Yes. Empty or incomplete headers or response body typically caused by broken connections or server side crash can cause 502 errors if accessed via a gateway or proxy.

For more information about the network errors 

https://en.wikipedia.org/wiki/List_of_HTTP_status_codes

I am use to using the &lt;kbd&gt;CTRL&lt;/kbd&gt; key to move faster when using the left and right arrow keys (goes to end of a word, instead of one char at a time).   

Can I do that in bash somehow?

I could probably code it, but I was wondering if there is something easier / already done.

Bash CTRL to move cursor between words/strings

    UPDATE CattleProds
    SET SheepTherapy=(ROUND((RAND()* 10000),0))
    WHERE SheepTherapy IS NULL


If I then do a SELECT I see that my random number is [identical in every row][1]. Any ideas how to generate unique random numbers?


  [1]: http://xkcd.com/221/

How can I fill a column with random numbers in SQL? I get the same value in every row

According to the RFC:

&gt;**10.5.3 502 Bad Gateway**&lt;br/&gt;
The server, while acting as a gateway or proxy, received an invalid response from the upstream server it accessed in attempting to fulfill the request.

Can *invalid response* also mean no response at all (e.g. connection refused)?





Should a 502 HTTP status code be used if a proxy receives no response at all?

According to the RFC:
>10.5.3 502 Bad Gateway 
The server, while acting as a gateway or proxy, received an invalid response from the upstream server it accessed in attempting to fulfill the request.
Can invalid response also mean no response at all (e.g. connection refused)?

I&#39;m trying to get the post data in Java. Seems like it should be one of the simplest things to do right? I mean, HttpServletRequest.getParameter has to do it right? So how can you get the raw post data?

I found https://stackoverflow.com/questions/3831680/httpservletrequest-get-post-data and used Kdeveloper&#39;s code to pull the post data from a request. It works, but theres a catch: I can only get that post data *once*.

Heres the method I made from Kdeveloper&#39;s code:

    public static String getPostData(HttpServletRequest req) {
        StringBuilder sb = new StringBuilder();
        try {
            BufferedReader reader = req.getReader();
            reader.mark(10000);

            String line;
            do {
                line = reader.readLine();
                sb.append(line).append(&quot;\n&quot;);
            } while (line != null);
            reader.reset();
            // do NOT close the reader here, or you won&#39;t be able to get the post data twice
        } catch(IOException e) {
            logger.warn(&quot;getPostData couldn&#39;t.. get the post data&quot;, e);  // This has happened if the request&#39;s reader is closed    
        }

        return sb.toString();
    }

Previously I had closed the reader at the end of this method, but that caused exceptions when the method ran more than once on the same request. Without closing it, no exceptions happen, but the method returns an empty string.

Honestly, there should just be an exposed req.getPostData() method - did no one think that would be useful?

So how can I write this method such that it always returns the correct post data?

How to retrieve raw post data from HttpServletRequest in java

I got application server running in Windows – IIS6.0 with Zend Server to execute PHP. I am looking for lightweight static content only web server on this same machine which will relive IIS form handling static content and increase performance.

It need to be only static content web server – maximum small and maximum effective – lighttpd seems too big because allow to FastCGI.

I am looking for: &lt;b&gt;Windows, static content only, fast, and lightweight&lt;/b&gt;.

I am using Windows Server 2003.


Best lightweight web server (only static content) for Windows

Is there anyway to upload a file more than 2 GB, using simple html form upload? Previously I have been uploading large files through silverlight using chunking (dividing a large file into segments and then uploading segments one by one &amp; then reassemble segments at server).

Now, we have a requirement that we just have to use simple html (though GWT) form uploads. Please guide me if there is any way to achieve large file upload this way.

If it is impossible to do it using simple html, can anyone guide me about how I can divide &amp; upload a file in segments using flex?


Large file upload though html form (more than 2 GB)

I&#39;m making a HTTP request and listen for &quot;data&quot;:

    response.on(&quot;data&quot;, function (data) { ... })

The problem is that the response is chunked so the &quot;data&quot; is just a piece of the body sent back.

How do I get the whole body sent back?

Get the whole response body when the response is chunked?

What is the best way to compose a rest PUT request in C#?

The request has to also send an object not present in the URI.

How to make a HTTP PUT request?

Are there are any Linux mysql command line tools that don&#39;t require the entire mysql db installation package to be installed?  

