Statement Resource

Statement Resource

POST /v1/statement

query query

SQL Query to execute

reqheader X-Presto-User

User to execute statement on behalf of (optional)

reqheader X-Presto-Source

Source of query

reqheader X-Presto-Catalog

Catalog to execute query against

reqheader X-Presto-Schema

Schema to execute query against

Submits a statement to openLooKeng for execution. The openLooKeng client executes queries on behalf of a user against a catalog and a schema. When you run a query with the openLooKeng CLI, it is calling out to the statement resource on the openLooKeng coordinator.

The request to the statement resource is the SQL query to execute as a post along with the standard X-Presto-Catalog, X-Presto-Source, X-Presto-Schema, and X-Presto-User headers.

The response from the statement resource contains a query identifier which can be used to gather detailed information about a query. This initial response also includes information about the stages that have been created to execute this query on openLooKeng workers. Every query has a root stage and the root stage is given a stage identifier of “0” as shown in the following example response.

This root stage aggregates the responses from other stages running on openLooKeng workers and delivers them to the client via the openLooKeng coordinator. When a client receives a response to this POST it will contain a “nextUri” property which directs the client to query this address for additional results from the query.

Example request:

POST /v1/statement HTTP/1.1
Host: localhost:8001 X-Presto-Catalog: jmx X-Presto-Source: presto-cli X-Presto-Schema: jmx User-Agent: StatementClient/0.55-SNAPSHOT X-Presto-User: tobrie1 Content-Length: 41

select name from “java.lang:type=runtime”

Example response:

HTTP/1.1 200 OK
Content-Type: application/json X-Content-Type-Options: nosniff Transfer-Encoding: chunked

{

“id”:”20140108_110629_00011_dk5x2”, “infoUri”:”http://localhost:8001/v1/query/20140108_110629_00011_dk5x2“, “partialCancelUri”:”http://10.193.207.128:8080/v1/stage/20140108_110629_00011_dk5x2.1“, “nextUri”:”http://localhost:8001/v1/statement/20140108_110629_00011_dk5x2/1“, “columns”: [ { “name”:”name”, “type”:”varchar” } ], “stats”: { “state”:”RUNNING”, “scheduled”:false, “nodes”:1, “totalSplits”:0, “queuedSplits”:0, “runningSplits”:0, “completedSplits”:0, “cpuTimeMillis”:0, “wallTimeMillis”:0, “processedRows”:0, “processedBytes”:0, “rootStage”: { “stageId”:”0”, “state”:”SCHEDULED”, “done”:false, “nodes”:1, “totalSplits”:0, “queuedSplits”:0, “runningSplits”:0, “completedSplits”:0, “cpuTimeMillis”:0, “wallTimeMillis”:0, “processedRows”:0, “processedBytes”:0, “subStages”: [ { “stageId”:”1”, “state”:”SCHEDULED”, “done”:false, “nodes”:1, “totalSplits”:0, “queuedSplits”:0, “runningSplits”:0, “completedSplits”:0, “cpuTimeMillis”:0, “wallTimeMillis”:0, “processedRows”:0, “processedBytes”:0, “subStages”:[] } ] } }

}

GET /v1/statement/{queryId}/{token}

query queryId

The query identifier returned from the initial POST to /v1/statement

query token

The token returned from the initial POST to /v1/statement or from a previous call to this same call

When a openLooKeng client submits a statement for execution, openLooKeng creates a query and then it returns a nextUri to the client. This call corresponds to that nextUri call and can contain either a status update for a query in progress or it can deliver the final results to the client.