Figure 1. HP Extended Cluster for
Cache Fusion is a key component of RAC that uses cluster interconnect technologies to facilitate virtual buffer sharing through the use of direct memory accessing. The Cache Fusion architecture creates a single virtual cache across all the nodes of the cluster. The resulting single view of all buffer caches minimizes disk I/O by allowing any database request to be served by any node in the cluster. In other words, Cache Fusion enables shared access to all the data on disk by all the nodes in the cluster.
The introduction of a second data center creates many advantages for risk management and mitigation. However, until virtualization with SGeRAC was available, it also had the potential to introduce significant levels of asset underutilization and operational complexity.
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