Networking

The network should not be taken for granted. It is a fundamental component in data replication and must be considered in the design process. Not only must it be fast, it must also be reliable. In the following paragraphs, we look at ways to make our network resilient to faults and subsequent outages in an effort to maintain zero downtime.

Surviving network outages

Probably one of the biggest fears in a replication environment is network failure. Should the network fail, the source trail will grow as the transactions continue on the source database, ultimately filling the filesystem to 100 percent utilization that will cause the Extract process to abend. Depending on the length of the outage, GoldenGate may have to extract data from the database's archived logs. This is not ideal, as you already have the backlog of data in the trail files that need to be shipped to the target site once the network is restored. It is essential that there is sufficient disk space on the source...