Simple scheduler issue

[Aydin]

I have a simple task to schedule:

def f():

    import time

    return()

from gluon.scheduler import Scheduler

Scheduler(db,dict(our_function=f))

When I run it with python web2py -K myapp, it gets stuck in "starting single-scheduler for "myapp"..." for long time and if I wait long enough it give "database is locked".

While waiting if I try to go to the app in the browser it won't work. Now, if I run the app without scheduler (removing -K myapp), and I go to my scheduler table I can see that the task had run successfully (while it was not accessible) 

Any one knows what's happening? and what the solution might be?

[黄祥]

perhaps, it related with database issue such as : sqlite

had you already tried another database like mysql or postgresql?

best regards,

stifan

[Aydin]

I have used the scheduler before without being worried about the database type. 

I tried to use mysql but it gave an error that it is not supported. I have mysql and pymysql installed and created a database "testdb" and used the manual format and got that error that it is not supported.

[Niphlod]

scheduler definitely works for mysql. 

what you experienced is perfectly fine. a scheduler process just sits there if there is nothing to do (i.e. no tasks to process).

[Aydin]

Would that break the connection to the server, because the website does not come up.

[Aydin]

I used the exact example shown by massimo (https://vimeo.com/27478796) and it gets stuck at (starting single-scheduler for myapp...) and the website does not come up saying browser cannot establish a connection). Running on ubuntu and debian.

On Monday, January 2, 2017 at 11:04:44 AM UTC-5, Niphlod wrote:

[Aydin]

I had defined a task to run every 30 seconds by the way. 

On Monday, January 2, 2017 at 11:04:44 AM UTC-5, Niphlod wrote:

[Dave S]

On Monday, January 2, 2017 at 8:22:55 AM UTC-8, Aydin wrote:

I used the exact example shown by massimo (https://vimeo.com/27478796) and it gets stuck at (starting single-scheduler for myapp...) and the website does not come up saying browser cannot establish a connection). Running on ubuntu and debian.

Can you show us your connection string (passwords obfuscated)?

/dps

[Aydin]

Sure, here are the databases I have tried to create:

# db2 = DAL('sqlite://scheduler_storage.sqlite')

# db2 = DAL('pymysql://root:pass@localhost/testdb2')

db2=DAL('mysql://root:pass@localhost/testdb2')

# db2 = DAL('MySQLdb://root:pass@localhost/testdb2')

# db2 = DAL('pymysql://root:pass@localhost/testdb1')

for MySQLdb and pymysql I get the error that they are not supported. mysql does not give that error but gets stuck in starting the task.

I even tried to import pymysql in web2py.py which did not help with the error of it being not supported.

[Aydin]

I had perfectly fine working app using scheduler in 2015, I tried to use that one but when trying to run the schedule (-K my app), the app does not run and web2py gets stuck in "starting single-scheduler...". This says to me something in terms of python and python tools version does not work well with web2py. I don't think there is anything wrong with the code I am using.

[Niphlod]

if you run a single process with 

python web2py.py -K appname 

ONLY the scheduler will be alive

the web-serving part needs to be started as usual, in addition to the previous process which just spins the scheduler process.

[Aydin]

I cann't believe I have spent 3 days trying every thing to find out what the hell is happening. Last time I used it, it was 2 years ago and I guess it was more intuitive to feel like python web2py.py -a pass -K myapp will run both the server and scheduler!!! Sorry everyone for the confusion.

[Niphlod]

you're probably referring to -X .

in any case, web2py.py -h is your best friend ;-)