Welcome!

@CloudExpo Authors: Liz McMillan, Kevin Benedict, Igor Drobiazko, Tim Hinds, Elizabeth White

Related Topics: Microsoft Cloud, Open Source Cloud, IoT User Interface, Silverlight, Release Management , CRM

Microsoft Cloud: Blog Feed Post

Performance Tuning Windows 2012: Network Subsystem | Part 1

NDIS, the protocol stack, and user mode applications

Offload Capabilities
Offloading tasks can reduce CPU usage on the server, which improves the overall system performance. The network stack in Windows 2012 (and prior versions of the OS) can offload one or more tasks to a network adapter permitted you have an adapter with offload capabilities. The table below lists the details about offload capabilities:

Receive-side scaling (RSS) is a network driver technology that enables the efficient distribution of network receive processing across multiple CPUs in multiprocessor systems.

Checksum calculation

The network stack can offload the calculation and validation of Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) checksums on send and receive code paths. It can also offload the calculation and validation of IPv4 and IPv6 checksums on send and receive code paths.

IP security authentication and encryption

The TCP/IP transport layer can offload the calculation and validation of encrypted checksums for authentication headers and Encapsulating Security Payloads (ESPs). The TCP/IP transport layer can also offload the encryption and decryption of ESPs.

Segmentation of large TCP packets

The TCP/IP transport layer supports Large Send Offload v2 (LSOv2). With LSOv2, the TCP/IP transport layer can offload the segmentation of large TCP packets to the hardware.

Receive Segment Coalescing (RSC)

RSC is the ability to group packets together to minimize the header processing that is necessary for the host to perform. A maximum of 64 KB of received payload can be coalesced into a single larger packet for processing.

Receive-Side Scaling (RSS)

Receive-Side Scaling (RSS)
Windows Server 2012 (as well as Windows Server 2008 R2, and Windows Server 2008) supports Receive Side Scaling (RSS). RSS directs network processing to up to one logical processor per core. For example, given a server with Intel Hyper-Threading and 4 cores (8 logical processors), RSS will use no more than 4 logical processors for network processing.
RSS distributes incoming network I/O packets among logical processors so that packets that belong to the same TCP connection are processed on the same logical processor. RSS also load balances UDP unicast and multicast traffic from Windows Server 2012, and it routes related flows (as determined by hashing the source and destination addresses) to the same logical processor, preserving the order of related arrivals. Windows Server 2012 provides the following methods to tune RSS behavior:

· Windows PowerShell: Get-NetAdapterRSS, Set-NetAdapterRSS, Enable-NetAdapterRss, Disable-NetAdapterRss. These cmdlets allow you to view and modify RSS parameters.

· RSS Profiles: Used to determine which logical processors are assigned to which network adapter. Possible profiles are:

o Closest. Logical processor numbers near the network adapter’s base RSS processor are preferred. Windows may rebalance logical processors dynamically based on load.

o ClosestStatic. Logical processor numbers near the network adapter’s base RSS processor are preferred. Windows will not rebalance logical processors dynamically based on load.

o NUMA. Logical processor numbers will tend to be selected on different NUMA nodes to distribute the load. Windows may rebalance logical processors dynamically based on load.

o NUMAStatic. This is the default profile. Logical processor numbers will tend to be selected on different NUMA nodes to distribute the load. Windows will not rebalance logical processors dynamically based on load.

o Conservative: RSS uses as few processors as possible to sustain the load. This option helps reduce the number of interrupts.

You can use the set-netadapterRSS cmdlet to choose how many logical processors can be used for RSS on a per-network adapter basis, the starting offset for the range of logical processors, and which node the network adapter allocates memory from:

· MaxProcessors: Sets the maximum number of RSS processors to be used, ensuring application traffic is bound to a maximum number of processors on an interface.

set-netadapterRSS –Name “Ethernet” –MaxProcessors <value>

· BaseProcessorGroup: Sets the base processor group of a NUMA node, affecting the processor array used by RSS.

set-netadapterRSS –Name “Ethernet” –BaseProcessorGroup <value>

· MaxProcessorGroup: Sets the Max processor group of a NUMA node, affecting the processor array used by RSS.

