In the last month i've received a lot of reports from users who encountered strange problems with the web application; while investigating those segnalations i noticed that all the problems were caused due to a random request that received a response starting with 1|X.
Since i remembered that a similar problem occurred to one of ours client due to an incorret setting of the reverse proxy on Tomcat, i suggested to check all the setting and their response was that all the configurations are correct; personally speaking i was dubious that they checked everything, so i suggested to check for firewall until starting from last Friday (26/04) i've encountered the same problem on my local workspace where i know that everything is correctly configured (and there are no firewall on localhost).
A strange thing about this problem is that it seems to add those three characters randomly (always those three characters!); up until now i've seen only .js and .html failing response.
If the failed call is repeated or the page is refreshed, then it will return a correct response (although the second option could lead to another call to fail...).
An example of the error, occurred while loading angular.js
I really don't know what can cause this problem, and due to this i don't know what could be helpful so i'll put here a few specs that maybe could be usefull:
- Tomcat 7.x (usually 7.0.59 or 7.0.82)
- Java JDK 8u202
- Atmosphere 2.6.1
Let me know if you need something more specific.
EDIT: it seems that the 1|X it's an Atmosphere HearthBeatInterceptor message, generated from the default initialization of the field paddingBytest.
The Atmosphere message response has the following structure:
- lenght of the message
- separator (pipe)
- real message
So, as show in the following image, sometimes Atmosphere make an HeartBeat message using the charater X.
Now the question is why sometimes those HeartBeat messages are merged to other response.