Data Synchronization in Hot Standby and Active-Active Modes

In both hot standby and active-active modes, the data centers are inter-connected with fully connected mesh topology in a ring configuration. The data synchronization happens at the application level and not through API Data Store. Hence, the data is symmetrical at any point of time.

As part of listener configuration you set up the port for gRPC channel through which each data center sends and receives the gossip. Later, with the ring configuration you establish connection with the associated data centers.

The underlying technology is same for both hot standby and active-active modes. The only difference is that, in the active-active mode you can have multiple data centers in a ring configuration and each data center can handle the client request. On the other hand, the hot standby data center can have only two data centers in a ring configuration and only one data center handles the client request.

Data Type	Possible Workaround
APIs	Handle using Promotion Management.
Policies	Handle using Promotion Management.
Aliases	Handle using Promotion Management.
Packages	Handle using Promotion Management.
Plans	Handle using Promotion Management.
Subscriptions	Handle using Promotion Management.
Teams	Handle using Promotion Management.
Approval configurations	Handle using Promotion Management.
Keystore and Truststore configurations	Handle using Promotion Management.
Group	Handle using Promotion Management.
Email destination	Handle using Promotion Management.
JMS connection alias	Handle using Promotion Management.
Web service endpoint alias	Handle using Promotion Management.
Custom destination	Handle using Promotion Management.
Port	Handle using Promotion Management.
Service Registry	Handle using Promotion Management.
LDAP configuration	Handle using Promotion Management.
Password expiry settings	Handle using Promotion Management.
Analytics and Transaction Logs	Handle using external destinations.
Server Logs	Handle by pushing the logs to a centralized server.

Promotion refers to moving API Gateway assets from the source stage to one or more target stages. For example, you might want to promote assets you have developed on servers in a QA stage (the source API Gateway instance) to data centers in a Production stage (the target API Gateway instance). If you have three data centers in a Production stage, you have to explicitly promote the API Gateway assets to each data center.