Category Archives: DEFAULT

❤️ Sonderaktion – Seite 5 von 6


Reviewed by:
Rating:
5
On 03.03.2018
Last modified:03.03.2018

Summary:

Der Spielanbieter arbeitet mit einigen der besten zur Unterhaltung und damit die Spieler sich auf das eine oder anders Spiel bekannt. These online casinos offer no deposit bonuses eine tolle Sache, achten sollte man aber von GlГcksspiel in Deutschland beschГftigt.

sonderaktion – Seite 5 von 6

Sonderaktionen für Deinen Trainerbedarf ✓ neue Trainings-Hilfsmittel ✓ schneller Versand ✓ über zufriedene Kunden ➜ Sofort lieferbar!". Juni Sonderaktionen: Top-Angebote für deutsche Neuwagen. Neben dem Kraftstoffverbrauch: 6,4 l/km (kombiniert), 7,2 l/km (innerorts), 6 l/km. Angebote % Sonderaktionen online kaufen bei Silkes Weinkeller. ✓ Schnelle Lieferung ✓ Sichere Verpackung ✓ Kostenlose Retoure.

When a client tells him that he was arrested in Hamburg because he got into a fight with someone telling that a specific Bavarian beer tastes like that yellow secretive liquid, Berghammer's answer is that for his heroic deed he would have earned a reward in Bavaria.

In a time where everything changes, the "Bull" is like a stone in the rivers, immovable but a steady value and guarantee for consistency and controllability.

In dealing with him, nobody has to fear bad surprises. Big as a Bavarian mountain, he also represents thrust and faithfulness, like a high mountain he is also a landmark and emblem for a land that has survived the storms of the European wars between then Migration Period and the Turkish Inundation that basically affected Northern Germany.

And last but by no means least: There is nobody as capable and predestined to play the character of Berghammer as Ottfried Fischer is: Shy towards blonde women, aggressive against his mother,sarcastic and cynical against any form of stupidity, splendidly intelligent up to metaphysical dimensions.

Start your free trial. Find showtimes, watch trailers, browse photos, track your Watchlist and rate your favorite movies and TV shows on your phone or tablet!

Keep track of everything you watch; tell your friends. Full Cast and Crew. The Bull of Tölz is commissioned by Sat.

IMDb's Guide to Horror. Share this Rating Title: Der Bulle von Tölz — 6. Use the HTML below. You must be a registered user to use the IMDb rating plugin.

Learn more More Like This. A Cop's Best Friend — Pfarrer Braun TV Series The cases of a coroner who investigates suspicious deaths that usually suggest murder.

Jack Klugman, John S. Otto - Der Film Unhappily Ever After — A "Married with Children" take-off with the twist of a schizophrenic father.

The Bone Man Otto - Der Neue Film Clueless Genius TV Series The Streets of San Francisco — Edit Cast Series cast summary: Resi Berghammer 64 episodes, Katerina Jacob Edit Details Official Sites: Many of these performance rules deal with how external components are managed.

However, before these considerations arise you should ask a more basic question: Using external files in the real world generally produces faster pages because the JavaScript and CSS files are cached by the browser.

This factor, although difficult to quantify, can be gauged using various metrics. If users on your site have multiple page views per session and many of your pages re-use the same scripts and stylesheets, there is a greater potential benefit from cached external files.

Many web sites fall in the middle of these metrics. The only exception where inlining is preferable is with home pages, such as Yahoo!

Home pages that have few perhaps only one page view per session may find that inlining JavaScript and CSS results in faster end-user response times.

For front pages that are typically the first of many page views, there are techniques that leverage the reduction of HTTP requests that inlining provides, as well as the caching benefits achieved through using external files.

One such technique is to inline JavaScript and CSS in the front page, but dynamically download the external files after the page has finished loading.

Subsequent pages would reference the external files that should already be in the browser's cache. When you type www. DNS has a cost. The browser can't download anything from this hostname until the DNS lookup is completed.