set-netadapterRSS –Name “Ethernet” –MaxProcessorGroup <value>

· BaseProcessorNumber: Sets the base processor number of a NUMA node, allowing partitioning processors across network adapters and specifying the first logical processor in the range of RSS processors that is assigned to each adapter.

set-netadapterRSS –Name “Ethernet” –BaseProcessorNumber <Byte Value>

· NumaNode: The NUMA node that each network adapter can allocate memory from.

set-netadapterRSS –Name “Ethernet” –NumaNodeID <value>

· NumberofReceiveQueues: If your logical processors seem to be underutilized for receive traffic, you can try increasing the number of RSS queues from the default of 2 to the maximum number supported.

set-netadapterRSS –Name “Ethernet” –NumberOfReceiveQueues <value>

RSS does not provide any interaction with virtual machines, instead you can configure VMQ. RSS can be enabled for virtual machines in the case of SR-IOV because the virtual function driver supports RSS capability. In this case, the guest and the host will have the benefit of RSS. The host however, does not get RSS capability because the virtual switch is enabled with SR-IOV.

Receive-Segment Coalescing (RSC)
Receive Segment Coalescing can improve performance by reducing the number of IP headers that are processed for a given amount of received data.  You should use RSC to tune performance of received data by grouping (or coalescing) smaller packets into larger units. This can reduce latency and increase throughput for received heavy workloads. On network adapters supporting RSC, make sure that it is enabled, unless you have low latency, low throughput networking needs that benefit from RSC being turned off.

In Windows Server 2012 you can use the following PowerShell cmdlets to configure RSC capable adapters: Enable-NetAdapterRsc, Disable-NetRsc, Get-NetAdapterAdvancedProperty, and Set-NetAdapterAdvancedProperty. RSC can be examined using the cmdlets Get-NetAdapterRSC and Get-NetAdapterStatistics. The Get cmdlet shows if RSC is enabled and if TCP enables RSC to be in operational state. In the example above, IPv4 RSC is enabled. To understand failures, you can view the coalesced bytes or exceptions caused by entering the following command:

PS C:\Users\Administrator> $x = Get-NetAdapterStatistics “myAdapter”

PS C:\Users\Administrator> $x.rscstatistics

CoalescedBytes : 0

CoalescedPackets : 0

CoalescingEvents : 0

CoalescingExceptions : 0

RSC and virtualization
If the host adapter is not bound to the virtual switch, RSC is supported on the physical host. If the adapter is bound to the virtual switch, Windows 2012 will disable RSC on the physical host.
RSC can be enabled for a virtual machine when SR-IOV is enabled. In this case, virtual functions will support RSC capability; hence, virtual machines will also get the benefit of RSC.

Network Adapter Resources

A few network adapters actively manage their resources to achieve optimum performance. Several network adapters let the administrator manually configure resources by using the Advanced Networking tab for the adapter. For such adapters, you can set the values of a number of parameters including the number of receive buffers and send buffers.  In Windows Server 2012, you can configure advanced network settings using the following PowerShell cmdlets:

  • Get-NetAdapterAdvancedProperty
  • SetNetAdapterAdvancedProperty
  • Enable-NetAdapter
  • Enable-NetAdapterBinding
  • Enable-NetAdapterChecksumOffload
  • Enable-NetAdapterLso
  • Enable-NetAdapterIPSecOffload
  • Enable-NetAdapterPowerManagemetn
  • Enable-NetAdapterQos
  • Enable-NetAdapterRDMA
  • Enable-NetAdapter
  • Enable-NetAdapterSriov

Message-Signaled Interrupts (MSI/MSI-X)
Network adapters that support MSI/MSI-X can target specific logical processors. If your network adapter also support RSS, then a logical processor can be dedicated to servicing interrupts and deferred procedure calls (DPCs) for a given TCP connection. This will greatly improve performance, by preserving the TCP cache.

