: take web application performance, scalability and reliability to the next level with Citrix NetScaler
Citrix NetScaler overview Deployed in front of web and database servers, Citrix NetScaler is an enterpriseclass solution that can speed performance of apps and services by up to five times by engaging a powerful combination of network-based acceleration, server offload, high availability and application security technologies. More than 2,000 enterprises use NetScaler for their public-facing and intranet web application delivery needs, including 8 out of the 10 largest web sites. An estimated 75 percent of Internet users hit a NetScaler daily. Introduction: rise to the challenge of service delivery Whether you re accessing transactional web apps or ones that require complex or time-sensitive content, the performance of those web apps ultimately depends on performance over the network. Developers can do their best to optimise client and server-side code to rapidly generate requested pages, but unless communication between the two ends goes smoothly, you ll only get marginal performance gains, and your users will still perceive the applications as slow. A market-leading application delivery controller (ADC), Citrix NetScaler resolves the network performance challenge for modern web apps. A nonintrusive, network-based solution, NetScaler intelligently engages a collection of application acceleration techniques to deliver predictable performance over unpredictable networks. It also helps you address other challenges, including cost-effective scaling of services, service availability and robust security and data protection. NetScaler, however, is far more than just an ordinary ADC. The breadth and depth of its core delivery capabilities is only the first item that sets it apart from the competition. Even more significant going forward are the NetScaler capabilities that extend delivery optimisation to the data tier, efficiently establish in-depth application-layer visibility, and provide a choice of platform that enables a thorough yet cost effective deployment. These help yield further performance gains and smoother operation of related infrastructure. They also improve NetScaler s support for the changing needs of your IT department as traditional application delivery gives way to the more broadly scoped practice of service delivery 1. Build infrastructure for accelerating, scaling and reliably delivering web applications The repertoire of the traditional ADC has long included both the original server load-balancing functions for application availability and scalability and the later additions pertaining to application performance and security. NetScaler excels in all of these areas. NetScaler makes available more core delivery capabilities and a richer a set of functionality in a single, network-based device than any other solution. A non-intrusive and truly comprehensive application and service delivery solution, NetScaler helps organisations of all types and sizes dramatically improve web application performance and operations while simultaneously reducing cost and complexity. NetScaler helps you rise to the challenges of the four primary domains of coverage: application acceleration, scalability, reliability and security. 2 1 For more information, see the Citrix whitepaper, The transformation from application delivery to service delivery
Application acceleration NetScaler capabilities deliver predictable performance for web applications and services running over unpredictable networks. They help you accelerate applications through features including: TCP optimisation. An extensive collection of protocol optimisation mechanisms ensures thorough utilisation of available bandwidth and reduces the number of exchanges required between client and server to complete a single, user-level action. These mechanisms include TCP buffering, window scaling, intelligent packet retransmit, selected acknowledgement (per IETF RFC 2018) and enhanced congestion control (per IETF RFC 3742). Multi-level compression. By integrating AppCompress, a high-performance compression engine, NetScaler relieves application servers of compression tasks, reduces end-user response time and effectively cuts bandwidth and capacity requirements for every network link and infrastructure device between itself and the clients being served. Dynamic content caching. Providing in-memory caching for both static and dynamically generated HTTP content, AppCache accelerates delivery to users while relieving back-end servers from having to repeatedly serve the same content. Flexible rules allow you to define precisely which content can be cached and how often it should be refreshed. Application scalability NetScaler capabilities that facilitate both scale-up and scale-out objectives for application and service infrastructure include: TCP multiplexing. NetScaler frees application servers to handle more user sessions by offloading connection management and aggregating a large number of HTTP requests over a much smaller number of long-lived TCP connections. SSL offload and acceleration. Hardware-based SSL accelerators further enable server scale-up by offloading compute-intensive key exchange, certificate management and bulk cryptographic operations. Load balancing and content switching. With L4 load balancing, you can scale out application capacity simply by adding another commodity server to a managed pool, instead of having to purchase high-end hardware and undertake a forklift upgrade. The ability to distribute traffic based on L7 attributes, such as HTTP header or SSL session ID, also improves scalability by allowing different application components to reside on different sets of servers that are tailored to the specific functions they are performing. Application reliability NetScaler helps ensure your application availability with capabilities that include: Server high availability. By dynamically routing app traffic among servers that are configured as part of a managed pool, NetScaler automatically accounts for both unanticipated failures and scheduled outages of individual systems. Health monitoring. NetScaler proactively avoids failed and hung user sessions by continuously issuing health checks to confirm not only the availability of server hardware, but also that essential app- and system-level processes are operating properly. 3
