Device Server gets stuck - then works as expected

# 4 years ago
dschick	Hi all, I am currently developing a TangoDS using PyTango on a Raspi that runs with tango 9.25 `tango-common/stable,now 9.2.5a+dfsg1-2 all [Installiert,automatisch] tango-starter/stable,now 9.2.5a+dfsg1-2 armhf [installiert] tango-test/stable,now 9.2.5a+dfsg1-2 armhf [installiert]` I encounter a strange behaviour whenever I start the PyTango DS or even the TangoTest DS: The DS starts with no error messages and then simply gets stuck. Then after some undefined time, something like a few minutes, I do get the message `Ready to accept request` and everything works as expected. I can then restart the DS as often as I like and everything is fine. Only after a reboot, the same situation as before sets in again. When I kill the DS during it hangs, I get the message: `Tango is not initialised !!!` The weired thing is, that I can connect to the TangoDB with PyTango from the Raspi while the local DS hangs. The TANGO_HOST is defined and pingable. So running a Tango Client is okay, just running the DS is not. I fear that this might be somehow related to my network but I have no clue how I should proceed with the debugging. Many thanks in advance for any help/suggestions Daniel

# 4 years ago

Hi all,

I am currently developing a TangoDS using PyTango on a Raspi that runs with tango 9.25

tango-common/stable,now 9.2.5a+dfsg1-2 all  [Installiert,automatisch]
tango-starter/stable,now 9.2.5a+dfsg1-2 armhf  [installiert]
tango-test/stable,now 9.2.5a+dfsg1-2 armhf  [installiert]

I encounter a strange behaviour whenever I start the PyTango DS or even the TangoTest DS:
The DS starts with no error messages and then simply gets stuck.
Then after some undefined time, something like a few minutes, I do get the message

Ready to accept request

and everything works as expected. I can then restart the DS as often as I like and everything is fine. Only after a reboot, the same situation as before sets in again.
When I kill the DS during it hangs, I get the message:

Tango is not initialised !!!

The weired thing is, that I can connect to the TangoDB with PyTango from the Raspi while the local DS hangs. The TANGO_HOST is defined and pingable. So running a Tango Client is okay, just running the DS is not.

I fear that this might be somehow related to my network but I have no clue how I should proceed with the debugging.

Many thanks in advance for any help/suggestions

Daniel

# 4 years ago
TCoutinho	Hi dschick, I noticed a similar behaviour when using PyTango 9.3.1 with Tango C++ 9.3.2 on my laptop when I had both my Ethernet and Wireless network interfaces enabled. If I disabled the wireless interface Tango server starts without a problem. Could you confirm if this is your case? Thanks in advance

# 4 years ago
dschick	Thanks for the quick reply, actually I also tried a few things with the different network interface. I think it was working better with only the Wifi but not with only the lan. However, I think I found the solution, which is not at all related to TANGO. I just noticed, that also the VNC server of the PI was not working, exactly for the same time as the TANGO DS. Some googling helped to find this post: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=230779 So it was a very Raspian specific problem, however, maybe it helps someone else to save some time and nerves.

# 4 years ago

dschick

Thanks for the quick reply,

actually I also tried a few things with the different network interface.
I think it was working better with only the Wifi but not with only the lan.

However, I think I found the solution, which is not at all related to TANGO.
I just noticed, that also the VNC server of the PI was not working, exactly for the same time as the TANGO DS.

Some googling helped to find this post:
https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=230779

So it was a very Raspian specific problem, however, maybe it helps someone else to save some time and nerves.