Leveraging InstaCompute for Scalable Web Hosting. InstaCompute Whitepaper July

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1 Leveraging InstaCompute for Scalable Web Hosting InstaCompute Whitepaper July

2 Contents 3. Traditional Web hosting challenges 4. Benefits of using InstaCompute to host your website 5. Recommendations: How to best use InstaCompute for scalable Web hosting 10. Simple architecture example 13. Sample architecture for scalable Web tier with dual load balancers 14. Sample architecture for master slave DB with caching tier 15. On-going maintenance best practices 21. Summary of best practice Web hosting on InstaCompute 2

3 Traditional Web hosting challenges Scaling your premises-based Web server is difficult you must acquire, install, and manage new hardware as demand increases, only to find that during slack periods these managed hardware assets go unused. In other words, you must always over provision to guarantee your site remains accessible during peak periods. This model relies on high maintenance, hardware-intensive, and dysfunctional scalability that results in the inefficient use of both human and capital resources. The bottom line is that your organization has a low return on investment with no end to escalating costs, as old Web servers and other hardware must not only be constantly upgraded but also replaced on a regular basis. Peak periods tax the system. This usually results in additional resources and provisioning. Adding these physical upgrades take time, however, including equipment purchase, preparation, and final deployment. In addition, management of this constantly changing infrastructure capacity is complex, and your IT team may struggle to maintain your website at greater than 99% availability. The bottom line is that your organization has a low return on investment with no end to escalating costs, as old Web servers and other hardware must not only be constantly upgraded but also replaced on a regular basis. 3

4 Benefits of using InstaCompute to host your website The greatest benefit of using infrastructure as a service offering, InstaCompute, to host your website is on-demand elasticity and scalability. InstaCompute allows you to move bursty Web based workloads offsite to better control cost, parallelize seasonal tasks and accommodate traffic spikes, enabling you to control dynamically the amount of resources available at any time. For example, companies that have predictable peak periods can add InstaCompute resources within minutes when required, and decommission them when the peak traffic subsides and pay only for what is used. In addition, if applications see a sudden spike in activity, demanding more CPU and memory to perform optimally, you can provision additional CPU and memory instantly through the InstaCompute management portal to handle the additional computing load. When Web traffic increases to front-end servers, the no-charge, basic load balancing functionality provided with InstaCompute can seamlessly spread traffic across multiple virtual machine instances within the same availability zone (which is the physical location of the computing servers) to balance traffic and seamlessly handle traffic spikes. You can also add storage at any time, and release that same storage if data demands decrease. There are no expensive yet abandoned or dormant resources as there are with premises-based infrastructure. continually updates the InstaCompute infrastructure in which your virtual machines instances (VMs) reside with the most recent technology to deliver the greatest performance and reliability, but with the shared-resource model, you leverage all InstaCompute technology improvements without bearing the full burden of purchasing, installing, maintaining and upgrading technology yourself. The InstaCompute infrastructure includes the physical and logical network appliances required to deliver your VM (such as hardware and software firewalls, virtual routers, and virtual load balancers). While you will not need to consider the deployment of physical network appliances when hosting your website on InstaCompute, you still have the option to deploy additional software-based virtual appliances on your VMs. For example, you may require the installation of an additional third party provided software global load balancer to expand the load balancing functionality provided by InstaCompute across availability zones. Intranet portals for content or collaboration, marketing microsites, consumer or B2B-facing websites, special event Web hosting, media delivery, global e-commerce, sales demos, special project launches, and other sites with variable spikes in demand and inconsistent traffic flow get the greatest return on their investment when you know you can scale up or down whenever your business requirements change. Since InstaCompute requires no volume commitments, there are no penalties to build up or tear down capacity, and you pay only for the resources you use. You can easily access tools to manage your resources, including usage controls and billing reports through the InstaCompute management portal. 4

