1. VDI on Windows Server 2008 R2 Hyper-V: Performance Monitoring Explained–Part 1
This post discusses best practices for VDI (virtual desktop interface) monitoring on Windows Server Hyper-V. It tells you which counters to utilize to determine whether your VM is overloaded, focusing on measuring networking, storage, and CPU usage. Metrics are broken down into five groups: Overall Health, Processor, Memory, Networking, and Storage.

2. NGINX Best Practices
NGINX is now the world’s second most popular server, which is quite impressive considering the strong competition from Apache and Microsoft IIS. These NGINX best practices will help you run the popular web server with optimal performance. Eight steps cover everything from improving Disk I/O to configuring NGINX as a load balancer to avoiding common configuration pitfalls.

3. You Can Monitor Your XenServer With Monitis!
Citrix’s XenServer is a leader in the virtualization platform space. This post shows how you can use the Monitis API to monitor XenServer. There is sample code in the Monitis Github repository for you to download. Then just follow 11 steps to run the daemon and create the custom Monitors to start monitoring XenServer.

4. Monitor Everything with Monitis – And do it easily with PowerShell – Part 14 (Final)
This is a continuation of the last article, which showed you how to create custom monitor updater commands which run a script to upload values to Monitis. This makes it very easy to convert any PowerShell script into a Monitis monitor. This post recaps some of the important points covered in this series of articles. This series focused on using Montiis with PowerShell’s in-the-box capabilities, but there are many other community modules out there you can use with Monitis. This post shows how to apply the approach covered in this series to those modules.

5. VDI on Windows Server 2008 R2 Hyper-V: Performance Monitoring Explained–Part 2
The last post in this series focused on Overall Health metrics of VDI. This post focuses more on processor, memory, and storage monitoring. For each of these, the most important counters are listed. For example, for memory monitoring, the metrics are Hyper-V Hypervisor Partition, Hyper-V Hypervisor Root Partition, Hyper-V VM Vid Partition, Memory. For storage, they are Physical Disk, Hyper-V Virtual Storage Device, and Hyper-V Virtual IDE Controller. All the necessary scripts are on Monitis’ Gifthub page.

6. Mongo and Monitis: A NoSQL Dream Come True
MongoDB is a great NoSQL database that’s grown very popular among developers. It’s known for being highly scalable and easy to work with. These best practices highlight some of the common issues developers face with Mongo and how to work around them, like how to deal with too many open connections. Load testing is recommended to test how many connections, or queries, your database can handle. And remember, using custom monitors, all these metrics can be tracked in Monitis.

As we have discussed on the Monitis blog virtualization is one of the hottest IT subjects today.

One leader in this field is Citrix — with the XenServer product family. XenServer is the most known commercial implementation of of the open source Xen hypervisor. By the way, you should pronounced Xen like “zen.” It comes from a Greek word meaning “guest.”

In the IT world, Xen originated as a research project, led by Ian Pratt at England’s Cambridge University. It was first developed by XenSource Inc., and after acquisition, the work was continued by Citrix. Currently, you can choose between 4 editions of XenServer:

• XenServer [Free Edition]
• XenServer Advanced Edition
• XenServer Enterprise Edition
• XenServer Platinum Edition

Other Citrix “Xen” technology, like XenApp or XenDesktop, are not related to the original Xen project.

In 2009, Citrix decided to open the source of XenServer, and the company created XCP (Xen Cloud Platform). In the first phase, XCP was a whole Linux distribution. Recently, the initiative has been extended to provide XAPI toolstack on standard Linux distribution, in the first place for Debian and Ubuntu. What this means is that you can try XAPI on your home machine.

Monitoring

In the article below, we’ll learn how to apply daemon exporting XenServer metrics to Monitis. This is only proof of concept, but it can be easily modified to do exactly what you want. (This is the power you get using Monitis Open API).

XenServer/XCP

There is a dedicated XenServer monitoring tool included in all paid editions. You can also find some third-party tools. Obviously, we are interested in how we can monitor XenServer and XCP with Monitis. One possible way is to enable SNMP on XenServer and treat it as a standard Linux in Monitis. After all, XenServer and XCP dom0 are based on CentOS. Another method that we are going to give an overview of today is XenServer/XCP-specific. XenServer enables you to download, host and store all VM statistic in a  RRD (Round Robin Database) using HTTP handler. You can find some information on how to use XenServer RRD data in two documents from the Citrix Community page (Click here and here). In the second document, you’ll see that there are two examples of Python scripts that we are going to use for the base to our daemon updating XenServer monitors in Monitis. Both scripts use the python “rrd_update” module. You can also find on this on the Citrix page or grab it from github.

