I&#39;ve been working on this for a few days now, and I&#39;ve found several solutions but none of them incredibly simple or lightweight.  The problem is basically this:  We have a cluster of 10 machines, each of which is running the same software on a multithreaded ESB platform. I can deal with concurrency issues between threads on the same machine fairly easily, but what about concurrency on the same data on different machines?  

Essentially the software receives requests to feed a customer&#39;s data from one business to another via web services.  However, the customer may or may not exist yet on the other system.  If it does not, we create it via a web service method.  So it requires a sort of test-and-set, but I need a semaphore of some sort to lock out the other machines from causing race conditions.  I&#39;ve had situations before where a remote customer was created twice for a single local customer, which isn&#39;t really desirable.

Solutions I&#39;ve toyed with conceptually are:

 1. Using our fault-tolerant shared file system to create &quot;lock&quot; files which will be checked for by each machine depending on the customer

 2. Using a special table in our database, and locking the whole table in order to do a &quot;test-and-set&quot; for a lock record.

 3. Using Terracotta, an open source server software which assists in scaling, but uses a hub-and-spoke model.

 4. Using EHCache for synchronous replication of my in-memory &quot;locks.&quot;


I can&#39;t imagine that I&#39;m the only person who&#39;s ever had this kind of problem.  How did you solve it?  Did you cook something up in-house or do you have a favorite 3rd-party product?

Distributed Concurrency Control

I&#39;m trying to dynamically scale text to be placed on images of varying but known dimensions. The text will be applied as a watermark.  Is there any way to scale the text in relation to the image dimensions?  I don&#39;t require that the text take up the whole surface area, just to be visible enough so its easily identifiable and difficult to remove. I&#39;m using Python Imaging Library version 1.1.7. on Linux.

I would like to be able to set the ratio of the text size to the image dimensions, say like 1/10 the size or something.

I have been looking at the font size attribute to change the size but I have had no luck in creating an algorithm to scale it.  I&#39;m wondering if there is a better way.

Any ideas on how I could achieve this?

Thanks

PIL how to scale text size in relation to the size of the image

I want to have a website where I can upload images of different sizes to be displayed in a jquery slider.
I can&#39;t seem to fit (scaling down) the image in a containing div. Here&#39;s how I&#39;m intending to do it

    &lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML 1.0 Transitional//EN&quot; &quot;http://www.w3.org    /TR/xhtml1/DTD/xhtml1-transitional.dtd&quot;&gt;
    &lt;html xmlns=&quot;http://www.w3.org/1999/xhtml&quot;&gt;
    &lt;head&gt;
    &lt;meta http-equiv=&quot;Content-Type&quot; content=&quot;text/html; charset=utf-8&quot; /&gt;
    &lt;title&gt;Untitled Document&lt;/title&gt; 
    &lt;link rel=&quot;stylesheet&quot; type=&quot;text/css&quot; href=&quot;Imtest.css&quot;/&gt;
    &lt;/head&gt;

    &lt;body&gt;

    &lt;div id=&quot;wrapper&quot;&gt; 

    &lt;div id=&quot;im&quot;&gt;&lt;img src=&quot;Images/Scarpa2_1.jpg&quot; /&gt;&lt;/div&gt;

    &lt;/div&gt;  
    &lt;/body&gt;
    &lt;/html&gt;

And the CSS

    #wrapper {
        width: 400px;
        height: 400px;
        border: 2px black solid;
        margin: auto;
    }

    #im {
        max-width: 100%;
    }
	
I&#39;ve tried to set the max-width of my image to 100% in CSS. But that doens&#39;t work. 

CSS scale down image to fit in containing div, without specifing original size

See http://jsfiddle.net/aJ333/1/ in Chrome and then in either Firefox or Internet Explorer. The image is originally 120px, and I&#39;m scaling down to 28px, but it looks bad pretty much no matter what you scale it down to.

The image is a PNG and it has an alpha channel (transparency).