5 Recommendations: How to best use InstaCompute for scalable Web hosting Obviously, no two websites are alike. Your application and database requirements will vary. Nonetheless, we can provide you with step-by-step recommendations and best practices to get the best performance, reliability and ease of maintenance in your InstaCompute environment. The following section details key elements you should consider when designing, launching and protecting your InstaCompute cloud-based website. Pre-build your Web application You should develop as much of your website as possible on a local machine using your preferred Web development tools (WordPress, Joomla, etc.). As you build and test your site, make note of the following: How much disk space is required? How much CPU and memory provide the best performance? If your applications require a database (DB), which DB structure and DB schema are you using? (Master-Master, Master-Slave, etc.) How much inbound and outbound traffic do you anticipate? Pre-building and initial performance testing of your website can simplify deployment and configuration of your website on InstaCompute VMs. Set up your InstaCompute account Create an InstaCompute account at Once your account has been created, you can log into the InstaCompute management portal at and then you can create users, projects, and set cost controls. The InstaCompute user guide located on the service website provides detailed steps on setting up accounts, users and projects. 5

6 Configure your initial VM instance Once your InstaCompute account, projects, and users are set up in the management portal, you can navigate to the Cloud Console tab in the portal to create new virtual machine instances. A wizard will take you through five steps to create your VMs. Here you will assign compute (CPU, RAM) and storage resources to each VM, and you must also select an operating system (OS) to load onto the machine. You may select a pre-configured and ready-to-load OS template. The OS templates currently available for use on your InstaCompute VM include: Windows 2008 R2 Datacenter Edition x86 (RDP enabled) Windows 2003 Datacenter Edition x86 (RDP enabled) Windows 2003 Datacenter Edition x64 (RDP enabled) Ubuntu LTS x 64 CentOS 5.4 x64 (SSH enabled) The Windows operating system templates include the standard, out-of-the box configuration, and you can enable or disable any functionality as required. When you select a Windows OS, provides the mandatory licenses for an additional fee, priced per hour of use. Please note that licenses are not included for any other OS. You also have the option of uploading your own OS ISO image to your InstaCompute virtual machine, whereby you manage the licensing. InstaCompute support includes the following operating systems, in addition to others: CentOS (32&64 bit) Debian Lenny 5.0 (32 bit) Oracle Enterprise Linux (32 & 64 bit) RHEL (32 & 64 bit) SUSE Linux Enterprise 9-11 (32 & 64 bit) Ubuntu Windows Windows 7 (32 & 64 bit) Windows 2003, 2008 (32 & 64 bit) Windows 2000 SP4 (32 bit) Windows Vista (32 bit) Windows XP (32 bit) Please see the InstaCompute user guide for detailed instructions on uploading and installing your own OS on your InstaCompute VM. By default, all VM instances include 50GB of storage, and while navigating through the VM creation wizard you can add up to 1TB of additional disk space if your site requires it at an additional charge. Use the information you gathered during your pre-build and testing to select the most appropriate configuration. 6

7 Even if you have tested your application beforehand, you should also consider the following: How CPU and/or memory intensive are your applications? Simple static sites with few applications and little or no database requirements will require fewer resources. Sites that store and deliver heavy amounts of data or run complex applications will need more CPU cores and memory, such as media and transaction applications. Is data traffic mainly out-bound, or will there be many users contributing data through collaborative and dynamic applications? If so, you may need to purchase additional storage as well as more CPU and memory. Although it is difficult to predict traffic patterns, how many hits/uses do you anticipate per day? Per month? Will your site experience predictable spikes in traffic, such as seasonal promotions or events? If so, you should consider these as well when choosing the right configuration and designing your process for monitoring usage and scaling when needed. Decide your architecture to determine how many VMs you will need and how you will configure them. Will you deploy your front-end Web server, an application server, and database on separate VMs? Or will you use a single VM instance to load the Web server, app server, and database? This will impact the number of VMs needed and their configuration. If you require the deployment of multiple VMs to host different services (i.e. Web server, application server, DB server), how will your VMs communicate with each other? What traffic should be allowed between VMs and which ports will need to be opened to enable secure communication? This will be important for configuring port forwarding rules on the virtual firewall provided and in IP address assignment. Remember regardless of your initial setup, you can build up and tear down resources whenever needed through the Cloud Console tab with no penalty, but choosing an initial configuration that best suits your website will save you time and could reduce your initial costs. Load balancing When you configure your InstaCompute VM, you will use the Network sub menu under the Cloud Console tab to assign a public IP address to your front-end Web server. By default, each VM is assigned one private IP address, so you must deliberately acquire a public IP if any inbound traffic requires access to your VM. To ensure security, the virtual firewall in front of your VM is configured with all ports closed, and you can open ports as required. Port forwarding rules can be set in the Network sub menu, allowing you to open the required HTTP/HTTPS ports on your front-end server's firewall, as well as enable SSH or RDP ports for remote access to your VMs by your system administrator. As you run your InstaCompute based website, you might experience spikes in traffic that may overload your VM and slow the website's performance. One of the easiest ways to remedy this type of performance issue is to build automatic scalability through load balancing and multiple virtual machine instances. With load balancing across multiple VMs, when additional traffic hits your website the load balancer automatically steps in to alleviate any congestion. The heavy traffic volume is distributed among the duplicate VM instances, insuring optimum performance across these redundant resources. 7

