# Scaling Out Non-Distributed  RDBMS Attempt A: Multi Nodes Shared Storage Architecture

__*Shared Everything Architecture Weakness*__

![left](./student-guide/diagram/rac-arch.png)

+ Take a well-known commercial database as an example

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No matter how many node are configured on the front end, the data is stored on shared storage, and the heartbeat in the middle is additionally responsible for transmitting memory-levelbuffer cache  data, which is an obvious bottleneck and expensive.