Here&#39;s the relevant code:

HTML:

    &lt;a href=&quot;http://tinypic.com?ref=2z5jbtg&quot; target=&quot;_blank&quot;&gt;
        &lt;img src=&quot;http://i44.tinypic.com/2z5jbtg.png&quot; border=&quot;0&quot; alt=&quot;Image and video hosting by TinyPic&quot;&gt;
    &lt;/a&gt;​

CSS:

    a {
        width: 28px;
        height: 28px;
        display: block;
    }

    img {
        max-width: 100%;
        max-height: 100%;
        image-rendering: -moz-crisp-edges;
        -ms-interpolation-mode: bicubic;
    }

The `image-rendering` and `-ms-interpolation-mode` lines of CSS didn&#39;t seem to do anything, but I found them online while doing some research on the problem.

Image scaling causes poor quality in firefox/internet explorer but not chrome

So I am trying to figure out how to take a range of numbers and scale the values down to fit a range.  The reason for wanting to do this is that I am trying to draw ellipses in a java swing jpanel.  I want the height and width of each ellipse to be in a range of say 1-30.  I have methods that find the minimum and maximum values from my data set, but I won&#39;t have the min and max until runtime.  Is there an easy way to do this?

How to scale down a range of numbers with a known min and max value

The declaration of `android.graphics.Bitmap.createScaledBitmap` is

    public static Bitmap createScaledBitmap
      (Bitmap src, int dstWidth, int dstHeight, boolean filter)

However, the documentation doesn&#39;t explain any of the parameters.  All of them are pretty obvious except for `boolean filter`.  Does anyone know what it does?

What does the filter parameter to createScaledBitmap do?

I can&#39;t tell the difference between `ImageView.ScaleType.CENTER_INSIDE` and `ImageView.ScaleType.FIT_CENTER`.

`CENTER_INSIDE`

&gt; Scale the image uniformly (maintain the image&#39;s aspect ratio) so that both dimensions (width and height) of the image will be equal to or less than the corresponding dimension of the view (minus padding). 

`FIT_CENTER`

&gt; Compute a scale that will maintain the original src aspect ratio, but will also ensure that src fits entirely inside dst. At least one axis (X or Y) will fit exactly. The result is centered inside dst.


Can someone illuminate the difference between the two?

What&#39;s the difference between CENTER_INSIDE and FIT_CENTER scale types?

I am unable to understand the [page][1] of the `StandardScaler` in the documentation of `sklearn`.

Can anyone explain this to me in simple terms?


  [1]: http://scikit-learn.org/stable/modules/generated/sklearn.preprocessing.StandardScaler.html#sklearn.preprocessing.StandardScaler

Can anyone explain me StandardScaler?

So, I have an imageview that should display an arbitrary image, a profile picture downloaded from the internet. I want this the ImageView to scale its image to fit inside the height of the parent container, and a set max width of 60dip. However, if the image is tall ratio-wise, and doesn&#39;t need the full 60dip of width, the ImageView&#39;s width should decrease so the view&#39;s background fits snugly around the image.

I tried this, 

    &lt;ImageView android:id=&quot;@+id/menu_profile_picture&quot;
    	android:layout_width=&quot;wrap_content&quot;
    	android:maxWidth=&quot;60dip&quot;
    	android:layout_height=&quot;fill_parent&quot;
    	android:layout_marginLeft=&quot;2dip&quot;
    	android:padding=&quot;4dip&quot;
    	android:scaleType=&quot;centerInside&quot;
    	android:background=&quot;@drawable/menubar_button&quot;
    	android:layout_centerVertical=&quot;true&quot;/&gt;
but that made the ImageView super large for some reason, maybe it used the intrinsic width of the image and wrap_content to set it - anyway, it didn&#39;t respect my maxWidth attribute.. Does that only work inside some types of containers? It&#39;s in a LinearLayout...

Any suggestions?

Android imageview not respecting maxWidth?

