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astrorafael / twisted-mqtt

MQTT Client protocol for Twisted.
MIT License
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Failure: mqtt.error.MQTTWindowError: Request exceeded maximun window size #4

Closed Wisit closed 8 years ago

Wisit commented 8 years ago

I got error message "Failure: mqtt.error.MQTTWindowError: Request exceeded maximun window size" , but my script can running. I would like to know what does it meaning.

my environment centos 6.8 python 2.7 twsited 16.3.2 twisted-mqtt 0.2.4

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yombo commented 8 years ago

Did you try the included python example files? Do they work? You might need to post a GIST to your code.

astrorafael commented 8 years ago

"Request exceeded maximun window size" is a concept belonging to PUBLISH packets at QoS = 1 or 2 QoS 1 & 2 PUBLISH packets must be acknowledged from the other side (the broker in this case) The library can keep a certain limit of packets in a buffer waiting for ACK.

The window size is = 1 by default but This limit is configurable (up to a certain internal limit). The downside of having a window size > 1 is that selective retransissions of lost packets cannot ensure in-order delivery of packets. If your application is resilent to this (i.e. you timestamp your payloads), then it is a good idea to increase this limit for better performance.

Hope it helps Rafael