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Blogs for tag 'cache'

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posted by Juan Rivera

It has been a few weeks since we released the trial for HDX MediaStream for Flash and I would like to share a few tips about this feature as well as highlight some of the capabilities in the trial release. First on the list is Window-less Mode.

Windowless mode allows web pages to overlay HTML content over the Flash player. This is important in certain scenarios like navigation menus that show on top of the flash player. Without windowless support, those sites would not be very usable. Here is an example of MSNBC.com with and without windowless support:

Flash content in windowed mode Flash content in windowless mode

Notice how the Flash ad on the left side covers part of the navigation menu while the one in the right does not. Flash in windowless mode allows the browser to do this. HDX MediaStream for Flash supports this mode even though the Flash player is rendered on the client while the browser is rendered on the server. Logic would dictate that since Citrix HDX renders the flash on the client device, any flash would always show up on top of any content in the browser. But not so. Here at Citrix, we've figured out how to retain this functionality so that users get a seamless experience.

It's easy to see how HDX MediaStream for Flash makes it easier for IT to choose XenApp and XenDesktop for application management and desktop delivery while preserving the experience that users are accustomed to. Stay tuned for more in my "Did you know" series on HDX MediaStream for Flash.

More of my blog posts on HDX MediaStream for Flash:

HDX MediaStream for Flash Tech Preview
Window-less Mode support in HDX MediaStream for Flash
Volume Synchronization in HDX MediaStream for Flash
Windows Scaling Support in HDX MediaStream for Flash
Multiple Tab Support and Diagnostics with HDX MediaStream for Flash

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posted by Juan Rivera


A key component of Citrix XenApp and Citrix XenDesktop, HDX MediaStream technology ensures that users receive a smooth, seamless experience with multimedia content as part of their virtual desktop (VDI) or virtual applications. To accomplish this, HDX MediaStream determines when it is best to leverage the processing power of the endpoint device to render the multimedia content.
Flash is one of the most pervasive technologies on the web. It is used for interactive content, video streaming and rich internet applications. But delivering Flash-based applications and media via a virtual desktop or virtualized web browser leads to lower user density in the data center, higher bandwidth usage when compared to native flash streams and, in most cases, a degraded user experience.

That's why Citrix has developed HDX MediaStream for Flash. The goal of this technology is to address the density, bandwidth and user experience challenges associated with virtualizing Flash media and Flash-based applications. With HDX MediaStream for Flash, Citrix has solved this problem by moving the execution of Flash content to the client whenever possible. While the browser remains in the data center, Flash content is redirected to the client and executed using the resources at the users end point device. The server is no longer responsible for decoding and compressing HD videos, executing animations or fetching the media content from the web servers. All of which require processing power and distort media in some way.

Moving the Flash execution to the client also enables Flash applications to access local resources like webcams and audio devices to provide a local-like user experience for rich internet applications like web-based collaboration solutions. Even with this local execution, however, HDX MediaStream for Flash lets administrators centrally manage delivery while taking advantage of available processing power on the users device. Check out the demo of HDX MediaStream for Flash below.

How can you get the Trial Release?

To use the HDX MediaStream for Flash trial release with XenApp you'll need XenApp 5.0 for Windows 2003, XenApp 5.0 for Windows 2008 or Citrix Presentation Server 4.5 for Windows 2003 (You might want to consider using the XenApp Evaluation Virtual Appliance if you don't have a test environment of your own). To use HDX MediaStream for Flash trial release with XenDesktop, you'll need Citrix XenDesktop 3 running on Windows XP, Windows Vista, or Windows 7 (may include XenDesktop 3 Feature Pack 1). Both with XenApp and XenDesktop, Internet Explorer 7 or 8 and the Flash 10 plug-in for Internet Explorer are also required. The trial requires the 32-bit versions of the software but support for the 64-bit platform is planned for the version 1.0 release.

On the client side, HDX MediaStream for Flash trial requires the Citrix Receiver 1.0 for Windows and the Flash 10 plug-in for Internet Explorer.

Download the trial release today and let us know what you think. Need to learn more, check out the release notes. Still need more information? Check out the support forum or comment below for a response from me or my team. Stay tuned for another post within a week or two where I'll be asking for your feedback via a quick poll.

More of my blog posts on HDX MediaStream for Flash:

HDX MediaStream for Flash Tech Preview
Window-less Mode support in HDX MediaStream for Flash
Volume Synchronization in HDX MediaStream for Flash
Windows Scaling Support in HDX MediaStream for Flash
Multiple Tab Support and Diagnostics with HDX MediaStream for Flash

Juan
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posted by Craig Ellrod

In the Application Expert series part 2, Caching, I released a Deployment Guide discussing Static and Dynamic Caching.  As we are partners with Microsoft, we recently did some work here internally setting up some Dynamic Caching for an ASP.NET application and thought we would share the knowledge. This Caching Deployment Guide for ASP.NET Web Applications discusses the way an Application Expert would find out the potential caching scenarios that a web application can benefit from, and shows how to create and test the NetScaler caching policies and settings to put these scenarios into effect.

