Redundancy Architecture

Hot Standby Configuration

[Primary Server]          [Secondary Server]
     TServer.exe    <-->      TServer.exe
     (Active)                 (Standby)
         |                        |
     [Shared Storage or Database Sync]

Synchronization Methods:

• Real-time tag synchronization
• Database replication
• File system mirroring

Configuration Steps

Primary Server Setup

1. Enable Redundancy: Runtime → Redundancy → Enable
2. Configure Primary:

   xml

   <redundancy>
     <role>Primary</role>
     <partner>192.168.1.101</partner>
     <heartbeat>1000</heartbeat>
     <timeout>5000</timeout>
   </redundancy>

3. Set Virtual IP: For transparent failover

Secondary Server Setup

1. Configure Secondary:

   xml

   <redundancy>
     <role>Secondary</role>
     <partner>192.168.1.100</partner>
     <syncMode>Full</syncMode>
   </redundancy>

2. Synchronization Settings:
   • Tag values: Real-time
   • Alarms: Real-time
   • History: Periodic

Failover Mechanisms

Automatic Failover

Heartbeat Monitoring:

• Interval: 1 second
• Timeout: 5 seconds
• Failure count: 3

Failover Process:

1. Heartbeat loss detected
2. Secondary validates primary failure
3. Secondary activates
4. Clients redirected
5. Alarms generated

Manual Switchover

For maintenance:

cmd

FrameworXCmd.exe /switchover /target:secondary

Database Redundancy

SQL Server Always On

Configuration:

sql

ALTER AVAILABILITY GROUP [FrameworX_AG]
ADD DATABASE [FrameworX_Production];

Database Mirroring

For SQL Server Standard:

sql

ALTER DATABASE FrameworX 
SET PARTNER = 'TCP://Secondary:5022'

Client Behavior

Connection Management

Client Failover:

xml

<connectionList>
  <primary>192.168.1.100:10108</primary>
  <secondary>192.168.1.101:10108</secondary>
  <retryInterval>5000</retryInterval>
</connectionList>

Session Persistence

• Maintain client state
• Preserve alarm acknowledgments
• Continue trends without gaps

Testing Procedures

Failover Test

1. Simulate Primary Failure:

   cmd

   Stop-Service "FrameworX Runtime"

2. Verify Secondary Activation:
   • Check service status
   • Verify client connections
   • Confirm data continuity
3. Test Failback:

   cmd

   Start-Service "FrameworX Runtime"

Performance Impact

Monitor during failover:

• Failover time < 30 seconds
• Data loss = 0
• Client reconnection < 10 seconds