Hi Graham, thanks for the response, that indeed looks like a tricky thing to implement.
There's another scenario that might also benefit from something like this, for example, when uploading large files (I know this is usually not the best thing to do, and rather it should be uploaded directly to the storage such as S3) and you do some server side checks with python that ends up with an error (such as checking the request content length to avoid large uploads) even if you return a response right away with the error without even touching the file, the user will still need to wait until the whole file is uploaded (and probably saved locally as a temp file with django) before getting the error back. El domingo, 4 de marzo de 2018, 0:49:31 (UTC-3), Graham Dumpleton escribió: > > I got quite a lot done on mod_wsgi during my holidays, but that didn't > include a simple answer to this. The idea I initially had couldn't work. > The only way I have been able to work out that might work is when have > request content and it is over a certain size, is to spawn a second thread > for the request handler in Apache that handles pushing the request content > through to the mod_wsgi daemon process, while the original thread deals > with the response. This is obviously going to be tricky to implement and I > ran out of time while I was on holidays. Am back busy at my day job now and > so haven't had a chance to pursue it further. I haven't even released a new > version with all of what I did manage to get done when on holidays, which I > should really do. > > Graham > > On 3 Mar 2018, at 2:57 am, Cristiano Coelho <[email protected] > <javascript:>> wrote: > > Hi Graham, got any updates related to this? Have been trying to reach out > AWS to update their mod_wsgi versions but seems like an useless effort. > > > > El domingo, 10 de diciembre de 2017, 20:23:01 (UTC-3), Graham Dumpleton > escribió: >> >> Anyway, am looking into something about how daemon mode works to see if I >> can short circuit things to possibly partly avoid the problem. >> >> Will update later. >> >> Graham >> >> On 11 Dec 2017, at 10:21 am, Cristiano Coelho <[email protected]> >> wrote: >> >> Sorry, I think it was a typo when I tried the commands, my tests were >> with just HTTP after all, and I see the same issue, if I use HTTPS the >> slowloris script just stops instantly. >> >> The logs from the main post were with HTTPS indeed but that's because the >> server uses HTTPS. The local test was done only with HTTP. >> >> >> El domingo, 10 de diciembre de 2017, 19:48:59 (UTC-3), Graham Dumpleton >> escribió: >>> >>> I will try and provide a better explanation of why solving it is hard >>> later, but if I change: >>> >>> slowhttptest -c 6 -B -i 10 -r 200 -s 8192 -t POST -u " >>> https://localhost:8080/test"; -x 10 -p 3 >>> >>> to: >>> >>> slowhttptest -c 6 -B -i 10 -r 200 -s 8192 -t POST -u " >>> http://localhost:8080/test"; -x 10 -p 3 >>> >>> Ie., non HTTPS, since mod_wsgi-express is only accepting HTTP, then I >>> don't see any immediate response being logged in the access log. >>> >>> mod_wsgi-express start-server app.py --port 8080 --body-timeout 62 >>> --log-to-terminal --access-log >>> >>> Other than that, the behaviour I see is as I would expect. >>> >>> Graham >>> >>> On 11 Dec 2017, at 5:06 am, Cristiano Coelho <[email protected]> >>> wrote: >>> >>> Update: Here's a small wsgi test script, tested with a fresh apache >>> mod_wsgi installation (through pip). >>> >>> The same issue can be easily replicated, and it seems that the only way >>> to improve it is with the request timeout values (header and body), which >>> sadly needs to be high when using AWS due to how the load balancer works >>> (keeping open connections to the apache server to improve loading time). >>> >>> The same issue happens with another server like gunicorn, which they >>> clearly state on their docs it's an issue that WILL happen unless the >>> reverse proxy (nginx) is properly set up. Now for Apache + mod_wsgi, I >>> would expect that apache is the reverse proxy (even if there's a load >>> balancer before it) and it should help with the issue just like nginx and >>> gunicorn, or even IIS + asp.net >>> >>> >>> from flask import Flask, request, jsonify >>> >>> # pip install Flask >>> >>> # Testing flask >>> # export FLASK_APP=app.py >>> # flask run >>> >>> >>> # Testing mod_wsgi >>> # pip install mod_wsgi (and apache2 + apache2-dev before this if it's >>> not installed) >>> # Create user wsgi or change user >>> # sudo -u wsgi mod_wsgi-express start-server app.py --port 8080 >>> --body-timeout 62 >>> # Set --body-timeout to simulate AWS setup >>> >>> # Interesting settings >>> # --connect-timeout defaults to 15s >>> # --queue-timeout defaults to 30s >>> # --body-timeout defaults to 15s >>> >>> >>> # Test slowloris: >>> # apt-get install slowhttptest >>> # 6 or a value > configured worked threads*processes >>> # slowhttptest -c 6 -B -i 10 -r 200 -s 8192 -t POST -u " >>> https://localhost:8080/test"; -x 10 -p 3 >>> # Note that GET also works in which case the request should be pretty >>> much ignored since it's an unsupported method >>> >>> >>> app = Flask(__name__) >>> application = app # For mod_wsgi >>> >>> >>> @app.route('/test', methods=['POST']) >>> def test(): >>> >>> data = request.get_json(silent=True) or request.form >>> >>> if not data: >>> r = jsonify({ >>> 'out': '', >>> 'err': 'No data provided' >>> }) >>> >>> r.status_code = 400 >>> >>> else: >>> r = jsonify({ >>> 'out': data, >>> 'err': None >>> }) >>> >>> r.status_code = 200 >>> >>> return r >>> >>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "modwsgi" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/modwsgi. >>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "modwsgi" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/modwsgi. >> For more options, visit https://groups.google.com/d/optout. >> >> >> > -- > You received this message because you are subscribed to the Google Groups > "modwsgi" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To post to this group, send email to [email protected] <javascript:> > . > Visit this group at https://groups.google.com/group/modwsgi. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "modwsgi" group. 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