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 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 your biggest fears in a replication environment is network failure. Should the network fail, the source trail will fill as the transactions continue on the source database, ultimately filling the filesystem to 100% utilization, causing the Extract process to abend. Depending on the length of the outage, data in the database's redologs may be overwritten causing you the additional task of configuring GoldenGate 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 to ship to the target site once the network is restored. Therefore, ensure...