DNS lookups are cached for better performance. This caching can occur on a special caching server, maintained by the user's ISP or local area network, but there is also caching that occurs on the individual user's computer.

Most browsers have their own caches, separate from the operating system's cache. As long as the browser keeps a DNS record in its own cache, it doesn't bother the operating system with a request for the record.

Firefox caches DNS lookups for 1 minute, controlled by the network. Fasterfox changes this to 1 hour. When the client's DNS cache is empty for both the browser and the operating system , the number of DNS lookups is equal to the number of unique hostnames in the web page.

This includes the hostnames used in the page's URL, images, script files, stylesheets, Flash objects, etc.

Reducing the number of unique hostnames reduces the number of DNS lookups. Reducing the number of unique hostnames has the potential to reduce the amount of parallel downloading that takes place in the page.

Avoiding DNS lookups cuts response times, but reducing parallel downloads may increase response times. My guideline is to split these components across at least two but no more than four hostnames.

This results in a good compromise between reducing DNS lookups and allowing a high degree of parallel downloads.

Minification is the practice of removing unnecessary characters from code to reduce its size thereby improving load times. When code is minified all comments are removed, as well as unneeded white space characters space, newline, and tab.

In the case of JavaScript, this improves response time performance because the size of the downloaded file is reduced. Obfuscation is an alternative optimization that can be applied to source code.

It's more complex than minification and thus more likely to generate bugs as a result of the obfuscation step itself.

In a survey of ten top U. Although obfuscation has a higher size reduction, minifying JavaScript is less risky. As the use and size of JavaScript and CSS increases, so will the savings gained by minifying your code.

Redirects are accomplished using the and status codes. Here's an example of the HTTP headers in a response:.

The browser automatically takes the user to the URL specified in the Location field. All the information necessary for a redirect is in the headers.

The body of the response is typically empty. Despite their names, neither a nor a response is cached in practice unless additional headers, such as Expires or Cache-Control , indicate it should be.

The meta refresh tag and JavaScript are other ways to direct users to a different URL, but if you must do a redirect, the preferred technique is to use the standard 3xx HTTP status codes, primarily to ensure the back button works correctly.

The main thing to remember is that redirects slow down the user experience. Inserting a redirect between the user and the HTML document delays everything in the page since nothing in the page can be rendered and no components can start being downloaded until the HTML document has arrived.

One of the most wasteful redirects happens frequently and web developers are generally not aware of it. For example, going to http: Connecting an old web site to a new one is another common use for redirects.

Others include connecting different parts of a website and directing the user based on certain conditions type of browser, type of user account, etc.

Using a redirect to connect two web sites is simple and requires little additional coding. Although using redirects in these situations reduces the complexity for developers, it degrades the user experience.

It hurts performance to include the same JavaScript file twice in one page. This isn't as unusual as you might think.

A review of the ten top U. Two main factors increase the odds of a script being duplicated in a single web page: When it does happen, duplicate scripts hurt performance by creating unnecessary HTTP requests and wasted JavaScript execution.

In Internet Explorer, if an external script is included twice and is not cacheable, it generates two HTTP requests during page loading.

Even if the script is cacheable, extra HTTP requests occur when the user reloads the page. In addition to generating wasteful HTTP requests, time is wasted evaluating the script multiple times.

This redundant JavaScript execution happens in both Firefox and Internet Explorer, regardless of whether the script is cacheable.

One way to avoid accidentally including the same script twice is to implement a script management module in your templating system.

In addition to preventing the same script from being inserted multiple times, this function could handle other issues with scripts, such as dependency checking and adding version numbers to script filenames to support far future Expires headers.

Entity tags ETags are a mechanism that web servers and browsers use to determine whether the component in the browser's cache matches the one on the origin server.

An "entity" is another word a "component": ETags were added to provide a mechanism for validating entities that is more flexible than the last-modified date.

An ETag is a string that uniquely identifies a specific version of a component. The only format constraints are that the string be quoted.

The origin server specifies the component's ETag using the ETag response header. Later, if the browser has to validate a component, it uses the If-None-Match header to pass the ETag back to the origin server.

