Layer 2-7 Blade Switch Enables Scalable On Demand Computing, Server Optimization,
Redundancy and Security.
Intelligent Load Balancing Solution for
IBM BladeCenter
White Paper
While business growth is a welcome trend for a company, it can be a double-edged sword for the IT
department, since it creates issues around mission critical application availability, performance, scalability and disaster recovery. To address these concerns, many organizations are deploying blade servers to consolidate their server infrastructure. This is being done to ease scalability with dense, cost- and energy- efficient
systems. However, this dense environment needs to be reconfigured to help share the load evenly among each node, keeping some systems from overloading and failing while others remain under-utilized.
Load balancing solutions, a key factor in addressing these concerns—whether in hardware or software—can help ease IT growing pains by intelligently sharing the compute load across multiple systems. As a result, blade environments are able to serve applications faster and more reliably, supporting larger applications and more users. Load balancing solutions also provide redundancy for enhanced reliability and disaster recovery, optimize server resources, enable on demand computing and improve security throughout the network. However, many of today‟s data center solutions stop short of delivering efficient load balancing benefits. Standalone switches and appliance solutions sit outside the blade chassis, requiring additional hardware, cabling, configuration and bandwidth. This architecture can add complexity to the server environment, increasing costs and decreasing application performance. A more efficient architecture approach—
consolidating load balancing within the blade chassis—can solve these issues by simplifying management, reducing capital and operational costs and improving application performance by being less of a burden on bandwidth and processing power.
The BLADE Network Technologies (BNT) Layer 2-7 Gigabit Ethernet Switch Module (GbESM) for IBM BladeCenter—a switch that consolidates network intelligence internally in the blade chassis—provides the benefits of load balancing without the cost and management required of external solutions. The solution intelligently balances the processing load throughout the blade environment while reducing the need for dedicated servers or external devices, saving tens of thousands of dollars in capital and operational costs. In this white paper, we will discuss:
The availability, scalability and disaster recovery issues related to scale-out server architecture How load balancing solutions solve these issues
The benefits of internal load balancing versus external solutions
An innovative load balancing solution through the BNT Layer 2-7 GbESM and its benefits
The Battle to Support Growing IT Environments
Today‟s business applications are growing larger, more powerful and more complex. At the same time, enterprises are seeing explosive growth in today‟s fast-paced, dynamic business environment. Some companies are adding hundreds or thousands of end users every month, requiring immediate access to the tools and information they need to make quick and accurate business decisions. Customer-facing applications on the Web are growing as well, putting massive strain on IT infrastructure in an effort to maintain
performance and availability service levels and ensure a successful customer experience.
Smart companies are looking toward powerful, efficient blade server solutions to meet the low-latency, high bandwidth requirements of today‟s business applications. IBM BladeCenter is designed to extend the performance and reliability benefits of scale-out architecture in a more dense, scalable and cost-efficient design. IBM‟s blades can be deployed in nearly any environment from small- to medium- sized businesses to
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the large server farms and distributed branch offices of an enterprise. Through this server consolidation, companies can save thousands of dollars per rack in capital and operational costs through equipment acquisition, bandwidth, power and cooling, cabling and management.
However, as companies scale-out their blade server environments, systems need to share the processing load to keep up with the increase in user traffic, otherwise some servers may become overloaded while others remain underutilized. An imbalance can cause serious bottlenecks, slowing down applications or preventing users from accessing the information they need. Underutilized systems are a drain on resources, requiring more power, bandwidth and management time than they are contributing to the compute environment. Underperformance also forces IT departments to purchase additional systems when they are not needed—an over-procurement strategy that further drains the IT budget.
In terms of configuration, it is important that multiple systems that support a specific application are identified as a single network address—or URL in a Web-serving environment. Otherwise, users will be hard-wired to a specific system, whether that machine is available or not. A more dynamic load balancing configuration allows users to access the server that provides the best performance each time, ensuring availability, optimal
performance and business continuity.
How Load Balancing can be applied in a Server Environment
Today, there are many load balancing solutions that spread the load across multiple servers, ensuring that all systems are highly utilized and users have reliable access to the business applications and information they need. The solutions also ensure that applications are reachable at a single known address and provide redundancy, disaster recovery and security benefits.
In addition to mission-critical business applications like Informix, Apache, Citrix and MySQL, load balancing solutions can work for any number of applications that rely on the TCP or UDP protocols for client-server or server-to-server communication. Load balancing technology is also used by many IT organizations to improve application security and distribute other network services.
