how i can effectively block "publish" from sending messages or check state of connection in more speed manner?

[poulch74]

The problem is - low heap. For example after onConnect I start publish messages each 1 sec to
remoute mqtt server. All ok until WAN interface of my router goes down. if keepAlive
is about 15 then "publish" eat all heap but I not receive any onError or onDisconnect
and MCU fail and reboot. I can limit keepAlive to 3, so until heap goes low
onDisconnect fired and i can recovery. but I think it not right way... (keepAlive can be under user control)
I can check heap and block "publish"... but... so which right way?

[philbowles]

Can you send me some diagnostic output from the serial monitor and/or wireshark traces please? Its very difficult to try to understand this without seeing some data. Also seeing your own code and how you are using Pangolin might be helpful too

[poulch74]

I use pangolin in simple manner like
`
setup() { .... mqtt.connect(); }

onConnect() { mqtt.subscribe(); can_publish = 1; }

onDisconnect() { can_publish = 0;}

onError() {can_publish = 0;}

void loop() { if(can_publish) mqtt.publish(); delay(1000);}
`
but if router WAN interface goes done no packets transmitted to remoute mqtt server, but heap eated by mqtt queue and tcp buffers -> low heap and reset before any callback (onDisconnect or onError) fired... maybe some timeout mangment for tcp ack must be added to api (asynctcp default about 5000ms?)?

[philbowles]

It looks like there may be an error in Pango's keepalive / server notification system. I will look into it using the very rough sketch you outlined.

On a separate note, is there a problem with you sending me the actual sketch? The more work you make me do to try to fix the problem, the less likely I am to get round to it - please show me the actual code you are running: a) there may be some other problem with it b) there is no point "debugging" NOT (the code you are running) to try to find a problem in the code you are running.

Also how do you detect / manage WAN reconnection? If the WAN goes down, then yes Pango should spot it and give you a timeout error. But even assuming it DID do that correctly. your example will just sit in the main loop forever , doing nothing until you reboot the MCU...anyway, post me the code and I will look into it.