---

name: citrix-infrastructure-design description: Citrix infrastructure architecture and capacity planning. Use when designing Citrix environments, planning capacity, sizing components, configuring high availability, designing multi-site deployments, or planning disaster recovery. Covers architecture patterns, component sizing, redundancy design, and best practices.

Citrix Infrastructure Design

Overview

This skill provides guidance for designing and architecting Citrix infrastructure, including component sizing, high availability patterns, multi-site deployments, and disaster recovery planning.

Architecture Patterns

Single-Site Architecture

Components:

• 2+ Delivery Controllers (N+1 redundancy)
• SQL Server (AlwaysOn or mirroring)
• StoreFront server group (2-5 servers)
• NetScaler ADC HA pair
• Hypervisor cluster

Use Cases:

• Small to medium deployments
• Single geographic location
• Simpler management requirements

Multi-Site Architecture

Components per site:

• Local Delivery Controllers
• Local StoreFront servers
• Local database replica
• Zone configuration in single site

Cross-site components:

• GSLB for user routing
• Database replication
• Image management strategy

Use Cases:

• Geographic distribution
• DR requirements
• Regional performance needs

Citrix Cloud Hybrid

Citrix Cloud (managed):

• Delivery Controllers
• Site database
• Studio/Director
• Licensing
• Gateway Service

Customer managed:

• Cloud Connectors (2+ per location)
• VDAs and applications
• Hypervisor/cloud infrastructure
• Active Directory

Benefits:

• Reduced infrastructure
• Automatic updates
• Built-in redundancy

Component Sizing

Delivery Controllers

Placement:

• Anti-affinity rules across hosts
• Different failure domains
• Separate from other workloads

SQL Database

Database sizing:

• Site DB: 500 MB - 2 GB
• Logging DB: Grows based on retention
• Monitoring DB: Grows based on retention

VDA Sizing

Single-Session (VDI):

Multi-Session (RDSH):

Storage Considerations

MCS Requirements:

• Identity disk: 16 MB per VM (fixed)
• Difference disk: 10-40 GB (grows with writes)
• Write cache: 10-20 GB SSD/NVMe recommended

IOPS Guidelines:

• Boot storm: 50-100 IOPS per VM (brief)
• Steady state: 5-30 IOPS per VM
• Use MCS I/O with RAM cache to reduce storage load

High Availability Design

Controller Redundancy

Copy# Local Host Cache provides outage protection
# Minimum 2 controllers per site
# Controllers share site database
# Automatic failover to LHC during outage

LHC Capabilities:

• VDA registration
• Session brokering
• Power management
• Some policy application

LHC Limitations:

• No new configurations
• No monitoring data
• Limited reporting

Database HA

SQL AlwaysOn Availability Groups (Recommended):

• Synchronous replication within site
• Automatic failover
• Multiple readable secondaries

SQL Mirroring:

• Simpler setup
• Single secondary
• Manual or automatic failover

Connection String:

CopyServer=SQLListener.domain.com;Database=CitrixSite;
MultiSubnetFailover=True;Integrated Security=True

StoreFront HA

• Server group with 2-5 members
• Sub-40ms latency required
• Configuration auto-synchronized
• Load balanced via NetScaler or NLB

NetScaler HA

• Active/Passive or Active/Active
• Synchronous configuration
• Virtual MAC for seamless failover
• Health monitoring for backend services

Network Design

VLAN Segmentation

Firewall Requirements

User to StoreFront:

• 443/TCP (HTTPS)

StoreFront to Controller:

• 80/TCP (HTTP)
• 443/TCP (HTTPS)

User to VDA (internal):

• 1494/TCP (ICA)
• 2598/TCP (Session Reliability)
• 443/TCP (TLS)

VDA to Controller:

• 80/TCP (Registration)
• 443/TCP (Secure registration)

Bandwidth Planning

Disaster Recovery

RTO/RPO Objectives

Active/Active Design

• Controllers at both sites
• GSLB routes users to nearest site
• Real-time database replication
• Both sites handle production load
• Automatic failover

Active/Passive Design

• Secondary site in standby
• Asynchronous replication acceptable
• Manual or automated failover
• Lower cost than active/active
• Longer RTO

DR Considerations

Non-persistent VDI advantages:

• No VM replication needed
• Rapid provisioning at DR site
• Only master images replicated
• Lower storage costs

Key data to replicate:

• Site database
• Master images
• User profiles (if persistent)
• Application data

Design Best Practices

Scalability

1. Design for growth - Size for 3-5 year projection
2. Use zones - Separate workloads by zone
3. Catalog organization - Group by OS, workload, location
4. Delivery group strategy - Align with user groups

Performance

1. MCS I/O - Use RAM cache with disk overflow
2. Storage tiering - SSD for write cache, HDD for read
3. Network optimization - EDT, Multi-Stream ICA
4. Profile optimization - Streaming, exclusions

Security

1. Segmentation - Isolate management plane
2. Encryption - TLS for all communications
3. MFA - Required for external access
4. Least privilege - RBAC for administration

Operations

1. Monitoring - Director, SCOM, third-party
2. Alerting - Proactive threshold alerts
3. Automation - PowerShell for routine tasks
4. Documentation - Architecture, runbooks, DR

Reference Materials

For detailed design guidance, see:

• citrix-knowledge/domain-knowledge/comprehensive-citrix-knowledge.md
• citrix-knowledge/architecture/ for design patterns
• citrix-knowledge/templates/ for documentation templates