Name resolution error

Emoncms Emoncms.org
1

i have been uploading data for ~20 hours and my python script crashed/stopped due to a dns name resoluton error

does that happen a lot and could i bot use the ip number instead? or does the ip change to often?

2

Its probably best to keep logging to the domain name, we may change the ip address in the future. Can you catch the case where you have a dns resolution error?

3

nope the script just crashed and i forgot to take a screenshot,

but from what i remember it was DNS related, so it could be any dns server between me and you (and that is no small number :smiley: )

but should it happen again over the next few days i will post a screenshot

4

it could also be a fault in my python script

https://github.com/boelle/Rpi-Heating-Control/blob/master/heatcontrol.py

bit i have looked it over many times and i cant find anything wrong

maybe something that prevents the script from executing even if it cant reach emoncms

5

Wrap the http request line in a try/except so that it cannot crash your script if it fails for any reason. You could then go the extra mile and change the code to retry (after a short wait) creating a smaller loop within the outer loop. You will have to change the way it sleeps for 60sec though because if it takes a few attempts to succeeed in sending, that 60s sleep becomes a “minimum time between sends” not a regular interval.

6

oh the 60 sec was just a nice round number i picked

so i should do just like the ping to google dns servers? that also fails and crashes the script from time to time

and i have not found out why etc… i’m tempted to just use a bash script to check if the script is not running and if not start it… along the lines of this page: bash - How to restart the Python script automatically if it is killed or dies - Unix & Linux Stack Exchange

its the answer just below the one with green mark (the one with 11 votes)

7

Traceback (most recent call last):

  File "test.py", line 175, in <module>
    emoncms()
  File "test.py", line 134, in emoncms
    conn.request("GET", "/"+emoncmspath+"/input/post.json?apikey="+apikey+"&node="+str(nodeid)+"&csv="+str_join)
  File "/usr/lib/python2.7/httplib.py", line 1042, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib/python2.7/httplib.py", line 1082, in _send_request
    self.endheaders(body)
  File "/usr/lib/python2.7/httplib.py", line 1038, in endheaders
    self._send_output(message_body)
  File "/usr/lib/python2.7/httplib.py", line 882, in _send_output
    self.send(msg)
  File "/usr/lib/python2.7/httplib.py", line 844, in send
    self.connect()
  File "/usr/lib/python2.7/httplib.py", line 821, in connect
    self.timeout, self.source_address)
  File "/usr/lib/python2.7/socket.py", line 575, in create_connection
    raise err
socket.timeout: timed out