Chapter 16. Managing Networks and Traffic

VMs automatically and launching new VMs when you need them, without the need for manual intervention.

NetScaler AutoScaling is designed to seamlessly launch or terminate VMs based on user-defined conditions. Conditions for triggering a scaleup or scaledown action can vary from a simple use case like monitoring the CPU usage of a server to a complex use case of monitoring a combination of server's responsiveness and its CPU usage. For example, you can configure AutoScaling to launch an additional VM whenever CPU usage exceeds 80 percent for 15 minutes, or to remove a VM whenever CPU usage is less than 20 percent for 30 minutes.

CloudPlatform uses the NetScaler load balancer to monitor all aspects of a system's health and work in unison with CloudPlatform to initiate scale-up or scale-down actions. The supported NetScaler version is 10.0.

Prerequisites

Before you configure an AutoScale rule, consider the following:

•Ensure that the necessary template is prepared before configuring AutoScale. When a VM is deployed by using a template and when it comes up, the application should be up and running.

Note

If the application is not running, the NetScaler device considers the VM as ineffective and continues provisioning the VMs unconditionally until the resource limit is exhausted.

•Deploy the templates you prepared. Ensure that the applications come up on the first boot and is ready to take the traffic. Observe the time requires to deploy the template. Consider this time when you specify the quiet time while configuring AutoScale.

•The AutoScale feature supports the SNMP counters that can be used to define conditions for taking scale up or scale down actions. To monitor the SNMP-based counter, ensure that the SNMP agent is installed in the template used for creating the AutoScale VMs, and the SNMP operations work with the configured SNMP community and port by using standard SNMP managers. For example, see Section 16.7.2, “Configuring SNMPCommunity String on a RHEL Server” to configure SNMP on a RHEL machine.

•Ensure that the endpointe.url parameter present in the Global Settings is set to the Management Server API URL. For example, http://10.102.102.22:8080/client/api. In a multi-node Management Server deployment, use the virtual IP address configured in the load balancer for the management server’s cluster. Additionally, ensure that the NetScaler device has access to this IP address to provide AutoScale support.

If you update the endpointe.url, disable the AutoScale functionality of the load balancer rules in the system, then enable them back to reflect the changes. For more information see Updating an AutoScale Configuration

•If the API Key and Secret Key are regenerated for an AutoScale user, ensure that the AutoScale functionality of the load balancers that the user participates in are disabled and then enabled to reflect the configuration changes in the NetScaler.

•In an advanced Zone, ensure that at least one VM should be present before configuring a load balancer rule with AutoScale. Having one VM in the network ensures that the network is in implemented state for configuring AutoScale.

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Citrix Systems 4.2 manual Prerequisites
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4.2 specifications

Citrix Systems, a leading provider of virtualization solutions and cloud computing technologies, released version 4.2 of its popular software, Citrix XenApp, which was previously known as Presentation Server. This version marked a significant evolution in providing users with remote access to applications and desktops, emphasizing simplicity, performance, and security.

One of the standout features of Citrix XenApp 4.2 is its improved application streaming capabilities. This technology allows applications to be delivered to users in real-time, reducing the need for extensive local installations and enhancing the user experience. With application streaming, administrators can efficiently manage applications on a central server while ensuring that users have immediate access to the necessary tools.

Another highlight of this version is the enhanced security measures put in place to protect sensitive data. Citrix XenApp 4.2 includes support for SSL encryption, providing a secure communication channel for data transmitted between the server and clients. This is particularly crucial for businesses that need to comply with strict data protection regulations. Additionally, the integration of endpoint security features ensures that unauthorized access to applications is minimized.

Performance enhancements are also a critical focus in this release. Citrix optimized the delivery of applications over various network conditions, ensuring that users experience minimal latency regardless of their location. This was achieved through the incorporation of SmartAccess and SmartControl technologies, which allow administrators to set policies based on user roles, device types, and network conditions. This level of granularity enables organization-wide security without compromising on usability.

The user experience was further improved with a revamped interface, making it easier for end-users to access their applications and data. Simplified menus, clear navigation paths, and the ability to customize user settings contributed to a more efficient workflow, allowing users to focus on their tasks rather than struggling with the software.

Finally, Citrix XenApp 4.2 was designed to be highly scalable. Organizations of all sizes could deploy this solution to deliver applications efficiently, adapting to their specific needs as their user base grows or changes. This flexibility is crucial for businesses looking to future-proof their IT investments while maintaining optimal performance.

In summary, Citrix XenApp 4.2 stands out with its enhanced application streaming, robust security features, improved performance under varying conditions, user-friendly interface, and scalability, making it an ideal choice for organizations seeking to leverage virtualization for remote access to applications and desktops.
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