|By Hovhannes Avoyan||
|December 19, 2012 10:27 PM EST||
In our previous article we discussed the hardware supported features of some of the high-end network adapters. Let’s take a look how you can use some of those settings to their best advantage. Remember that the correct settings depend on the network adapter, your workload, the resources of the host computer, and of course your performance goals.
Turning on network adapter offload features typically will benefit performance.However, sometimes the network adapter might not be powerful enough to handle the offload capabilities with high throughput. For example, enabling segmentation offload can reduce the maximum sustainable throughput on some network adapters because of limited hardware resources. However, if the reduced throughput is not expected to be a limitation, you should enable offload capabilities, even for those network adapters. Some network adapters require offload features to be independently enabled for send and receive paths.
RSS can improve web scalability and performance if you have fewer network adapters than logical processors in your server. When all the web traffic is going through the RSS-capable network adapters, incoming web requests from different connections can be simultaneously processed across different CPUs. Because of the logic in RSS and HTTP for load distribution, performance can be degraded if a non-RSS-capable network adapter accepts web traffic on a server that has one or more RSS-capable network adapters. It is recommended that you use RSS-capable network adapters or disable RSS from the Advanced Properties tab. To determine whether a network adapter is RSS-capable, view the RSS information on the Advanced Properties tab for the device.
RSS Profiles and RSS Queues
RSS Profiles are new in Windows Server 2012. The default profile is NUMA Static, which changes the default behavior from previous versions of Windows. We suggest reviewing the available profiles and understanding when they are beneficial. For example, you can use Task Manager to examine if your logical processors is underutilized for receive traffic, and try increasing the number of RSS queues from the default of 2 to the maximum that your network adapter supports. Changing the number of RSS queues is an option your network adapter may have as part of the driver.
For network adapters that allow manual configuration of resources, such as receive and send buffers, you should increase the allocated resources. Some network adapters set their receive buffers low to conserve allocated memory from the host. The low value results in dropped packets and decreased performance. Therefore, for receive-intensive scenarios, it is recommended to increase the receive buffer value to the maximum. If your adapter does not supports or exposes manual configuration, it most likely dynamically configures the resources, or it might be a fixed value that you can’t change.
To control interrupt moderation, some network adapters expose different interrupt moderation levels, buffer coalescing parameters (sometimes separately for send and receive buffers), or both. You should consider interrupt moderation for CPU-bound workloads, and consider the trade-off between the host CPU savings and latency versus the increased host CPU savings because of more interrupts and less latency. If the network adapter does not perform interrupt moderation, but it does expose buffer coalescing, increasing the number of coalesced buffers allows more buffers per send or receive, which improves performance.
Your network adapter has a number of options to optimize latency caused by the operating system. This latency is the time between the network driver processing an incoming packet and the sending it back, and is usually measured in microseconds. As a comparison, the transmission time for packets transmitted over long distances is usually expressed in milliseconds. This tuning will not reduce the time a packet spends in transit.
Some tuning suggestions for microsecond-sensitive networks include:
· Set the computer BIOS to High Performance, with C-states disabled. However, this is system and BIOS dependent. Some systems provide higher performance if the operating system controls power management. You can check and adjust your power management settings from the Control Panel or by using the powercfg command.
· Set the operating system power management profile to High Performance System. For this to work as expected, your system’s BIOS has to be set to enable operating system control of power management.
· Enable Static Offloads, for example, UDP Checksums, TCP Checksums, and Send Large Offload (LSO)
· Enable RSS if the traffic is multi-streamed, such as high-volume multicast receive
· Disable the Interrupt Moderation setting for network drivers that require the lowest possible latency. The tradeoff is that this can use more CPU time.
· Handle network adapter interrupts and DPCs on a core processor that shares CPU cache with the core that is being used by the program that is handling the packet. CPU affinity tuning can be used to direct a process to certain logical processors in conjunction with RSS configuration to accomplish this. Using the same core for the interrupt, DPC, and user mode thread exhibits worse performance as load increases because the ISR, DPC, and thread contend for the use of the core.
Many hardware systems use System Management Interrupts (SMI) for a variety of maintenance functions, including reporting of ECC memory errors, legacy USB compatibility, fan control, and BIOS controlled power management. The SMI is the highest priority interrupt on the system and places the CPU in a management mode, which preempts all other activity while it runs an interrupt service routine, typically contained in BIOS.
