Linkis provides an adaption method by WebSocket, for the convenience of the frontend of functional applications.
The data development IDE tool Scriptis combined both ways to adapt with Linkis. It communicates with Linkis by websocket in normal circumstances, and failover to HTTP protocol in case the Websocket connection was down.
Linkis defined its own specs for front-backend adaption.
1).URL specs
/api/rest_j/v1/{applicationName}/.+ /api/rest_s/v1/{applicationName}/.+
2).Request specs
{ "method":"/api/rest_j/v1/entrance/execute", "data":{}, "websocketTag":"37fcbd8b762d465a0c870684a0261c6e" }
3).Response specs
{"method":"/api/rest_j/v1/entrance/execute","status":0, "message":Success!","data":{}}
1).Establish connection
Used to establish a WebSocket connection with Linkis.
/api/rest_j/entrance/connect
2).Request execution
Used to submit user jobs to Linkis for execution.
/api/rest_j/entrance/execute
POST
{ "method":"/api/rest_j/v1/entrance/execute", "data":{ "params": { "variable":{ "k1":"v1" }, "configuration":{ "special":{ "k2":"v2" }, "runtime":{ "k3":"v3" }, "startup":{ "k4":"v4" } } }, "executeApplicationName":"spark", "executionCode":"show tables", "runType":"sql", "source":{ "scriptPath": "/home/Linkis/Linkis.sql" }, "websocketTag":"37fcbd8b762d465a0c870684a0261c6e" } }
Parameter Name | Parameter Definition | Type | Comments |
---|---|---|---|
executeApplicationName | The Engine service expected by the user, such as Spark or hive | String | Not null |
requestApplicationName | The name of the system launching this request | String | Nullable |
params | User-defined parameters to run services | Map | Required, but values are nullable |
executionCode | The execution code submitted by the user | String | Not null |
runType | Assuming that the user executes a spark job, he may choose python, R or SQL as runType | String | Not null |
scriptPath | The script path of the execution code | String | For Scriptest, it shouldn't be null with executionCode at the same time |
Table 1 Descriptions for the parameters
{ "method": "/api/rest_j/v1/entrance/execute", "status": 0, "message": "Execution request succeeded", "data": { "execID": "030418IDEhivebdpdwc010004:10087IDE_johnnwang_21", "taskID": "123" } }
3).The push mechanism for task status, logs and progress
After submission, the status, logs and progress information will be pushed by the server. They could be retrieved by websocket protocol. The API is consistent with HTTP protocol as mentioned below. The only difference is that the schema of websocket is ws://, but http:// for HTTP protocol.
Sample response of WebSocket API
{ "method": "/api/rest_j/v1/entrance/${execID}/log", "status": 0, "message": "Returned log information", "data": { "execID": "${execID}", "log": ["errorLog","warnLog","infoLog", "allLog"], "taskID":28594, "fromLine": 56 }, "websocketTag":"37fcbd8b762d465a0c870684a0261c6e" }
{ "method": "/api/rest_j/v1/entrance/${execID}/status", "status": 0, "message": "Return status information", "data": { "execID": "${execID}", "taskID":28594, "status": "Running", }, "websocketTag":"37fcbd8b762d465a0c870684a0261c6e" }
{ "method": "/api/rest_j/v1/entrance/${execID}/log", "status": 0, "message": "Return progress information", "data": { "execID": "${execID}", "taskID":28594, "progress": 0.2, "progressInfo": [ { "id": "job-1", "succeedTasks": 2, "failedTasks": 0, "runningTasks": 5, "totalTasks": 10 }, { "id": "job-2", "succeedTasks": 5, "failedTasks": 0, "runningTasks": 5, "totalTasks": 10 } ] }, "websocketTag":"37fcbd8b762d465a0c870684a0261c6e" }