TCP_DEFER_ACCEPT can help boost performance by reducing the amount of preliminary formalities that happen between the server and client.

You can read more about it &lt;a href=&quot;http://www.techrepublic.com/article/take-advantage-of-tcp-ip-options-to-optimize-data-transmission/&quot;&gt;HERE&lt;/a&gt;.

How do you detect what environment an expressJS app is running in? (development, test, production?). There&#39;s nothing in `process.env` indicating an environment...

I&#39;m aware that you can declare variables in your configuration file under each environment, but that doesn&#39;t help if you are dynamically loading modules...

How do you detect the environment in an express.js app?

[Before immediately marking as a duplicate, I&#39;ve read through a few others with the same problem description but don&#39;t have a solution after applying answers from them]

Several days ago I created a profile and was successfully able to use it to run app on my iPhone.

Now however I am using a different laptop for development and am unable to progress as I keep getting a &quot;Xcode could not find a valid private-key certificate pair for this profile in your keychain&quot;.
I have tried with the same iPhone/profile combination as I used previously, in additional I have another iPhone and have generated a new profile with that device&#39;s id. However I get the same message with that profile/phone too.

From other postings on this site seems people got this problem when the profile had not been dragged/dropped in the Library section of Organizer - I dragged the profiles on Xcode and there is a resulting Provisioning Profiles section containing the relevant profile in both the Library section and Devices section of Organizer.


The certificate is showing as being valid in Keychain Access.

Any suggestions?


Added Later: trying this Q&amp;A from Apple:

https://web.archive.org/web/20141029102125/http://developer.apple.com/library/ios/qa/qa1618/_index.html

They say within Keychain Access click on the .p12 file. What are they talking about, what and where is the .p12 file? Its not shown in their own documentation screen shots and nor does it appear in my Keychain Access. Is it supposed to?


Xcode could not find a valid private-key certificate pair for this profile in your keychain

I&#39;ve seen example NGINX configurations with the &quot;deferred&quot; option added to the listen directive


    server { 
      listen 80 default deferred;
      ... 
    }

I can&#39;t work out what it does (and whether or not I should use it) and the documentation doesn&#39;t make too much sense to me

&gt; deferred -- indicates to use that postponed accept(2) on Linux with
&gt; the aid of option TCP_DEFER_ACCEPT

Can anyone explain what this option is for?



What does the deferred option mean in NGINXs listen directive?

I've seen example NGINX configurations with the "deferred" option added to the listen directive
<pre><code class="hljs language-arduino">server { 
 listen 80 default deferred;
 ... 
}
</code></pre>
I can't work out what it does (and whether or not I should use it) and the documentation doesn't make too much sense to me
> deferred -- indicates to use that postponed accept(2) on Linux with
> the aid of option TCP_DEFER_ACCEPT
Can anyone explain what this option is for?

I have a Sinatra application hosted with Unicorn, and nginx in front of it. When the Sinatra application errors out (returns 500), I&#39;d like to serve a static page, rather than the default &quot;Internal Server Error&quot;. I have the following nginx configuration:

    server {
      listen 80 default;
      server_name *.example.com;
      root /home/deploy/www-frontend/current/public;

      location / {
        proxy_pass_header Server;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Scheme $scheme;
        proxy_connect_timeout 5;
        proxy_read_timeout 240;
        proxy_pass http://127.0.0.1:4701/;
      }

      error_page 500 502 503 504 /50x.html;
    }

The error_page directive is there, and I have sudo&#39;d as www-data (Ubuntu) and verified I can `cat` the file, thus it&#39;s not a permission problem. With the above config file, and `service nginx reload`, the page I receive on error is still the same &quot;Internal Server Error&quot;.

What&#39;s my error?

nginx not serving my error_page

I would like to know the difference between Nginx and Unicorn. As far as I understand, Nginx is a web server while Unicorn is a Ruby HTTP server.

Since both Nginx and Unicorn can handle HTTP requests, what is the need to use the combination of Nginx and Unicorn for RoR applications?