Monitis

Monitis has dedicated libraries in many programing languages. You need to use python to export XenServer RRD; therefore to update results on Monitis, we are going to use the python library, too. The code can be obtained from our github repository. Please remember that you need the elementtree module, which is not a part of standard python distribution. Plus, you have to get it from the official website or obtain it from your distribution repository. There is a note about it in the code, but not in the original article.

xen2monitis

Having these two weapons, we are now ready to attack. First, there is the example code in our git repository that you can install on XenServer or Linux distribution with XCP. Alternately, you can choose another server with a connection to both Monitis and the XenServer that you want to monitor. However, installing our daemon on XenServer/XCP seems to be the best choice.

Here are some easy directions:

1.) Create the Xen2Monitis default directory:

mkdir /var/local/lib/xen2monitis

2.) Download the xen2monitis code which is part of Monitis-Linux-Scripts:

git clone https://github.com/monitisexchange/Monitis-Linux-Scripts.git

3.) Copy Xen2Monits file to default location:

cp  Monitis-Linux-Scripts.git/Xen2Monits/* /var/local/lib/xen2monitis

4.) Go to created directory:

cd /var/local/lib/xen2monitis

5.) Obtain the elementtree module:
- You can get the source code:

wget http://effbot.org/media/downloads/elementtree-1.2.6-20050316.tar.gz

- Or you can get a dedicated package for your distribution. If you plan to use XenServer, the elementtree is already installed there.

6.) Install the elementtree (if not already done by your distribution)
- for source code (the last command as root):

tar -xzf elementtree-1.2.6-20050316.tar.gz
cd elementtree-1.2.6-20050316
python setup.py install

7.) Next, add your API Key and Secret to a file. Please separate them with “,”.The default ‘secret file’ is  /usr/local/xen2monitis/secret

8.) Add the xenserver root password to your secret file, so it should be similar to:

5DQQ0460S18ERNRNRUI7M905N1, 7MA9XJNDL3KAMBAKFR9981N04J, secret_password

9.) Now you can start the daemon:

/usr/local/lib/xen2monitis/xen2monitis.py start

10.) You need to wait few minutes. You can check if your script works without any problems in /var/log/xs2monitis.log.

11.) After a few minutes, you should have a bunch of new graphs that you can add to the Dashboard by Monitors->Custom Monitor menu.

Monitor Name Conventions

When you look at newly created monitor names, you might be a bit confused. The names tend to be very long and have a strange set of strings separated by ‘-’, for example:

lisbon – cpu1 (HOST: 0c1bb847-d867-75ff-27e0-7b468f1385f2)

Such name conventions were chosen to ensure the uniqueness of each monitor. Imagine that you have two VMs called “Win7″. Daemon would not be able to distinguish between them and would save all data into one monitor! To address it, XenServer UUID (universally unique identifier), what looks like set of strings separated by “-”, is added to each title.

Daemon Modification

Using xen2monitis.py script, please remember that there are some values you can define at the beginning of the file, for example:

• where is the secret file (default /usr/local/lib/xen2monitis/secret)
• where is the lock file (default /var/run/xen2monitis.pid)
• where is the log file (default /var/log/xen2monitis.log)
• the url to pool master (default http://localhost)

You might prefer not to use daemon, but, instead, call up script from cron job. It’s not a big problem. You need to copy the main loop, start after line 115 to separate the file and convert it.

We hope this article showing you how to monitor your XenServer with Monitis makes your IT life a lot easier. Please share some tips of your own!

1. Integrate NGINX Monitoring into Monitis.com
NGINX is one of the most popular new web servers out there. It is lightweight and powerful. But monitoring it is no small task. The statistics module that comes with NGINX is not reader friendly, so this post shows you how to monitor NGINX performance with Monitis. In 5 quick and easy steps, Monitis creates a monitor for your NGINX server, with a column for each performance metric. Graphs are shown.

2. Using Tomcat With a Database – Performance Optimization Tips
Do you use Apache Tomcat with a database? Here are 6 tips for optimizing performance for that combination. For example, it’s important to determine the cause of database connection timeouts. One of the common causes is garbage collection. Tip 2 describes how this happens and what can be done to improve performance.

3. Cassandra and Monitis
Cassandra is one of the more popular highly scalable NoSQL databases. If you work with Cassandra, this article will show you how to use Monitis to keep track of the performance of your Cassandra cluster. Code is provided on the Monitis Github page that shows you how many Cassandra nodes you have up and running as well as read and write latencies. You can set alerts on these metrics.

4. M3 code refactor & DBI support
M3, the Monitis Monitor Manager, was first described in this article. Monitis has recently decided to make M3 pluggable to make it easy to add execution and parsing plugins. This posts introduces some of the things you can do with this pluggability. It describes Database integration with Monitis using M3. There are many benefits monitoring your database health in Monitis. This post shows how to make a query and monitor its results. Monitis is anxious to hear your input on how best to use M3 to meet your monitoring needs.

