“greener” APEX apps

This started as a fun discussion in an syntegris internal chat group. But it got me thinking:

Is there a way to make APEX applications more energy efficient?

I came up with a set of ideas and options that have the potential to save energy. Not all options are useful and not all options have a measureable effect. Some are very controversial. The ideas presented here are far from complete.

I added my thoughts to a kialo discussion. Feel free to enter your own arguments there. This is my first kialo discussion – I want to try it out. So please be kind. 😉

I will try to add any interesting considerations that are in the kialo discussion also to this post.

From a very high level view point, we have three areas where we can influence the amount of energy that is used: server – network – client.

server side considerations

Using less CPU means using less energy. APEX applications should avoid wasting CPU.

serve APEX files from the Oracle CDN

A content delivery network provides common files from a server that is geographically close to the client. This also means that the company webserver will not provide the file but the CDN server will. It is possible to configure APEX to get its static files (like jquery, core apex css, etc.) from the CDN.

https://blogs.oracle.com/apex/announcing-oracle-apex-static-resources-on-oracle-content-delivery-network

PRO: The company web/app server will need less energy when the static files are delivered by the CDN.

CON: For local clients the time to get the files from the CDN will be longer. Which also means that energy is wasted somewhere. Probably on the network. Maybe on the firewall.

PRO: Ressources (images, css, js files) that are identical for multiple applications even from different host urls, will be cached only once on the clients browser if they are served from the same CDN.

ORDS should run on the same machine as the database.

PRO: One less server is one less server.

CON: Servers nowadays are mostly virtualized containers running on the same hardware.

ORDS standalone is better than ORDS on Tomcat

A similar consideration could be made for Tomcat vs. Glashfish or Tomcat vs. WebFly (formerly known as JBoss)

PRO: ORDS standalone runs with the Jetty Webserver. Jetty is considered to be very lightweight. Which means it uses less RAM and probably less CPU.

So far I couldn’t test this theory, but there should be a way to measure the impact of ORDS on the different application servers.
Here is a very analytical paper that studies the implications of running java based application on Jetty.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjPn5mqgYXjAhUD5aYKHddkDOAQFjAAegQIARAC&url=https%3A%2F%2Fhal.inria.fr%2Fhal-00652992v2%2Fdocument&usg=AOvVaw2TAsQuz5MBwOcE7K8Mccav

Using more disk space does not correlate to energy consumption the same way as CPU does. Discs are cheap and they don’t need more energy to store more data.

CON: More data that needs to be transfered and backuped will inevitably need more energy.

PRO: Powered down disks keep the data regardless of how much they store. 4 GB or 5 GB is not a difference to them.

CON: Even a powered down hard drive will still use a little energy. https://superuser.com/questions/565653/how-much-power-does-a-hard-drive-use

Avoid pagination schemes that include Z (x of y from z)

PRO: A pagination scheme with Z means the query is rewritten to include the analytical row_number() over () function. This also means, that more data needs to be read from disk into memory, just to know how many potential rows there are.

CON: For smaller tables a multi-block-read count will load the whole table into memory. Counting or numbering the rows will then have no noticable impact on energy consumption.

client side considerations

In general a tablet uses less energy than a laptop which uses less energy than a desktop PC. So should APEX applications be build for tablets first and foremost?

CON: It does not make sense to exclude users that prefere a certain screen size.

CON: We should make the whole screen available to the end user. More information on a single page will mean less need to navigate to other pages. Which potentially saves energy.

PRO: APEX applications should be carefully tested and optimized for usage on a tablet. If they work really well on a smaller screen, then users will not feel forced to switch to another device when using the app.

APEX 19 has a dark mode. Developers should use dark mode and dark themes to save energy.

The idea is that a monitor uses less energy to show “blackness” than to show “whiteness”.

PRO: That seems to be true. See this fairly recent recommendation by google: https://www.xda-developers.com/google-wants-developers-to-add-dark-themes-to-save-battery-life/

  • Brightness affects power usage, and battery life, in a mostly linear fashion.
  • A dark theme can reduce battery usage, even with max brightness, by up to 63% on AMOLED displays.
  • Pixel color value can also affect power usage quite a bit, with white being the most power-hungry color.

Classic Reports use less energy than Interactive Reports (or Interactive Grids)

PRO: A classic report will be created on the webserver and send as static html to the browser. An interactive report will add a lot of javascript functionality to the data. Which means all those JS files need to be loaded and some are executed during page load.

CON: Interactive Grids have this lazy loading pagination scheme. Data will only be fetched when the end user requests to see more data by scrolling down.

PRO: With APEX 18.2 we also get the option to create a column toggle report. This is slightly more flexible than a classic report without all the interactions made available by an IR.

network traffic

The computers that run the network are there anyway. However we can speculate that by sending less information over the internet, there would be less powerhungry computers that are the internet nodes.