8 If you anticipate that your website will experience heavy or sporadic spikes in traffic, you should create additional VMs in the same availability zone, and then configure the load balancer provided to enable the distribution of inbound traffic between the VMs. To do this, under the Load Balancer tab in the Network, IP Addresses sub menu, select the desired load balancer algorithm, or rule, you would like to apply. You can select from the following load balancing rules: 1. Round robin Places the VMs in a circular list and allocates connections to each server in turn Works on a rotating basis; one server IP address is handed out, then moves to the back of the list and so on 2. Least connections Directs network connections to the server with the fewest connections Effective in smoothing distribution when a server becomes bogged down In maintaining the same number of connections to all servers, those servers that are capable of processing (and thus terminating) connections the fastest receive more connections over time A server identified as twice as powerful as another server receives about twice as many connections per second 3. Source IP hashing Uses a static hash of the source IP address to allocate connections Figure 1. Configuring load balancing. You will then add the rule, and select manage to assign VMs to the load balancer. Please note that traffic is balanced only among VMs in the same availability zone. You can also upload and configure your own third-party software load balancers to your InstaCompute VMs to enable scalable and global load balancing across availability zones, including NetScaler, Zeus, HAProxy, nginx, and F5. 8

9 Use RDP or SSH to connect to your virtual machine The best way to log in, configure, and manage your VMs is via a remote desktop application either the Remote Desktop application (RDP) for VMs running Windows OS or SSH for VMs running Linux OS. Most of the pre-configured templates provided in the InstaCompute management portal have Windows RDP or Linux SSH already enabled. You will need to open the RDP/SSH ports on your VM's firewall by navigating to the Network, IP Address sub menu in the Cloud Console tab and establishing a port forwarding rule for your VM's public IP address. To do this, in the Port Forwarding tab, set the public and private ports to 3389 (for Windows/RDP) or 22 (for Linux/SSH), the protocol to TCP, and select your VM instance from the drop-down list. Click Add to set the rule. From the remote machine you will use to manage the VM, you will use RDP/SSH clients or controls to log in to your VM. In your Windows-based remote machine, open a remote desktop connection. When you open the RDP client, you will log in as administrator and you will use the password provided in the InstaCompute management portal when you created your VM. If you did not make a note of that password, you can find it in the confirmation sent to you after you created the VM. To access your Linux server remotely, you can use the SSH command on the command line from a terminal, or download and use the SSHell, PuTTY SSH (see figure 2.) or other SSH client software on a Windows machine to securely connect to your Linux VM as root. Please refer to the InstaCompute user guide for more details on how to configure the RDP/SSH ports and how to remotely log into your VM. Figure 2. PuTTY SSH connection for Linux. 9