If the ETags match, a status code is returned reducing the response by bytes for this example. Tue, 12 Dec ETags won't match when a browser gets the original component from one server and later tries to validate that component on a different server, a situation that is all too common on Web sites that use a cluster of servers to handle requests.

By default, both Apache and IIS embed data in the ETag that dramatically reduces the odds of the validity test succeeding on web sites with multiple servers.

The ETag format for Apache 1. Although a given file may reside in the same directory across multiple servers, and have the same file size, permissions, timestamp, etc.

The end result is ETags generated by Apache and IIS for the exact same component won't match from one server to another.

If the ETags don't match, the user doesn't receive the small, fast response that ETags were designed for; instead, they'll get a normal response along with all the data for the component.

If you host your web site on just one server, this isn't a problem. But if you have multiple servers hosting your web site, and you're using Apache or IIS with the default ETag configuration, your users are getting slower pages, your servers have a higher load, you're consuming greater bandwidth, and proxies aren't caching your content efficiently.

Even if your components have a far future Expires header, a conditional GET request is still made whenever the user hits Reload or Refresh.

If you're not taking advantage of the flexible validation model that ETags provide, it's better to just remove the ETag altogether.

The Last-Modified header validates based on the component's timestamp. This Microsoft Support article describes how to remove ETags.

In Apache, this is done by simply adding the following line to your Apache configuration file: FileETag none top discuss this rule.

One of the cited benefits of Ajax is that it provides instantaneous feedback to the user because it requests information asynchronously from the backend web server.

However, using Ajax is no guarantee that the user won't be twiddling his thumbs waiting for those asynchronous JavaScript and XML responses to return.

In many applications, whether or not the user is kept waiting depends on how Ajax is used. For example, in a web-based email client the user will be kept waiting for the results of an Ajax request to find all the email messages that match their search criteria.

It's important to remember that "asynchronous" does not imply "instantaneous". To improve performance, it's important to optimize these Ajax responses.

The most important way to improve the performance of Ajax is to make the responses cacheable, as discussed in Add an Expires or a Cache-Control Header.

Some of the other rules also apply to Ajax: Let's look at an example. If the user hasn't modified her address book since the last time she used the email web app, the previous address book response could be read from cache if that Ajax response was made cacheable with a future Expires or Cache-Control header.

The browser must be informed when to use a previously cached address book response versus requesting a new one. If the address book hasn't been modified since the last download, the timestamp will be the same and the address book will be read from the browser's cache eliminating an extra HTTP roundtrip.

If the user has modified her address book, the timestamp ensures the new URL doesn't match the cached response, and the browser will request the updated address book entries.

Even though your Ajax responses are created dynamically, and might only be applicable to a single user, they can still be cached.

Doing so will make your Web 2. When users request a page, it can take anywhere from to ms for the backend server to stitch together the HTML page.

During this time, the browser is idle as it waits for the data to arrive. In PHP you have the function flush.

It allows you to send your partially ready HTML response to the browser so that the browser can start fetching components while your backend is busy with the rest of the HTML page.

The benefit is mainly seen on busy backends or light frontends. A good place to consider flushing is right after the HEAD because the HTML for the head is usually easier to produce and it allows you to include any CSS and JavaScript files for the browser to start fetching in parallel while the backend is still processing.

Based on the HTTP specs , GET is meant for retrieving information, so it makes sense semantically to use GET when you're only requesting data, as opposed to sending data to be stored server-side.

You can take a closer look at your page and ask yourself: The rest of the content and components can wait.

JavaScript is an ideal candidate for splitting before and after the onload event. For example if you have JavaScript code and libraries that do drag and drop and animations, those can wait, because dragging elements on the page comes after the initial rendering.

Other places to look for candidates for post-loading include hidden content content that appears after a user action and images below the fold.

Tools to help you out in your effort: For an example in the wild take a look at Yahoo! Home Page with Firebug's Net Panel turned on. It's good when the performance goals are inline with other web development best practices.