1. Top 10 Open Source eCommerce Software (Joomla and Drupal) – Part 1/2
This is for all you eCommerce store owners. Previous posts compared 20 shopping cart software vendors, including Shopify and Volusion. This post is similar, but focuses on open source shopping cart softwares for Drupal and Joomla. The first post covers the following 5 products/vendors: Hikashop, SimpleCaddy, OpenCart, redShop and RokQuickCart. Each is described with a list of Pros and Cons.

2. Monitor Everything with Monitis – And do it easily with PowerShell – Part 13
This is a fun post that shows you how to monitor Out of Paper errors on your printers using Monitis Custom Performance Counters. You can see all of the out of paper errors, for all printers on a machine, with the line Get-Counter “\Print Queue(*)\Out of Paper Errors. A script is provided which calls this line and posts your printer’s status to Monitis via the API. Once it’s running, you will receive a notification by email or SMS or Phone call when a printer is out of paper.

3. Hadoop 101
Hadoop is a framework for distributed computing across thousands of nodes and petabytes of data. Much of it comes from major Google projects, like MapReduce and Big Table. This post is a very basic but interesting introduction to Hadoop. MapReduce is at the core of how Hadoop handles data processing. It’s what allows Google to search petabytes of data using commodity hardware. MapReduce creates a “master” server which distributes various tasks to “slaves” which then return answers to the master. To store all the data, you would use HBase, the official Hadoop database. Hadoop is comprised of several projects which work together to meet today’s Big Data needs.

4. Top 10 Open Source eCommerce Software (Joomla and Drupal) – Part 2/2
The last article in this post covered 5 open source shopping cart softwares for Joomla and Drupal: Hikashop, SimpleCaddy, OpenCart, redShop and RokQuickCart. This post covers VirtueMart, Wazala, Ubercart, Tienda, and LiteCommerce. To help you gauge the popularity of these options, there is a graph comparing web traffic to their homepages.

5. Performance Tuning Windows Server 2008 R2 Hyper-V: Network
The last article in this series was about performance tuning of Hyper-V storage I/O. This post focuses tells some best practices for optimizing network I/O performance. It shows how to configure the Synthetic Network Adapter and offload hardware to reduce the CPU usage of network I/Os in virtual scenarios. It also explains the Network Switch Topology and how to reduce load on VM’s by routing them to different virtual switches to better use the physical network adapters.

In our last article we discussed performance tuning of Hyper-V storage I/O. In this article we’ll focus on network I/O performance best practices.

Hyper-V supports synthetic and emulated network adapters in the virtual machines, but in general the synthetic devices offer much better performance and also reduce CPU overhead. Both types of adapters are connected to a Hyper-V virtual network switch. If you need external network connectivity you can connect the virtual switch(es) to a physical network adapter.

Let’s start by taking a look at synthetic network adapter configuration.

Synthetic Network Adapter

The Hyper-V synthetic network adapter is designed specifically for virtual machines to achieve reduced CPU overhead on network I/O compared to an emulated network adapter mimicking existing hardware. The synthetic network adapter communicates between the child and root partitions over VMBus by using shared memory for more efficient data transfer.

For best performance, the emulated network adapter should be removed through the VM settings dialog box and replaced with a synthetic network adapter. Remember that the VM integration services need to be installed.

Perfmon counters representing the network statistics for the installed synthetic network adapters are available under the counter set \Hyper-V Virtual Network Adapter (*) \ *.

Install Multiple Synthetic Network Adapters on Multiprocessor VMs

Virtual machines with more than one virtual processor might benefit from having more than one synthetic network adaptor installed into the virtual machine. Network intensive workloads such as a Web server, benefit by having a second synthetic network adapter because use of parallelism in the virtual network stack.

Offload Hardware

We touched on this in our first article “Hardware Selection”. Offload capabilities in the physical network adapter reduce the CPU usage of network I/Os in virtual scenarios. Hyper-V supports LSOv1 and TCPv4 checksum offload. To utilize these settings you must enable the driver settings for the physical network adapter in the root partition. Make sure to explicitly enable LSOv1.

Network Switch Topology

Hyper-V supports creating multiple virtual network switches, each of which can be attached to a physical network adapter if needed. Each network adapter in a VM can be connected to a virtual network switch. If the physical server has multiple network adapters, VMs with network-intensive loads can benefit from being connected to different virtual switches to better use the physical network adapters.

Perfmon counters representing the network statistics for the installed synthetic switches are available under the counter set \Hyper-V Virtual Switch (*) \ *.

VLAN Performance

Hyper-V’s synthetic network adapter supports VLAN tagging. It provides significantly better network performance if the physical network adapter supports NDIS_ENCAPSULATION_IEEE_802_3_P_AND_Q_IN_OOB encapsulation for both large send and checksum offload.

VMQ

Windows Server 2008 R2 supports VMQ-enabled network adapters which can maintain a separate hardware queue for each VM, up to the limit supported by each network adapter.

