HP Extended Cluster for RAC Continuous availability with the flexibility of virtualization

Figure 1. HP Extended Cluster for RAC—100 km
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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