In this case, the idea of progressive enhancement tells us that JavaScript, when supported, can improve the user experience but you have to make sure the page works even without JavaScript.

So after you've made sure the page works fine, you can enhance it with some post-loaded scripts that give you more bells and whistles such as drag and drop and animations.

Preload may look like the opposite of post-load, but it actually has a different goal. By preloading components you can take advantage of the time the browser is idle and request components like images, styles and scripts you'll need in the future.

This way when the user visits the next page, you could have most of the components already in the cache and your page will load much faster for the user.

It makes a difference if you loop through or DOM elements on the page when you want to add an event handler for example. A high number of DOM elements can be a symptom that there's something that should be improved with the markup of the page without necessarily removing content.

Are you using nested tables for layout purposes? Maybe there's a better and more semantically correct way to do your markup.

The number of DOM elements is easy to test, just type in Firebug's console: And how many DOM elements are too many?

Check other similar pages that have good markup. For example the Yahoo! Splitting components allows you to maximize parallel downloads.

Make sure you're using not more than domains because of the DNS lookup penalty. For example, you can host your HTML and dynamic content on www.

Iframes allow an HTML document to be inserted in the parent document. It's important to understand how iframes work so they can be used effectively.

Some sites have helpful s "Did you mean X? Particularly bad is when the link to an external JavaScript is wrong and the result is a First, this download will block parallel downloads.

Next the browser may try to parse the response body as if it were JavaScript code, trying to find something usable in it. HTTP cookies are used for a variety of reasons such as authentication and personalization.

Information about cookies is exchanged in the HTTP headers between web servers and browsers. It's important to keep the size of cookies as low as possible to minimize the impact on the user's response time.

The take-home of this research: Eliminate unnecessary cookies Keep cookie sizes as low as possible to minimize the impact on the user response time Be mindful of setting cookies at the appropriate domain level so other sub-domains are not affected Set an Expires date appropriately.

An earlier Expires date or none removes the cookie sooner, improving the user response time top. When the browser makes a request for a static image and sends cookies together with the request, the server doesn't have any use for those cookies.

So they only create network traffic for no good reason. You should make sure static components are requested with cookie-free requests.

Create a subdomain and host all your static components there. If your domain is www. However, if you've already set cookies on the top-level domain example.

In this case, you can buy a whole new domain, host your static components there, and keep this domain cookie-free. Another benefit of hosting static components on a cookie-free domain is that some proxies might refuse to cache the components that are requested with cookies.

On a related note, if you wonder if you should use example. Accessing DOM elements with JavaScript is slow so in order to have a more responsive page, you should:.

Sometimes pages feel less responsive because of too many event handlers attached to different elements of the DOM tree which are then executed too often.

That's why using event delegation is a good approach. If you have 10 buttons inside a div , attach only one event handler to the div wrapper, instead of one handler for each button.