Typically, load balancing solutions are configured as a virtual server with its own unique Virtual IP (VIP) address, assigning itself IP addresses—or range of addresses—of available server resources. As traffic comes in, the solution identifies the application type and makes the decision to allow, deny or redirect traffic according to available IP addresses. Load balancing solutions can also ensure that the same client is consistently directed at the same server, ensuring persistency throughout the environment. When multiple requests come in, the solution binds the session to the IP address of the best available physical server and automatically remaps the fields in each frame from virtual addresses to real addresses. In this way, traffic can be routed to the most appropriate compute resource given the current state of the server environment
(system utilization, availability bandwidth, etc.) and predetermined policies (availability and performance service level agreements, QoS, etc.).
Load balancing solutions can also enhance security by obscuring the real addresses of the blade server from the public network and by reducing the number or public routable IP addresses. For example, a large server farm being used for Web serving can be seen as a single address—the load balancing solutions essentially acting as a traffic cop that intercepts content requests. The solution then modifies the TCP header, performing TCP sequence number translation and recalculating checksums on every packet that travels between the client and the server. This feature ensures that clients are properly authenticated before requests are processed and shields individual servers from malicious attacks.
A New Architecture: Internal Load Balancing Solutions
Many companies deploy routers or appliances with Layer 4-7 capabilities as an adequate external load balancing solution that sits outside the blade chassis and intelligently directs traffic to the appropriate blade depending on utilization, performance and availability factors determined by the IT staff. While these external solutions provide load balancing benefits and help distribute traffic intelligently throughout the blade
environment, there is a more efficient and powerful architectural option.
Organizations can negate the challenges and inefficiencies of external hardware and software-based load balancing solutions by consolidating networking intelligence directly inside the blade chassis. This embedded networking option reduces complexity throughout the blade server environment, providing a simpler,
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efficient, secure and scalable server solution that can meet the performance and availability requirements of today‟s high bandwidth, low latency business applications.
Figure 1 shows the consolidation made possible by integrating network intelligence directly in the blade chassis. Migrating rack-mounted servers to blade chassis and scaling them with embedded Layer 2-7 switching functions eliminates much clutter, reducing equipment procurement and cabling while simplifying management. The consolidation also reduces latency, improving application performance and network functionality.
Figure 1:
Consolidating
network
intelligence in
the blade chassis
dramatically
reduces
complexity
In addition, internal solutions do not require a dedicated server and do not sap bandwidth and work for all TCP and UDP traffic, thus providing efficient load balancing features for all applications. Also, the deployment of internal load balancing solutions is quite simple compared to external solutions and help ease the process of scaling server capacity and performance. Since the network intelligence is already embedded in the blade chassis, configuration to the LAN and storage—as well as other network functions—is streamlined.
Most importantly, however, network intelligence consolidated within the blade chassis allows organizations to take advantage of application availability, performance, security and scalability benefits of load balancing without the additional cost of external software or hardware implementations. This cost-efficient blade network architecture simplifies IT infrastructure, saving much of the management typically associated with additional hardware maintenance as well as tens of thousands of dollars in capital and operational costs.
The BNT Layer 2-7 Gigabit Ethernet Switch Module for IBM BladeCenter
The BNT Layer 2-7 GbESM is the only blade switch that provides this internal load balancing technology for IBM BladeCenter, eliminating the need for external hardware or software. Engineered to sit inside the BladeCenter chassis, the BNT Layer 2-7 GbESM improves application performance, decreases capital and operational costs and enhances security and scalability.Due to its innovative design internal to the blade chassis, the BNT Layer 2-7 GbESM provides many benefits:
Performance: According to benchmarks tested by the Tolly Groupi, an independent analyst firm, the switch improves throughput by nearly 60 percent, reducing latency and ultimately improving application performance.
Capital Cost: By eliminating the need to deploy at least one or likely two server load balancing appliances and server connectivity modules from the BladeCenter, the BNT Layer 7 GbESM—the only internal Layer 2-7 blade switch for blade systems—can save nearly $19,000 or 48 percent in acquisition costs.
Operational Cost: A more extensive ROI case study by research firm IDC compared the TCO of an internal blade switch versus a rack-mounted switch and showed a 65 percent reduction in TCO over three years for the internal solution.ii
Power: Due to an energy efficient design, organizations can save nearly $250 per year in power costs and save up to 22 percent less rack space. The total cost of ownership is 49 percent lower over three years, the average lifespan of a server blade. In addition, the reduction in power requirements allows for more servers to
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be added to the rack, providing more services to business customers and increasing the number of business transactions computed per minute.