10 Install and configure your Web server, application server and your database Once connected via RDP or SSH to your InstaCompute VM, you will have full administrator or root access to your VM and you can begin to install and configure your Web server, application server, and your selected database, if required. The fastest way to get your website up and running is to install open source development technologies to build a general-purpose Web server, and then download your website to the configured Web server. The following are a few of the most popular open source Web technology packages in use today: LAMP stack (for Linux), consisting of Apache Web server, MySQL, PHP, Perl, Ruby, Python LAPP stack (for Linux)containing Apache Web server, PostgreSQL, PHP, Perl, Python WAMP stack (for Windows) containing Apache Web server, MySQL, and PHP There are many informative websites providing detailed instruction on how to build a LAMP server for popular Linux installations. A good resource includes Additionally, open source WAMP server downloads and instructions are available at *. In addition, the National Institute of Science and Technology (NIST) has published useful guidelines and best practices for installing and securing Web servers that can be found at: * Simple architecture example An example of a simple architecture where the Web server, application server, and DB are loaded on the same VM is the following (see figure 3). The illustration also depicts a storage volume attached to the VM. DNS Web App DB Vol InstaCompute VM Figure 3. Web, application, and DB server within one VM *The links provided in this document are meant to direct customers to resources in the public domain for additional information that may be out of scope for the services provided by. In providing these links, however, is not authenticating nor able to support all practices covered in these sites. 10

11 If your website requirements include separate VMs for the Web server, application server, and database server, you can install the different services as different servers on your InstaCompute virtual LAN (VLAN, which is a private network created for your account, that sits behind your virtual router and that contains only the VMs you create for your account) and through network and application configuration, enable private communications between them. Such a configuration allows the application server VM and database server VM to utilize private IP addresses, isolating them from inbound Internet traffic. To separate your Web services across multiple VMs, you can perform the following steps: 1. Through the InstaCompute management portal, create three VMs in your account; one for the Web server, one for your application server, and one for a database server. 2. In the InstaCompute management portal, acquire a public IP address for the VM designated as the front-end w eb server. The VMs designated as the application server and database server will use the private IP addresses that are automatically assigned to them when the VMs are created. VM Name Private IP Public IP Web X xxx.xxx.xxx.xxx Application y Not applicable Database z Not applicable The private IP addresses are automatically assigned to the VMs while they are being created. You must acquire the public IP address for the Web server in the InstaCompute management portal. For additional details on how to obtain a public IP address, please see the InstaCompute user guide. To separate your Web services across multiple VMs, you can perform the following steps: 3. Next, configure the public IP address for the Web server using a port-forwarding rule to open the HTTP/HTTPS port in order to allow public Internet traffic to access it. 4. In the private and public port boxes, enter port numbers (public port will be 8080 for HTTPS or 80 for HTTP, and the private port will be a port you assign for private communication between the Web server and the virtual firewall VM.) 5. Select TCP as the protocol and select the Web server VM instance name 6. Then click Add Figure 4. Establishing Port Forwarding Rules 11

12 7. You can now configure the other two virtual machine instances, opening the ports required by your application and database to enable private communications between them. In this example, the application server may communicate with the MySQL database server using TCP port 3306 or MSSQL using port You would then need to open these required ports on your database server using the port forwarding rules, and then write a call script on the application server in order to retrieve data from the database server using the required open ports. To secure the channel from the application server to database server, you can use SSL, which requires a server certificate installed on the database server. Please refer to your application and/or database documentation for specific capabilities and guidance on port configuration and management. Public incoming traffic can now access the website with secure insulation for the application and database virtual machines from potential corruption, theft or hacking. A sample architecture where the DB is loaded on a VM separate from the Web server and application server is the following (see figure 5). DNS Web App InstaCompute VM DB Vol InstaCompute VM Figure 5. Separate VM for database server. Regardless of whether you have deployed a simple website on a single VM or have deployed a more complex architecture using multiple VMs, you will still need to work with your DNS provider for Internet name resolution to ensure your website's publicly published domain name now points to the public IP address acquired by your InstaCompute front-end Web server. Once your Web, application and database servers have been created, you can upload, enable, and use any application, programming model, language, and database required, such as MySQL, Oracle, SQL, DB2, Apache Tomcat, Ruby on Rails, Microsoft IIS, Micrsoft.Net (NET 2.0,.NET 3, and.net 3.5) and many others. does not limit the type or number of applications or services you may install and manage on your servers. 12