Decrease image size. Provide smaller images depending on screen resolution.

PRO: Smaller images allow faster loading times which positivly effects network traffic and also client rending times. This is especially noticable on low bandwith machines like mobile phones.

CON: There is a huge starting effort to create and provide images for all sizes. It is highly doubtful that this original energy spent will ever be overtaken by the energy savings from smaller network traffic.

How do web applications build with APEX compare to other web applications?

APEX applications have a tendency to consume data in a very efficient way.

The overhead for communication with the database is less then for other types of web applications, like PHP.

CON: Not all applications are data centric.

PRO: There is no additional network between the application layer and the database layer.

CON: With APEX 18 and even more so with APEX 19, reports can be built on top of a web service. The web service provider would be the same no matter what kind of framework was used to build the application. In many cases a pure javascript framework (like Oracle JET) might be more efficient to consume those REST based web services, than an APEX application.

PRO: Because the APEX repository already resides in the database all the optimizions for database logic are used while preparing a page for rendering.

Result?

What started out as a “Schnapsidee” quickly got me thinking. There are actually quite a few ways to influence the energy consumption of an APEX application. And this is true during developement but also for running the application.

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add JET 5.1/5.2 to APEX via CDN

How to use the newest Oracle JET version in APEX?

While writing this blog post the most recent version of Oracle JET is version 5.1.0. 5.2.0.

5.1 was an interesting version, since charts have been improved to accept an data provider attribute (http://www.oracle.com/webfolder/technetwork/jet/jetCookbook.html?component=chart&demo=dataProvider)

So let’s assume we want to use this version.

Some time ago I published how to integrate JET [2.2.0] into Apex 5.0. It needed quite some setup to do. Some steps probably could have been done in a more elegant way. Additionally see John Snyders recommendations Using Oracle JET from APEX which do eliminate some of the issues that I encountered. For example there is really no need to throw out hammer.js from the theme.

Meanwhile Oracle has made JET available via the Oracle Content Delivery Network (CDN). And this makes it possible to load the necessary JET libraries from this CDN instead of installing it locally to our webserver. Awesome stuff!

I tested this solution with Apex 5.1.1 (on premise) and with Apex 18.1 (on apex.oracle.com).

Which source files are needed?

We need three types of sources.

  • require to load and install additional libraries
  • the Oracle Jet stylesheets
  • various Oracle Jet javascript libraries

Some comments about those files.

Require.js already comes installed in your local Apex installation. It might be a different version, but still is an option to be considered. I only tested using require in the version that matches with Oracle Jet.

Oracle jet now has a file bundled-config.js which adds all of the jet libraries. This might be a bit too much, but it provides a quick and easy way to install JET. In case we only want to use a special visualization, this provides access to way more libraries than needed. I didn’t test if performance improves if I install only the necessary libraries for a special visualization. I hope that because of require, the performance difference would be minimal. Require only loads a file, when it is really needed. Inspecting the network traffic seems to support that notice.

Once those sources are installed to our page, we can copy any example from the Jet Cookbook and use it in our application. Be aware some cookbook examples use additional resources, like JSON data files. You need to copy and reference those too.

New page template

The three source files need to be added to the page. I suggest to create a new page template so that the logic can be reused for multiple pages.

Make a copy of the standard page template. I named it something like “Standard + Jet 5.1”. Then add a few lines to enable Oracle Jet 5.1.0 on this new template.

The two javascript files need to be added to the javascript file section.

https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/require/require.js
https://static.oracle.com/cdn/jet/v5.1.0/default/js/bundles-config.js

page_template_javascript

As an alternative to the bundles-config.js file, we can install the whole set of the require config in the function declaration section:

//-----------------------------JET STUFF -----------------------------
// alternative source locations
//#APP_IMAGES#oraclejet/main.js
//#IMAGE_PREFIX#libraries/oraclejet/js
requirejs.config({
  // Path mappings for the logical module names
  paths: {
    'knockout': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/knockout/knockout-3.4.2',
    'jquery': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/jquery/jquery-3.1.1.min',
    'jqueryui-amd': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/jquery/jqueryui-amd-1.12.0.min',
    'ojs': 'https://static.oracle.com/cdn/jet/v5.1.0/default/js/min',
    'ojL10n': 'https://static.oracle.com/cdn/jet/v5.1.0/default/js/ojL10n',
    'ojtranslations': 'https://static.oracle.com/cdn/jet/v5.1.0/default/js/resources',
    'text': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/require/text',
    'promise': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/es6-promise/es6-promise.min',
    'hammerjs': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/hammer/hammer-2.0.8.min',
    'signals': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/js-signals/signals.min',
    'ojdnd': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/dnd-polyfill/dnd-polyfill-1.0.0.min',
    'css': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/require-css/css.min',
    'customElements': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/webcomponents/custom-elements.min',
    'proj4js': 'https://static.oracle.com/cdn/jet/v5.1.0/3rdparty/proj4js/dist/proj4'
  },
  // Shim configurations for modules that do not expose AMD
  shim: {
    'jquery': {
      exports: ['jQuery', '$']
    }
  }

