.addVertex(T.label, 'man');" +
    "hugegraph.tx().commit();" +
    "try {" +
        "sleep(1000);" +
    "} catch (InterruptedException e) {" +
        "break;" +
    "}" +
"}"

Method & Url

PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/2?action=cancel

cancel it in 10s. if more than 10s, the task may already be finished, then can’t be cancelled.

Response Status

202

Cancelling a task that is already completed or already cancelling returns 400.

Response Body

The whole task object is returned, with task_status set to cancelling or cancelled:

{
	"task_name": "for (int i = 0; i < 10; i++) {...}",
	"task_progress": 0,
	"task_create": 1532943976585,
	"task_status": "cancelling",
	"task_update": 1532943977001,
	"task_retries": 0,
	"id": 2,
	"task_type": "gremlin",
	"task_callable": "org.apache.hugegraph.api.job.GremlinAPI$GremlinJob"
}

At this point, the number of vertices whose label is man must be less than 10.

7.2 Algorithm Job

Schedules an OLAP algorithm as an asynchronous task inside the server. The task id in the response can be followed with the Task API above.

Params

Path parameters

• graphspace: Graphspace name
• graph: Graph name
• name: Algorithm name. The registered algorithms are count_vertex, count_edge, degree_centrality, stress_centrality, betweenness_centrality, closeness_centrality, eigenvector_centrality, triangle_count, cluster_coefficient, lpa, louvain, weak_connected_component, fusiform_similarity, rings, k_core, page_rank and subgraph_stat. An unknown name returns 404.

Method & Url

POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/jobs/algorithm/page_rank

Request Body

The body is the parameter map of the algorithm, and each algorithm validates its own parameters. Pass {} to run with the defaults.

{
    "alpha": 0.15,
    "times": 10
}

Response Status

201

Response Body

{
    "task_id": 1
}

7.3 Computer Job

Schedules a HugeGraph-Computer job as an asynchronous task. The computer job runs outside the server, see HugeGraph-Computer.

Params

Path parameters

• graphspace: Graphspace name
• graph: Graph name
• name: Computer name. The registered computers are page_rank, weak_connected_component, lpa, triangle_count and louvain. An unknown name returns 404.

Method & Url

POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/jobs/computer/page_rank

Request Body

The body is the parameter map of the computer job. Pass {} to run with the defaults.

{}

Response Status

201

Response Body

{
    "task_id": 2
}