13 Sample architecture for scalable Web tier with dual load balancers To enhance application reliability through redundancy in case of a single server failure, you may consider deploying dual front-end virtual load balancers on two separate VMs. You can place the load balancers in different availability zones to increase the reliability and availability of the application even further. This configuration depicts third-party software load balancers (HA Proxy or nginx) on InstaCompute VMs, enabling scalable and global load balancing. DNS LB LB HA Proxy/nginx Web Web Web CDN CDN Static Data App App App DB Vol Bkp Figure 6. Scalable Web Tier with Dual Load Balancers and Edge-caching Load balancers are designated as either layer 4 or layer 7. Layer 4 load balancers perform operations on data found in network and transport layer protocols (IP, TCP, FTP, UDP), while layer 7 load balancers distribute requests based on data in application layer protocols such as HTTP. Layer 7 load balancers can also distribute requests based on application-specific data such as HTTP headers, cookies, or data within the application message itself, such as the value of a specific parameter. You should select the load balancer that best suits your application and data requirements. The above illustration (figure 6) also depicts a dual load balancer solution with edge-caching using Tata Communication's CDN. The CDN affords acceleration of your application performance through a local edge cache at the point-of-presence (POP), making the loading of streaming or downloaded static content (e.g. flash videos or images) much faster by serving this content from a closer location. By using CDN, your website will benefit from the reduced bandwidth required to service and download content. An InstaCompute solution specialist can work with you to understand your specific CDN requirements and recommend an appropriate solution for your site and its applications. 13

14 Sample architecture for master slave DB with caching tier For better performance, consider redesigning some of your previous premises-based applications as stateless applications on your Web platform. In other words, cut the dependencies on storing user/session information on disk whenever possible so that the majority of operations occur in the Web session's RAM and CPU rather through disk-based reads and writes. Obviously, it is nearly impossible and impractical to write all applications as stateless, yet you can still streamline performance by creating a software-based cache solution on a VM instance for Web and application layer caching of databases and applications that cache most frequently accessed data. Software based caching solutions include memcached ( ) and couch DB ( ). Memcached creates an in-memory shard on top of a pool of servers, which an application can easily retrieve, and set up to 1MB of unstructured data. In the following configuration, a MySQL DB uses a memcached front-end farm to scale reads. Applications access memcached first for data, but if the data is not in memcache the application requests go to the database. This removes a great deal of the load on a database, freeing it to continue to perform its write transactions. In this architecture, the database remains the system for the true value of data. DNS LB LB HA Proxy/nginx Web Web Web CDN CDN Static Data App App App Cache Cache Memchached Tier Master Multiple Slaves Slave Slave in Another AZ Slave Figure 7. Using Memcache to enhance performance. Not all application architectures benefit from a data-caching solution, however, most scalable applications will realize increased performance by using a distributed cache. For applications that are read-intensive, a caching implementation provides great performance gains because application processing time and database access is reduced dramatically. Write-intensive applications typically see less benefit. 14

15 Auto-scaling a memcached tier should be avoided since it typically requires a configuration file update and a restart of the application, but it is a fairly straight-forward manual process. The presence of multiple slave databases increases the overall reliability and availability of the application, as well as enables horizontal scaling of the database using a proxy mechanism for database reads, such as those provided by MySQL Proxy. Placing a HAProxy instance in front of additional slaves to balance requests and randomizing read sources in your application code can also provide a level of horizontally scaling of your master/slave configuration. If an application is performing a database write, the proxy server passes this request directly to the master database server. However, if an application sends a read request, the MySQL proxy server will send this request to one of the slave database servers, thereby distributing the overall read load of the application (see figure 7). Performing backups on the slave does not affect your site during the backup process. Connecting databases in your enterprise data center to your Web server in the cloud In some cases, you may want to house your database in your company's data centre while hosting your front-end Web server on InstaCompute. You can accomplish this by using several third-party solutions that extend the corporate data centre into the cloud, including Citrix's Cloudbridge. An InstaCompute solution specialist can work with you to understand your specific requirements and recommend an appropriate solution for your site. On-going maintenance best practices The following best practices will improve the performance and reliability of your InstaCompute installation, add a greater level of security to your applications and data, and make your InstaCompute environment easier to manage and maintain. Take snapshots to protect data Data loss, from accidental deletion, hardware failures, or other potential disasters, is an important consideration of any IT infrastructure design, and cloud services are no exception. To help you protect your VM instances and data residing on them, InstaCompute enables you to take snapshots, or point-in-time copies, of your VM disk volumes that are saved on the InstaCompute local storage devices. Snapshots are taken for an entire volume or file system and cannot be done for a specific directory structure. Snapshots are different from backups in that backup is the process of making copies of data inside a file system which can be used to restore the original data due to deletion or corruption or to recover data from an earlier time. Both backup and snapshots do not work well for file systems that are constantly changing or database files that are constantly locked and in an inconsistent state. With backup solutions, hot backup agents are sold for complex scenarios such as this. Hot backup agents generally should only be used if the service must have 100% up time, as it requires stopping SQL, or other actions that create negative impacts to the live system. As an alternative to hot backups, if the data on any volume is in a locked or inconsistent state like a database, the data must be quiesced or the DB exported to a flat file prior to the snapshot being made. 15