Security: Keeping server-to-server communication within the chassis enhances security, retaining data where it is harder for hackers to gain access.
Scalability: Because the switch is hot-swappable directly inside the chassis, administrators can scale
networking function and intelligence automatically whenever new blades are added to the server environment. Networking
hardware
External Load Balancer Solution
BLADE Network Technologies Solution
2 IBM Server Connectivity Modules
2 External F5 switches
2 BNT Layer 2-7 GbESM switches
Deployment cost $38,798iii $19,998iv
Networking Power consumption 372 Wattsv 72 Wattsvi Energy costs (3 years)vii $925 $179 TCO $39,723 $20,177
Cost savings N/A $19,546 or 49 percent
Enabling Scalable On Demand Computing
The efficiency and performance benefits of the BNT Layer 2-7 GbESM enables on demand computing, allowing businesses to meet dynamic demand by quickly and seamlessly provisioning server and networking resources based on current need. The BNT Layer 2-7 GbESM facilitates this flexible resource allocation by detecting trends in traffic load and spreading traffic intelligently to server blades that have available capacity, helping to meet application performance and availability service levels.
The BNT Layer 2-7 GbESM can redirect growing traffic to blades that typically support less-critical
applications. When traffic returns to normal levels, all traffic is shifted back to the original blades, and the re-purposed systems are reallocated back to their primary applications or can be shut down to save energy, bandwidth and maintenance costs. As a result, end users always get the best performance at any given time without the company having to over-procure compute and networking resources.
On demand computing is a more scalable environment, allowing organizations to scale IT infrastructure quickly, cost-efficiently and more in line with business growth without over-extending itself or settling for an underperforming server environment. Given that network intelligence is consolidated in each blade chassis, a company can simply hook an IBM BladeCenter to the Internet and add a firewall, deploying a self-contained „data center in a box‟.
IBM‟s datacenter in a box concept allows companies to scale the corporate network more easily and efficiently through a building block approach in the main data center and in remote offices with servers, storage and networking packaged together in one blade chassis. Additional blades can be installed in an existing chassis without the need for an expensive IT consultant. Additional chassis can also be installed with less effort than would be required for traditional servers. This building block approach provides employees out on the edge of the network the same processing power and level of IT service as people based closer to the data center, while keeping implementation and management risks low and total costs down.
Server optimization
Organizations can leverage virtualization and load balancing technology to get the most compute power out of existing systems, fully optimizing current server deployments. Using server resources to their fullest potential ensures optimal application availability and performance while saving thousands of dollars on procurement and operational costs.
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The BNT Layer 2-7 GbESM works with most virtualization solutions—including VMWare, Virtual Iron,
ZenWorks and Microsoft Virtual Server—to help distribute compute load across multiple virtual machines in a multi-core server environment. Global Server Load Balancing extends load balancing across multiple data centers regardless of geographic location (data centers can potentially be deployed across several countries), making them appear as a single server to clients.
Redundancy for Business Continuity
The BNT Layer 2-7 GbESM can provide application, blade, chassis and data center redundancy for high availability and disaster recovery, ensuring seamless business continuity—even in the aftermath of a major natural disaster. The BNT Layer 2-7 GbESM conducts regular health checks to make sure that servers in a load-balanced cluster—whether they in the same chassis as the switch, an adjacent chassis, or even free-standing servers—are available to support the application. The BNT Layer 2-7 GbESM will automatically fail over to a healthy server if a failure is detected. Likewise, if a blade, or even an entire chassis, is unavailable— regardless of the reason—the BNT Layer 2-7 GbESM will find one that is available, automatically redirecting the request. If a user is in mid-session, the session will be restarted on a healthy sever with minimal impact and minimal delay.
For example, a customer that is shopping online will not lose the items in his or her shopping cart if a blade fails in the middle of the transaction. The purchase items, as well as any billing information, will be carried over to the new server without having to log back in or re-enter information. The BNT Layer 2-7 GbESM can facilitate this automatic failover, eliminating disruptive sessions and potentially saving thousands of dollars in transactions.
Planned downtime can be virtually eliminated through the use of the BNT Layer 2-7 GbESM by shifting traffic to other resources during maintenance. (This is sometimes referred to as a “rolling upgrade.”) Because some of the servers are online throughout the entire duration of the maintenance window, this technique ensures that employees and customers have virtually uninterrupted access to the applications that they need. The effects of a widespread system outage—such as a fire in the data center or a regional natural disaster— can be alleviated when the BNT Layer 2-7 GbESM automatically shifts processing and client requests to an off-site disaster recovery facility. As shown in Figure 3, the DR site (Site B) can be deployed miles away from the main data center (Site A) and is able to support
mission-critical business functions, giving the organization the ability to continue operations soon after a disaster. The BNT Layer 2-7 GbESM seamlessly re-routes requests to the new data center so there is little interruption in business continuity and no degradation in application performance (as long as the equipment and bandwidth at the DR site are equal to those at the primary site).