I have tried the following to fit the webpage based on the device screen size.

    mWebview.setInitialScale(30);

and then set the metadata viewport

    &lt;meta name=&quot;viewport&quot; content=&quot;width=320, initial-scale=1.0, maximum-scale=1.0, user-scalable=no&quot; /&gt;
    &lt;meta name=&quot;viewport&quot; content=&quot;width=device-width; initial-scale=1.0; maximum-scale=1.0; minimum-scale=1.0; user-scalable=0;&quot;/&gt;
    &lt;meta name=&quot;viewport&quot; content=&quot;width=device-width, target-densityDpi=medium-dpi&quot;/&gt;
   
   
But nothing works, webpage is not fixed to the device screen size.

Can anyone tell me how to get this?


Android Webview - Webpage should fit the device screen

I am attempting to use vector drawables in my Android app.  From http://developer.android.com/training/material/drawables.html (emphasis mine):

&gt; In Android 5.0 (API Level 21) and above, you can define vector drawables, **which scale without losing definition.**

Using this drawable:

    &lt;vector xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
    android:height=&quot;24dp&quot;
    android:width=&quot;24dp&quot;
    android:viewportWidth=&quot;24&quot;
    android:viewportHeight=&quot;24&quot;&gt;
    &lt;path android:fillColor=&quot;@color/colorPrimary&quot; android:pathData=&quot;M14,20A2,2 0 0,1 12,22A2,2 0 0,1 10,20H14M12,2A1,1 0 0,1 13,3V4.08C15.84,4.56 18,7.03 18,10V16L21,19H3L6,16V10C6,7.03 8.16,4.56 11,4.08V3A1,1 0 0,1 12,2Z&quot; /&gt;
&lt;/vector&gt;

and this ImageView:

    &lt;ImageView
        android:layout_width=&quot;400dp&quot;
        android:layout_height=&quot;400dp&quot;
        android:src=&quot;@drawable/icon_bell&quot;/&gt;

produces this blurry image when attempting to display the icon at 400dp (on a largish high-res circa 2015 mobile device running lollipop):

[![blurryBellIcon][1]][1]


  [1]: http://i.stack.imgur.com/ELOQi.png

Changing the width and height in the definition of the vector drawable to 200dp significantly improves the situation at the 400dp rendered size.  However, setting this as a drawable for a TextView element (i.e. icon to the left of the text) now creates a huge icon.

My questions:

1) Why is there a width/height specification in the vector drawable?  I thought the entire point of these is that they scale up and down losslessly making width and height meaningless in its definition?

2) Is it possible to use a single vector drawable which works as a 24dp drawable on a TextView but scales up well to use as much larger images too?  E.g. how do I avoid creating multiple vector drawables of different sizes and instead use one which scales to my rendered requirements?

3) How do I effectively use the width/height attributes and what is the difference with viewportWidth/Height?

Additional details:

 - Device is running API 22
 - Using Android Studio v1.5.1 with Gradle version 1.5.0
 - Manifest is compile and target level 23, min level 15.  I&#39;ve also tried moving min level to 21, but this made no difference.
 - Decompiling the APK (with min level set to 21) shows a single XML resource in the drawable folder.  No rasterized images are produced.

Why isn&#39;t my vector drawable scaling as expected?

This seems like it ought to be easy, but I&#39;m just not getting something.

I want to make an HTML page containing a single SVG image that automatically scales to fit the browser window, without any scrolling and while preserving its aspect ratio.

For example, at the moment I have a 1024x768 SVG image; if the browser viewport is 1980x1000 then I want the image to display at 1333x1000 (fill vertically, centred horizontally).  If the browser was 800x1000 then I want it to display at 800x600 (fill horizontally, centred vertically).

Currently I have it defined like so:

    &lt;body style=&quot;height: 100%&quot;&gt;
      &lt;div id=&quot;content&quot; style=&quot;width: 100%; height: 100%&quot;&gt;
        &lt;svg xmlns=&quot;http://www.w3.org/2000/svg&quot; version=&quot;1.1&quot;
             width=&quot;100%&quot; height=&quot;100%&quot;
             viewBox=&quot;0 0 1024 768&quot;
             preserveAspectRatio=&quot;xMidYMid meet&quot;&gt;
          ...
        &lt;/svg&gt;
      &lt;/div&gt;
    &lt;/body&gt;

However this is scaling up to the full width of the browser (for a wide but short window) and producing vertical scrolling, which isn&#39;t what I want.