Interrupt Moderation
Lastly, we’ll discuss interrupt moderation. Some network adapters expose different interrupt moderation levels, or buffer coalescing parameters, or both. You definitely should consider buffer coalescing when the network adapter does not perform interrupt moderation. Interrupt moderation will reduce CPU utilization because it minimizes the per-buffer processing cost, but you should consider that interrupt-moderation  and buffer coalescing can have a negative impact on latency-sensitive situations. The table below lists the suggested adapter features for various server roles.

Role

Checksum offload

Large Send Offload (LSO)

Receive-side scaling (RSS)

Receive Segment Coalescing (RSC)

File server

X

X

X

X

Web server

X

X

X

Mail server (short-lived connections)

X

X

Database server

X

X

X

FTP server

X

X

X

Media server

X

X

X

These settings serve as guidelines only . Depending on the workload, your network adapter(s), and your specific situation, your experience can be different. In our next article we’ll go deeper into tuning the network adapter and utilizing some of the features we discussed.

Read the original blog entry...

More Stories By Hovhannes Avoyan

Hovhannes Avoyan is the CEO of PicsArt, Inc.,

@CloudExpo Stories
Increasing IoT connectivity is forcing enterprises to find elegant solutions to organize and visualize all incoming data from these connected devices with re-configurable dashboard widgets to effectively allow rapid decision-making for everything from immediate actions in tactical situations to strategic analysis and reporting. In his session at 18th Cloud Expo, Shikhir Singh, Senior Developer Relations Manager at Sencha, will discuss how to create HTML5 dashboards that interact with IoT devic...
The increasing popularity of the Internet of Things necessitates that our physical and cognitive relationship with wearable technology will change rapidly in the near future. This advent means logging has become a thing of the past. Before, it was on us to track our own data, but now that data is automatically available. What does this mean for mHealth and the "connected" body? In her session at @ThingsExpo, Lisa Calkins, CEO and co-founder of Amadeus Consulting, will discuss the impact of wea...
trust and privacy in their ecosystem. Assurance and protection of device identity, secure data encryption and authentication are the key security challenges organizations are trying to address when integrating IoT devices. This holds true for IoT applications in a wide range of industries, for example, healthcare, consumer devices, and manufacturing. In his session at @ThingsExpo, Lancen LaChance, vice president of product management, IoT solutions at GlobalSign, will teach IoT developers how t...
There is an ever-growing explosion of new devices that are connected to the Internet using “cloud” solutions. This rapid growth is creating a massive new demand for efficient access to data. And it’s not just about connecting to that data anymore. This new demand is bringing new issues and challenges and it is important for companies to scale for the coming growth. And with that scaling comes the need for greater security, gathering and data analysis, storage, connectivity and, of course, the...
The IoTs will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform. In his session at @ThingsExpo, Craig Sproule, CEO of Metavine, will demonstrate how to move beyond today's coding paradigm and share the must-have mindsets for removing complexity from the development proc...
Artificial Intelligence has the potential to massively disrupt IoT. In his session at 18th Cloud Expo, AJ Abdallat, CEO of Beyond AI, will discuss what the five main drivers are in Artificial Intelligence that could shape the future of the Internet of Things. AJ Abdallat is CEO of Beyond AI. He has over 20 years of management experience in the fields of artificial intelligence, sensors, instruments, devices and software for telecommunications, life sciences, environmental monitoring, process...
SYS-CON Events announced today that Ericsson has been named “Gold Sponsor” of SYS-CON's @ThingsExpo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. Ericsson is a world leader in the rapidly changing environment of communications technology – providing equipment, software and services to enable transformation through mobility. Some 40 percent of global mobile traffic runs through networks we have supplied. More than 1 billion subscribers around the world re...
In the world of DevOps there are ‘known good practices’ – aka ‘patterns’ – and ‘known bad practices’ – aka ‘anti-patterns.' Many of these patterns and anti-patterns have been developed from real world experience, especially by the early adopters of DevOps theory; but many are more feasible in theory than in practice, especially for more recent entrants to the DevOps scene. In this power panel at @DevOpsSummit at 18th Cloud Expo, moderated by DevOps Conference Chair Andi Mann, panelists will dis...