This behavior can result in latency spikes of 100 microseconds or more. If you need to achieve the lowest latency, look for a BIOS version from your hardware provider that reduces SMIs to the lowest degree possible, referred to as “low latency BIOS” or “SMI free BIOS.” It is not possible to eliminate SMI activity altogether because it is used to control some essential functions, such as fan control.
TCP Receive Window Auto-Tuning
Prior to Windows Server 2008, the network stack used a fixed-size receive-side window that limited the overall potential throughput for connections. One of the most significant changes to the TCP stack is TCP receive window auto-tuning. You can calculate the total throughput of a single connection when you use this fixed size default as:
Total achievable throughput in bytes = TCP window * (1 / connection latency)
As an example, the achievable throughput is only 51 Mbps on a 1 GB connection with 10ms latency. With auto-tuning, the receive-side window is adjustable, and it can grow to meet the demands of the sender. It is possible for a connection to achieve a full line rate of a 1 GB connection. Network usage requirements that might have been limited in the past by the total achievable throughput of TCP connections can now fully use the network.
Windows Filtering Platform
The Windows Filtering Platform (WFP) that was introduced in Windows Vista and Windows Server 2008 provides APIs to non-Microsoft independent software vendors (ISVs) to create packet processing filters. Examples include firewall and antivirus software. Be careful that a poorly written WFP filter can significantly decrease networking performance.
The following registry keywords from Windows Server 2003 are no longer supported, and they are ignored in Windows Server 2012, as well as Windows Server 2008 R2, and Windows Server 2008:
· TcpWindowSize – HKLM\System\CurrentControlSet\Services\Tcpip\Parameters
· NumTcbTablePartitions – HKLM\system\CurrentControlSet\Services\Tcpip\Parameters
· MaxHashTableSize – HKLM\system\CurrentControlSet\Services\Tcpip\Parameters
This section lists the counters that are relevant to managing network performance.
· IPv4, IPv6
- Datagrams Received/sec
- Datagrams Sent/sec
· TCPv4, TCPv6
- Segments Received/sec
- Segments Sent/sec
- Segments Retransmitted/sec
· Network Interface(*), Network Adapter(*)
- Bytes Received/sec
- Bytes Sent/sec
- Packets Received/sec
- Packets Sent/sec
- Output Queue Length
This counter is the length of the output packet queue (in packets). If this is longer than 2, delays occur. You should find the bottleneck and eliminate it if you can. Because NDIS queues the requests, this length should always be 0.
· Processor Information
- % Processor Time
- DPCs Queued/sec
This counter is an average rate at which DPCs were added to the logical processor’s DPC queue. Each logical processor has its own DPC queue. This counter measures the rate at which DPCs are added to the queue, not the number of DPCs in the queue. It displays the difference between the values that were observed in the last two samples, divided by the duration of the sample interval.
Potential Network Problems
· Network Interface(*), Network Adapter(*)
- Packets Received Discarded
- Packets Received Errors
- Packets Outbound Discarded
- Packets Outbound Errors
· WFPv4, WFPv6
- Packets Discarded/sec
· UDPv4, UDPv6
- Datagrams Received Errors
· TCPv4, TCPv6
- Connection Failures
- Connections Reset
· Network QoS Policy
- Packets dropped
- Packets dropped/sec
· Per Processor Network Interface Card Activity
- Low Resource Receive Indications/sec
- Low Resource Received Packets/sec
· Microsoft Winsock BSP
- Dropped Datagrams
- Dropped Datagrams/sec
- Rejected Connections
- Rejected Connections/sec
Receive Side Coalescing (RSC) performance
· Network Adapter(*)
- TCP Active RSC Connections
- TCP RSC Average Packet Size
- TCP RSC Coalesced Packets/sec
- TCP RSC Exceptions/sec
The 4th International Internet of @ThingsExpo, co-located with the 17th International Cloud Expo - to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA - announces that its Call for Papers is open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
May. 25, 2015 09:00 AM EDT Reads: 1,991
The worldwide cellular network will be the backbone of the future IoT, and the telecom industry is clamoring to get on board as more than just a data pipe. In his session at @ThingsExpo, Evan McGee, CTO of Ring Plus, Inc., discussed what service operators can offer that would benefit IoT entrepreneurs, inventors, and consumers. Evan McGee is the CTO of RingPlus, a leading innovative U.S. MVNO and wireless enabler. His focus is on combining web technologies with traditional telecom to create a new breed of unified communication that is easily accessible to the general consumer. With over a de...
