shared-disk architecture
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A shared-disk architecture (SD) is a distributed computing architecture in which the nodes share same disk devices but each node has its own private memory.{{Cite web|date=2020-05-18|title=Difference between Shared Nothing Architecture and Shared Disk Architecture|url=https://www.geeksforgeeks.org/difference-between-shared-nothing-architecture-and-shared-disk-architecture/|access-date=2021-02-24|website=GeeksforGeeks|language=en-US}} The disks have active nodes which all share memory in case of any failures.{{Cite journal|title=Solar: Towards a Shared-Everything Database on Distributed Log-Structured Storage|url=https://www.cs.utah.edu/~dongx/paper/solar-atc.pdf|journal=|pages=13|via=Solar}} In this architecture, the disks are accessible from all the cluster nodes. This architecture has quick adaptability to the changing workloads.{{Cite web|last=Rylan|first=John|date=1 April 2018|title=Big Database (Part 2): Database Architecture|url=https://dzone.com/articles/big-database-2-database-architecture|website=DZone}} It uses robust optimization techniques. Multiple processors can access all disks directly via intercommunication network and every processor has local memory.
It contrasts with shared-nothing architecture, in which all nodes have sole access to distinct disks,{{cite web |date=November 24, 2009 |title=Shared Nothing v.s. Shared Disk Architectures: An Independent View |url=http://www.benstopford.com/2009/11/24/understanding-the-shared-nothing-architecture/ |access-date=November 1, 2012}} and with shared-memory, in which they also share memory.
Shared-disk has two advantages over Shared-memory. Firstly, each processor has its own memory, the memory bus is not a bottleneck; secondly, the system offers a simple way to provide a degree of fault tolerance.
