Distributed Systems Transparency

Location transparency is important because it allows resources to be moved without affecting how they can be accessed.

Replication transparency ensures data availability by storing multiple copies of a resource, making it accessible even if one copy is unavailable.

The primary goal of concurrency transparency is to hide the fact that resources are shared by multiple competitive users.

Failure transparency hides the fact of failure and recovery of a particular resource, ensuring uninterrupted access to resources.

Persistence transparency allows users to access resources without knowing whether they are stored in memory or storage.

Migration transparency enables resources to be moved without affecting how they can be accessed, ensuring seamless relocation.

The DNS name space is hierarchically organized into a tree of Domains, which are divided into non-overlapping Zones.

Replication increases availability and balances load between components, which leads to better performance.

Caching is a decision made by the client, whereas replication is a decision made by the owner of the resource.

They can affect scalability, causing consistency problems due to modification in one copy making it different from the others.

Resolving a name means returning the network address of the associated host.

To avoid that a single server has to deal with all requests for name resolution.

Each machine has its own private memory.

Bus and Switch.

All CPUs have direct access to shared memory.

The bus will usually be overloaded and performance drops drastically.

It holds the most recently accessed words and acts as a high-speed buffer between the CPU and main memory.

When CPU A writes a word to memory, and a microsecond later B reads that word, then B will get the value just written.