Use the Hyper-V WMI API to make sure that the virtual machines are assigned a hardware queue.

VM Chimney

Windows Server 2008 R2 supports VM Chimney which will benefit those network connections that have a long lifetime the most. Make sure that for your virtual machines having this type of network load you enable VM Chimney.

Live Migration

Live migration is the process that allows you to move running virtual machines from one node of a the failover cluster to another node without dropping network connection

Best practice is to provide a dedicated network for Live Migration traffic. This helps to minimize the time required to complete a migration.

Another option to improve migration performance is by increasing the number of receive and send buffers on each network adapter that is involved in the migration.

This is the second of two articles about open source ecommerce software that we hope will help web developers and system administrators in selecting what is best for their needs. The first article  Top 10 Open Source eCommerce Software (Joomla and Drupal) reviewed: HikaShop, SimpleCaddy, OpenCart, redSHOP and RokQuickCart.

The following article details our own analysis of the last 5 vendors in our article series.

6.   VirtueMart – http://virtuemart.net/

Founded in 2005, the company VirtueMart has developed a free and open source shopping cart software as an extension for Joomla. Formerly known as mambo-phpShop, VirtueMart is a popular Joomla extension written in PHP, within a MySQL database environment.

Pros

• Has an enormous amount of features and comes with a large number of options to choose from.
• Powerful extensions with great performance in the back-end.
• One of the most popular components used by Joomla users.

Cons

• Installation can be complex and its extension directly is not optimally organization for easy selection.
• Does not provide the SEO features that other comparable platforms offer.
• Unable to upload or download catalog of products using the basic version.  Must pay for the full version to receive a lot of the advanced features.
• Documentation is not available and setup time can take more time in comparison to similar products.

7. Wazala ecommerce – www.wazala.com

With headquarters in Los Angeles, CA, Wazala is one of eight software applications offered by a group of programmers/engineers working at Boxador.  Wazala provides the ability to be integrated into any existing website, and help to transform the site into a commerce site

Pros

• Great alternative as a low-budget application, for those who cannot afford the higher priced solutions.
• Once the buyer commits to purchase a product/service, Wazala does not leave the client’s website; unlike PayPal which brings up a new page.
• Mobile-optimized for users on smartphone devices.
• Configuration is very easy, and can be quickly integrated into any Drupal website.

Cons

• Not suitable for product catalogs greater than 25 items.
• Free version is very limited, not allowing for any inventory tracking.
• Very limited customization features.
• Cannot be fully integrated into an existing site, matching similar colors etc.

8.   Ubercart – http://www.ubercart.org/

Started in 2006 by two employees of a restaurant equipment sales company in Louisville, KY, Ubercart was originally designed to work on Drupal only sites.  The private company currently employees 5 individuals, who spend most of their time coding the new version of the application.

Pros

• Lots of functionality and add-on features available.
• One of the most powerful ecommerce software solutions in the market, providing options such as user roles, permissions etc.
• Excellent option for a small ecommerce site looking for superior usability.
• Quick and easy to install, required only a small amount of time to get things up and running.

Cons

• The software has a number of bugs that are not being addressed or fixed in the near term.
• Poor documentation structure that is not written in a simplistic step-by-step manner.
• Poor community assistance, with regards to any tips or tricks etc.
• Not recommended for large ecommerce sites that need an abundant amount of modules.

9.   Tienda – http://dioscouri.com/joomla-extensions/tienda-ecommerce

Based in New York, NY, Dioscouri Design is the developer a dozen open source PHP packages for Joomla.  Founded in 2007, the privately held company also provides Joomla website development consultancy services for its large client base.

Pros

• A well laid out, and easy to follow, back-end that makes most configurations quick and easy.
• Very robust and very powerful for a simple tool, with a clean interface.
• Installation is straight forward, simple and quick.
• Documentation is well structured with a number of examples, making it very easy to follow.

Cons

• Form styling takes an enormous amount of time, and needs to be completed for each type (login, registration etc.)
• Customization is very complex, and recommend for advanced users only.
• Not an “out of the box” application, and requires an enormous effort to be integrated into an existing site.
• Does not provide several key options for some countries, i.e. Multiple taxes in Canada.

10.   LiteCommerce – http://www.litecommerce.com/

LiteCommerce is one of a number of online solutions developed by Qualiteam, a company formed in 2000, with its headquarters in Ulyanovsk, Russia.  With its original name Creative Development, the company was one of the first providers of commercial open source shopping cart applications.  The company has a number of well-known clients, including Siemens; a global company specializing in electronics and electronic engineering.