Much of the value of DevOps comes from a (renewed) focus on measurement, sharing, and continuous feedback loops. In increasingly complex DevOps workflows and environments, and especially in larger, regulated, or more crystallized organizations, these core concepts become even more critical. In his session at @DevOpsSummit at 18th Cloud Expo, Andi Mann, Chief Technology Advocate at Splunk, will show how, by focusing on 'metrics that matter,' you can provide objective, transparent, and meaningfu...
In his session at 18th Cloud Expo, Sagi Brody, Chief Technology Officer at Webair Internet Development Inc., will focus on real world deployments of DDoS mitigation strategies in every layer of the network. He will give an overview of methods to prevent these attacks and best practices on how to provide protection in complex cloud platforms. He will also outline what we have found in our experience managing and running thousands of Linux and Unix managed service platforms and what specifically c...
Many private cloud projects were built to deliver self-service access to development and test resources. While those clouds delivered faster access to resources, they lacked visibility, control and security needed for production deployments. In their session at 18th Cloud Expo, Steve Anderson, Product Manager at BMC Software, and Rick Lefort, Principal Technical Marketing Consultant at BMC Software, will discuss how a cloud designed for production operations not only helps accelerate developer...
Redis is not only the fastest database, but it has become the most popular among the new wave of applications running in containers. Redis speeds up just about every data interaction between your users or operational systems. In his session at 18th Cloud Expo, Dave Nielsen, Developer Relations at Redis Labs, will shares the functions and data structures used to solve everyday use cases that are driving Redis' popularity.
See storage differently! Storage performance problems have only gotten worse and harder to solve as applications have become largely virtualized and moved to a cloud-based infrastructure. Storage performance in a virtualized environment is not just about IOPS, it is about how well that potential performance is guaranteed to individual VMs for these apps as the number of VMs keep going up real time. In his session at 18th Cloud Expo, Dhiraj Sehgal, in product and marketing at Tintri, will discu...
Whether your IoT service is connecting cars, homes, appliances, wearable, cameras or other devices, one question hangs in the balance – how do you actually make money from this service? The ability to turn your IoT service into profit requires the ability to create a monetization strategy that is flexible, scalable and working for you in real-time. It must be a transparent, smoothly implemented strategy that all stakeholders – from customers to the board – will be able to understand and comprehe...
You deployed your app with the Bluemix PaaS and it's gaining some serious traction, so it's time to make some tweaks. Did you design your application in a way that it can scale in the cloud? Were you even thinking about the cloud when you built the app? If not, chances are your app is going to break. Check out this webcast to learn various techniques for designing applications that will scale successfully in Bluemix, for the confidence you need to take your apps to the next level and beyond.
SYS-CON Events announced today that Peak 10, Inc., a national IT infrastructure and cloud services provider, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Peak 10 provides reliable, tailored data center and network services, cloud and managed services. Its solutions are designed to scale and adapt to customers’ changing business needs, enabling them to lower costs, improve performance and focus inter...
So, you bought into the current machine learning craze and went on to collect millions/billions of records from this promising new data source. Now, what do you do with them? Too often, the abundance of data quickly turns into an abundance of problems. How do you extract that "magic essence" from your data without falling into the common pitfalls? In her session at @ThingsExpo, Natalia Ponomareva, Software Engineer at Google, will provide tips on how to be successful in large scale machine lear...
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
SYS-CON Events announced today that Enzu, a leading provider of cloud hosting solutions, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Enzu’s mission is to be the leading provider of enterprise cloud solutions worldwide. Enzu enables online businesses to use its IT infrastructure to their competitive advantage. By offering a suite of proven hosting and management services, Enzu wants companies to foc...
Internap Corporation has expanded its OpenStack-based bare-metal Infrastructure-as-a-Service offering, AgileSERVER 2.0, to its data centers in Amsterdam, Dallas and Santa Clara, Calif. Launched in 2015 out of Internap’s New York Metro data center in Secaucus, N.J., AgileSERVER 2.0 is now available in four locations globally, enabling enterprises and devops teams running mission-critical applications and big data workloads to build scale-out infrastructure environments that are higher performing ...