16 Snapshots are initiated with the Storage sub menu under the Cloud Console tab for a particular data volume. You can regularly schedule automatic hourly, daily, weekly and monthly snapshots (see figure 8) or take manual on-demand snapshots of disk volumes at any time. With each snapshot schedule, you can specify the time snapshots start and also the number of snapshots to retain per schedule, with a maximum of eight snapshots retained. Older snapshots that exceed the retention limit are automatically deleted. When a recurring snapshot policy is set, a snapshot is skipped if a volume has remained inactive since its last snapshot was taken. A volume is considered to be inactive if it is either detached or attached to a VM that is not running. Whenever you take a manual snapshot, it is created regardless of whether a volume has been active or not. If you have a VM with more than one data volume, each data volume must be snapped independently to ensure a full VM copy. You may create as many snapshots as you would like and are charged for the storage associated with the retention of the snapshots. Once the snapshot is made, you can navigate to the Snapshots submenu under Storage and create a data volume for the snapshot within the same availability zone, create a template from the snapshot in any availability zone or delete the snapshot. Figure 8. InstaCompute snapshot scheduling. 16

17 InstaCompute snapshots can be used to support the following work flows: 1. Full disk volume capture and full recovery- snapshots can capture the disk volume data in a single state. If the disk volume is a boot disk image, the boot disk can be snapped in its entirety and stored as a snapshot. Should you wish to restore the boot disk to a new VM, you can create a template from the snapshot and then use that template to create a new VM. 2. Full disk volume capture and partial file recovery snapshots can capture the disk data in a single state. For partial recovery, the snapshot can be made into a volume and attached to another VM. The host VM can then mount the file system within the operating system and the desired files can be recovered from the disk image produced by the snapshot. 3. Fault tolerance when you take a snapshot of the data volumes you wish to protect from data loss, the snapshot is stored within the same availability zone as the source disk image. To enable fault tolerance, the data can be migrated to a second availability zone in a different geographic location. To do this, you should create a template from the snapshot. Then navigate to the Templates sub menu under the Cloud Console and copy the template to another availability zone. This protects against a catastrophic data loss in a single availability zone and creates a template from the original data volume that is now ready to be deployed within another availability zone. Please note: If your VM contains multiple mounted volumes, those volumes must also be snapped to ensure a full VM copy. Then the snapshots should be turned into volumes and attached to the host VM before the VM is launched in order to assure a successful recovery. For detailed instruction on how to create snapshots and restore data from snapshots, please refer to the InstaCompute User Guide. Please note that in order to better manage your direct cloud computing costs, does not pro-actively create any snapshot copies on your behalf and does not backup your data. Therefore, it is important that you regularly and pro-actively protect your data through the snapshot functionality provided and devise an offpremise backup plan as described in the next section. Data backup While snapshots provide local data protection by creating point-in-time copies of your VM volumes on the InstaCompute storage network, you should supplement that with a long distance disaster recovery backup plan as a best practice. This ensures that if the InstaCompute host data centre ever experiences an outage, your data is still available onpremises or at a remote site. To enable this, you may: 1. Take a snapshot of your data volume, turn the snapshot into a saved template, and then create a new VM in a different geographic availability zone using that saved template, as described in the section above. 2. Stop your data volume (or take a snapshot of your volume) and then download the VHD file created, containing your data volumes, to a specified location such as a server on your company network. Please see the InstaCompute User Guide for detailed instructions on how to perform a volume download as a VHD file. The volume download functionality is currently not available for Windows VMs. 3. Backup your VM volumes containing your database files and other critical data using third-party software or with built in backup utilities. MySQL, Oracle, and others provide tools for creating hot backups, incremental backups, and archiving of data. These backups can then be replicated to your company site via FTP or to an off-site storage facility for added disaster recovery protection. 17

