We're running continuous Web Jobs under a WebApp that is set to AlwaysOn.
One of the jobs, perhaps badly written, is set to run in a loop as long as there are items in an Azure Storage queue, and this queue is being populated faster than the job can consume - effectively making the loop infinite. I want to sometimes stop this job manually.
In the Azure Management Portal (manage.windowsazure.com), I've "Stopped" the job and restarted the WebApp, but the job still seems to be running. How exactly does Azure stop/kill a job?
Apparently it creates a 'disable.job' file in the job directory to signal not to runit, but that of course doesn't get checked until the next startup of the job, which never happens since it's in an infinite loop. Restarting the WebApp doesn't seem to help either.
The only thing that seems to help is when we redeploy which includes swapping with a staging environment (shutting down the previous one with the running job).
The (partial) answer my question of how exactly Azure stops jobs can be found in the kudu source:
private bool IsDisabled
{
get { return FileSystemHelpers.FileExists(_disableFilePath) || Settings.IsWebJobsStopped(); }
}
So either if disable.job exists, or WEBJOBS_STOPPED is set in the application settings.
I already knew this though, and in our particular case it wasn't helping. It turned out the jobs were running on the swapped (and also stopped!!) staging environment. Jobs will keep running in a staging environment, even after the slot is stopped. To me, this is a serious bug with Azure, but no one seems to acknowledge it as an issue.
Related
I have an Azure webjob created using the SDK that runs hourly. The job runs, and works fine, but when I look at the job in the portal it always shows Failed. I can run the job from the Debug Console and everything appears fine. When run from the console the job typically takes seconds to run, but when run on the schedule it usually shows 12-20 minutes, before it fails.
How can I get more details as to why this is failing? Do I need to be telling webjobs somehow the task is finished and it's waiting on me?
Thanks,
Russ
Webjob Failure
This error happens if the job uses TimerTrigger.
If the job is long-running use WEBJOBS_IDLE_TIMEOUT and SCM_COMMAND_IDLE_TIMEOUT in Azure app settings instead of web.config.
If the job is not long-running, it should have scheduled timers less than 2 minutes, which will probably work well for testing only.
Finally, the ultimate solution is to use Basic or Standard offering of AppPlan.
In that case you can ENABLE Always On to keep the container loaded all the time.
However, WEBJOBS_IDLE_TIMEOUT and SCM_COMMAND_IDLE_TIMEOUT must also be set as described above. Continuous WebJobs or of WebJobs triggered using a CRON (TimerTrigger) expression without Always On, will not run reliably.
For more details, you could refer to this article.
I have used Azure Schedulers before for quick jobs before. It targets a URL which is ASPX page or WebApi and it did the job.
Now I have a job that takes up to 15-20 minutes. Of course, I am getting timeout error after 30 seconds.
I'm trying to avoid creating a Windows Service or some console application that would run on Azure VM, rather have a non-UI application that runs in the background.
Do you have any suggestion what should I do?
You should use an Azure WebJob for this. WebJobs support simple scheduling via a cron expression (details here). Basically you upload a simple script file or exe that performs the work you want done, upload it to your WebApp along with a cron schedule expression, and Azure WebJobs will make sure it runs on schedule.
For your scenario, you'll want to create a "Continuous" WebJob and ensure you've enabled "Always On" which ensures the background job continues running (i.e. it isn't request triggered).
WebJobs sure is a good solutions, but it will share resources with its attached Web App.
You could consider using an Azure Cloud Service. I do that myself for longer running tasks, that are more CPU intensive.
Read more
For long running WebJobs, you have to tinker with the Timeout value (by default 2 minutes) or make sure your Webjob makes some Console.Writes.
To achieve that, go to the Web App Settings > Application Settings and add the following configurations:
WEBJOBS_IDLE_TIMEOUT - Time in seconds after which we'll abort a running triggered job's process if it's in idle, has no cpu time or output.
SCM_COMMAND_IDLE_TIMEOUT - Time in milisecods. By default, when your build process launches some command, it's allowed to run for up to 60 seconds without producing any output. If that is not long enough, you can make it longer, e.g. to make it 10 minutes:
I have an Azure Website where I would like to be able to republish the website without stopping any webjobs that might be running in the background.
Ignoring the fact that it's bad practice to publish while the site is being used, this scenario means that a large queue might keep the webjobs firing 24/7 as load increases on the website.
I'm not sure if publishing the website (and not the webjobs) cause the webjobs (scheduled and on-demand) to cancel. Do they?
I think they do, and in that case, is there anything you can do to prevent that? I risk jobs being stopped halfway-through because of the need to publish, and I don't want to sit there waiting for the queue to be empty before publishing. A method of allowing currently running jobs to finish without starting new runs would be fine too.
If the webjob files are not updated (under wwwroot/app_data/jobs/...) they will not restart.
I have a Scheduled Azure WebJob which runs every 5 mins. It's not clear what happens if the running times takes 10 mins. Is a new one started parallel to the one still running, or is it not started until the previous one has finished?
From this answer What happens when a scheduled WebJob runs for a long time :
As i understand it scheduled webjobs is just triggered webjobs that is run using Azure Scheduler, if you open Azure Scheduler in management portal you can see the webjobs and even configure them in more detail. (You can see the log too which would give you the simple answer to your question).
If you like to look at whats going on your scheduled webjob is run as a Triggered webjob by Kudu, if you look in the Kudu source you will see that a lockfile is created when a job is started, and if you try to start another job a ConflictException is thrown if there is already a lock file.
The Azure scheduler calls your job using a webhook that catches the ConflictException and gives you the "Error_WebJobAlreadyRunning" warning which will tell you: "Cannot start a new run since job is already running."
I've created a simple Azure WebJob that uses a QueueInput trigger. It deployed without any problems and I've schedule it via the management portal so that it 'Runs continuously'
Initial testing seemed fine, with the job triggering shortly after placing anything in the queue.
By chance I then left it about a day before placing anything else in the queue. This time the job hadn't triggered within a few minutes so I logged in to the portal to view the invocation logs - which showed that the job had just that moment been triggered.
That seemed too much of a coincidence so I left it another day before placing something in the queue. Again, the job didn't trigger. I left it overnight and by morning it still hadn't triggered.
When I logged in to the management portal this time I noticed that the job was marked as 'Aborted' on the WebJobs page. It was like that only for about 10 seconds before the status changed to 'Running'. And then the job immediately triggered from what was placed in the queue the night before, as expected.
As it's an alpha release I'm expecting glitches. Just wondering whether anyone else has had a similar experience.
For WebJobs SDK, your job must be running in order to listen for triggers (new queue messages, new blobs, etc). Azure Websites free tier has quotas and will put your job to sleep which means it's no longer listening on triggers. Using the site may cause it to come back to life and start listening to triggers again.
The SDK dashboard will show a warning icon next to functions if the hosting job is not running (it detects this via heartbeats).
Make sure that your website is configured with the "Always On" setting Enabled.
If your site contains continuously running jobs they may not perform reliably if this setting is disabled.
http://azure.microsoft.com/en-us/documentation/articles/web-sites-configure/
By default, web sites are unloaded if they have been idle for some period of time. This lets the system conserve resources. You can enable the Always On setting for a site in Standard mode if the site needs to be loaded all the time. Because continuous web jobs may not run reliably if Always On is disabled, you should enable Always On when you have continuous web jobs running on the site.