Task Resource#
The Task resource provides a set of REST endpoints that give Presto servers the ability to communicate about tasks and task output. This isn’t a service that will be used by end users, but it supports the execution of queries on a Presto installation.
- GET /v1/task
Returns information about all tasks known to a Presto server.
Note that the output of a call to
/v1/taskcan be quite large. If you execute this against a busy Presto server the response received will include a listing of every task known to that server along with detailed statistics about operators and drivers.The following example response shows a trivial task response that has been truncated to fit this manual. A real response from a busy Presto server would generate pages and pages of output. Here there is a
taskIdfor a task which is in theCANCELEDstate.Example response:
[ { "taskId" : "20131222_183944_00011_dk5x2.1.0", "version" : 9223372036854775807, "state" : "CANCELED", "self" : "unknown", "lastHeartbeat" : "2013-12-22T13:54:46.566-05:00", "outputBuffers" : { "state" : "FINISHED", "masterSequenceId" : 0, "pagesAdded" : 0, "buffers" : [ ] }, "noMoreSplits" : [ ], "stats" : { "createTime" : "2013-12-22T13:54:46.566-05:00", "elapsedTime" : "0.00ns", "queuedTime" : "92.00us", "totalDrivers" : 0, "queuedDrivers" : 0, "runningDrivers" : 0, "completedDrivers" : 0, "memoryReservation" : "0B", "totalScheduledTime" : "0.00ns", "totalCpuTime" : "0.00ns", "totalBlockedTime" : "0.00ns", "rawInputDataSize" : "0B", "rawInputPositions" : 0, "processedInputDataSize" : "0B", "processedInputPositions" : 0, "outputDataSize" : "0B", "outputPositions" : 0, "pipelines" : [ ] }, "failures" : [ ], "outputs" : { } }]
- POST /v1/task/{taskId}
- DELETE /v1/task/{taskId}
Deletes a given task from a Presto server.
- GET /v1/task/{taskId}
Retrieves information about a specific task by
taskId.The following example lists the output of a task. It contains the following high-level sections:
outputBuffersnoMoreSplitsstatsfailuresoutputs
This is the same output that is also present in the response from the Query resource which lists all of the stages and tasks involved in a particular query. This is call is used by Presto to coordinate a queries.
Example response:
{ "taskId" : "20140115_170528_00004_dk5x2.0.0", "version" : 42, "state" : "FINISHED", "self" : "http://10.193.207.128:8080/v1/task/20140115_170528_00004_dk5x2.0.0", "lastHeartbeat" : "2014-01-15T12:12:12.518-05:00", "outputBuffers" : { "state" : "FINISHED", "masterSequenceId" : 0, "pagesAdded" : 1, "buffers" : [ { "bufferId" : "out", "finished" : true, "bufferedPages" : 0, "pagesSent" : 1 } ] }, "noMoreSplits" : [ "8" ], "stats" : { "createTime" : "2014-01-15T12:12:08.520-05:00", "startTime" : "2014-01-15T12:12:08.526-05:00", "endTime" : "2014-01-15T12:12:12.518-05:00", "elapsedTime" : "4.00s", "queuedTime" : "6.39ms", "totalDrivers" : 1, "queuedDrivers" : 0, "runningDrivers" : 0, "completedDrivers" : 1, "memoryReservation" : "174.76kB", "totalScheduledTime" : "4.19ms", "totalCpuTime" : "4.09ms", "totalBlockedTime" : "29.50ms", "rawInputDataSize" : "10.90kB", "rawInputPositions" : 154, "processedInputDataSize" : "10.90kB", "processedInputPositions" : 154, "outputDataSize" : "10.90kB", "outputPositions" : 154, "pipelines" : [ { "inputPipeline" : true, "outputPipeline" : true, "totalDrivers" : 1, "queuedDrivers" : 0, "runningDrivers" : 0, "completedDrivers" : 1, "memoryReservation" : "0B", "queuedTime" : { "maxError" : 0.0, "count" : 1.0, "total" : 5857000.0, "p01" : 5857000, "p05" : 5857000, "p10" : 5857000, "p25" : 5857000, "p50" : 5857000, "p75" : 5857000, "p90" : 5857000, "p95" : 5857000, "p99" : 5857000, "min" : 5857000, "max" : 5857000 }, "elapsedTime" : { "maxError" : 0.0, "count" : 1.0, "total" : 4.1812E7, "p01" : 41812000, "p05" : 