Let’s take a quick look at some components of the deployment architecture that allows Citrix Lifecycle Management to deploy desktops, apps, and data as services onto public or private clouds, on-premises or within a hybrid infrastructure.
Citrix Lifecycle Management is an essential service delivered as part of Citrix Workspace Cloud. If you’re not yet familiar with Citrix Workspace Cloud, it replaces Citrix management infrastructure with cloud-based management services that are easier to use. This post is an excellent primer for the platform and is a great introduction.
The Citrix Lifecycle Management architecture delivers holistic lifecycle management services for Citrix workloads and enterprise applications, and it makes it easy for you to adopt new target deployment environments.
Citrix Lifecycle Management performs as a multitenant cloud orchestrator, delivered as a SaaS offering, and supported by distributed clustered systems and subsystems running on more than 20 servers, all of which are highly available and perform different functionality. After reading this article you’ll have a good overview of the architecture of Citrix Lifecycle Managment.
Let’s begin by defining three key components:
- A Resource Location in Lifecycle Management is the cloud service provider or on-premise hypervisor where you launch virtual machines and deploy the blueprints that you create the Citrix or enterprise application environments.
- The Lifecycle Management Agent is a secure software package that coordinates software deployments, collects metrics, and transmits logs.
- The Citrix Lifecycle Management Connector is a machine in your resource location on which the Lifecycle Management Agent has been installed; the Connector enables Lifecycle Management to securely communicate with your firewalled environment over port 443 (using HTTPS).
A Connector operates as a server that communicates with Lifecycle Management and has access to a virtualization instance or cloud resource location behind a firewall. The connector is needed only if the virtualization instance or cloud resource location cannot be accessed over the Internet, as shown in Figure 1:
Figure 1: Citrix Lifecycle Management Architecture Diagram
The Citrix Lifecycle Management App Servers mainly coordinate and automate the execution of Citrix blueprints. App Servers support a REST interface, allowing other services to request blueprint task execution and management. App Servers depend on other internal services to receive Citrix Lifecycle Management Connector status, blueprint metadata and communication channels. App Servers execute as Jetty servers.
Citrix Lifecycle Management Discovery Servers (dserver) run as a TCP Servers to provide a presence layer, allowing other internal services to reach Citrix Lifecycle Management Connectors running in private networks. Dservers implement a binary protocol to exchange data with Connectors. During startup time, Connectors immediately connect to a dserver using SSL sockets. Connectors keep this connection open at all times to receive instant task request messages from dservers. This process allows Connectors to run in private networks while receiving information from dservers.
Citrix Lifecycle Management provides comprehensive server and application monitoring features that give you deep visibility into the performance of critical system components; it also lets you create alerts to notify yourself or others when trigger conditions occur.
Citrix Lifecycle Management Monitoring is composed of multiple services, which includes a rules engine, queuing services (ZeroMQ), business layer workers, and NoSQL and time series databases. All these services performing in conjunction provide a highly scalable solution that is capable of operating under heavy compute loads while receiving continuous real-time monitoring data from each active Citrix Lifecycle Management Connector.
A Connector receives monitoring configuration management requests from App servers to initiate real-time monitoring; it sends the monitoring data to Citrix Lifecycle Management monitoring load balancers. Once monitoring data is received, the data is analyzed and processed, and can be examined and analyzed in the Monitoring section of the UI.
Citrix Lifecycle Management Connectors are installed in each virtual machine instance that is created by Blueprint “Server” steps, which can be added to a blueprint and then configured in the Blueprint Designer, as shown in Figure 2:
Figure 2: Adding a Server Step in the Blueprint Designer
Connectors allow the VMs to be further configured and monitored by Citrix Lifecycle Managment. Each Connector connects to dserver and App Servers via the Monitor Load Balancer. A Connector first connects to dservers, then establishes a session with App Servers to receive action requests, such as ‘execute file’ and ‘create file’, as shown in Figure 3:
Figure 3: App Server instructing a Resource Location to create a VM
These action requests are derived from the execution of blueprints. In a way, Connectors behave more like servers than agents, as they server Citrix Lifecycle Management when executing blueprints.
Citrix Lifecycle Management Gateways provide routing and tunneling services to both Connectors and App Servers. Connectors initiate gateway instances at the request of App Servers. A Gateway’s main job is to establish a secure TCP tunnel between App Servers and private network services. For example, during the execution of a blueprint, an App Server can directly instruct a XenServer running in the Gateway’s private network to create virtual machines (figure 4):
Figure 4: Gateway communicating with XenServer and App Server
This has been a very short technical introduction to some of the primary communications components of Citrix Lifecycle Management. We’ll be covering more features and functionality in the coming weeks and months.
In the meantime, we encourage you to explore Citrix Lifecycle Management and deploy using one of the included blueprints, such as the XenDesktop and XenApp Proof of Concept blueprint; you can deploy to any available resource location, including Amazon Web Services EC2, XenServer and vSphere. In order to access Citrix Lifecycle Management, enroll for a Citrix Workspace Cloud free trial here.