Pros

• Excellent technical support and quick to reply to any questions or comments.
• Well integrated with Drupal, making it a very good solution for this platform.
• Flexible and easy-to-use, with a large amount of add-ons available to suit any needs.
• A free 30 day trial is available for the fully functional version, providing a great opportunity to explore and test the application.
• Allows a fair amount of inventory products (5,000 – 10,000) and also a large number of categories (up to 10,000).

Cons

• Not recommended for large scale ecommerce sites exceeding annual sales of 1 million dollars.
• Technical support is not provided by telephone, and only web-based support is available.
• Does not allow the ability to include a number of optional features such as; Product Reviews, Wish List etc.
• Is not a multi-language or multi-currency capable solution.

Statistics 

The below graph and table shows a one year sites traffic comparison for all 10 of the Open Source eCommerce Software products that we reviewed.

We hope that web developers and online retailers have found our articles both interesting and useful in helping them select an open source ecommerce software vendor.

Monitis offers full page load testing and synthetic transactions monitoring services to ensure the online shops are operable 24/7. Without such monitoring, the investment in implementing an online shop will not only bring little revenue but may also affect the overall company’s brand image and reputation.

For more information on Monitis please visit our website: www.monitis.com.

More e-commerce articles are here - http://blog.monitis.com/index.php/category/articles/ecommerce/ 

At Monitis we want to make the lives of web developers and system administrators easy!

We have reviewed the 10 most popular open source ecommerce platforms for Joomla and Drupal and would like to share our thoughts with you. In our two articles there is a list and short analysis of the 10 open source ecommerce software products to help guide you in finding a solution that best suits your needs.

Our first article will cover the following 5 products/vendors: Hikashop, SimpleCaddy, OpenCart, redShop and RokQuickCart.

1. Hikashop – www.hikashop.com

Developed by the private French company, Hikari Software, Hikashop is used as an ecommerce Joomla extension. The application provides a wide variety of marketing tools, statistics and a convenient dashboard to suit any website ecommerce needs.

Pros

• Easier to configure in comparison to similar products.
• Excellent customer service and great support.
• Provides the ability to make modifications on-the-fly.
• Access to forum support is available and very helpful.

Cons

• Does not provide choices to process payments, other than via PayPal.
• A number of sections need to be configured.
• When assigning modules, it can get a bit tricky to configure.

2.   SimpleCaddy – http://atlanticintelligence.net/

Created by Atlantic Intelligence, a private company owned by Mr. Henk Von Pickartz, that develops other open source software (Raw Content, Simple Photo History) for various markets. SimpleCaddy provides a multitude of tools for easy and quick shopping cart setup.

Pros

• Excellent support, with quick response time from the developers.
• Quickly integrates with PayPal to provide fast payment processing.
• Simple to install and very customizable.

Cons

• Once initial extension setup is complete, expanding the product line can be somewhat challenging.
• Lacks a lot of the flare and features available by similar product developers.
• Unable to setup customer accounts, whereby they can login, to link to a current database.
• Does not provide any reporting features.

3.   OpenCart – http://www.opencart.com

Started in 2005, OpenCart is a private company that offers an open source shopping cart for Internet merchants. The company provides a large amount of extensions that can be used within a number of website types (i.e. WordPress, Joomla etc.)

Pros

• The default layout includes most of the necessary features required by an average ecommerce site.
• Provides multi-language and multi-currency features.
• Support is better than most similar open source vendors.
• A fair amount of additional modules are available, including a large number that are free.
• A Joomla component is available, called JooCart, which integrates with any Joomla-based site.

Cons

• Customization is very difficult to implement, and requires advanced coding knowledge.
• A fair amount of small bugs currently exist, and they don’t seem to be addressed by the developers.
• Developer’s assistance is offered for a fee, and documentation is not structured in an easy to read/understand manner.

4. redShop – http://redcomponent.com/redshop

Developed by the Red Component, the company offers several Joomla extensions including redShop, redMemember, and redEvent.  In addition, RedComponent also provides hosting services for Joomla specific websites.

Pros

• Provides great configuration capability and installation takes a very short period of time.
• It comes with a large number of flexible templates that can be assigned to each product, or category.
• Support is very quick, via the company forum.
• Allows the ability to handle volume shipments and calculate the cost of each; something not common in other similar products.

Cons

• Software requires a fair amount of space for hosting.  Not recommended for self-hosting users.
• Does not provide support for a number of payment gateways (i.e. EBS, CCAvenue)
• The software is not as stable as many similar products, and has a number of bugs that still need to be resolved.
• Priced higher than similar products on the market.
• A fair amount of configuration is needed, and a basic knowledge of html is required for a number of options.

5.   RokQuickCart – http://www.rockettheme.com/extensions-joomla/rokquickcart

With headquarters in Golden, Columbia, RocketTheme develops a number of Joomla templates and Drupal and WordPress themes. The company provides membership services, whereby a set rate of $50 will provide access to all of their Joomla templates. The company also designs a number of add components to their templates.