18 There are a number of third party solutions that provide high-performance data transfer to, from and within the cloud. One popular solution, particularly aimed at data-intensive applications such as video transcoding, media asset management, 3D animation and visual effects rendering, genomic sequence processing, and large database hosting is Aspera Ondemand ( This solution can be used to move data off-site for backup as well as for loading data into your VM from an off-site location. Performance monitoring and scaling Monitor the performance of your website, and scale CPU, memory, and storage capacity as needed, as well as adding and adjusting load balancing as required. For example, if you find performance lagging due to overburdened CPU and memory, you can scale your VM vertically by first removing one VM from the load balancer, stopping the running VM, allocating additional CPU and memory, add the VM back to the load balancer, and then restarting the virtual machine instance with the additional resources at its disposal. You can then repeat these steps across all other VMs in this load-balanced group. You may scale horizontally at any time by adding more VMs, and then balancing the incoming traffic between them using the load balancing functionality, as described earlier. To make the scaling process easier, you may take advantage of the APIs available to automate processes. Please see the developer API guide located on the InstaCompute management portal under the Support tab for detailed API instructions and commands. Alternatively, you may deploy third-party cloud management solutions, such as those offered by Right Scale, to enable autoscaling capabilities. The InstaCompute management portal provides basic monitoring parameters, including percent CPU used and network read and write data used. You can find this data in the Instance sub menu under the Cloud Console tab by clicking the Statistics tab for your VM instance. For detailed monitoring parameters, you should install third-party monitoring solutions such as Nagios, a popular open source tool. Updating your website Websites change. As your website evolves, you may want to add more applications, delete material, or simply update static content. Rather than working on the live website hosted on the InstaCompute VM, you can use the dynamic nature of the cloud to your advantage by instantly creating new staging VMs and then seamlessly transferring data between staging and production systems. You can take the following steps to make this transfer without disrupting your live website: 1. Create a new, second VM instance in the InstaCompute management portal. 2. Assign the new VM instance a new IP address. 3. Install the new version of your software code on the new VM instance. 4. Perform testing and make certain the new code is running as it should. 5. Finally, attach the old IP address from the original production server or application to the new and thoroughly tested VM and terminate the old production instance through the InstaCompute management portal. You can use this technique on the entire website or at the application and database layers if you are running a multi-tiered website on InstaCompute. 18

19 Public IPs Your InstaCompute VM instance includes up to 20 public IP addresses for use. Most often, you should only use these IPs for front-end, public facing servers or to enable RDP/SSH access by administrators, and use sub domain private IP addresses with associated port assignments to point to back-end Web applications and databases. Security There are a number of actions you can take to enhance security of the VMs hosting your website, including: Proper hardening and security patching of the OS Ensuring proper access controls to the InstaCompute management portal and to the VMs and applications/databases hosted on them Proper port and IP address management Running different network services on separate servers or VM instances Log monitoring Using HTTPS where possible The paper InstaCompute Security Features and User Recommendations located on the InstaCompute website provides details of specific best practice guidance for securing your InstaCompute VMs. Port restrictions By default, all firewall ports are closed on your InstaCompute VM. You must open and assign ports based on applications and access you want to enable. Below are typical public port assignments for InstaCompute Web hosting installations: HTTP: 80 HTTPS: 8080 FTP: 21 SSH: 22 RDP: 3389 Important note: unless needed, do not open ports on the firewall. Before deploying your website into production, it is a best practice to perform load and performance testing. Third-party solutions such as HP's Load Runner-in-the-Cloud software can perform such cloud performance testing. 19