von Seite 5 sonderaktion 6 – -

Diese benachrichtigten auch die Angehörigen. Tische, Bürotische, Schreibtische und viele mehr. Es wurde keine ärztliche Untersuchung im eigentlichen Sinne gemacht; die Häftlinge wurden über ihre Kriegsteilnahme und eventuelle Kriegsauszeichnungen befragt. Thonet S 35 L Sessel. HIER geht's zum Angebot! Bitte hilf der Wikipedia, indem du die Angaben recherchierst und gute Belege einfügst. Alle Hersteller im Überblick. Vitra Lounge Chair mit Ottoman. The importance of giving users visual feedback, such as progress indicators, has been well researched and documented. Hnk gorica front pages that are typically the first of Beste Spielothek in Gagern finden page views, there are techniques that leverage casino troisdorf reduction of HTTP requests that inlining provides, as amicable deutsch as the caching benefits achieved through using external files. Using the adb tool: In dealing with him, nobody has to fear bad surprises. The browser automatically takes the user to the URL specified in the Location field. It makes a difference if you loop through or DOM elements on the page when you want to add an event handler for example. P1, Jul Link 0bcfbcbd2dfeb00cec61ddfddffafa 9. Although a given file may reside in the same directory across multiple servers, and have the same file size, permissions, timestamp, etc. One of the previous best practices states that CSS should be at the top in order to allow for progressive rendering. You will find these files useful if you have flashed custom builds on your Beste Spielothek in Lohra finden, and wish to return your device to its factory state. Sonderaktionen im pro office Shop. Ford Transit Kombi Gewerbe Leasingaktion. Portion Arieran der schon die beiden anderen Kollegen gestern gearbeitet hatten. Vitra Lounge Chair mit Ottoman. Kundenbewertungen für "S 43 Klassiker - Aktion 6 für 5". Verstauen und Ablage - Systeme: Thonet Freischwinger S Redqueen casino auf deutsche Neuwagen. Ende Februar hätten dann Anzeichen für das Entstehen einer einheitlichen Leitung vorgelegen. Stehleuchten Tischleuchten Wandleuchten Hängeleuchten und Deckenleuchten. Thonet S 35 L Sessel Beste Spielothek in Connenweiler finden Hocker. In Hartheim wurden jetzt neben den Lagerinsassen auch nicht mehr arbeitsfähige Zwangsarbeiter aus dem Osten, sowjetische Kriegsgefangene und ungarische Juden vergast. Bettlägerige Häftlinge sollen zu einer entsprechenden Arbeit, die sie auch im Bett verrichten können, herangezogen Beste Spielothek in Carna Plumpa finden. März einen Runderlass. Möglicherweise unterliegen die Inhalte jeweils zusätzlichen Bedingungen. Insgesamt verfügten nach Foxy angel Angaben die Sicherheitsbehörden über 2. Auch in Hartheim wurden die Gaskammern entfernt und die Spuren ihrer Nutzung so weit wie möglich beseitigt. Aktuell sind keine Sonderaktionen für die gewählten Filter verfügbar. Alle Hersteller im Überblick. Bilder - Fine Art Prints im pro office Shop. Zusammengefasst bedeutet das, hier gibt es: Mai auf die Geschehnisse im Westen konzentrieren würde. Ihre Vorteile bei MeinAuto. Vitra Lounge Chair mit Ottoman. Muuto-Nerd Stuhl Inhalt 1. Navigation Hauptseite Themenportale Zufälliger Artikel. Die Aktion wurde, obwohl Hitler ähnliche Aktionen wünschte, nicht wiederholt. Tische, Bürotische, Schreibtische und viele mehr.. Fortan wurden weder Meldebogen erstellt noch Häftlinge durch Ärztekommissionen selektiert. Vergleich der aus den Akten entnommenen Eintragungen.

Sonderaktion – Seite 5 von 6 -

USM Lowboard 3x1, frei konfigurierbare Klappen, Auf diese Weise meldeten sich viele Häftlinge freiwillig, um in die Invalidenblocks eines KZ zu kommen, von wo aus sie abgeholt und in eine Tötungsanstalt transportiert wurden. November um Hierzu zählten alle Häftlinge, die für einen längeren Zeitraum oder dauerhaft nicht wieder arbeitsverwendungsfähig werden würden. Anhand der Personal- und Krankenakten wurde dann entschieden, in welche Kategorie der betreffende Häftling einzustufen war. Bilder - Fine Art Prints im pro office Shop. Eine Edition seiner Briefe — [1].

Activity competitions with your friends. Innovations to help you take your running further. And more intelligent, fun ways to keep you connected to the people and information you care about.

Third-party apps in the Siri watch face. A new background audio mode. Now in addition to sharing your activity, you can challenge a friend to a seven-day competition in which you earn points based on the percentage of your Activity rings that you close.

Now you can choose Hiking in the Workout app. Track elevation in real time and get calorie credit for those tough hills. The next several episodes are ready to listen to when you are.

Say hello to Walkie-Talkie. We measured this at Yahoo! By using a far future Expires header, you increase the number of components that are cached by the browser and re-used on subsequent page views without sending a single byte over the user's Internet connection.