Pros

• Very easy to install and configure – installation time is significantly less than similar competitive products.
• Provides the ability to make easy adjustments.
• Major payment platforms can be used, including Google and PayPal.
• Great for vendors selling a small quantity of products, i.e. less than 20 items.

Cons

• Has not been upgraded to the latest version of Joomla, still running on v.1.5.
• There are compatibility issues with certain browsers, i.e. Google Chrome.
• Does not provide the ability to calculate or process shipping by weight.

Hopefully our first of 3 articles on open source ecommerce platforms has been of interest to web developers and online retailers. Our second article will cover the following 5 vendors: VirtueMart; Wazala ecommerce; Ubercart; Tienda; and LiteCommerce.

More information on Monitis can be found on our website: www.monitis.com

1. Performance Tuning Windows Server 2008 R2 Hyper-V: Hardware Selection
This is a followup to a previous article that got substantial reads, Performance Tuning Windows Server 2008 R2 Hyper-V: Hardware Selection. Several future posts will delve deeper into this topic. This post walks you through selecting the optimal hardware on which to run Hyper-V. Recommendations are given for selecting the right processor, memory, network adapter, storage, and installation process. If you’re interested in running Windows 2008 in a virtual environment, these tips can save you a lot of headaches.

2. Monitis Monitoring Strategies- Start Small and Go Big! (Part 1)
If you’re new to implementing monitoring solutions, the process can be overwhelming. The next five posts in this series hold your hand through it and show how Monitis can help. This post shows how you can start small without risk. Select a month-to-month plan with no contracts and grow your account as needed. There is no lock-in on Monitis’ part. Also, you can start with external and internal monitoring and later add other monitoring types such as fullpage and transaction monitoring.

3. Performance Tuning Windows Server 2008 R2 Hyper-V: Processor & Memory
The last post showed how to select the right hardware for your virtual environment. This post shows you how to optimize processor power and memory once it’s all up and running. Multiple virtual machines share one hardware instance by time-slicing the processor. This process is explained. Then a list of tips is provided along with definitions of key performance related metrics that will save you time and computing power.

4. Performance Tuning Windows Server 2008 R2 Hyper-V: Storage I/O
This post shows you how to optimize Storage I/O in your virtual Hyper-V environment. It explains the two types of virtual storage, the so-called synthetic and emulated. It also explains Virtual Hard Disk Types, Dynamically expanding VHD, Fixed-size VHD, and Differencing VHD. There’s also an explanation of how to balance I/O controls. Following these tips will ensure that your VM’s run smoothly and minimize the chance of overusing your hardware.

In our last article we focused on tuning processor and memory, and in this article we’ll look at tuning the performance of Hyper-V and in particular at aspects that of the storage system used by your Windows Server 2008 R2 Hyper-V solution.

Supported Technology

Hyper-V supports so-called synthetic and emulated storage devices in virtual machines, where the synthetic devices generally offer better throughput and response times as well as reduced CPU overhead. The exception to this statement is if a filter driver can be loaded and reroutes I/Os to the synthetic storage device. Virtual hard disks (VHDs) can be backed by three types of VHD files or raw disks. This article describes the different options and considerations for tuning storage I/O performance.

Synthetic SCSI Controller

The synthetic storage controller provides significantly better performance and has less CPU overhead than the emulated IDE device. There is an enlightened driver for this storage device type and it is in fact required for the guest operating system. The operating system disk is mounted on the IDE device to boot from, but the virtual machine integration services load a filter driver that reroutes IDE device I/Os to the synthetic storage device.

Microsoft recommends that you mount the data drives directly to the synthetic SCSI controller because of the reduced CPU overhead in this type of configuration. You should also mount log files and the operating system paging file directly to the synthetic SCSI controller if their expected I/O rate is high.

For highly intensive storage I/O workloads that span multiple data drives, each VHD should be attached to a separate synthetic SCSI controller for better overall performance. In addition, each VHD should be stored on separate physical disks.

Virtual Hard Disk Types

There are three types of Virtual Hard Disk (VHD) type files. For production servers it is recommended to use fixed-sized VHD files for better performance and to make sure that the virtualization server has sufficient disk space for expanding the VHD file at run time. The following are the performance characteristics and trade-offs between the three VHD types:

· Dynamically expanding VHD – Space for the VHD is allocated on demand. The blocks in the disk start as zeroed blocks but are not backed by any actual space in the file. Reads from such blocks return a block of zeros. When a block is first written to, the virtualization stack must allocate space within the VHD file for the block and then update the metadata. This increases the number of necessary disk I/Os for the write and increases CPU usage. Reads and writes to existing blocks incur both disk access and CPU overhead when looking up the blocks’ mapping in the metadata.

· Fixed-size VHD – Space for the VHD is allocated when the VHD file is created. This type of VHD will have less fragmentation, reducing the I/O. It has the lowest CPU overhead of the three VHD types because reads and writes do not need to look up the mapping of the block.

