When I try to switch to multiprocess mode by setting workers>0 in cfg, I got "bus.bus unavailable" error.

I found some tips in forum and configure the ngix to reverse proxy longpolling request, but finally I found there is no process listen to longpolling_port:8072.Even after I make sure to install psycogreen and gevent,and restart odoo, there is no process listen to port 8072.

I have investigate the source code and found only one line will use longpolling_port, which is in the __init__() of GeventServer, and only when the odoo is configured to use gevent server, the GeventServer will be constructed instead of PreforkServer.

So I am totally confused, which port will be used for longpolling under multiprocess mode?

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After further investigating the source code, I found even under multiprocess mode, odoo will use subprocess.popen() to init a gevent mode instance, the call sequence is PreforkServer.run()->process_spawn()->long_polling_spawn(). In fact I have found the gevent process with PS AUX command, but the process still not open 8072 port and are created and closed frequently. I will keep on looking into it and try to figure out the reason.

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The reason I can not start geventserver is when import gevent.wsgi, it throws exception. Because wsgi was deprecated in gevent 1.3, change the line to import gevent.pywsgi can work around. Now I get gevent process listen to 8072.

But client still report 'bus.bus unavailable' error , I will check reverse proxy settings.

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I have updated the proxy settings to correctly forward to destination /longpolling/,

and then restart all client(otherwise the client will still use old port), the error message 'bus.bus unavailable' disappear finally.