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posted by Craig Ellrod

Policies are used to configure various Citrix NetScaler Application Switch features. For example, the parameters for compressing content are defined in a compression policy.

The features that use policies are:

  • Load Balancing
  • Content Switching
  • Content Filtering
  • AppCompress
  • Cache Redirection
  • SSL VPN
  • Priority Queuing
  • DoS Protection
  • Sure Connect

Policy expressions are applied to content that enters the switch. Expressions are shared among features, but actions are feature-specific. For example, you can create an expression to identify .pdf files being sent through the system. You can then create a compression policy that uses this expression to compress those files. The Policy Engine (PE) refers to the architecture in the Citrix NetScaler Application Switch for versions up to 8.x. The architecture for Policy Engine and the manner in which it operates is presented in this Deployment Guide.  Did you know that each feature in the Citrix NetScaler Application Switch is processed in a certain order, and the Policy Engine (PE) applies policy according to that order.  That order is represented in this diagram and discussed in the Deployment Guide for Policy Engine (PE).

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posted by Craig Ellrod

As web applications grow in complexity, the art of accelerating them seems to remain the same. This art is performed by applying some basic concepts to the application; that is, Caching, Compression, Load Balancing, Global Server Load Balancing, SSL Offload & Acceleration, Content Switching, TCP Multiplexing and SSL Session Reuse.

Citrix® is a leader in Gartners magic quadrant for Application Delivery with their flagship appliance NetScaler®. NetScaler accelerates web application performance by leveraging multiple acceleration technologies and innovative TCP optimizations.

Whether you are building out a new datacenter and architecting it the right way, or retrofitting an existing datacenter, Citrix NetScaler will perform and keep costs down. Whether you are looking to accelerate legacy enterprise applications such as Oracle or SAP, or building a new web 2.0 social community, Citrix NetScaler contains all of the tools to get you there.

Citrix NetScaler web application delivery solutions are purpose built appliances that accelerate application performance, while simultaneously reducing datacenter costs and improving web application security. Platforms range from the entry level 7000 to the latest MPX-series appliances that provide an industry-leading 15 Gbs of throughput at Layers 4 through 7.

There's more here: Case Studies, White Papers, Analysts , Datasheets

Check out the new MPX!

Buy it here!

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posted by Craig Ellrod

Becoming an Application Expert means that you can profile an application and quickly determine how it can be architected or re-constructed for higher performance. Of course, we want you to use the Citrix Application Switch as part of the architecture. In Part 1, we learned how to profile an application to learn what it looks like as the traffic flows through the Citrix Application Switch. Now we will determine what parts of an application are cacheable and what parts are non-cacheable.

By Application Profiling we can determine which parts of the application are cacheable and non-cacheable just by looking at the Request and Response headers. The application will sometimes tell you through it's "Cache-Control" header directives. Some content that we just know is static and doesn't ever change, we can consider cacheable as static content. Content that changes, such as reports, are often considered non-cacheable but with the help of Selectors and Dynamic Content Groups in the Citrix NetScaler, this content can be cached. As a proof of concept, we deployed the Citrix NetScaler Application Switch in the front of Oracle E-Business Suite v12 application and implemented caching policies for both static and dynamic content. As it turns out, alot of static content is cached by default policies and setting up dynamic policies is not that difficult. To see how, read the Caching Deployment Guide for Oracle E-Business Suite v12.

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posted by Craig Ellrod

Application Profiling

Introduction:

I can turn you into an Application expert in 5 minutes by reading this post.  Just do what the experts do, or even the not-so-experts.  They pay meticulous attention to the requests from clients and the responses from servers, both headers and body content.  You do this the old fashioned way by taking a trace.  There are better tools out there, some free, some not-so-free.

Running a trace:

Running a trace will help you 'profile' the application. It is recommended that you do this before placing the Citrix Application Switch in-line of the Application traffic. This will gather important information about the Application that will help you understand it's basic operation at Layer 7, and help you begin to understand what it is that needs to be accelerated - cached, compressed, load balanced, ssl offloaded, etc.

Running a trace exposes the flow of transactions between all points of interest. Traces are especially helpful when digging in to find what is contained within the headers being exchanged between the client and the application.