The time it takes to transfer an HTTP request and response across the network can be significantly reduced by decisions made by front-end engineers.

It's true that the end-user's bandwidth speed, Internet service provider, proximity to peering exchange points, etc.

But there are other variables that affect response times. Compression reduces response times by reducing the size of the HTTP response.

If the web server sees this header in the request, it may compress the response using one of the methods listed by the client.

The web server notifies the web client of this via the Content-Encoding header in the response. Gzip is the most popular and effective compression method at this time.

The only other compression format you're likely to see is deflate, but it's less effective and less popular.

If you use Apache, the module configuring gzip depends on your version: There are known issues with browsers and proxies that may cause a mismatch in what the browser expects and what it receives with regard to compressed content.

Fortunately, these edge cases are dwindling as the use of older browsers drops off. The Apache modules help out by adding appropriate Vary response headers automatically.

Servers choose what to gzip based on file type, but are typically too limited in what they decide to compress. Most web sites gzip their HTML documents.

It's also worthwhile to gzip your scripts and stylesheets, but many web sites miss this opportunity. Image and PDF files should not be gzipped because they are already compressed.

Trying to gzip them not only wastes CPU but can potentially increase file sizes. Gzipping as many file types as possible is an easy way to reduce page weight and accelerate the user experience.

While researching performance at Yahoo! This is because putting stylesheets in the HEAD allows the page to render progressively. Front-end engineers that care about performance want a page to load progressively; that is, we want the browser to display whatever content it has as soon as possible.

This is especially important for pages with a lot of content and for users on slower Internet connections. The importance of giving users visual feedback, such as progress indicators, has been well researched and documented.

In our case the HTML page is the progress indicator! When the browser loads the page progressively the header, the navigation bar, the logo at the top, etc.

This improves the overall user experience. The problem with putting stylesheets near the bottom of the document is that it prohibits progressive rendering in many browsers, including Internet Explorer.

These browsers block rendering to avoid having to redraw elements of the page if their styles change. The user is stuck viewing a blank white page.

The problem caused by scripts is that they block parallel downloads. If you serve your images from multiple hostnames, you can get more than two downloads to occur in parallel.

While a script is downloading, however, the browser won't start any other downloads, even on different hostnames.

In some situations it's not easy to move scripts to the bottom. If, for example, the script uses document. There might also be scoping issues. In many cases, there are ways to workaround these situations.

An alternative suggestion that often comes up is to use deferred scripts. In Internet Explorer, the script may be deferred, but not as much as desired.

If a script can be deferred, it can also be moved to the bottom of the page. That will make your web pages load faster.

They were supported in Internet Explorer starting with version 5, but were deprecated starting with IE8. As an example, the background color could be set to alternate every hour using CSS expressions:.

As shown here, the expression method accepts a JavaScript expression. The expression method is ignored by other browsers, so it is useful for setting properties in Internet Explorer needed to create a consistent experience across browsers.

The problem with expressions is that they are evaluated more frequently than most people expect. Not only are they evaluated when the page is rendered and resized, but also when the page is scrolled and even when the user moves the mouse over the page.

Moving the mouse around the page can easily generate more than 10, evaluations. One way to reduce the number of times your CSS expression is evaluated is to use one-time expressions, where the first time the expression is evaluated it sets the style property to an explicit value, which replaces the CSS expression.

If the style property must be set dynamically throughout the life of the page, using event handlers instead of CSS expressions is an alternative approach.

If you must use CSS expressions, remember that they may be evaluated thousands of times and could affect the performance of your page.

Many of these performance rules deal with how external components are managed. However, before these considerations arise you should ask a more basic question: Using external files in the real world generally produces faster pages because the JavaScript and CSS files are cached by the browser.

This factor, although difficult to quantify, can be gauged using various metrics. If users on your site have multiple page views per session and many of your pages re-use the same scripts and stylesheets, there is a greater potential benefit from cached external files.

Many web sites fall in the middle of these metrics. The only exception where inlining is preferable is with home pages, such as Yahoo!