· Differencing VHD – The VHD points to a parent VHD file. Any writes to blocks never written to before result in space being allocated in the VHD file, as with a dynamically expanding VHD. Reads are serviced from the VHD file if the block has been written to. Otherwise, they are serviced from the parent VHD file. In both cases, the metadata is read to determine the mapping of the block. Reads and writes to this VHD can consume more CPU and result in more I/Os than a fixed-sized VHD.

Snapshots by itself do not affect performance all that much, however, having a large chain of snapshots can affect performance because reading from the VHD can require checking for the requested blocks in many differencing VHDs. Keep your snapshot chains short to maintain good disk I/O performance.

Pass-through Disks

The VHD in a VM can be mapped directly to a physical disk or logical unit number (LUN), instead of a VHD file. This has the benefit that this configuration bypasses the file system (NTFS) in the root partition, which reduces the CPU usage of storage I/O. The risk is that physical disks or LUNs can be more difficult to move between machines than VHD files.

Large data drives are good candidates for pass-through disks, especially if they are I/O intensive. VMs that can be migrated between virtualization servers (such as quick migration) must also use drives that reside on a LUN of a shared storage device.

Disabling File Last Access Time Check

Windows Server 2003 and earlier update the last-accessed time of a file when applications open, read, or write to the file, increasing the number of disk I/Os and this increasing the CPU overhead of virtualization. If your applications do not use the last-accessed time, you should consider setting this registry key to disable these updates:

NTFSDisableLastAccessUpdate

HKLM\System\CurrentControlSet\Control\FileSystem\ (REG_DWORD)

Windows Server 2008 R2 disables the last-access time updates by default.

Physical Disk Topology

It is recommended that VHDs used by I/O-intensive virtual machines are not be placed on the same physical disks as this can cause those disks to become a bottleneck. If possible, they should also not be placed on the same physical disks that the root partition uses.

I/O Balancer Controls

The virtualization stack balances storage I/O streams from various virtual machines so that each VM has similar I/O response times when the system’s I/O bandwidth is saturated. You can fine-tune this balancing algorithm by using the following registry keys can be used to adjust the balancing algorithm:

HKLM\System\CurrentControlSet\Services\StorVsp\<Key> = (REG_DWORD)

HKLM\System\CurrentControlSet\Services\VmSwitch\<Key> = (REG_DWORD)

The virtualization stack tries to fully use the I/O device’s throughput while providing a reasonable balance. The first path listed should be used for storage scenarios, and the second path should be used for networking scenarios.

Both storage and networking have three registry keys that can be used to fine tune I/O balancing. Microsoft does ot recommend this advanced tuning option unless you have a specific reason to use it. There is also no guarantee that these registry keys are available in future versions of Hyper-V:

· IOBalance_Enabled – The balancer is enabled when set to a nonzero value and disabled when set to 0. The default is enabled for storage and disabled for networking. Enabling the balancing for networking can add significant CPU overhead in some scenarios.

· IOBalance_KeepHwBusyLatencyTarget_Microseconds – This controls how much work, represented by a latency value, the balancer allows to be issued to the hardware before throttling to provide better balance. The default is 83 ms for storage and 2 ms for networking. Lowering this value can improve balance but will reduce some throughput. Lowering it too much significantly affects overall throughput. Storage systems with high throughput and high latencies can show added overall throughput with a higher value for this parameter.

· IOBalance_AllowedPercentOverheadDueToFlowSwitching – This controls how much work the balancer issues from a VM before switching to another VM. This setting is primarily for storage where finely interleaving I/Os from different VMs can increase the number of disk seeks. The default is 8 percent for both storage and networking.

In our next article we’ll tacle network I/O performance tuning best practices.

This is our second article in our series about tuning performance of your Windows Server 2008 R2 Hyper-V environment. In our first article we discussed the considerations you should make when selecting the hardware components for your Hyper-V server(s).

We mentioned in our first article that the way the hypervisor virtualizes the physical processors is by time-slicing between the virtual processors. Obviously, moving a workload into a virtual machine increases CPU usage. In this article we’ll discuss how to optimize the processor(s).

VM Integration Services

The VM Integration Services include enlightened drivers for the synthetic I/O devices, which significantly reduces CPU overhead for I/O compared to emulated devices. You should install the latest version of the VM Integration Services in every supported guest. The services decrease the CPU usage of the guests, from idle guests to heavily used guests, and improves the I/O throughput. This is the first step in tuning a Hyper-V server for performance. For the list of supported guest operating systems, see the documentation that is provided with the Hyper-V installation.