Why does Unicorn need to be deployed together with Nginx?

I&#39;m running a Sinatra app behind passenger/nginx. I&#39;m trying to get it to respond to both http and https calls. The problem is, when both are defined in the server block https calls are responded to normally but http yields a 400 &quot;The plain HTTP request was sent to HTTPS port&quot; error. This is for a static page so I&#39;m guessing Sinatra has nothing to do with this. Any ideas on how to fix this?

Here&#39;s the server block:


    server {
            listen 80;
            listen 443  ssl;
            server_name localhost;
            root /home/myhome/app/public;
            passenger_enabled on;
    
            ssl on;
            ssl_certificate      /opt/nginx/ssl_keys/ssl.crt;
            ssl_certificate_key  /opt/nginx/ssl_keys/ssl.key;
            ssl_protocols        SSLv3 TLSv1;
            ssl_ciphers          HIGH:!aNULL:!MD5;
    
            location /static {
                root  /home/myhome/app/public;
                index  index.html index.htm index.php;
            }
    
            error_page 404 /404.html;
    
            # redirect server error pages to the static page /50x.html
            error_page 500 /500.html;
    
            access_log /home/myhome/app/logs/access.log;
            error_log /home/myhome/app/logs/error.log;
    }



Dealing with nginx 400 &quot;The plain HTTP request was sent to HTTPS port&quot; error

I have a webapp on a NGinx server. I set `gzip on` in the conf file and now I&#39;m trying to see if it works. YSlow says it&#39;s not, but 5 out of 6 websites that do the test say it is. How can I get a definite answer on this and why is there a difference in the results?

How can I tell if my server is serving GZipped content?

I want to have my API controller use SSL, so I added another listen directive to my nginx.conf


    upstream unicorn {
      server unix:/tmp/unicorn.foo.sock fail_timeout=0;
    }

    server {
      listen 80 default deferred;
      listen 443 ssl default;
      ssl_certificate /etc/ssl/certs/foo.crt;
      ssl_certificate_key /etc/ssl/private/foo.key;

      server_name foo;
      root /var/apps/foo/current/public;

      try_files $uri/system/maintenance.html $uri/index.html $uri @unicorn;

      location @unicorn {
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_pass http://unicorn;
      }

      error_page 502 503 /maintenance.html;
      error_page 500 504 /500.html;
      keepalive_timeout 5;
    }

which passes the nginx conftest without any problems. I also added a `force_ssl` directive to my ApiController


    class ApiController &lt; ApplicationController
      force_ssl if Rails.env.production?

      def auth
        user = User.authenticate(params[:username], params[:password])
        respond_to do |format|
          format.json do
            if user
              user.generate_api_key! unless user.api_key.present?
              render json: { key: user.api_key }
            else
              render json: { error: 401 }, status: 401
            end
          end
        end
      end

      def check
        user = User.find_by_api_key(params[:api_key])
        respond_to do |format|
          format.json do
            if user
              render json: { status: &#39;ok&#39; }
            else
              render json: { status: &#39;failure&#39; }, status: 401
            end
          end
        end
      end
    end

which worked just fine when I wasn&#39;t using SSL, but now when I try to `curl --LI http://foo/api/auth.json`, I get properly redirected to `https`, but then I keep on getting redirected to `http://foo/api/auth` ending in an infinite redirect loop.

My routes simply have

    get &quot;api/auth&quot;
    get &quot;api/check&quot;

I&#39;m using Rails 3.2.1 on Ruby 1.9.2 with nginx 0.7.65

Content Type	Original Author	Original Content on Stackoverflow
Question	bodacious	View Question on Stackoverflow
Solution 1 - Nginx	Dayo	View Answer on Stackoverflow

What does the deferred option mean in NGINXs listen directive?

Nginx Problem Overview

Nginx Solutions

Solution 1 - Nginx

Xcode could not find a valid private-key certificate pair for this profile in your keychain

How do you detect the environment in an express.js app?

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