What am I missing?

How to scale SVG image to fill browser window?

At the [startup][1] I&#39;m working at we are now considering scaling solutions for our database. Things get somewhat confusing (for me at least) with MySQL, which has the [MySQL cluster][2], [replication][3] and [MySQL cluster replication][4] (from ver. 5.1.6), which is an asynchronous version of the MySQL cluster. The MySQL manual explains some of the differences in its [cluster FAQ][5], but it is hard to ascertain from it when to use one or the other.

I would appreciate any advice from people who are familiar with the differences between those solutions and what are the pros and cons, and when do you recommend to use each.


  [1]: http://www.binpress.com
  [2]: http://dev.mysql.com/doc/refman/5.0/en/faqs-mysql-cluster.html
  [3]: http://dev.mysql.com/doc/refman/5.0/en/replication.html
  [4]: http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-replication.html
  [5]: http://dev.mysql.com/doc/refman/5.0/en/faqs-mysql-cluster.html#qandaitem-22-10-3

Scaling solutions for MySQL (Replication, Clustering)

I need to scale down an image, but in a sharp way. In Photoshop for example there are the image size reduction options &quot;Bicubic Smoother&quot; (blurry) and &quot;Bicubic Sharper&quot;.

Is this image downscaling algorithm open sourced or documented somewhere or does the SDK offer methods to do this?

How to scale down a UIImage and make it crispy / sharp at the same time instead of blurry?

I&#39;ve got HTML code like this:

    &lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML 1.0 Transitional//EN&quot; &quot;http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd&quot;&gt; 
        &lt;html xmlns=&quot;http://www.w3.org/1999/xhtml&quot;&gt; 
        &lt;head&gt; 
        &lt;meta http-equiv=&quot;Content-Type&quot; content=&quot;text/html; charset=windows-1251&quot; /&gt; 
        &lt;title&gt;&lt;/title&gt; 
        &lt;/head&gt; 
        
        &lt;body&gt; 
           &lt;table style=&quot;width:100%;&quot;&gt; 
              &lt;tr&gt; 
                 &lt;td&gt; 
                    &lt;table style=&quot;width:100%; max-width:1000px; background:#000099;&quot;&gt; 
                           &lt;tr&gt; 
                               &lt;td&gt; 
                                   001 
                               &lt;/td&gt; 
                           &lt;/tr&gt; 
                       &lt;/table&gt; 
                   &lt;/td&gt; 
               &lt;/tr&gt; 
           &lt;/table&gt; 
        &lt;/body&gt; 
        &lt;/html&gt; 

The problem is that Chrome and Safari are ignoring `&quot;max-width:1000px&quot;`
My friend has found that we can prevent it by adding `&quot;display:block&quot;` for the inner table, and it&#39;s somehow working.

So, what I want to know is - are there any other ways of solving this problem and why is this happening?

Chrome, Safari ignoring max-width in table

I have a source rectangle and a destination rectangle. I need to find the maximum scale to which the source can be scaled while fitting within the destination rectangle and *maintaining its original aspect ratio*.

Google found [one][1] way to do it but I&#39;m not sure if it works in all cases. Here is my home-brewed solution:

 - Calculate Height/Width for each rectangle. This gives the slopes of the diagonals `msrc` and `mdest`.
 - If `msrc &lt; mdst`, scale source *width* to fit the destination *width* (and scale height by the same ratio)
 - Otherwise, scale source *height* to fit the destination *height* (and scale width by the same ratio)

  [1]: http://www.vbdotnetforums.com/graphics-gdi/33829-scale-rectangle-fit-another.html

Looking for other possible solutions to this problem. I&#39;m not even sure if my algorithm works in all cases!

How do I scale one rectangle to the maximum size possible within another rectangle?

I would like to scale a `Bitmap` to a runtime dependant width and height, where the aspect ratio is maintained and the `Bitmap` fills the entire width and centers the image vertically, either cropping the excess or filling in the gap with 0 alpha pixels.