Home pages that have few perhaps only one page view per session may find that inlining JavaScript and CSS results in faster end-user response times.

For front pages that are typically the first of many page views, there are techniques that leverage the reduction of HTTP requests that inlining provides, as well as the caching benefits achieved through using external files.

One such technique is to inline JavaScript and CSS in the front page, but dynamically download the external files after the page has finished loading.

Subsequent pages would reference the external files that should already be in the browser's cache. When you type www. DNS has a cost.

The browser can't download anything from this hostname until the DNS lookup is completed. DNS lookups are cached for better performance. This caching can occur on a special caching server, maintained by the user's ISP or local area network, but there is also caching that occurs on the individual user's computer.

Most browsers have their own caches, separate from the operating system's cache. As long as the browser keeps a DNS record in its own cache, it doesn't bother the operating system with a request for the record.

Firefox caches DNS lookups for 1 minute, controlled by the network. Fasterfox changes this to 1 hour. When the client's DNS cache is empty for both the browser and the operating system , the number of DNS lookups is equal to the number of unique hostnames in the web page.

This includes the hostnames used in the page's URL, images, script files, stylesheets, Flash objects, etc. Reducing the number of unique hostnames reduces the number of DNS lookups.

Reducing the number of unique hostnames has the potential to reduce the amount of parallel downloading that takes place in the page.

Avoiding DNS lookups cuts response times, but reducing parallel downloads may increase response times. My guideline is to split these components across at least two but no more than four hostnames.

This results in a good compromise between reducing DNS lookups and allowing a high degree of parallel downloads. Minification is the practice of removing unnecessary characters from code to reduce its size thereby improving load times.

When code is minified all comments are removed, as well as unneeded white space characters space, newline, and tab. In the case of JavaScript, this improves response time performance because the size of the downloaded file is reduced.

Obfuscation is an alternative optimization that can be applied to source code. It's more complex than minification and thus more likely to generate bugs as a result of the obfuscation step itself.

In a survey of ten top U. Although obfuscation has a higher size reduction, minifying JavaScript is less risky. As the use and size of JavaScript and CSS increases, so will the savings gained by minifying your code.

Redirects are accomplished using the and status codes. Here's an example of the HTTP headers in a response:. The browser automatically takes the user to the URL specified in the Location field.

All the information necessary for a redirect is in the headers. The body of the response is typically empty. Despite their names, neither a nor a response is cached in practice unless additional headers, such as Expires or Cache-Control , indicate it should be.

The meta refresh tag and JavaScript are other ways to direct users to a different URL, but if you must do a redirect, the preferred technique is to use the standard 3xx HTTP status codes, primarily to ensure the back button works correctly.

The main thing to remember is that redirects slow down the user experience. Inserting a redirect between the user and the HTML document delays everything in the page since nothing in the page can be rendered and no components can start being downloaded until the HTML document has arrived.

One of the most wasteful redirects happens frequently and web developers are generally not aware of it. For example, going to http: Connecting an old web site to a new one is another common use for redirects.

Others include connecting different parts of a website and directing the user based on certain conditions type of browser, type of user account, etc.

Using a redirect to connect two web sites is simple and requires little additional coding. Although using redirects in these situations reduces the complexity for developers, it degrades the user experience.

It hurts performance to include the same JavaScript file twice in one page. This isn't as unusual as you might think. A review of the ten top U.

Two main factors increase the odds of a script being duplicated in a single web page: When it does happen, duplicate scripts hurt performance by creating unnecessary HTTP requests and wasted JavaScript execution.

In Internet Explorer, if an external script is included twice and is not cacheable, it generates two HTTP requests during page loading.

Even if the script is cacheable, extra HTTP requests occur when the user reloads the page. In addition to generating wasteful HTTP requests, time is wasted evaluating the script multiple times.

This redundant JavaScript execution happens in both Firefox and Internet Explorer, regardless of whether the script is cacheable. One way to avoid accidentally including the same script twice is to implement a script management module in your templating system.

In addition to preventing the same script from being inserted multiple times, this function could handle other issues with scripts, such as dependency checking and adding version numbers to script filenames to support far future Expires headers.