Taking a trace with wireshark:

The free network protocol analyzer called wireshark, http://www.wireshark.org, will capture packets for you on the localhost, whether it's windows or linux. By filtering the stream of packets by IP Address, right clicking and selecting 'Follow TCP Stream' inside of wireshark, you can see the headers for both requests and responses.

Wireshark tip 1
Find the first 'SYN' in the stream, right click, 'Follow TCP Stream'.


Wireshark tip 2
Client requests are in Red, Server responses are in Blue.


Taking a trace with the Citrix Application Switch:

If the Citrix Application Switch is already in place, a trace can be run directly on the Citrix Application Switch. Running a trace will expose the flow of transactions between all points of interest, especially the client, load balancing VIPs and backend servers. Traces are especially helpful when digging in to find out if the proper headers are being exchanged between client & VIP and VIP & backend servers. A trace can be run directly on the Citrix Application Switch. Once downloaded this file can be opened and request and response headers read with Wireshark, a free network trace utility, http://www.wireshark.org. From the Citrix Application Switch GUI, navigate to NetScaler -> System -> Diagnostics -> New Trace -> Run. 

Viewing headers with Paros:

Paros was originially written for web security, but has value when viewing request and response headers, cookies and the like. Through Paros's proxy nature, all HTTP and HTTPS data between server and client, including cookies and form fields, can be intercepted. There is an additional option of trapping and modifying data before sending it on to the server, or client. Paros can be found at http://parosproxy.org. Free.

Viewing headers with Live HTTP Headers:

Live HTTP Headers, http://livehttpheaders.mozdev.org/, was developed for use with the Firefox web browser. It is a free add-on and allows you to view HTTP header information in real time. Free.

Viewing headers with IE Analyzer:

IEInspector HTTP Analyzer, http://www.ieinspector.com, is a tool that allows you to monitor, trace, debug and analyze HTTP/HTTPS traffic in real-time. It works with Microsoft Internet Explorer. Not-Free.

Viewing headers with IE Watch:

IEWatch, http://www.iewatch.com, is another plug-in for Microsoft Internet Explorer that helps you profile your web applications. You can use this tool to dig deep into the inner workings of web applications to find hidden issues. Not-Free.

Watch this Application Profiling Tip:

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posted by Craig Ellrod

The SAP Enterprise Service Oriented Architecture (SOA) provides a blueprint for services-based, enterprise scale business solutions that are adaptable, flexible, and open. Enterprise Services Architecture takes the concept of service-oriented architecture to a new level by transforming Web services into enterprise services. Bringing Citrix and SAP Enterprise Services Architecture together reduces the dependence on customized applications, and increases flexibility and reduces time to deployment while reducing operational expenses.


This Citrix / SAP Enterprise SOA Deployment Guide was created out of a joint engagement between Citrix and SAP at the Co-Innovation Laboratory in Palo Alto, California, USA. This deployment guide walks through the step-by-step configuration details of how to configure the Citrix NetScaler for use as front-end to SAP Portal for end-user traffic, that is HTTP ~ HTML. To further complement the value of the Enterprise SOA, this guide walks through the details of how to configure the Citrix NetScaler for use as a front-end to the SAP Composite Application Framework and SAP ERP Web Services platforms, providing a flexible load balancer and HTTPS encryption point for machine to machine web service traffic. With this deployment Citrix becomes an integral and flexible part of the SAP Enterprise SOA "Applistructure" bringing together applications and technology for a fast, flexible and highly effective service oriented IT infrastructure.


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posted by Craig Ellrod

We recently had a meeting with a large partner of ours and they handed down some hefty requirements.  An average of 100 partners using their portal on any given month to access their development environments on the backend.  It was clear that NetScaler could scale, but the question was how to keep all of those partners separated from each other, without them peeking into each others traffic. It turned out to be easier than we thought using the NetScaler as an SSL VPN with the addition of some policies bound to each partner's user group.  The following is an overview of the network diagram, and there are some deployment guides to walk you through these installations. 


The Citrix SSL VPN CPS Deployment Guide walks you through deploying NetScaler SSL VPN as an ICA Proxy and authentication point.  It then walks you through deploying Citrix Presentation Server and the steps necessary to connect the SSL VPN to the CPS Applications.  The guide includes Session policies which direct users upon authentication to specific CPS farms on the backend of the NetScaler SSL VPN.  Think of it as an authentication portal.

The Citrix SSL VPN Deployment Guide walks you through deploying NetScalers as an HA Pair, and then as an SSL VPN with ICA Proxy OFF.  The intention was to use the SSL VPN for regular VPN traffic, and not Citrix Presentation Server traffic.  Just as well, policies can be combined on the same NetScaler Application Switch to allow both non-CPS and CPS traffic to traverse the same SSL VPN.

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