What I&#39;m trying to do is from server #1 (app server), execute mysql commands that will get executed on server #2 (db server).  I do not want to run the db on the local server or to install the full blown mysql db.

Is there a way to only install the mysql client (Linux)?

Is there a c# client that follows the socket.io protocol? I have a socket.io server that is communicating with a socket.io javascript client via a website, but i also need to connect a c# piece to it that can send and receive messages. Is there a clean way to do this currently or will I have to write my own client.

Communicating with a socket.io server via c#

Basically the question is in the title.

Many people have had the question stackoverflow of how to create a data URI and problems therein.

My question is *why use data URI?*

What are the advantages to doing:

    &lt;img src=&quot;data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA
    AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
    9TXL0Y4OHwAAAABJRU5ErkJggg==&quot; alt=&quot;Red dot&quot; /&gt;

Over doing:

    &lt;img src=&quot;dot.png&quot; alt=&quot;Red dot&quot; /&gt;


I understand one has less overhead on the server side (maybe), but what are the **real** advantages/disadvantages to using *data URI*?

Why use data URI scheme?

As far as I have seen, there is no explanation as to where we are to locate the client side script for `socket.io` if `node.js` is not used as the web server. I&#39;ve found a whole directory of client side files, but I need them in a combined version (like it&#39;s served when using node.js webs servers). Any ideas?

Where is the socket.io client library?

Is there any advantages of having two distinct websocket connections to the same server from the same client? To me this seems a bad design choice, but is there any reason why/where it should work out better?

Multiple websocket connections

A common scenario for a web app is to redirect after a POST that modifies the database.  Like redirecting to the newly created database object after the user creates it.  

It seems like most web apps use 302 redirects, but 303 seems to be the correct thing to do according to the specification if you want the url specified in the redirect to be fetched with GET.  Technically, with a 302, the browser is supposed to fetch the specified url with the same method that the original url was fetched with, which would be POST. Most browsers don&#39;t do that though.

302 - http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.3

303 - http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.4


So should I be using 302 or 303?

After a POST, should I do a 302 or a 303 redirect?

It is unclear to me when you should and should not return a HTTP 412: Precondition Failed, error for a web service?  I am thinking of using it when validating data.  For example, if a client POST&#39;s XML data and that data is missing a required data element, then responding with a 412 and a description of the error.

Does that align with the spirit of responding with an HTTP 412, or should something else be used (e.g. another http error code or web application exception)?

When is it appropriate to respond with a HTTP 412 error?

I&#39;m curious what&#39;s the most appropriate HTTP status code for an &quot;item does not exist&quot; page.

If the page itself doesn&#39;t exist, I&#39;ll obviously use 404. However, one of my pages has a `userid` argument (it&#39;s an &quot;edit user&quot; page) and in case no user with the given user ID exists I&#39;m displaying an error page, but I&#39;d also like to send a 4xx status header (since &quot;200 OK&quot; doesn&#39;t really fit).

I guess 404 would be ok since it&#39;s &quot;not found&quot; and not &quot;file not found&quot;, but I wonder if there&#39;s a better code for this case.

What&#39;s the most appropriate HTTP status code for an &quot;item not found&quot; error page

Does anyone know if/where the HTTP status codes, [as specified here][1], are defined in the iOS SDK? Or should I expect to manually re-define them in a constants file? 



  [1]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

Are the HTTP status codes defined anywhere in the iOS SDK?

I have a list of URLS that I need to check, to see if they still work or not. I would like to write a bash script that does that for me.

I only need the returned HTTP status code, i.e. 200, 404, 500 and so forth.  Nothing more.

*EDIT* Note that there is an issue if the page says &quot;404 not found&quot; but returns a 200 OK message. It&#39;s a misconfigured web server, but you may have to consider this case.

For more on this, see https://stackoverflow.com/questions/6439993/check-if-a-url-goes-to-a-page-containing-the-text-404

Script to get the HTTP status code of a list of urls?

What would the code be for checking whether the Wi-Fi is enabled or not?


Checking Wi-Fi enabled or not on Android

In a project I&#39;m working on, we are using shell scripts to execute different tasks. Some are sh/bash scripts that run rsync, and some are PHP scripts. One of the PHP scripts is running some integration tests that output to JUnit XML, code coverage reports, and similar.

Jenkins is able to **mark the jobs as successful / failed based on [exit status][1]**. In **PHP, the script exits with 1** if it has detected that the tests failed during the run. The other shell scripts run commands and use the exit codes from those to mark a build as failed.

