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Configuring Disaster Recovery Using DNS Failover and Oracle GoldenGate

This section describes the configuration of a Disaster Recovery / Business Continuity architecture, as described in Disaster Recovery Architecture. The configuration is based on the Oracle GoldenGate software.

Operation

System Startup Procedure and Normal Operating Mode

1. Start the replication process. [+] Show steps
2. Start the system. [+] Show steps

Disaster Recovery Switchover

At this point, all system components residing at the MAIN site on Host 3 are lost and not running:

  • MAIN live Master Configuration Server primary/backup pair
  • MAIN live Master Solution Control Server
  • MAIN Message server at Site 1
  • Oracle database
  • Oracle GoldenGate

Operations on other sites can be continued non-stop in limited mode without a configuration change using Configuration Server Proxies running in Read-Only mode until the SECONDARY Master Configuration Server is brought on-line.

Perform the following steps to move activity to the SECONDARY live Master Configuration Server primary/backup pair.

1. On the SECONDARY live standby system, using GGSCI, issue the LAG REPLICAT command until it returns At EOF (end of file) to confirm that REPLICAT applied all of the data from the trail to the database.
LAG REPLICAT CSP
LAG REPLICAT MSP
2. Stop the REPLICAT processes.
STOP REPLICAT CSP
STOP REPLICAT MSP
3. On the SECONDARY system, run the script that grants INSERT, UPDATE, and DELETE permissions to the CFG_DB and MS_DB users.
4. Run the script that enables triggers and cascade delete constraints.
5. Launch the SECONDARY live Master Configuration Server primary/backup pair at Site 2.
6. Launch the SECONDARY live Master Solution Control Server to control the MAIN Master Configuration server pair at Site 2.
7. Launch the SECONDARY Message Server at Site 2 to support communication for Solution Control Servers controlling site components.
8. Run the dnscmd script that switches over cfgmaster host name IP resolution to a MAIN live system.
9. On the host running Configuration Server Proxies, run the switch over script to flush the DNS cache.

Communication Server Proxies reconnect to the SECONDARY live Master Configuration Server primary/backup pair and resume normal operation.

Warning
Do not start the data EXTRACTOR on the SECONDARY system. The user transactions must accumulate in the SECONDARY system database until the MAIN system is to be restored. Use the Secondary CSS replication group for database replication from SECONDARY to MAIN system before switching back to the MAIN system.

The diagram below shows the system in completed failover mode.

Multi-Site Disaster Recovery Architecture

Configuration Example

Configuration for Oracle GoldenGate Replication Processes

1. At the MAIN and SECONDARY Oracle databases, create a user CFG_DB for the Configuration Server database, and user MS_DB for the Log Message Server database.
2. Using the initialization scripts in the Installation Package, create the database objects for the Configuration and Log Message Server Databases.
3. Use Oracle® GoldenGate Oracle Installation and Setup Guide11g Release 1 (11.1.1) E17799-01 (Ref 1.) and the examples of Parameter files below to configure the EXTRACT and REPLICAT processes. [+] Show details
4. Register Oracle GoldenGate EXTRACT and REPLICAT using GGSCI. [+] Show steps

Extract Group CSP at Primary Site Configuration Example

1. At MAIN system, start GGSCI.
2. Use the ADD EXTRACT command to create an Extract group CSP.

     ADD EXTRACT CSP , TRANLOG, BEGIN NOW
Use TRANLOG as the data source option.

3. Use the ADD RMTTRAIL command to specify a remote trail to be created on the target system.

     ADD RMTTRAIL ./CS, EXTRACT CSP
Use the EXTRACT argument to link this trail to the Extract group.

4. Use the EDIT PARAMS command to create a parameter file for the Extract group. Include the following parameters plus any others that apply to your database environment.

     EDIT PARAMS CSP

CSP EXTRACT Parameters File Example: [+] Show file

REPLICAT Group CSP at Secondary Site Configuration Example

1. At the SECONDARY system, start GGSCI.
2. Use the ADD REPLICAT command to create a Replicat group CSP.

     ADD REPLICAT CSP, EXTTRAIL CSP, BEGIN NOW
Use the EXTTRAIL argument to link the Replicat group to the remote trail.

3. Use the EDIT PARAMS command to create a parameter file for the Replicat group. Include the following parameters plus any others that apply to your database environment:

     EDIT PARAMS CSP

CSP REPLICAT Parameters File Example: [+] Show file

Configuration of Genesys Components

1. Start the replication process (P.3.3.1.1).
2. Run the dnscmd script that switches over cfgmaster host name IP resolution to a MAIN live system.
3. Install the MAIN live Master Configuration Server primary/backup pair at Site 1.
4. Install the SECONDARY dormant Configuration Server primary/backup pair at Site 2.
5. Launch the MAIN live Master Configuration Server primary/backup pair at Site 1.
6. Using Genesys Administrator connected to the Primary Master Configuration Server at Site 1, configure Master Solution Control Server, Message Server for distributed SCS, and Backup Master Configuration Server.
7. Install Master Solution Control Server, Message Server for distributed SCS, and Master Backup Configuration Server on Site 1.
8. Copy Master Solution Control Server, Message Server for distributed SCS, and Master Backup Configuration Server working directories to Site 2.
9. Launch Master Solution Control Server and Message Server for distributed SCS.
10. Using Genesys Administrator connected to the Primary Master Configuration Server at Site 1, configure and install Configuration Server Proxies, Solution Control Servers, and Message Servers for network logging for Sites 1 and 2.
11. Start Configuration Server Proxies at Sites 1 and 2.
12. Start Solution Control Servers at Sites 1 and 2.
13. Start Message Servers for network logging at Sites 1 and 2.
14. Install Framework Components at Site 1 using the Configuration Server Proxy host and port at Site 1.
15. Install Framework Components at Site 2 using the Configuration Server Proxy host and port at Site 2.

File and Script Examples

EXTRACT Parameters File

[+] Show file

REPLICAT Parameters File

[+] Show file

dnscmd Scripts

[+] Show scripts

Switch over Script

[+] Show script
This page was last modified on May 5, 2017, at 11:26.

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