Global server load balancing (GSLB). In the event of a site-level outage or based on administrator-configured parameters pertaining to user proximity or data centre performance NetScaler can automatically direct users to an alternate data centre to access business-critical apps and services. Application security NetScaler addresses the need for greater application security with capabilities including: Citrix application firewall. NetScaler incorporates a full-featured application firewall that protects against exploitation of app-layer vulnerabilities and helps prevent unauthorised disclosure of sensitive data. Citrix Access Gateway. An integral SSL VPN thoroughly establishes the security state of client devices before allowing application access. Access Gateway also provides essential authentication and encrypted tunneling capabilities for remote users. Network-layer defenses. NetScaler s proxy architecture and optimised connection handling routines inherently protect downstream apps and infrastructure from a wide range of threats, including DoS/flood-based attacks. All this, and more... These capabilities are just a subset of what NetScaler has to offer. In addition, some of them have multiple benefits. For example, though the example above calls out its performance-enhancing benefits, dynamic caching also boosts scalability by reducing the processing load on back-end app servers. Extend delivery optimisation to the data tier with NetScaler DataStream technology The data tier has always been a crucial element of web application infrastructure. These days this is more true than ever as social networking, video, and the web in general continue to drive an unprecedented explosion of both structured and unstructured data. The result is a rapidly escalating need to optimise performance and enhance scalability, high availability, and security of the data tier to keep it from becoming a bottleneck to the apps and services that rely on it. NetScaler DataStream technology is a new Citrix solution that responds to this need by extending applicability of familiar web tier delivery capabilities to the data tier. 4
A high-speed SQL proxy and protocol parser, DataStream is a completely non-intrusive, network-based solution. You don t need any custom scripting, application changes, or operating system modifications to enable its powerful set of data tier optimisations and enhancements, including: SQL connection multiplexing. NetScaler DataStream consolidates numerous client SQL requests over a few long-lived SQL connections, reducing database connection requirements by 50:1 or more depending on the application. Benefits include reduced CPU and memory load, which leads to accelerated response times and the need for fewer database servers. Intelligent SQL load balancing. DataStream leverages SQL awareness to split multiple transactions originating from a single client connection among different database servers, thereby reducing the potential for overload situations and diminished performance. Because it can distinguish among select, drop, insert, update and other SQL statements, DataStream can also split read and write transactions, allowing for more efficient database configurations. Health monitoring and failover. DataStream continuously monitors the health of database servers based on factors including replication backlog and response times, then intelligently distributes SQL requests to the server best able to provide the requested content. In the event of a database server failure, DataStream automatically re-routes outstanding SQL requests to another available server without terminating client-side SQL connections. Enhanced data security. You can enforce data access policies on per-user basis, implement SQL protocol validation and generate a consolidated log of all SQL transactions, all without taxing associated database servers. The net result is a solution that facilitates database scale-up and scale-out, while also delivering improved performance and stronger data security. Ensure peak performance, smooth operations with in-depth application-layer visibility As a general rule, you can t fix what you can t measure and can t measure what you can t see. NetScaler helps address this lack of application-layer visibility, letting you see, measure, and fix application-layer performance with EdgeSight for NetScaler. An agentless solution that transparently instruments client HTML pages, EdgeSight provides real-time performance monitoring for web applications. Once you ve got the information you need about the user experience from EdgeSight, you can use Citrix AppFlow to gain in-depth insight into the inner workings of applications and their performance. AppFlow reveals details such as who is using which services, when, to what extent and from where, by extending the TCP-level information already captured by IPFIX the IETF standard for NetFlow to include per-flow application-layer data records. 5
A distinct advantage of AppFlow is its use of a widely supported standardsbased data format, rather than a proprietary one. This enhances the value of existing analytic and performance monitoring tools and ensures organisations have a choice. Popular management tools from Solarwinds and Splunk are among the first to incorporate the use of AppFlow data. AppFlow leverages your organisation s existing NetScaler devices, which are already in an ideal location for gathering application and service-oriented data. There is no need to implement an array of proprietary taps, consume multiple span ports, or deploy any additional devices. Neither is AppFlow dependent on agents, which can be onerous and expensive to deploy and manage. The result is a cloud-friendly and completely non-intrusive solution for obtaining application-layer visibility. You can leverage AppFlow to help with a number of crucial management tasks, including SLA monitoring, performance tuning and capacity planning. With AppFlow, you can perform tasks including: Quickly identify app response times that exceed SLAs and may lead to loss of page views and/or revenue Determine whether changes to the computing environment have negatively impacted any application or service and pinpoint the cause Immediately identify aborted customer transactions so you