41812000, "p10" : 41812000, "p25" : 41812000, "p50" : 41812000, "p75" : 41812000, "p90" : 41812000, "p95" : 41812000, "p99" : 41812000, "min" : 41812000, "max" : 41812000 }, "totalScheduledTime" : "4.19ms", "totalCpuTime" : "4.09ms", "totalBlockedTime" : "29.50ms", "rawInputDataSize" : "10.90kB", "rawInputPositions" : 154, "processedInputDataSize" : "10.90kB", "processedInputPositions" : 154, "outputDataSize" : "10.90kB", "outputPositions" : 154, "operatorSummaries" : [ { "operatorId" : 0, "operatorType" : "ExchangeOperator", "addInputCalls" : 0, "addInputWall" : "0.00ns", "addInputCpu" : "0.00ns", "addInputUser" : "0.00ns", "inputDataSize" : "10.90kB", "inputPositions" : 154, "getOutputCalls" : 1, "getOutputWall" : "146.00us", "getOutputCpu" : "137.90us", "getOutputUser" : "0.00ns", "outputDataSize" : "10.90kB", "outputPositions" : 154, "blockedWall" : "29.50ms", "finishCalls" : 0, "finishWall" : "0.00ns", "finishCpu" : "0.00ns", "finishUser" : "0.00ns", "memoryReservation" : "0B", "info" : { "bufferedBytes" : 0, "averageBytesPerRequest" : 11158, "bufferedPages" : 0, "pageBufferClientStatuses" : [ { "uri" : "http://10.193.207.128:8080/v1/task/20140115_170528_00004_dk5x2.1.0/results/ab68e201-3878-4b21-b6b9-f6658ddc408b", "state" : "closed", "lastUpdate" : "2014-01-15T12:12:08.562-05:00", "pagesReceived" : 1, "requestsScheduled" : 3, "requestsCompleted" : 3, "httpRequestState" : "queued" } ] } }, { "operatorId" : 1, "operatorType" : "FilterAndProjectOperator", "addInputCalls" : 1, "addInputWall" : "919.00us", "addInputCpu" : "919.38us", "addInputUser" : "0.00ns", "inputDataSize" : "10.90kB", "inputPositions" : 154, "getOutputCalls" : 2, "getOutputWall" : "128.00us", "getOutputCpu" : "128.64us", "getOutputUser" : "0.00ns", "outputDataSize" : "10.45kB", "outputPositions" : 154, "blockedWall" : "0.00ns", "finishCalls" : 5, "finishWall" : "258.00us", "finishCpu" : "253.19us", "finishUser" : "0.00ns", "memoryReservation" : "0B" }, { "operatorId" : 2, "operatorType" : "OrderByOperator", "addInputCalls" : 1, "addInputWall" : "438.00us", "addInputCpu" : "439.18us", "addInputUser" : "0.00ns", "inputDataSize" : "10.45kB", "inputPositions" : 154, "getOutputCalls" : 4, "getOutputWall" : "869.00us", "getOutputCpu" : "831.85us", "getOutputUser" : "0.00ns", "outputDataSize" : "10.45kB", "outputPositions" : 154, "blockedWall" : "0.00ns", "finishCalls" : 4, "finishWall" : "808.00us", "finishCpu" : "810.18us", "finishUser" : "0.00ns", "memoryReservation" : "174.76kB" }, { "operatorId" : 3, "operatorType" : "FilterAndProjectOperator", "addInputCalls" : 1, "addInputWall" : "166.00us", "addInputCpu" : "166.66us", "addInputUser" : "0.00ns", "inputDataSize" : "10.45kB", "inputPositions" : 154, "getOutputCalls" : 5, "getOutputWall" : "305.00us", "getOutputCpu" : "241.14us", "getOutputUser" : "0.00ns", "outputDataSize" : "10.90kB", "outputPositions" : 154, "blockedWall" : "0.00ns", "finishCalls" : 2, "finishWall" : "70.00us", "finishCpu" : "71.02us", "finishUser" : "0.00ns", "memoryReservation" : "0B" }, { "operatorId" : 4, "operatorType" : "TaskOutputOperator", "addInputCalls" : 1, "addInputWall" : "50.00us", "addInputCpu" : "51.03us", "addInputUser" : "0.00ns", "inputDataSize" : "10.90kB", "inputPositions" : 154, "getOutputCalls" : 0, "getOutputWall" : "0.00ns", "getOutputCpu" : "0.00ns", "getOutputUser" : "0.00ns", "outputDataSize" : "10.90kB", "outputPositions" : 154, "blockedWall" : "0.00ns", "finishCalls" : 1, "finishWall" : "35.00us", "finishCpu" : "35.39us", "finishUser" : "0.00ns", "memoryReservation" : "0B" } ], "drivers" : [ ] } ] }, "failures" : [ ], "outputs" : { } }
- GET /v1/task/{taskId}/results/{outputId}/{token}
This service is used by Presto to retrieve task output.
- DELETE /v1/task/{taskId}/results/{outputId}
This service is used by Presto to delete task output.