HPE Shadowbase Solution: Asymmetric Capacity Expansions
Internet travel companies send transaction requests to book to the master-booking node in Figure 1. The master-booking node is hosted on an HPE NonStop server, which is connected to any number of scalable NonStop and Windows query nodes via HPE Shadowbase data replication. This read-only function is offloaded from the master-booking node, since travel agents and Internet travel companies use the query nodes to look-up vacancy/seat availability information, etc.
- The outsource provider’s application is configured (no application modification was required) to perform all queries against the query nodes, yet still apply the booking transactions to the master booking node.
- At least one NonStop query node is architected to also act as a disaster recovery standby system for the booking application if that system fails.
- Additional query node replicates can be added as the query volume increases.
- The key structure on the master-booking node remains optimized for OLTP access (“skinny” keys), and the key structure on the query node is optimized for query (“fat” keys).
- Data from the master-booking node is also replicated to Windows servers running SQL, which supports a large Operational Data Store (ODS) application.
- Each of the NonStop read-only query nodes acts as a disaster recovery backup for the NonStop master node.
- The entire database resides on each of the read-only nodes, in essence allowing the provider to scale the application across multiple systems to handle unpredictable query volumes.
Please see the article in the Availability Digest for more information.
The above was adapted from the book: Breaking the Availability Barrier, Volume III: Active/Active Systems in Practice by Paul J. Holenstein, Dr. Bruce Holenstein, and Dr. Bill Highleyman.