New Django middleware not getting called

Question

I am quite new to web development. I am working on a website hosted on amazon ec2 server. The site is in python using django framework. I am using memcached to cache some client information. My site and caching works on local machine but not on the EC2 server. I checked memcached server and found out that it was not able to set the keys. Is there something I might need to change in settings.py so that keys are set appropriately on the server or something else that I might be missing.

EDIT: Found out the problem. I added a new middleware for setting keys in the memcache. That is not getting called. It works perfectly on the local machine. On the server I am using gunicorn as the app server and nginx as the reverse proxy. Can any of these cause the problems. Also I tried to reload nginx but that didn't help either.

"_it was not able to set the keys_"? Why is so? Do you actually mean that the caching on EC2 is disabled? In such case, just use Dummy Cache - it will work transparently as if nothing was saved in the cache. — Tadeck, Dec 01 '12 at 14:20
@Tadeck I am on production server so I am not sure if using Dummy cache is a good idea — Mayank, Dec 01 '12 at 14:50
Are you sure the memcached port is accessible from your application/web server instance? Try 'telnet 11211' from your web intance. — rhetonik, Dec 01 '12 at 15:17
@rhetonik I tried that, telnet works but when i do stats items it shows nothing. — Mayank, Dec 02 '12 at 15:10

score 2 · Accepted Answer · answered Dec 03 '12 at 19:53

2

It was a silly glitch. I found out that i needed to reload gunicorn server to make the new middleware work. Thanks everybody for the help.

answered Dec 03 '12 at 19:53

Mayank

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nimasmi · Answer 2 · 2012-12-01T15:43:39.333

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Is it a case of add this to your settings.py?

MIDDLEWARE_CLASSES = (
    'django.middleware.common.CommonMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.cache.UpdateCacheMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.cache.FetchFromCacheMiddleware',
)

From the docs.

Only I'm not too clear what steps you mean when you say you 'added a new middleware'.

edited Dec 01 '12 at 15:43

answered Dec 01 '12 at 15:29

nimasmi

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I added the middleware to settings.py That is why it is running on local machine as I mentioned so that is not the problem. I would like to point out site is using nginx and gunicorn as web servers so my query now boils down to is there a step that I am missing so that this new middleware gets called each time user does a specific task. I hope I am clear enough. – Mayank Dec 02 '12 at 15:09

score 0 · Answer 3 · answered Dec 01 '12 at 17:03

First of all, you need to set caching in CACHES setting, taking into account all credentials needed to access the cache server: https://docs.djangoproject.com/en/dev/topics/cache/#memcached

Also make sure the cache server is accessible from the instance you are trying to use.

When it comes to using new middleware (a slightly different issue), then:

make sure it is defined properly in the settings (not overwritten by other settings, like eg. commonly used local_settings.py file, which should be different depending on the environment you use),
make sure middleware class is defined properly (defines eg. process_request(), if you want to do something for the incoming request),
if you are using eg. mod_wsgi with Apache, remember to reload the service (in this case Apache), by eg. invoking sudo service apache2 reload (as in the mentioned case),

the site is using gunicorn and nginx as web servers. Do you think they need to be reloaded or something needs to be done there? — Mayank, Dec 02 '12 at 15:12

New Django middleware not getting called

3 Answers3