[Pywps-dev] Problem calling a WPS service from another WPS service

Jachym Cepicky jachym.cepicky at gmail.com
Sun Jun 19 01:23:45 PDT 2016


Hi Lorenzo,

the problem could be that you use flask in single thread mode - therefore
it can handle only one request at time. [1] it should be possible to switch
to multihread mode, but consider for this case to setup some real web
server, like Apache2 or nginx

J

[1]
http://stackoverflow.com/questions/14814201/can-i-serve-multiple-clients-using-just-flask-app-run-as-standalone

ne 19. 6. 2016 v 0:54 odesílatel Lorenzo Bottaccioli <
lorenzo.bottaccioli at gmail.com> napsal:

> Hi Jachym,
>
> Yes is using flask, I just ad process to the demo.py.
>
> Best, Lorenzo
> Il 18 giu 2016 11:40 PM, "Jachym Cepicky" <jachym.cepicky at gmail.com> ha
> scritto:
>
>> Lorenzo,
>>
>> are you using flask server or what WebServer are you using?
>>
>> J
>>
>> pá 10. 6. 2016 v 16:26 odesílatel Lorenzo Bottaccioli <
>> lorenzo.bottaccioli at gmail.com> napsal:
>>
>>> Hi list,
>>>
>>> I'm having a problem with a service when I call another service inside
>>> the process.
>>>
>>>    def _handler(self, request, response):
>>>
>>>          df = self.get_real_sky(geodf,start,end,model)
>>>
>>>     def get_real_sky(self,geodf,start,end,model):
>>>         #print 'eccolo dentro'
>>>         import requests
>>>         url = "http://130.192.5.114:8080/wps"
>>>
>>>         payload = "<wps:Execute service=\"WPS\" version=\"1.0.0\"
>>> xmlns:wps=\"http://www.opengis.net/wps/1.0.0\" xmlns:ows=\"
>>> http://www.opengis.net/ows/1.1\" xmlns:xlink=\"
>>> http://www.w3.org/1999/xlink\" xmlns:xsi=\"
>>> http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"
>>> http://www.opengis.net/wps/1.0.0\n../wpsExecute_request.xsd\">\n
>>> <ows:Identifier>real_sky</ows:Identifier>\n  <wps:DataInputs>\n
>>>  <wps:Input>\n      <ows:Identifier>layer_in</ows:Identifier>\n
>>>  <wps:Data>\n    <wps:ComplexData>"+geodf.to_json()+"</wps:ComplexData>\n
>>>  </wps:Data>\n    </wps:Input>\n    <wps:Input>\n
>>>  <ows:Identifier>start</ows:Identifier>\n        <wps:Data>\n
>>>  <wps:LiteralData dataType=\"xs:string\">"+start+"</wps:LiteralData>\n
>>>    </wps:Data>\n    </wps:Input>\n    <wps:Input>\n
>>>  <ows:Identifier>end</ows:Identifier>\n        <wps:Data>\n
>>>  <wps:LiteralData dataType=\"xs:string\">"+end+"</wps:LiteralData>\n
>>>  </wps:Data>\n    </wps:Input>\n    <wps:Input>\n
>>>  <ows:Identifier>model</ows:Identifier>\n        <wps:Data>\n
>>>  <wps:LiteralData dataType=\"xs:string\">"+model+"</wps:LiteralData>\n
>>>    </wps:Data>\n    </wps:Input>\n  </wps:DataInputs>\n
>>>  <wps:ResponseForm>\n    <wps:RawDataOutput>\n
>>>  <ows:Identifier>layer_out</ows:Identifier>\n    </wps:RawDataOutput>\n
>>>  </wps:ResponseForm>\n</wps:Execute>"
>>>         headers = {
>>>             'content-type': "application/xml",
>>>             'cache-control': "no-cache",
>>>             'postman-token': "78829681-df08-3317-2e0e-90a31ea4f2a6"
>>>             }
>>>
>>>         response = requests.request("POST", url, data=payload,
>>> headers=headers)
>>>
>>>         return response.text
>>>
>>>
>>> The process inside def get_real_sky works if I call it by it self, but
>>> if I call inside another process dosent work, it simply blocks and do not
>>> go forward. I have tried to run only the service real_sky in another port
>>> not in 8080 like the one who calls it but in 8082. In this way it works. I
>>> dont understand if the problem is Flask or the problem is PyWPS.
>>>
>>> If I press crtl+c to stop the process I get this:
>>>
>>> Exception happened during processing of request from ('130.192.5.114',
>>> 49246)
>>> Traceback (most recent call last):
>>>   File "/usr/lib/python2.7/SocketServer.py", line 295, in
>>> _handle_request_noblock
>>>     self.process_request(request, client_address)
>>>   File "/usr/lib/python2.7/SocketServer.py", line 321, in process_request
>>>     self.finish_request(request, client_address)
>>>   File "/usr/lib/python2.7/SocketServer.py", line 334, in finish_request
>>>     self.RequestHandlerClass(request, client_address, self)
>>>   File "/usr/lib/python2.7/SocketServer.py", line 649, in __init__
>>>     self.handle()
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/serving.py",
>>> line 216, in handle
>>>     rv = BaseHTTPRequestHandler.handle(self)
>>>   File "/usr/lib/python2.7/BaseHTTPServer.py", line 340, in handle
>>>     self.handle_one_request()
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/serving.py",
>>> line 251, in handle_one_request
>>>     return self.run_wsgi()
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/serving.py",
>>> line 193, in run_wsgi
>>>     execute(self.server.app)
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/serving.py",
>>> line 181, in execute
>>>     application_iter = app(environ, start_response)
>>>   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1836,
>>> in __call__
>>>     return self.wsgi_app(environ, start_response)
>>>   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1817,
>>> in wsgi_app