20 Database security and protection You should backup databases on a regular basis. Some databases, particularly transactional DBs continually updated with new information, should be synchronously replicated to insure that the backup DB is as complete as possible in the event the original database fails. Follow the guidance of the database provider for performing incremental, full, and synchronous backups and data mirroring with its product. The vendor may have built-in tools or have recommendations for third-party tools for this purpose. Important note: as mentioned earlier, we advise customers not to use the InstaCompute snapshot utility to perform backups of your databases. It is not designed to close the records stored in memory or replicate fully the data in your DB applications. Here are some general tips on the backup and protection of databases under InstaCompute: Create a master-slave database schema to support fail-over and greater availability. Masterslave caches changes to a set number of records or amount of data, then commits the changes to the slave DB. You can achieve this schema by deploying your database server across two or more availability zones in different geographies, using passive slaves as back-up servers in the second availability zone for fail-over purposes. By keeping duplicate master and/or slave database repositories in separate availability zones, if the primary repository goes down, you can bring up the untouched master or slave in the other zone. As mentioned earlier, for the most thorough protection, replicate DB files and data to your own premises, and/or to another geographical zone to ensure availability of your critical data in the event the InstaCompute host data centre experiences an outage. You should regularly perform application and database disaster recovery drills to make certain you are prepared to restore your business in the event of an outage, natural disaster, or data corruption. By keeping duplicate master and/or slave database repositories in separate availability zones, if the primary repository goes down, you can bring up the untouched master or slave in the other zone. 20

21 Summary of best practice Web hosting on InstaCompute Following best practices and guidelines for deploying your website on InstaCompute will enable you to get the most out of your virtual machine resources, as well as deliver the greatest performance and reliability for your end users and customers. The best practices cited in this paper also aim to provide a better level of security and reliability for your installation, and serve as the foundation for establishing the most efficient and costeffective website for your business. Please refer to for other informative videos, white papers and answers to frequently asked questions (FAQs) that cover everything from basic account setup to advanced security recommendations, account governance, creating redundancy and many other useful topics. 21

22 Leveraging InstaCompute for Scalable Web Hosting TM India Plot No C 21 & 36, G Block, Bandra Kurla Complex Bandra (E), Mumbai Tel Fax North America 2355 Dulles Corner Blvd 7th floor Herndon, VA 20171, USA Tel Fax Europe 1st Floor, 20 Old Bailey London EC4M 7AN United Kingdom Tel Fax Asia International Pte Ltd Exchange 35 Tai Seng Street #06-01 Singapore Tel Fax Bank of America Tower 12 Harcourt Road Central, Hong Kong Tel Fax Australia King Street Wharf Suite 503, 35 Lime Street Sydney NSW 2000 Australia Tel Fax Matawan Rd 3rd Floor Matawan, NJ 07747, USA Tel Fax Rue Carrie-Derick Montréal, Québec Canada, H3C 6W2 Tel Fax Middle East & North Africa Hamdan Street, City Center Building, Block A, 2nd Floor, Office # 204 P.O. Box Abu Dhabi, United Arab Emirates Tel Fax Avenue Charles de Gaulle Neuilly sur Seine France Tel Fax Avenida de Europa 4, Bajo A Parque Empresarial La Moraleja Alcobendas Madrid, Spain Tel Fax Bettinastrasse 30 D Frankfurt am Main Germany Tel Fax For more information about InstaCompute visit and try InstaCompute today. Contact a representative: Write to instacomputesales@tatacommunication.com or call below toll-free nos. Singapore toll-free India toll-free India direct dial About is a leading global provider of a new world of communications. With a leadership position in emerging markets, leverages its advanced solutions capabilities and domain expertise across its global and pan-india network to deliver managed solutions to multi-national enterprises, service providers and Indian consumers. The Tata Global Network includes one of the most advanced and largest submarine cable networks, a Tier-1 IP network, with connectivity to more than 200 countries across 400 PoPs, and nearly 1 million square feet of data center and collocation space 2012 Ltd. All Rights Reserved. and the Tata logo are trademarks or registered trademarks of Tata Sons, Ltd. in the United States and certain other countries. All other trademarks mentioned in this document are the property of their respective owners. worldwide. ' depth and breadth of reach in emerging markets includes leadership in Indian enterprise data services, leadership in global international voice, and strategic investments in operators in South Africa (Neotel), Sri Lanka ( Lanka Limited) and Nepal (United Telecom Limited). Limited is listed on the Bombay Stock Exchange and the National Stock Exchange of India and its ADRs are listed on the New York Stock Exchange. (NYSE: TCL) 22