    // :: End of PHP script:
    // If any tests have failed, fail the build
    if ($build_error) exit(1);

In [Jenkins Terminology][2], an unstable build is defined as:

&gt; A build is unstable if it was built successfully and one or more publishers report it unstable. For example if the JUnit publisher is configured and a test fails then the build will be marked unstable.

How can I get Jenkins to mark a build as unstable instead of only success / failed when running shell scripts?


  [1]: http://en.wikipedia.org/wiki/Exit_status
  [2]: https://wiki.jenkins-ci.org/display/JENKINS/Terminology

How to mark a build unstable in Jenkins when running shell scripts

When I do a `git status` I get a list of files prefixed with `new file:` . How can I get only this list? I want to process this files in a simple loop in a little shell script.

git: list new files only

Is it possible to find out whether a task with a certain task id exists? When I try to get the status, I will always get pending.

    &gt;&gt;&gt; AsyncResult(&#39;...&#39;).status
    &#39;PENDING&#39;

I want to know whether a given task id is a real celery task id and not a random string. I want different results depending on whether there is a valid task for a certain id.

There may have been a valid task in the past with the same id but the results may have been deleted from the backend.

Find out whether celery task exists

# Background

Using Git 1.8.1.1 on Linux. The repository looks as follows:

    master
      book

The submodule was created as follows:

    $ cd /path/to/master
    $ git submodule add https://user@bitbucket.org/user/repo.git book

The `book` submodule is clean:

    $ cd /path/to/master/book/
    $ git status
    # On branch master
    nothing to commit, working directory clean

# Problem

The master, on the other hand, shows there are &quot;new commits&quot; for the book submodule:

    $ cd /path/to/master/
    $ git status
    # On branch master
    # Changes not staged for commit:
    #   (use &quot;git add &lt;file&gt;...&quot; to update what will be committed)
    #   (use &quot;git checkout -- &lt;file&gt;...&quot; to discard changes in working directory)
    #
    #       modified:   book (new commits)
    #
    no changes added to commit (use &quot;git add&quot; and/or &quot;git commit -a&quot;)

Git should ignore the submodule directory completely, so that the master is also clean:

    $ cd /path/to/master/
    $ git status
    # On branch master
    nothing to commit, working directory clean

# Failed Attempt #1 - dirty

Inside the file `master/.gitmodules` is the following, as per this [answer][1]:

    [submodule &quot;book&quot;]
            path = book
            url = https://user@bitbucket.org/user/repo.git
            ignore = dirty

# Failed Attempt #2 - untracked

Changed `master/.gitmodules` to the following, as per this [answer][2]:

    [submodule &quot;book&quot;]
            path = book
            url = https://user@bitbucket.org/user/repo.git
            ignore = untracked

# Failed Attempt #3 - showUntrackedFiles

Edited `master/.git/config` to the following, as per this [answer][3]:

    [status]
       showUntrackedFiles = no

# Failed Attempt #4 - ignore

Added the book directory to the master ignore file:

    $ cd /path/to/master/
    $ echo book &gt; .gitignore

# Failed Attempt #5 - clone

Added the book directory to the master as follows:

    $ cd /path/to/master/
    $ rm -rf book
    $ git clone https://user@bitbucket.org/user/repo.git book

# Question

How can the `book` submodule be in its own repository directory under the `master` repository yet have git ignore the `book` submodule? That is, the following should not display:

    #
    #       modified:   book (new commits)
    #

How to suppress that message when executing `git status` in the master repository?

An article about [git submodule pitfalls][4] suggests this an inappropriate submodule usage?


  [1]: https://stackoverflow.com/a/5542452/59087
  [2]: https://stackoverflow.com/a/5127213/59087
  [3]: https://stackoverflow.com/a/4345788/59087
  [4]: http://codingkilledthecat.wordpress.com/2012/04/28/why-your-company-shouldnt-use-git-submodules/


Content Type	Original Author	Original Content on Stackoverflow
Question	primroot	View Question on Stackoverflow
Solution 1 - Http	blinkingled	View Answer on Stackoverflow

Should a 502 HTTP status code be used if a proxy receives no response at all?

Http Problem Overview

Http Solutions

Solution 1 - Http

How can I fill a column with random numbers in SQL? I get the same value in every row

Bash CTRL to move cursor between words/strings

Attributions