Oracle Global Data Services (GDS) FAQs

General

What is Oracle Global Data Services (GDS) and what are its primary benefits?

GDS is an Oracle Database feature that provides automated workload management, high availability, and disaster recovery across replicated databases using technologies like Oracle Active Data Guard and GoldenGate. It ensures dynamic load balancing, failover, and centralized service management, reducing downtime, optimizing performance, and simplifying administration for mission-critical systems.

What are the key components of a GDS configuration?

A GDS configuration includes the Global Service Manager (GSM), GDS Catalog, GDS database pools, and global services. The GSM manages workload routing and failover, the GDS Catalog stores GDS configuration metadata, GDS database pools group databases for service placement and management, and global services enable load balancing and failover across replicated databases.

What are the installation requirements for the Global Service Manager (GSM)?

The GSM is currently installed in a separate Oracle home directory from other Oracle products, requiring its own media. It needs at least 4GB of RAM, open ports (e.g., 1522 for the GSM listener, 6123/6234 for ONS), and the ORACLE_HOME, PATH, and TNS_ADMIN environment variables set correctly for operation. For real-time load balancing and faster failover, applications should use Oracle integrated drivers and connection pools such as JDBC UCP.

Can GDS manage workloads across different database types and replication methods?

Yes, GDS supports Oracle RAC, single-instance databases, and various replication methods like Oracle Data Guard and GoldenGate as well as True Cache and Raft Replication. It provides unified workload management, load balancing, and failover across these setups, ensuring optimal resource utilization and performance for diverse database environments.

How does GDS ensure high availability across regions?

GDS ensures high availability by deploying multiple GSMs per region (recommended three) to handle regional GSM failures. Databases replicated across regions can be put in a single database pool and GDS transparently orchestrates the operation, switchover, and failover of global services across regions. GDS utilizes Fast Application Notification (FAN), Fast Connection Failover (FCF), and Transparent Application Continuity (TAC) to redirect connections during outages. It leverages replication technologies like Active Data Guard for zero-downtime and zero data loss switchover and failover and supports buddy regions for inter-region resilience.

How do you create and manage a global service in GDS?

Use the GDSCTL utility to create a global service with “gdsctl add service” command and configure parameters such as region, role, or lag. Start service with “gdsctl start service” command. This enables centralized management, load balancing, and failover across pool databases.