>>>     response = self.full_dispatch_request()
>>>   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1478,
>>> in full_dispatch_request
>>>     response = self.make_response(rv)
>>>   File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1577,
>>> in make_response
>>>     rv = self.response_class.force_type(rv, request.environ)
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/wrappers.py",
>>> line 847, in force_type
>>>     response = BaseResponse(*_run_wsgi_app(response, environ))
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/wrappers.py",
>>> line 57, in _run_wsgi_app
>>>     return _run_wsgi_app(*args)
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/test.py",
>>> line 871, in run_wsgi_app
>>>     app_rv = app(environ, start_response)
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/Werkzeug-0.11.4-py2.7.egg/werkzeug/wrappers.py",
>>> line 291, in application
>>>     return f(*args[:-2] + (request,))(*args[-2:])
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/pywps-4.0-py2.7.egg/pywps/app/Service.py",
>>> line 529, in __call__
>>>     request_uuid
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/pywps-4.0-py2.7.egg/pywps/app/Service.py",
>>> line 296, in execute
>>>     response = self._parse_and_execute(process, wps_request, uuid)
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/pywps-4.0-py2.7.egg/pywps/app/Service.py",
>>> line 358, in _parse_and_execute
>>>     wps_response = process.execute(wps_request, uuid)
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/pywps-4.0-py2.7.egg/pywps/app/Process.py",
>>> line 145, in execute
>>>     wps_response = self._run_process(wps_request, wps_response)
>>>   File
>>> "/usr/local/lib/python2.7/dist-packages/pywps-4.0-py2.7.egg/pywps/app/Process.py",
>>> line 151, in _run_process
>>>     wps_response = self.handler(wps_request, wps_response)
>>>   File
>>> "/home/lorenzo/tools/pywps-4/pywps-4-demo/processes/solar/PV_NOCT.py", line
>>> 45, in _handler
>>>     df = self.get_real_sky(geodf,start,end,model)
>>>   File
>>> "/home/lorenzo/tools/pywps-4/pywps-4-demo/processes/solar/PV_NOCT.py", line
>>> 101, in get_real_sky
>>>     response = requests.request("POST", url, data=payload,
>>> headers=headers)
>>>   File "/usr/lib/python2.7/dist-packages/requests/api.py", line 44, in
>>> request
>>>     return session.request(method=method, url=url, **kwargs)
>>>   File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line
>>> 455, in request
>>>     resp = self.send(prep, **send_kwargs)
>>>   File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line
>>> 558, in send
>>>     r = adapter.send(request, **kwargs)
>>>   File "/usr/lib/python2.7/dist-packages/requests/adapters.py", line
>>> 330, in send
>>>     timeout=timeout
>>>   File "/usr/lib/python2.7/dist-packages/urllib3/connectionpool.py",
>>> line 562, in urlopen
>>>     body=body, headers=headers)
>>>   File "/usr/lib/python2.7/dist-packages/urllib3/connectionpool.py",
>>> line 414, in _make_request
>>>     httplib_response = conn.getresponse(buffering=True)
>>>   File "/usr/lib/python2.7/httplib.py", line 1051, in getresponse
>>>     response.begin()
>>>   File "/usr/lib/python2.7/httplib.py", line 415, in begin
>>>     version, status, reason = self._read_status()
>>>   File "/usr/lib/python2.7/httplib.py", line 371, in _read_status
>>>     line = self.fp.readline(_MAXLINE + 1)
>>>   File "/usr/lib/python2.7/socket.py", line 476, in readline
>>>     data = self._sock.recv(self._rbufsize)
>>> KeyboardInterrupt
>>> ----------------------------------------
>>> 130.192.5.114 - - [10/Jun/2016 16:25:45] "POST /wps HTTP/1.1" 200 -
>>> INFO:werkzeug:130.192.5.114 - - [10/Jun/2016 16:25:45] "POST /wps
>>> HTTP/1.1" 200 -
>>> ----------------------------------------
>>> Exception happened during processing of request from ('130.192.5.114',
>>> 49248)
>>> Traceback (most recent call last):
>>>   File "/usr/lib/python2.7/SocketServer.py", line 295, in
>>> _handle_request_noblock
>>>     self.process_request(request, client_address)
>>>   File "/usr/lib/python2.7/SocketServer.py", line 321, in process_request
>>>     self.finish_request(request, client_address)
>>>   File "/usr/lib/python2.7/SocketServer.py", line 334, in finish_request
>>>     self.RequestHandlerClass(request, client_address, self)
>>>   File "/usr/lib/python2.7/SocketServer.py", line 651, in __init__
>>>     self.finish()
>>>   File "/usr/lib/python2.7/SocketServer.py", line 710, in finish
>>>     self.wfile.close()
>>>   File "/usr/lib/python2.7/socket.py", line 279, in close
>>>     self.flush()
>>>   File "/usr/lib/python2.7/socket.py", line 303, in flush
>>>     self._sock.sendall(view[write_offset:write_offset+buffer_size])
>>> error: [Errno 32] Broken pipe
>>> ----------------------------------------
>>>
>>>
>>> Any suggestion?
>>>
>>> Best,
>>>
>>> Lorenzo
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> pywps-dev mailing list
>>> pywps-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/pywps-dev
>>
>>
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