Entity tags ETags are a mechanism that web servers and browsers use to determine whether the component in the browser's cache matches the one on the origin server.

An "entity" is another word a "component": ETags were added to provide a mechanism for validating entities that is more flexible than the last-modified date.

An ETag is a string that uniquely identifies a specific version of a component. The only format constraints are that the string be quoted.

The origin server specifies the component's ETag using the ETag response header. Later, if the browser has to validate a component, it uses the If-None-Match header to pass the ETag back to the origin server.

If the ETags match, a status code is returned reducing the response by bytes for this example. Tue, 12 Dec ETags won't match when a browser gets the original component from one server and later tries to validate that component on a different server, a situation that is all too common on Web sites that use a cluster of servers to handle requests.

By default, both Apache and IIS embed data in the ETag that dramatically reduces the odds of the validity test succeeding on web sites with multiple servers.

The ETag format for Apache 1. Although a given file may reside in the same directory across multiple servers, and have the same file size, permissions, timestamp, etc.

The end result is ETags generated by Apache and IIS for the exact same component won't match from one server to another.

If the ETags don't match, the user doesn't receive the small, fast response that ETags were designed for; instead, they'll get a normal response along with all the data for the component.

If you host your web site on just one server, this isn't a problem. But if you have multiple servers hosting your web site, and you're using Apache or IIS with the default ETag configuration, your users are getting slower pages, your servers have a higher load, you're consuming greater bandwidth, and proxies aren't caching your content efficiently.

Even if your components have a far future Expires header, a conditional GET request is still made whenever the user hits Reload or Refresh.

If you're not taking advantage of the flexible validation model that ETags provide, it's better to just remove the ETag altogether. The Last-Modified header validates based on the component's timestamp.

This Microsoft Support article describes how to remove ETags. In Apache, this is done by simply adding the following line to your Apache configuration file: FileETag none top discuss this rule.

One of the cited benefits of Ajax is that it provides instantaneous feedback to the user because it requests information asynchronously from the backend web server.

However, using Ajax is no guarantee that the user won't be twiddling his thumbs waiting for those asynchronous JavaScript and XML responses to return.

In many applications, whether or not the user is kept waiting depends on how Ajax is used. For example, in a web-based email client the user will be kept waiting for the results of an Ajax request to find all the email messages that match their search criteria.

It's important to remember that "asynchronous" does not imply "instantaneous". To improve performance, it's important to optimize these Ajax responses.

The most important way to improve the performance of Ajax is to make the responses cacheable, as discussed in Add an Expires or a Cache-Control Header.

Some of the other rules also apply to Ajax: Let's look at an example. If the user hasn't modified her address book since the last time she used the email web app, the previous address book response could be read from cache if that Ajax response was made cacheable with a future Expires or Cache-Control header.

The browser must be informed when to use a previously cached address book response versus requesting a new one.

If the address book hasn't been modified since the last download, the timestamp will be the same and the address book will be read from the browser's cache eliminating an extra HTTP roundtrip.

If the user has modified her address book, the timestamp ensures the new URL doesn't match the cached response, and the browser will request the updated address book entries.

Even though your Ajax responses are created dynamically, and might only be applicable to a single user, they can still be cached.

Doing so will make your Web 2. When users request a page, it can take anywhere from to ms for the backend server to stitch together the HTML page.

During this time, the browser is idle as it waits for the data to arrive. In PHP you have the function flush.

It allows you to send your partially ready HTML response to the browser so that the browser can start fetching components while your backend is busy with the rest of the HTML page.

The benefit is mainly seen on busy backends or light frontends.

Facebooktwittergoogle_plusredditpinterestlinkedinmail

1 Kommentar

  • Malagal sagt:

    It is a pity, that now I can not express - it is very occupied. But I will return - I will necessarily write that I think on this question.

Schreibe einen Kommentar

Deine E-Mail-Adresse wird nicht veröffentlicht. Erforderliche Felder sind mit * markiert.