Figure 3: The BNT Layer 2-7 GbESM can
provide multi-site redundancy across
geography, providing robust disaster recovery
protection
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Secure Blade Environments
Some security threats target data as it travels between switches and servers. Therefore, companies can effectively limit their security exposures by internalizing network intelligence and load balancing. The BNT Layer 2-7 GbESM can act as a traffic cop, limiting or denying server access by those who are not
authorized. The BNT Layer 2-7 GbESM can also splice the TCP connection between client and end server to ensure the client request is valid before allowing a TCP session to be established. This prevents the spread of attacks between blades and between blade chassis, helping to quarantine affected servers. The BNT Layer 2-7 GbESM can ensure that applications are not being abused by cutting off server access to suspected attackers if traffic reaches a certain threshold or acts in suspicious ways. It does this by analyzing traffic as it comes in, building a repository of trends and predicting normal traffic load. If the load veers from this assumption, alarms are triggered, shutting down affected systems or an entire chassis before the attacks can spread. Safe application traffic continues unabated, redirected to other, available servers.
Conclusion
Enterprises today that are facing explosive growth in application traffic are relying on scalable and dense IBM BladeCenter environments to meet this dynamic demand. Current hardware- and software- based load balancing solutions help spread traffic load evenly among processing resources, however, these external solutions lack the price per performance ratio that attracts IT directors to blades in the first place. BLADE Network Technologies offers a unique load balancing option that consolidates network
intelligence directly in the blade chassis, eliminating the costs, network complexity and performance issues associated with external solutions. The BNT Layer 2-7 GbESM for the IBM BladeCenter provides cost-efficient load balancing capabilities that save businesses nearly 50 percent in capital and operational costs while enabling on demand computing, optimizing the blade environment, providing redundancy for business continuity and improving security.
About BLADE Network Technologies
BLADE Network Technologies is the leading supplier of Gigabit and 10G Ethernet network infrastructure solutions that reside in blade servers and “scale-out” server and storage racks. BLADE‟s new “virtual, cooler and easier” top-of-rack switches demonstrate the promise of “Rackonomics”—a revolutionary approach for scaling out data center networks to drive down total cost of ownership. The company‟s customers include half of the Fortune 500 across 26 industry segments, and an installed base of over 250,000 network switches connecting more than 2,000,000 servers and over 5 million switch ports.
©2009 BLADE Network Technologies, Inc. All rights reserved. Information in this document is subject to change without notice. BLADE Network Technologies assumes no responsibility for any errors that may appear in this document. All statements regarding BLADE‟s future direction and intent are subject to change or withdrawal without notice, at BLADE‟s sole discretion.
http://www.bladenetwork.net. MKT080925
i IBM eServer BladeCenter with BNT‟s Layer 2-7 Gigabit Ethernet Switch Module, Price/Performance of Integrated vs External
Switching. The Tolly Group. January 2004. www.tolly.com/TS/2004/IBM/eServer_BladeCenter/TollyTS204104-IBMeServerBladeCenter15Jan03.pdf
ii
Humphreys, Borovick, Perry. Making the Business Case for Blade Servers with Embedded Layer 2-7 Switches. IDC. September
2003. www.bladenetwork.net/media/PDFs/WP_IBM_MakingCase_Layer_2-7.pdf
iii Server connectivity module ($1,399 x 2) + External F5 Load Balancing switches ($18,000 x 2) = $38,798. IBM SCM web pricing as
of September 24, 2008. F5 BIG-IP Link Controller 1600: List price $18,000 per Network World, July 24, 2008: http://www.networkworld.com/news/2008/072408-f5-big-ip-gear.html?hpg1=bn.
iv
BNT Layer 2-7 GbESM ($9,999 x 2) = $19,998. IBM web pricing as of September 24, 2008.
v Server connectivity module: 36 Watts x 2=72 Watts + F5 Big-IP 1600 150 Watts x 2 = 300
vi
BNT Layer 2-7 GbESM consumes 36 Watts x 2 = 72 Watts. vii
Cost projection is based on the 2006/2007 Average Commercial Electric Price of US$0.0946 per kilowatt hour. The power does not include the energy for cooling so actual costs would be higher.
