I'm writing an ASP.NET webapp that will copy the contents of a CD to a network share. I need to check periodically if the copy job is finished.
One way of doing this is checking the network share folder to see if the file size has changed since the last check, but that seems kind of dodgy. Does anyone have a better idea how to do this?
Thanks in advance,
Stijn
EDIT
some more explanation:
Basically I'm calling a JsonResult action method every 5 seconds, called getStatus(source,destination). This method needs to check the following:
- if the source dir is still empty, copy cannot start --> return status "waiting"
- if the source dir contains files, copy can start -_> call copy method + return status "copying"
- if the destination dir contains files, and file size stays the same, copy is finished --> return status "finished"
Thanks!
In your webapp, use a blocking file copy operation, such as File.Copy, but run the procedure that does the copying in a background thread. In your background thread, write status information (e.g. "3 of 9 files finished" or "I'm done!" or "Error occurred: ...") into some shared object (static variable, Session object, database, ...). Then write some Status.aspx page which shows the content of that shared object.
Create web services available from client's javascript side with 2 methods: StartCopying, CheckStatus.
Implementation of StartCopying can either start backgorund thread to copy, or have [SoapDocumentMethod(OneWay = true)] that is mean that method returns immediately without waiting accomplishment.
CheckStatus just checks what you have described above, and return to client status of task.
Related
Would you know how to run a background task on Symfony 4, based on the setup of a form ? This would avoid that the user has to remain on the form until the task is finished.
The idea would be that when the form is validated, it starts an independant background task. Then the user can continue its navigation and come back once the task is finished to get the results.
Thanks for your help,
You need to use pattern Message Bus. Symfony has own implementation of this pattern since version 4.1 introducing Messenger Component.
You can see documentation here: https://symfony.com/doc/current/components/messenger.html
To get it work you need some external program that will implement AMQP protocol. Most popular in PHP world IMHO RabbitMQ.
A very simple solution for this could be the following procedure:
Form is valid.
A temporary file is created.
Cronjob gets executed every five minutes and starts a symfony command.
The command checks if the file exists and if it's empty.
If so, the command works of the background task. But before this, the command write it's process id in the file to prevent from beeing excuted a second time.
Remove the file when the command has finished.
As long as the file exists you can show a hint for the user that the task is running.
We have multiple jobs that serves as threads for file loading. But we want to trigger jobs only when file is received. So we created a file watcher job in control-M. We want to trigger thread Job for each file. So one file will be processed by a single thread job.
For example: If only one file is received only one thread job should be triggered say Thread1 job is triggered. Now after 1 min a new file is received then since Thread1 job is already running so Thread 2 job should be initiated.
I think, if we could post condition pro-grammatically in Control-M my purpose will be solved.
Please help and comment if any more information is required.
You could have the filewatcher post a generic out-condition then configure a dummy job at the start of each thread that would require exclusive control over a control resource and on completion delete it's in-condition and kickoff the rest of the thread.
3 file arrive.
Filewatcher completes and posts out-condition.
Only one thread header can start, it then removes the out-condition and continues the thread.
Filewatcher runs again, completes and posts out-condition.
Only one thread header can start, it then removes the out-condition and continues the thread.
etc..
Its not clear where you are trying to use the conditions, but its possible to add conditions programatically using the ctmcontb utility.
ex: ctmcontb -ADD Condition_Name ODAT
I want to be notified when a file is added to "/test". So I used QFilesystemWatcher's directoryChanged signal. But when "cp aa.txt /test" I got directoryChanged signal and there when I read aa.txt I had incomplete aa.txt.
In this case how can I know the file is completed to read?
FYI, I can't use fileChanged signal since don't know exact file name.
Unfortunately, there's no way to know this in general, without some cooperation from the process that writes to the file. The writing process would need to lock the file for exclusive access, and the reading process would need to keep trying to open the file for reading until it succeeded - when the writing process has dropped the lock.
All that the directoryChanged signal tells you is what it says on the box: the directory has changed, or in this case, there's a new entry in the directory. This is completely separate from what's represented by that entry - what the contents of the file are.
The filesystem watcher is only a half of what's needed here, and this is not an issue with Qt, but with the processes. Remember that you're trying to cooperate with the writer.
As a workaround, if you have some way of validating the file contents, you can do the same while reading and validating the file: keep retrying the read, with some delay until the validation succeeds. To avoid runaway resource use, it may be worthwhile for the delays to form an exponential back-off.
I'm running batch Java on an IBM mainframe under JZOS. The job creates 0 - 6 ".txt" outputs depending upon what it finds in the database. Then, I need to convert those files from Unix to MVS (ebcdic) and I'm using OCOPY command running under IKJEFT01. However, when a particular output was not created, I get a JCL error and the job ends. I'd like to check for the presence or absence of each file name and set a condition code to control whether the IKJEFT01 steps are executed, but don't know what to use that will access the Unix file pathnames.
I have resolved this issue by writing a COBOL program to check the converted MVS files and set return codes to control the execution of subsequent JCL steps. The completed job is now undergoing user acceptance testing. Perhaps it sounds like a kludge, but it does work and I'm happy to share this solution.
The simplest way to do this in JCL is to use BPXBATCH as follows:
//EXIST EXEC PGM=BPXBATCH,
// PARM='pgm /bin/cat /full/path/to/USS/file.txt'
//*
// IF EXIST.RC = 0
//* do whatever you need to
// ENDIF
If the file exists, the step ends with CC 0 and the IF succeeds. If the file does not exist, you get a non-zero CC (256, I believe), and the IF fails.
Since there is no //STDOUT DD statement, there's no output written to JES.
The only drawback is that it is another job step, and if you have a lot of procs (like a compile/assemble job), you can run into the 255 step limit.
I have an executable (no source) that I need to wrap, to make sure that it is not called more than once at a time. I immediately think of some sort of queue wrapper, but how do I actually make it so that my wrapper is called instead of the executable itself? Is there a better way to do this? The solution needs to be invisible because the users are other applications. Any information/recommendations are appreciated.
Method 1: Put the executable in some location not in the standard path. Create a shell script that checks a sentinel file and, if the sentinel file is absent, executes the program, waits for the ptogram to complete, then deletes the sentinel file. If the sentinel file is present, the script will enter a loop with a short delay (1 second? How long is the standard execution of this program? Take that and half it), check the sentential file again, and so on.
Method 2: Create a separate program that does the same thing as the script, but using a system-level semaphore or lock instead. You could even simply use a read/write lock on a file. The program would do a fork() and exec() on the real program, waiting for child exit before clearing the sentinel.
If the users are other applications, you can just rename the executable (e.g. name -> name.real) and call the wrapper with the original name. To make sure that it's only called once at a time, you can use the pidof command (e.g. pidof name.real) to check if the program is running already (pidof actually gives you the PID of the running process, so that you can use stuff such as kill or whatever to send signals to it).