Virtual Processors

Hyper-V in Windows Server 2008 R2 supports a maximum of four virtual processors per VM. VMs that have loads that are not CPU intensive should be configured to use one virtual processor. This will avoid the additional overhead that is associated with multiple virtual processors, such as additional synchronization costs in the guest operating system. More CPU-intensive loads should be configured with 2 to 4 virtual processor if the VM requires more than one CPU of processing under peak load.

Windows Server 2008 R2 features enlightenments to the core operating system that improve scalability in multiprocessor VMs. Workloads can benefit from the scalability improvements in Windows Server 2008 R2 if they run in 2 to 4 virtual processor virtual machines.

Background Activity Best Practices

Minimizing the background activity in idle VMs releases CPU cycles that can be used elsewhere by other VMs or saved to reduce energy consumption. Windows guests typically use less than 1 percent of one CPU when they are idle. The following are several best practices for minimizing the background CPU usage of a VM:

· Install the latest version of the VM Integration Services.

· Remove the emulated network adapter through the VM settings dialog box (use the Microsoft synthetic adapter).

· Remove unused devices such as the CD-ROM and COM port, or disconnect their media.

· Keep the Windows guest at the logon screen when it is not being used.

· Use Windows Server 2008 or Windows Server 2008 R2 for the guest operating system.

· Disable the screen saver.

· Disable, throttle, or stagger periodic activity such as backup and defragmentation.

· Review the scheduled tasks and services that are enabled by default.

· Improve server applications to reduce periodic activity (such as timers).

· Use the Balanced power plan instead of the High Performance power plan.

The following are additional best practices for configuring a client version of Windows in a VM to reduce the overall CPU usage:

· Disable background services such as SuperFetch and Windows Search.

· Disable scheduled tasks such as Scheduled Defrag.

· Disable AeroGlass and other user interface effects (through the System application in Control Panel).

Setting the Processor Weight

Hyper-V supports setting the weight of a virtual processor to grant it a larger or smaller share of CPU cycles than average and specifying the reserve of a virtual processor to make sure that it gets a minimal percentage of CPU cycles. The CPU that a virtual processor consumes can also be limited by specifying usage limits. System administrators can use these features to prioritize specific VMs, but we recommend the default values unless you have a compelling reason to alter them.

Weights and reserves prioritize or de-prioritize specific VMs if CPU resources are overcommitted. This makes sure that those VMs receive a larger or smaller share of the CPU. Highly intensive loads can benefit from adding more virtual processors instead, especially when they are close to saturating an entire physical CPU.

Non-Uniform Memory Access (NUMA)

On Non-Uniform Memory Access (NUMA) hardware, each VM has a default NUMA node preference. Hyper-V uses this NUMA node preference when assigning physical memory to the VM and when scheduling the VM’s virtual processors. A VM performs optimally when its virtual processors and memory are on the same NUMA node.

By default, the system assigns the VM to its preferred NUMA node every time the VM is run. An imbalance of NUMA node assignments might occur depending on the memory requirements of each VM and the order in which each VM is started. This can lead to a disproportionate number of VMs being assigned to a single NUMA node.

Use Perfmon to check the NUMA node preference setting for each running VM by examining the \Hyper-V VM Vid Partition (*)\ NumaNodeIndex counter.

You can change NUMA node preference assignments by using the Hyper-V API (WMI) and accessing the NumaNodeList property of the Msvm_VirtualSystemSettingData class.

Memory Performance

The hypervisor virtualizes the guest physical memory to isolate VMs from each other and provide a contiguous, zero-based memory space for each guest operating system. In general, memory virtualization can increase the CPU cost of accessing memory. On non-SLAT-based hardware, frequent modification of the virtual address space in the guest operating system can significantly increase the cost.

CPU Performance Counters

Hyper-V supports performance counters to measure the behavior and performance of the virtualization server. The standard set of tools for viewing performance counters in Windows includes Performance Monitor (Perfmon.exe) and Logman.exe, which can display and log the Hyper-V performance counters.

Microsoft recommends you measure CPU usage of the physical system by using the Hyper-V Hypervisor Logical Processor performance counters. The CPU utilization counters that Task Manager and Performance Monitor report in the root and child partitions do not accurately capture the CPU usage. Use the following performance counters to monitor performance:

· \Hyper-V Hypervisor Logical Processor (*) \% Total Run Time – The counter represents the total non-idle time of the logical processor(s).

· \Hyper-V Hypervisor Logical Processor (*) \% Guest Run Time – The counter represents the time spent executing cycles within a guest or within the host.

· \Hyper-V Hypervisor Logical Processor (*) \% Hypervisor Run Time – The counter represents the time spent executing within the hypervisor.

· \Hyper-V Hypervisor Root Virtual Processor (*) \ * – The counters measure the CPU usage of the root partition.

· \Hyper-V Hypervisor Virtual Processor (*) \ * - The counters measure the CPU usage of guest partitions.

In our next article we’ll discuss how to tune Hyper-V storage I/O performance.