IR809 IOx application fail and debug

[HarryDing0224]

I have a C Docker application on IR809. This application is used to receive socket from a device and send it to the database. The app will receive more than 2 messages (each message contains less than 200 characters) in 1 second.

This docker application works fine locally on my develop machine with the command:

CMD "/opt/apps/test3" 

But deployed on 809, this application stopped processing after it received about 30 messages, while the application was still in running status.

I try to to debug this problem through the following steps:

1. I have a loop application "loop_apps"
2. I changed the target option in package.yaml from

   # Specify runtime and startup
     startup:
       rootfs: rootfs.tar
       target: ["/opt/apps/test3"]

   to

   # Specify runtime and startup
     startup:
       rootfs: rootfs.tar
       target: ["/opt/apps/loop_app"]

3. After running this application on IR809, I console to this app with

   $ ioxclient app console test

4. I manually run "/opt/apps/test3"
5. Then I found that it worked fine with my manual start.

Question:

I am confused that on IR809, this app can't keep working by auto start, but it can work fine by manual start.

I would like to know:

1. What is the possible cause of this problem ? Is there any difference between IOx docker on IR809 and local docker on my develop machine ? If so, is there any other specific configuration I need to pay attention to ?
2. This app will print something for debug on terminal and for example I can debug them on my dev machine by using

   docker run -t -p 1500:1500 test809 /opt/apps/test3

   Is there any way for me to monitor the terminal print of the app on IOx by auto start ? I think this will help me to debug the app (I have tried to print some debug information in a file, but I think it was an inefficient way).

Thanks,

Ding

[suressan · Accepted solution]

You are hitting this issue - https://community.cisco.com/t5/cisco-iox-discussions/paas-python-app-hangs-until-ioxclient-app-console-done-which/td-p/3780169

We do have a way to retrieve logs printed on terminal console from watchdog.log file when you activate the docker app in "debug mode". 

$ ioxclient app activate <appname> --debug

OR

Check box "debug" in Local Manager activation page.

You can find the watchdog.log from app logs directory.

[HarryDing0224]

Thanks for you prompt reply, suressan. Maybe that is the problem and I will try it later.