});

If you want to use this option and Jet 5.2 then I suggest to look into the 5.2.0 bundles-config.js file, and copy the correct paths out of it.

page_template_function_declaration

Remember above code is not needed! It comes preconfigured in the bundle-config.js file. I offer it only as an alternative installation that gives a little more control over the libraries.

Finally we need to add some css. Add the link for the JET style to the CSS file section.

https://static.oracle.com/cdn/jet/v5.1.0/default/css/alta/oj-alta-min.css

And additionally you might want to add a little inline css. See the issues section for an explanation.

page_template_css

And finally use this new page template for your page.

Example result

And this is how using Oracle Jet 5.1/5.2 in Apex can look like.

JET_Dashboard_Sunburst
The source code for that chart can be found at the end of the post. Or go to the Jet Cookbook and try it our there. Did you notice, you can spin the whole wheel around?

Issues

There are some minor problems that I encountered. Especially some css issues because JET overwrites several of the Apex Theme css settings. Which is not good. I made a sample demo to show the issues. I only tested it with the red theme style, but I think the issues persist in all styles.
Theme Bug Demo

I do have css based workarounds for the issues I found so far. The solution is also demonstrated in the demo app. Here is the css code that can be added to the page or the template (css section).

.t-Header .t-Button--header, .t-Header .t-Button--header.is-active, .t-Header-logo, a.t-Header-logo-link{
    color:#fff
}

.t-Alert--horizontal .t-Alert-icon .t-Icon,
.apex-icons-fontapex .t-Alert--defaultIcons.t-Alert--horizontal .t-Alert-icon .t-Icon {
    width: 48px;
    height: 48px;
    line-height: 48px;
}

I think those issue are really bugs. And the Apex team and the Jet team can both be held responsible. The APEX side should have used a better css specificity for the header styles, the JET side should not set styles for things like a:visited for the whole html page.

And I believe there are more side effects. That is also the main reason why I would add JET only to specific pages. And why I would avoid mixing normal apex charts with newer version JET charts. Don’t mistake me, I made a few simple tests and it worked. I could create a region with a normal apex jet chart (apex 5.1) and combine it with a region using a CDN loaded JET chart (Legend + PictoChart). I just didn’t test it thoroughly enough to recommend it.

What is a CDN and is it safe?

https://en.wikipedia.org/wiki/Content_delivery_network

A content delivery network provides ressources, like in the JET case, javascript and css files, in a way that optimizes access times. So if a user accesses our application from Europe, the ressources will be delivered from a European server. If the user sits in America, an American server is choosen to deliver the files. This also frees up some bandwidth for our own webserver. After the first load, the browser usually caches the files.

If different applications all use the same remote ressource via CDN, the browser can reuse the cached files. This is especially interesting for the very common libraries, like JQuery.

But performance is not the only argument. With Oracle JET I find it way more convinient to load the newest JET version directly from Oracle instead of going through the hassle and install it to the local webserver. Often this involves using deployments scripts and documenting what exactly to do, so that in an enterprise environment, the same steps can be later made for the production server.

But is it safe to use? The most secure method is, if you download the js files from a trusted source (Oracle CDN). Then inspect each file, if there is any malicious code in it. Once you are sure it is safe, you install the files onto your own webserver and serve the ressources from there.

One of the most basic security features is to use HTTPS and not HTTP, especially when accessing remote ressources. This lowers the chance for man in the middle attacks essentially.

Especially the DNS lookup to the CDN server might be a performance drain. But in terms of web speed there are many things to consider.
Pros

  • Ease of installation
  • Performance boost for global user base
  • Browsers limit parallel loads from the same source. Loading additional ressources from a second source circumvents that issue.
  • Bandwidth moved from own webserver to CDN

Cons

  • Less control over the logic that is loaded – you need to trust the CDN provider
  • CDN provider could be down
  • For local users CDN will be slower than serving from local webserver

quick conclusion

Oracle JET via Oracle CDN is a good concept especially during a developement and testing phase. For on premise production usage you might want to consider to install Oracle JET to your local webserver and run it from there.

more

Here are a few links that I found interesting and that cover several other topics about using or not using a CDN.

updates and addendum

Oracle JET 5.2.0

Very recently Oracle JET 5.2.0 was released. I test it only very briefly. You just have to change the version number in the source file path.

Here is the official release schedule for the future Jet versions.