I&#39;m currently redrawing the bitmap myself by creating a `Bitmap` of all 0 alpha pixels and drawing the image `Bitmap` on top of it, scaling to the exact specified width and maintaining the aspect ratio, however, it ends up losing/screwing up the pixel data.

Here is how I&#39;m doing it:

    Bitmap background = Bitmap.createBitmap((int)width, (int)height, Config.ARGB_8888);
    float originalWidth = originalImage.getWidth(), originalHeight = originalImage.getHeight();
    Canvas canvas = new Canvas(background);
    float scale = width/originalWidth;
    float xTranslation = 0.0f, yTranslation = (height - originalHeight * scale)/2.0f;
    Matrix transformation = new Matrix();
    transformation.postTranslate(xTranslation, yTranslation);
    transformation.preScale(scale, scale);
    canvas.drawBitmap(originalImage, transformation, null);
    return background;

Is there a library out there or some better code that can do this better? I would like the image to look as crisp as possible, but I knew that my function wouldn&#39;t provide a great result.

I know I could have the image stay fine by using integer scaling, instead of float scaling, but I need the width to be 100% filled.

Also, I know about an `ImageView`&#39;s `Gravity.CENTER_CROP` capability, however, that also uses integer scaling, so it cuts off the width of the image when it shouldn&#39;t.

Scaled Bitmap maintaining aspect ratio

How do I make a background image fit the view but keep its aspect ratio when using `&lt;bitmap /&gt;` as a background drawable XML?
None of `&lt;bitmap&gt;`&#39;s `android:gravity` values gives the desired effect.

Scale image keeping its aspect ratio in background drawable

A little background.

Very big monolithic Django application. All components use the same database. We need to separate services so we can independently upgrade some parts of the system without affecting the rest. 

We use RabbitMQ as a broker to Celery.

Right now we have two options:

 1. HTTP Services using a REST interface.
 2. JSONRPC over AMQP to a event loop service

My team is leaning towards HTTP because that&#39;s what they are familiar with but I think the advantages of using RPC over AMQP far outweigh it.

AMQP provides us with the capabilities to easily add in load balancing, and high availability, with guaranteed message deliveries. 

Whereas with HTTP we have to create client HTTP wrappers to work with the REST interfaces, we have to put in a load balancer and set up that infrastructure in order to have HA etc.

With AMQP I can just spawn another instance of the service, it will connect to the same queue as the other instances and bam, HA and load balancing.

Am I missing something with my thoughts on AMQP?





Service Oriented Architecture - AMQP or HTTP

I am using an embedded font for the top navigational elements on a site
`Helvetica65` and at `16px` it is the perfect WIDTH but I need it to be
about `90%` of it&#39;s current height.

In Photoshop, the solution is simple - adjust the vertical scaling.

Is there a way to do essentially the same thing using CSS? And if so, how
well is it supported?

Here is a [jsFiddle][1] of the basic nav coding. 


  [1]: http://jsfiddle.net/Jd5Y7/

Is it possible to adjust a font&#39;s vertical scaling using CSS?

I&#39;m doing:

`button.setLayoutParams(new GridView.LayoutParams(65, 65));`

According to the docs the units for the width and height (both 65 in the above) are &quot;pixels&quot;. How do you force this to be device independent pixels, or &quot;dp&quot;?

Android and setting width and height programmatically in dp units

How do I scale a series such that the first number in the series is 0 and last number is 1. I looked into &#39;approx&#39;, &#39;scale&#39; but they do not achieve this objective.

    # generate series from exponential distr
    s = sort(rexp(100))

    # scale/interpolate &#39;s&#39; such that it starts at 0 and ends at 1?
    # approx(s)
    # scale(s)


Scale a series between two points

I want to have an inline svg element&#39;s contents scale when size is non-native. Of course I could have it as a separate file and scale it like that.

index.html: `&lt;img src=&quot;foo.svg&quot; style=&quot;width: 100%;&quot; /&gt;`

foo.svg: `&lt;svg width=&quot;123&quot; height=&quot;456&quot;&gt;&lt;/svg&gt;`

However, I want to add additional styles to the SVG thru CSS, so linking an external one is not an option. How do I make an inline SVG scale?

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