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In the master‐slave model only the slaves are guaranteed against single point of failure. The cluster still suffers from single point of failure, if the master fails. Also, the writes are limited to the maximum capacity that a master can handle; hence, it provides only read scalability. These drawbacks in the master‐slave model are overcome in the peer‐to‐peer model. In a peer‐to‐peer configuration there is no master‐slave concept, all the nodes have the same responsibility and are at the same level. The nodes in a peer‐to‐peer configuration act both as client and the server. In the master‐slave model, communication is always initiated by the master, whereas in a peer‐to‐peer configuration, either of the devices involved in the process can initiate communication. Figure 2.10 shows replication in the peer‐to‐peer model.

Figure 2.9 Master‐Slave model.

In the peer‐to‐peer model the workload or the task is partitioned among the nodes. The nodes consume as well as donate the resources. Resources such as disk storage space, memory, bandwidth, processing power, and so forth, are shared among the nodes.

Reliability of this type of configuration is improved through replication. Replication is the process of sharing the same data across multiple nodes to avoid single point of failure. Also, the nodes connected in a peer‐to‐peer configuration are geographically distributed across the globe.