May. 25, 2015 06:00 AM EDT Reads: 4,754
Disruptive macro trends in technology are impacting and dramatically changing the "art of the possible" relative to supply chain management practices through the innovative use of IoT, cloud, machine learning and Big Data to enable connected ecosystems of engagement. Enterprise informatics can now move beyond point solutions that merely monitor the past and implement integrated enterprise fabrics that enable end-to-end supply chain visibility to improve customer service delivery and optimize supplier management. Learn about enterprise architecture strategies for designing connected systems tha...
May. 25, 2015 05:00 AM EDT Reads: 6,031
Cloud is not a commodity. And no matter what you call it, computing doesn’t come out of the sky. It comes from physical hardware inside brick and mortar facilities connected by hundreds of miles of networking cable. And no two clouds are built the same way. SoftLayer gives you the highest performing cloud infrastructure available. One platform that takes data centers around the world that are full of the widest range of cloud computing options, and then integrates and automates everything. Join SoftLayer on June 9 at 16th Cloud Expo to learn about IBM Cloud's SoftLayer platform, explore se...
May. 25, 2015 04:45 AM EDT Reads: 3,241
SYS-CON Media announced today that 9 out of 10 " most read" DevOps articles are published by @DevOpsSummit Blog. Launched in October 2014, @DevOpsSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development cycles that produce softw...
May. 25, 2015 04:15 AM EDT Reads: 4,238
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal an...
May. 25, 2015 04:00 AM EDT Reads: 2,881
15th Cloud Expo, which took place Nov. 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA, expanded the conference content of @ThingsExpo, Big Data Expo, and DevOps Summit to include two developer events. IBM held a Bluemix Developer Playground on November 5 and ElasticBox held a Hackathon on November 6. Both events took place on the expo floor. The Bluemix Developer Playground, for developers of all levels, highlighted the ease of use of Bluemix, its services and functionality and provide short-term introductory projects that developers can complete between sessions.
May. 25, 2015 04:00 AM EDT Reads: 6,394
From telemedicine to smart cars, digital homes and industrial monitoring, the explosive growth of IoT has created exciting new business opportunities for real time calls and messaging. In his session at @ThingsExpo, Ivelin Ivanov, CEO and Co-Founder of Telestax, shared some of the new revenue sources that IoT created for Restcomm – the open source telephony platform from Telestax. Ivelin Ivanov is a technology entrepreneur who founded Mobicents, an Open Source VoIP Platform, to help create, deploy, and manage applications integrating voice, video and data. He is the co-founder of TeleStax, a...
May. 25, 2015 04:00 AM EDT Reads: 6,500
The Internet of Things (IoT) promises to evolve the way the world does business; however, understanding how to apply it to your company can be a mystery. Most people struggle with understanding the potential business uses or tend to get caught up in the technology, resulting in solutions that fail to meet even minimum business goals. In his session at @ThingsExpo, Jesse Shiah, CEO / President / Co-Founder of AgilePoint Inc., showed what is needed to leverage the IoT to transform your business. He discussed opportunities and challenges ahead for the IoT from a market and technical point of vie...
May. 25, 2015 04:00 AM EDT Reads: 6,880
Grow your business with enterprise wearable apps using SAP Platforms and Google Glass. SAP and Google just launched the SAP and Google Glass Challenge, an opportunity for you to innovate and develop the best Enterprise Wearable App using SAP Platforms and Google Glass and gain valuable market exposure. In his session at @ThingsExpo, Brian McPhail, Senior Director of Business Development, ISVs & Digital Commerce at SAP, outlined the timeline of the SAP Google Glass Challenge and the opportunity for developers, start-ups, and companies of all sizes to engage with SAP today.
May. 25, 2015 03:00 AM EDT Reads: 5,121
The 3rd International @ThingsExpo, co-located with the 16th International Cloud Expo – to be held June 9-11, 2015, at the Javits Center in New York City, NY – is now accepting Hackathon proposals. Hackathon sponsorship benefits include general brand exposure and increasing engagement with the developer ecosystem. At Cloud Expo 2014 Silicon Valley, IBM held the Bluemix Developer Playground on November 5 and ElasticBox held the DevOps Hackathon on November 6. Both events took place on the expo floor. The Bluemix Developer Playground, for developers of all levels, highlighted the ease of use of...