Sunburst Example

The following code is a direct copy from the Oracle Jet Cookbook.

Create a static region and add this as the region source.
Unfortunatly I encounter some issues when posting oj-tags here. The code is missing in the final view. Best way is to go directly to the source and copy the code from there. Everything inside the body tag is needed.

<div id="sampleDemo" class="demo-padding demo-container">
  <div id="componentDemoContent" style="width:1px;min-width:100%;">

    <div id='sunburst-container'>
        <div style="padding-left:16px;float:left;">
          Update values
        </div>
        <div style="padding-left:16px;float:left;">
          Update colors
        </div>
        <div style="padding-left:16px;float:left;">
          Add/Remove Node
        </div>
        <br style="clear:left;" />

        
        
    </div>


  </div>
</div>

Or copy the code from this screenshot
JET_Sunburst_html_source

Add this on the page level to the “function and global variable declaration”:


require(['ojs/ojcore', 'knockout', 'jquery', 'ojs/ojknockout',
    'ojs/ojbutton', 'ojs/ojsunburst'],
function(oj, ko, $)
{
    function SunburstModel() {
        var self = this;

        var colorHandler = new oj.ColorAttributeGroupHandler();

        var MA = createNode("Massachusetts", "0", getValue(), getColor());
        var CT = createNode("Connecticut", "1", getValue(), getColor());
        var ME = createNode("Maine", "2", getValue(), getColor());
        var VT = createNode("Vermont", "3", getValue(), getColor());
        var RI = createNode("Rhode Island", "4", getValue(), getColor());

        addChildNodes(MA, [
          createNode("Boston", "00", getValue(), getColor()),
          createNode("Springfield", "01", getValue(), getColor()),
          createNode("Worcester", "02", getValue(), getColor())
        ]);
        addChildNodes(CT, [
          createNode("Hartford", "10", getValue(), getColor()),
          createNode("New Haven", "11", getValue(), getColor())
        ]);
        addChildNodes(ME, [
          createNode("Portland", "20", getValue(), getColor()),
          createNode("Augusta", "21", getValue(), getColor())
        ]);
        addChildNodes(VT, [
          createNode("Burlington", "30", getValue(), getColor())
        ]);
        addChildNodes(RI, [
          createNode("Providence", "40", getValue(), getColor()),
          createNode("Newport", "41", getValue(), getColor())
        ]);
        var nodes = [MA, CT, ME, VT, RI];
        function createNode(label, id, value, color) {
          return {label: label,
                id: id,
                value: value,
                color: color,
                shortDesc: "<b>" + label +
                  "</b>
Value: " + value};
        }

        function addChildNodes(parent, childNodes) {
          parent.nodes = [];
          for (var i = 0; i &lt; childNodes.length; i++) {
            parent.nodes.push(childNodes[i]);
          }
        }

        function getValue() {
            return Math.round(50 + 100 * Math.random());
        }

        function getColor() {
            return colorHandler.getValue(Math.floor(Math.random() * 4));
        }

        self.nodeValues = ko.observableArray(nodes);

        self.valueButtonClick = function(event) {
            for (var i = 0; i &lt; nodes.length; i++) {
                if (Math.random() &lt; 0.4)
                    nodes[i].value = getValue();
                for (var j=0; j &lt; nodes[i].nodes.length; j++) {
                    if (Math.random() &lt; 0.4)
                        nodes[i].nodes[j].value = getValue();
                }
            }
            self.nodeValues(nodes);
            return true;
        }

        self.colorButtonClick = function(event) {
            for (var i = 0; i &lt; nodes.length; i++) {
                if (Math.random() &lt; 0.3)
                    nodes[i].color = getColor();
                for (var j=0; j &lt; nodes[i].nodes.length; j++) {
                    if (Math.random() &lt; 0.3)
                        nodes[i].nodes[j].color = getColor();
                }
            }
            self.nodeValues(nodes);
            return true;
        }

        self.nodeButtonClick = function(event) {
            if (nodes.length &lt;= 5) {
                var newNode = {
                  id: &quot;5&quot;, value: getValue(),
                  color: getColor(), label: &quot;New York&quot;,
                  nodes: [
                     {id: &quot;50&quot;, value: getValue(),
                        color: getColor(), label: &quot;New York City&quot;},
                     {id: &quot;51&quot;, value: getValue(),
                        color: getColor(), label: &quot;Albany&quot;}
                  ]
                };
                nodes.push(newNode);
            }
            else {
                nodes.pop();
            }
            self.nodeValues(nodes);
            return true;
        }
    }

    var sunburstModel = new SunburstModel();

    $(
        function()
        {
            ko.applyBindings(sunburstModel,
                    document.getElementById(&#039;sunburst-container&#039;));
	}
    );
});