Trains: reusing previous task id - trains

I am using reuse_last_task_id=True to overwrite an existing task (with same project and task name). But the experiment contains the torch model and therefore does not overwrite the existing task but creates a new one. How can I detach the model from the task?

Copying the answer from Trains team here.
Try to do reuse_last_task_id=<task_id_here> ,to specify the exact Task to continue )click on the ID button next to the task name in the UI)
If this value is true it will try to continue the last task on the current machine (based on project/name, combination) if the task was executed on another machine, it will just start a new one


Setting global properties in Composed Task which would be accessible in each of subtasks

Setting 'common' properties for child tasks is not working
The SCDF version I'm using is 2.9.6.
I want to make CTR A-B-C, each of tasks does follows:
A : sql select on some source DB
B : process DB data that A got
C : sql insert on some target DB
Simplest way to make this work seems to define shared work directory folder Path "some_work_directory", and pass it as application properties to A, B, C. Under {some_work_directory}, I just store each of task result as file, like select.result, process.result, insert.result, and access them consequently. If there is no precedent data, I could assume something went wrong, and make tasks exit with 1.
I tried with a composed task instance QWER, with two task from same application "global" named as A, B. This simple application prints out test.value application property to console, which is "test" in default when no other properties given.
If I tried to set test.value in global tab on SCDF launch builder, it is interpreted as app.*.test.value in composed task's log. However, SCDF logs on child task A, B does not catch this configuration from parent. Both of them fail to resolve input given at launch time.
If I tried to set test.value as row in launch builder, and pass any value to A, B like I did when task is not composed one, this even fails. I know this is not 'global' that I need, it seems that CTR is not working correctly with SCDF launch builder.
The only workaround I found is manually setting app.QWER.A.test.value=AAAAA and app.QWER.B.test.value=BBBBB in launch freetext. This way, input is converted to,, and print well.
I understand that, by this way, I could set detailed configurations for each of child task at launch time. However, If I just want to set some 'global' that tasks in one CTR instance would share, there seems to be no feasible way.
Am I missing something? Thanks for any information in advance.
CTR will orchestrate the execution of a collection of tasks. There is no implicit data transfer between tasks. If you want the data from A to be the input to B and then output of B becomes the input of C you can create one Task / Batch application that have readers and writers connected by a processor OR you can create a stream application for B and use JDBC source and sink for A and C.

how to switch a schedule task from one host to other in a cluster, when host that contain the schedule task is down in marklogic?

I scheduled a task in a bootstrap node in marklogic and but there might be chance that the host will down ,somehow ,in that case how I switched that task to other host in the cluster.
Note: I have to schedule the task only on a single host at a time from the cluster.
The options for assigning scheduled tasks are currently to set for a specific host, or to leave empty and have it execute on all hosts.
So, if you want to ensure that in the event of a host failure, the task is still executed, you could leave the host assignment empty and add logic inside of the task to determine which host should execute the code, and the others become a no-op.
An example of how to achieve that is to add code to the task to evaluate whether the xdmp:host() is the same host with the open Security forest (assuming that you have HA-replica forest for your Security DB to ensure availability, but could be achieved with any database)
xquery version "1.0-ml";
let $status := xdmp:database("Security") => xdmp:database-forests() => xdmp:forest-status()
where $status/*:host-id/data() eq xdmp:host()
(: this will only execute on the host with the open Security forest:)
"execute task logic"

Get status of a task Elasticsearch for a long running update query

Assuming I have a long running update query where I am updating ~200k to 500k, perhaps even more.Why I need to update so many documents is beyond the scope of the question.
Since the client times out (I use the official ES python client), I would like to have a way to check what the status of the bulk update request is, without having to use enormous timeout values.
For a short request, the response of the request can be used, is there a way I can get the response of the request as well or if I can specify a name or id to a request so as to reference it later.
For a request which is running : I can use the tasks API to get the information.
But for other statuses - completed / failed, how do I get it.
If I try to access a task which is already completed, I get resource not found .
P.S. I am using update_by_query for the update
With the task id you can look up the task directly:
GET /_tasks/taskId:1
The advantage of this API is that it integrates with
wait_for_completion=false to transparently return the status of
completed tasks. If the task is completed and
wait_for_completion=false was set on it them it’ll come back with a
results or an error field. The cost of this feature is the document
that wait_for_completion=false creates at .tasks/task/${taskId}. It is
up to you to delete that document.
From here
My use case went like this, I needed to do an update_by_query and I used painless as the script language. At first I did a reindex (when testing). Then I tried using the update_by_query functionality (they resemble each other a lot). I did a request to the task api (the operation hasn't finished of course) and I saw the task being executed. When it finished I did a query and the data of the fields that I was manipulating had disappeared. The script worked since I used the same script for the reindex api and everything went as it should have. I didn't investigate further because of lack of time, but... yeah, test thoroughly...
I feel GET /_tasks/taskId:1 confusing to understand. It should be
GET http://localhost:9200/_tasks/taskId
A taskId looks something like this NCvmGYS-RsW2X8JxEYumgA:1204320.
Here is my trivial explanation related to this topic.
To check a task, you need to know its taskId.
A task id is a string that consists of node_id, a colon, and a task_sequence_number. An example is taskId = NCvmGYS-RsW2X8JxEYumgA:1204320 where node_id = NCvmGYS-RsW2X8JxEYumgA and task_sequence_number = 1204320. Some people including myself thought taskId = 1204320, but that's not the way how the elasticsearch codebase developers understand it at this moment.
A taskId can be found in two ways.
wait_for_deletion = false. When sending a request to ES, with this parameter, the response will be {"task" : "NCvmGYS-RsW2X8JxEYumgA:1204320"}. Then, you can check a status of that task like this GET http://localhost:9200/_tasks/NCvmGYS-RsW2X8JxEYumgA:1204320
GET http://localhost:9200/_tasks?detailed=false&actions=*/delete/byquery. This example will return you the status of all tasks with action = delete_by_query. If you know there is only one task running on ES, you can find your taskId from the response of all running tasks.
After you know the taskId, you can get the status of a task with this.
GET /_tasks/taskId
Notice you can only check the status of a task when the task is running, or a task is generated with wait_for_deletion == false.
More trivial explanation, wait_for_deletion by default is true. Based on my understanding, tasks with wait_for_deletion = true are "in-memory" only. You can still check the status of a task while it's running. But it's completely gone after it is completed/canceled. Meaning checking the status will return you a 'resouce_not_found_exception'. Tasks with wait_for_deletion = false will be stored in an ES system index .task. You can still check it's status after it finishes. However, you might want to delete this task document from .task index after you are done with it to save some space. The deletion request looks like this
You will receive resouce_not_found_exception if a taskId is not present. (for example, you deleted some task twice, or you are deleting an in-memory task, whose wait_for_deletetion == true).
About this confusing taskId thing, I made a pull request to help clarify the Elasticsearch document. Unfortunately, they rejected it. Ugh.

