A task represents the state of a long running process. vp-describe-task can be used to query the state of several tasks in many ways. The most common usage is simply to block on a task until it is completed. It is also useful for debugging as all of the errors generated during the run of the process will pushed to the task.
Every task contains a state, total number of steps in that task, total number of completed steps, a timestamp of last update, and a list of messages. The JSON structure to this object is described below.
Usage: vp-describe-task [options]
Options:
-h, --help show this help message and exit
--host=HOST Host of webservice to contact
--name=NAME Name of cluster, defaults to local
--show Print out any messages present
--show-error Print out only error messages
--show-debug Print out any debug messages
--show-all Print out all messages
--debug Print debugging messages
--nc Filtered out completed tasks
--exit-code Exit with a non zero value if any tasks are not in a
completed state
-b, --block Block on the tasks until they have completed or errored
--no-print-polling If block is true, do not print while polling to see what
is happening in real time
Give summary information on all tasks:
vp-describe-task
Output:
Task: tagData-1291329692.91 Type: tagData State: completed Num: 1/1 (100%) LastUpdated: 2010/12/02 22:41:33 UTC
Task: downloadTag-1291329665.33 Type: downloadTag State: completed Num: 2/2 (100%) LastUpdated: 2010/12/02 22:41:35 UTC
Task: tagData-1291329694.28 Type: tagData State: completed Num: 1/1 (100%) LastUpdated: 2010/12/02 22:41:34 UTC
Task: tagData-1291407449.22 Type: tagData State: completed Num: 1/1 (100%) LastUpdated: 2010/12/03 20:17:30 UTC
Give summary information on only those tasks that have not completed (this includes failed and running tasks):
vp-describe-task --nc
Output:
Task: realizeTag-1291215268.4 Type: realizeTag State: failed Num: 0/2 ( 0%) LastUpdated: 2010/12/01 15:04:14 UTC
Task: uploadTag-1291215267.24 Type: uploadTag State: failed Num: 1/2 ( 50%) LastUpdated: 2010/12/01 15:04:40 UTC
Task: addInstances-1291216121.4 Type: addInstances State: failed Num: 0/1 ( 0%) LastUpdated: 2010/12/01 15:08:42 UTC
Task: startCluster-1291319864.71 Type: startCluster State: failed Num: 0/2 ( 0%) LastUpdated: 2010/12/02 19:57:48 UTC
Block on all running task printing updates periodically. The output to this is not shown because it involves a periodic update of the screen.
vp-describe-task --block
Block on a specific task.
vp-describe-task --block startCluster-1291319864.71
Show all message associated with a particular task.
Note: You can list as many tasks as you want, none of these options are limited to a single task
vp-describe-task --show-all startCluster-1291319864.71
Output:
Task: startCluster-1291319864.71 Type: startCluster State: failed Num: 0/2 ( 0%) LastUpdated: 2010/12/02 19:57:48 UTC
Notification - 2010/12/02 19:57:44 UTC: Starting test
Debug - 2010/12/02 19:57:44 UTC: Starting master
Notification - 2010/12/02 19:57:44 UTC: Loading credential...
Error - 2010/12/02 19:57:48 UTC: Unable to run program u'/opt/ec2-api-tools-1.3-42584/bin/ec2-run-instances -K /tmp/diag_key.pem -C /tmp/diag_cert.pem -k vappio_00 -t m1.small -g vappio -g web -n 1 -f /tmp/master_user_data.sh' with exit code 1
Stacktrace:
Traceback (most recent call last):
File "/opt/vappio-py/vappio/tasks/utils.py", line 85, in runTask
f()
File "/opt/vappio-py/vappio/tasks/utils.py", line 98, in <lambda>
return runTask(options(optionsTaskName), lambda : func(options, args))
File "/opt/vappio-py/vappio/cli/remote/startClusterR.py", line 99, in main
cl = cl.startMaster(updateCluster)
File "/opt/vappio-py/vappio/cluster/control.py", line 112, in startMaster
dataFile)[0]
File "/opt/vappio-py/vappio/cluster/control.py", line 396, in runInstancesWithRetry
userDataFile=dataFile)
File "/opt/vappio-py/vappio/ec2/control.py", line 248, in runInstances
runWithCred(cred, cmd, _instanceParse, log=log)
File "/opt/vappio-py/vappio/ec2/control.py", line 114, in runWithCred
return commands.runSingleProgramEx(cmdPrefix + ' '.join(addCredInfo(cmd, cred)), stdoutf, stderrf, log=log, addEnv=cred.env)
File "/opt/vappio-py/igs/utils/commands.py", line 121, in runSingleProgramEx
raise ProgramRunError(pr.cmd, pr.exitCode)
ProgramRunError: Unable to run program u'/opt/ec2-api-tools-1.3-42584/bin/ec2-run-instances -K /tmp/diag_key.pem -C
/tmp/diag_cert.pem -k vappio_00 -t m1.small -g vappio -g web -n 1 -f /tmp/master_user_data.sh' with exit code 1
The output shows that this tag failed, how many steps through starting a cluster it made it (none) and the last update time. It is also shown that There were 2 notification messages, 1 debug, and 1 error message. This task failed trying to run the described program and the stack trace is shown.
Note: There are several options for vp-describe-task. Almost all of them work well together and one is encouraged to experiment with them.
/vappio/task_ws.py
Note: The webservice interface is under considerable overhaul
| Parameter | Required | Type | Meaning |
|---|---|---|---|
| cluster | Yes | String | Name of cluster to run on. |
The response is always a list of tasks. Each task looks like the following:
| Parameter | Required | Type | Meaning |
|---|---|---|---|
| state | Yes | String | The state of the task (idle, running, failed, completed). |
| name | Yes | String | The name of the task. |
| timestamp | Yes | Float | Decimal value for the timestamp. |
| tType | Yes | String | The type of operation the task is associated with (this is not a closed set of values). |
| completedTasks | Yes | Int | Number of steps completed. |
| numTasks | Yes | Int | Number of steps in the task. |
| messages | Yes | Dictionary List | A list of message objects, described below. |
Each message object is a dictionary that requires a mtype key. The mtype key describes the type of message the entry is and has one of the following values: notification, silent, error, and result.
The following describes what the message will look like depending on the value of mtype:
notification or silent:
| Parameter | Type | Meaning |
|---|---|---|
| timestamp | Float | Time the message was added. |
| text | String | Text of the notification message. |
result:
| Parameter | Type | Meaning |
|---|---|---|
| timestamp | Float | Time the message was added. |
| result | String | Text of the result. |
error:
| Parameter | Type | Meaning |
|---|---|---|
| timestamp | Float | Time the message was added. |
| stacktrace | String | The stacktrace, could be empty. |
| text | String | Description of the error. |
| name | String | Name of the error, could be empty. |