I would like to create a cron job in GAE but I do not want it to be scheduled.
I would like to call it manually whenever I need it.
What should I put in the schedule element?
From Scheduling Tasks With Cron for Python:
A cron job makes an HTTP GET request to a URL as scheduled. The
handler for that URL executes the logic when it is called.
So, as #snakecharmerb mentioned, you have to create that handler doing whatever you want the cron job to do and map it to the desired cron url.
In order to avoid scheduling you simply don't upload the cron configuration, instead you manually trigger the job by making that same GET request that the scheduler would otherwise do, for example using curl:
curl https://your_app.appspot.com/cron_handler_url
You can also do something like
schedule: every 99999 hours
That way, its almost like 11 years so you know that cron won't be triggered till then.
Before reading, this is slightly hacky although it does work.
I needed something similar to this, primarily due to the need for a slightly longer processing time than 60 seconds.
In my cron.yaml I specified:
- description: My example cron
url: /cron/my/example/cron
schedule: 25 of dec 12:00
Then within my handler I check if the date is the 25th december and abandon the request.
This seems to be the only way to have a 'manual' cron.
In Python this is simple to check the date.
from datetime import datetime
import logging
now = datetime.utcnow()
if now.day == 25 and now.month == 12:
logging.info("Skipping as it's the 25th December")
return
Related
We have multiple App Engine Cron entries triggering our App Engine application, but recently we detected a decrease on the number of the processed events handled by one of the endpoints of our application. By looking at the App Engine Cron logs for this specific Cron entry on StackDriver, we found out that, during the days we invesgated (March 11-15), that are missing entries. Most of the missing triggers coincide through the days (12:15, 14:15, 16:15, 18:15, 20:15, 22:15, 00:15).
The screenshot below displays one specific day, and the red lines indicate the missing entries:
There are no requests with HTTP status code different than 200.
This is the configuration of the specific Cron entry (replaced some words with XXX due to business restrictions):
- description: 'Hourly job for XXX'
url: /schedule/bigquery/XXX
schedule: every 1 hours from 00:15 to 23:15
timezone: UTC
target: XXX
retry_parameters:
min_backoff_seconds: 2.5
max_doublings: 5
Could someone # GCP side take a look? The task name is 53751dd6a70fb9af38f49993b122b79f.
it seems like if the request takes longer than an hour, then the next one gets skipped (i.e. cron doesn't launch the next iteration if the current iteration is still running)
maybe do the actual work in a separate task and then the only thing the cron task does is launch this separate task
I want to run a cron for every 2 minutes interval, 0,2,4,6,8 .... each cron execution runs for 2 minutes.
I configured cron schedule with synchronized as below. But I still see scheduler is behaving as if synchronized not given.
Crons are scheduled at
0-2 First cron
4-6 Second cron
8-10 third cron
Cron scheduler is waiting for 2 minutes after last cron execution.
If I understand synchronized correctly, it is added to avoid this behavior.
Why this happening.
<cron>
<url>/cron/syncPrices</url>
<description>Fetch data from source and cache it in data store.</description>
<schedule>every 2 minutes synchronized</schedule>
</cron>
You can check the actual cron configuration for your application on the old GAE console in the Cron Jobs menu on the left. You're looking to confirm if synchronized (or its from 00:00 to 23:59 equivalent) is present for the respective job:
if synchronized is missing it's possible that the cron.yaml file wasn't uploaded/updated during the regular app upload - I noticed this to be the case with my multi-module (python) application. You have to specifically update the cron configuration using the update_cron option of your AppCfg utility.
if synchronized is indeed present and the unexpected behaviour continues you should open a support case with Google.
FYI It looks like 'synchronized' is no longer part of the cron.yaml documentation. I've reached out to Google via the documentation feedback link.
I have this cron job in GAE
cron:
- description: interactive
url: /interactive
schedule: every 1 minutes
everytime I want to change schedule to 5 minutes or 10 minutes, I have to open cron.yaml file, change the parameter and update the app. I think it is too annoying.
Is there anyway I can change the parameter without doing those steps.
For example, store schedule parameter in an entity and update the entity. Is it possible?
The only way to change these params is to update the cron.yaml and redeploy the app.
To make your life easier though you could enable the push to deploy for your app and edit this file (or any other file) either on GitHub or directly from Google Console.
I have configured Google App Engine to record exception with ereporter.
The cron job is configured to run every 59 minutes. The cron.yaml is as follows
cron:
- description: Daily exception report
url: /_ereporter?sender=xxx.xxx#gmail.com # The sender must be an app admin.
schedule: every 59 minutes
How to do I run this immediately.
What I am trying to do here is simulate a 500 HTTP error and see the stack trace delivered immediately via the cron job.
Just go to the URL from your browser.
You can't using cron. Cron is a scheduling system, you could get it to run every minute.
Alternately you could wrap your entire handler in a try/except block and try to catch everything. (You can do this for some DeadlineExceededErrors for instance) then fire off a task which invokes ereporter handler, and then re-raise the Exception.
However in many cases Google infrastructure can be the cause of the Error 500 and you won't be able to catch the error. To be honest you are only likely to be able to cause an email sent for a subset of all possible Error 500's. The most reliable way probably be to have a process continuously monitor the logs, and email from there.
Mind you email isn't consider reliable or fast so a 1 min cron cycle is probably fast enough.
I came across this thread as I was trying to do this as well. A (hacky) solution I found was to add a curl command at the end of my cloudbuild.yaml file that triggers the file immediately per this thread. Hope this helps!
Make a curl request in Cloud Build CI/CD pipeline
I have AppEngine Java application which use cron to activate a servlet.
Because I'm doing very short operation I do it inside a loop every few seconds.
I want to know how much time I have left to finish the work before I get the deadline exception so I use getCurrentEnvironment().getRemainingMillis() but for some reason it return 10 minutes instead of 1 minute.
Thank you,
Ido.
This is expected behavior. The cron docs page clearly states that requests invoked by cron can run for 10 minutes.