How to restrict windows tasks to weekdays only?

I have a task that triggers on "user session logon". I now want to restrict that task to fire only on weekdays, and being ignored on the weekend.
Is that possible?
Sidenote: I cannot use the trigger on schedule as I do not want to run the task periodically, but only on logon, and only on weekdays.
click Weekly (NOT Daily)
Choose the days you want
As far as I understand, this is not possible using the task scheduler alone.
You could use a piece of VBScript to achieve this.
Set up a file, e.g. mytask.vbs, like this:
If DatePart("w", Date, vbMonday) < 6 Then
Set Shell = CreateObject("WScript.Shell")
WScript.Quit(Shell.Run("C:\Windows\System32\notepad.exe", 10, True))
End If
Replace notepad by the task you actually want to run. What this things does is: It checks whether the current day is Mo-Fr (this is done by specifying the start of the week as Monday, so DatePart will return values from 1=Monday to 7=Sunday, and then we're checking if it's below 6), and if yes, it runs a certain program, waits for it to finish and forwards its exit code. (The magic number 10 here means that it will respect whatever setting for window display (normal, maximized, minimzed) was passed by the task scheduler, if any, and also forward it to the program.)
Then you can create a scheduled task with a logon trigger only, which runs wscript.exe /e:vbscript c:\path\to\your\mytask.vbs. That's it!

Job with multiple tasks on different servers

I need to have a Job with multiple tasks, being run on different machines, one after another (not simultaneously), and while the current job is running, another same job can arrive to the queue, but should not be started until the previous one has finished. So I came up with this 'solution' which might not be the best but it gets the job done :). I just have one problem.
I figured out I would need a JobQueue (either MongoDb or Redis) with the following structure:
hostname: 'host where to execute the task',
task: 'current task number',
[task_id:1, commands:'run these ecommands', hostname:'aaa'],
[task_id:2,commands:'another command', hostname:'bbb']
search for the jobs with same hostname, and running==FALSE
execute the task that is set in that job
upon finish, host sets running=FALSE, checks if there are any other tasks to perform and increases task number + sets the hostname to the next machine from the next task
Because jobs can accumulate, imagine situation when jobs are queued for one host like this: A,B,A
Since I have to run all the jobs for the specified machine how do I not start the 3rd A (first A is still running)?
_id : ObjectId("xxxx"), // unique, generated by MongoDB, indexed, sortable
hostname: 'host where to execute the task',
task: 'current task number',
[task_id:1, commands:'run these ecommands', hostname:'aaa'],
[task_id:2,commands:'another command', hostname:'bbb']
The question is how would the next available "worker" know whether it's safe for it to start the next job on a particular host.
You probably need to have some sort of a sortable (indexed) field to indicate the arrival order of the jobs. If you are using MongoDB, then you can let it generate _id which will already be unique, indexed and in time-order since its first four bytes are timestamp.
You can now query to see if there is a job to run for a particular host like so:
// pseudo code - shell syntax, not actual code
var jobToRun = db.queue.findOne({hostname:<myHostName>},{},{sort:{_id:1}});
if (jobToRun.running == FALSE) {
myJob = db.queue.findAndModify({query:{_id:jobToRun._id, running:FALSE},update:{$set:{running:TRUE}}});
if (myJob == null) print("Someone else already grabbed it");
else {
/* now we know that we updated this and we can run it */
} else { /* sleep and try again */ }
What this does is checks for the oldest/earliest job for specific host. It then looks to see if that job is running. If yes then do nothing (sleep and try again?) otherwise try to "lock" it up by doing findAndModify on _id and running FALSE and setting running to TRUE. If that document is returned, it means this process succeeded with the update and can now start the work. Since two threads can be both trying to do this at the same time, if you get back null it means that this document already was changed to be running by another thread and we wait and start again.
I would advise using a timestamp somewhere to indicate when a job started "running" so that if a worker dies without completing a task it can be "found" - otherwise it will be "blocking" all the jobs behind it for the same host.
What I described works for a queue where you would remove the job when it was finished rather than setting running back to FALSE - if you set running to FALSE so that other "tasks" can be done, then you will probably also be updating the tasks array to indicate what's been done.