can correct associated problems Easily generate TopN reports to better understand how users are leveraging online resources Maximise impact, minimise investment with choice of platform NetScaler is available in three options to match the broadest range of business, performance and deployment requirements. In addition to high-performance NetScaler MPX hardware appliances, Citrix offers a software-based virtual appliance, NetScaler VPX, and NetScaler SDX, a solution architected for high-volume multi-tenant use cases. All NetScaler appliances use the same binary, ensuring consistency of features, simplifying ongoing management and enabling heterogeneous deployments that combine different platforms in different parts of the network. Flexible Pay-as-You-Grow and Burst Pack purchasing programs deliver additional investment protection and deployment flexibility, allowing you to meet future performance requirements without the need for expensive and disruptive forklift upgrades. NetScaler MPX. Most of the world s largest and highest traffic volume web sites are powered by NetScaler MPX. Featuring dedicated SSL encryption hardware and patented Citrix ncore technology, which enables simultaneous use of up to 12 CPU cores, NetScaler MPX delivers multi-gigabit performance and massive scalability. With throughput from 500 Mbps to 50 Gbps, the ability to execute thousands of SSL transactions per second and support for multiple 10G ports and FIPS-certified platforms, NetScaler MPX is the best choice for the most demanding application delivery scenarios. 6
NetScaler VPX. A virtual appliance capable of running on Citrix XenServer, Microsoft Hyper-V and VMware ESX, NetScaler VPX supports the full ADC feature set, including GSLB, application firewall, and SSL VPN. As a flexible software-based solution, it can be deployed on demand, anywhere in enterprise or cloud data centres, using off-the-shelf standard servers. With throughput up to 3 Gbps, NetScaler VPX is a simple yet highly capable platform that is well suited not only for SMBs, but also for larger companies looking for a cost-effective way to more thoroughly implement app delivery technology, for example, to support a greater percentage of their web app portfolio and to have development, testing, and staging environments more accurately reflect the configuration of their product networks. It is also an ideal fit for emerging cloud architectures. NetScaler SDX. NetScaler SDX is a next-generation service delivery platform for enterprise and cloud data centres. An advanced virtualised architecture that supports multiple NetScaler instances on a single hardware appliance, it delivers the industry-leading performance of the NetScaler MPX system architecture while an advanced control plane unifies provisioning, monitoring and management to meet the most demanding multi-tenant requirements. Full network and resource isolation guarantees performance SLAs and data separation, while supporting completely independent fault domains, software version control and policy management. Optimised for hybrid enterprise/ public-cloud scenarios, NetScaler SDX also provides a foundation for the consolidation of adjacent services including WAN optimisation, network security and desktop delivery. Conclusion: make the transition from application delivery to successful service delivery with NetScaler NetScaler boosts web application performance and scalability by optimising delivery over networks, offloading compute-intensive processes and making it easy and inexpensive to scale out related infrastructure. It also offers an integral set of capabilities for ensuring application availability and establishing superior levels of application security and data protection. These capabilities alone make it a top choice among enterprises and service providers alike for powering their business-critical applications and services. More than just an ordinary application delivery controller, however, NetScaler also extends delivery optimisation to the data tier, supplies an efficient method for establishing indepth application-layer visibility and provides your organisation an unmatched choice of platform so that you can achieve maximum impact at minimum cost. 7
Worldwide Headquarters Citrix Systems, Inc. 851 West Cypress Creek Road Fort Lauderdale, FL 33309, USA Tel: +1 (800) 393 1888 Tel: +1 (954) 267 3000 European Headquarters Citrix Systems International GmbH Rheinweg 9 8200 Schaffhausen Switzerland Tel: +41 (0)52 6 35 77-00 European Subsidiaries Citrix Systems GmbH Am Söldnermoos 17 85399 Hallbergmoos/München Germany Tel: +49 (0)811 83-0000 www.citrix.de Citrix Systems SARL 7, place de la Défense 92974 Paris la Défense 4 Cedex France Tel: +33 (0)1 49 00 33 00 www.citrix.fr Citrix Systems UK Limited Chalfont Park House, Chalfont Park Chalfont St. Peter Gerrards Cross Buckinghamshire, SL9 0DZ United Kingdom Tel: +44 (0)1753 276 200 www.citrix.co.uk Citrix Systems Benelux Clarissenhof 3c, 4133 AB Vianen Netherlands Tel: +31 (347) 324800 www.citrix.nl Citrix Systems Nordic Kalkbrænderiløbskaj 4 2100 Copenhagen Ø Denmark Tel: +45 39193400 www.citrix.dk Asia Pacific Citrix Systems Hong Kong Ltd. Suite 3201, 32nd Floor One International Finance Centre 1 Harbour View Street Central, Hong Kong Tel: +852 2100 5000 Citrix Online Division 5385 Hollister Avenue Santa Barbara, CA 93111 Tel: +1 (805) 690 6400 About Citrix Citrix Systems, Inc. (NASDAQ:CTXS) is a leading provider of virtual computing solutions that help people work and play from anywhere on any device. More than 230,000 enterprises rely on Citrix to create better ways for people, IT and business to work through virtual meetings, desktops and datacentres. Citrix virtualization, networking and cloud solutions deliver over 100 million corporate desktops and touch 75 percent of Internet users each day. Citrix partners with over 10,000 companies in 100 countries. Annual revenue in 2010 was $1.87 billion. 2011 Citrix Systems, Inc. All rights reserved. Citrix, Netscaler, XenServer, Access Gateway, AppFlow, SDX, VPX, MPX and DataStream are trademarks of Citrix Systems, Inc. and/or one or more of its subsidiaries, and may be registered in the United States Patent and Trademark Office and in other countries.all other trademarks and registered trademarks are property of their respective owners.