May. 25, 2015 03:00 AM EDT Reads: 3,515
Enthusiasm for the Internet of Things has reached an all-time high. In 2013 alone, venture capitalists spent more than $1 billion dollars investing in the IoT space. With "smart" appliances and devices, IoT covers wearable smart devices, cloud services to hardware companies. Nest, a Google company, detects temperatures inside homes and automatically adjusts it by tracking its user's habit. These technologies are quickly developing and with it come challenges such as bridging infrastructure gaps, abiding by privacy concerns and making the concept a reality. These challenges can't be addressed w...
May. 25, 2015 02:45 AM EDT Reads: 6,821
The industrial software market has treated data with the mentality of “collect everything now, worry about how to use it later.” We now find ourselves buried in data, with the pervasive connectivity of the (Industrial) Internet of Things only piling on more numbers. There’s too much data and not enough information. In his session at @ThingsExpo, Bob Gates, Global Marketing Director, GE’s Intelligent Platforms business, to discuss how realizing the power of IoT, software developers are now focused on understanding how industrial data can create intelligence for industrial operations. Imagine ...
May. 25, 2015 02:00 AM EDT Reads: 5,340
SYS-CON Events announced today that Liaison Technologies, a leading provider of data management and integration cloud services and solutions, has been named "Silver Sponsor" of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York, NY. Liaison Technologies is a recognized market leader in providing cloud-enabled data integration and data management solutions to break down complex information barriers, enabling enterprises to make smarter decisions, faster.
May. 25, 2015 01:30 AM EDT Reads: 5,440
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal today!
May. 25, 2015 01:15 AM EDT Reads: 4,539
Hadoop as a Service (as offered by handful of niche vendors now) is a cloud computing solution that makes medium and large-scale data processing accessible, easy, fast and inexpensive. In his session at Big Data Expo, Kumar Ramamurthy, Vice President and Chief Technologist, EIM & Big Data, at Virtusa, will discuss how this is achieved by eliminating the operational challenges of running Hadoop, so one can focus on business growth. The fragmented Hadoop distribution world and various PaaS solutions that provide a Hadoop flavor either make choices for customers very flexible in the name of opti...
May. 25, 2015 12:30 AM EDT Reads: 4,018
Cultural, regulatory, environmental, political and economic (CREPE) conditions over the past decade are creating cross-industry solution spaces that require processes and technologies from both the Internet of Things (IoT), and Data Management and Analytics (DMA). These solution spaces are evolving into Sensor Analytics Ecosystems (SAE) that represent significant new opportunities for organizations of all types. Public Utilities throughout the world, providing electricity, natural gas and water, are pursuing SmartGrid initiatives that represent one of the more mature examples of SAE. We have s...
May. 24, 2015 11:00 PM EDT Reads: 6,143
The Internet of Things will put IT to its ultimate test by creating infinite new opportunities to digitize products and services, generate and analyze new data to improve customer satisfaction, and discover new ways to gain a competitive advantage across nearly every industry. In order to help corporate business units to capitalize on the rapidly evolving IoT opportunities, IT must stand up to a new set of challenges. In his session at @ThingsExpo, Jeff Kaplan, Managing Director of THINKstrategies, will examine why IT must finally fulfill its role in support of its SBUs or face a new round of...
May. 24, 2015 10:00 PM EDT Reads: 5,509
Can call centers hang up the phones for good? Intuitive Solutions did. WebRTC enabled this contact center provider to eliminate antiquated telephony and desktop phone infrastructure with a pure web-based solution, allowing them to expand beyond brick-and-mortar confines to a home-based agent model. It also ensured scalability and better service for customers, including MUY! Companies, one of the country's largest franchise restaurant companies with 232 Pizza Hut locations. This is one example of WebRTC adoption today, but the potential is limitless when powered by IoT.
May. 24, 2015 09:00 PM EDT Reads: 6,598
One of the biggest challenges when developing connected devices is identifying user value and delivering it through successful user experiences. In his session at Internet of @ThingsExpo, Mike Kuniavsky, Principal Scientist, Innovation Services at PARC, described an IoT-specific approach to user experience design that combines approaches from interaction design, industrial design and service design to create experiences that go beyond simple connected gadgets to create lasting, multi-device experiences grounded in people's real needs and desires.
May. 24, 2015 09:00 PM EDT Reads: 6,161