We survey strategies for distributing and accessing shared objects in large parallel and distributed systems. Examples for
such objects are, e.g., global variables in a parallel program, pages or cach lines in a virtual shared memory system, or
shared files in a distributed system, for example in a distributed data server. We focus on strategies for distributing, accessing,
and (consistently) updating such objects, which are provably efficient with respect to various cost measures. Our focus is
on presenting strategies that are tailored to situations where the bandwidth of the network is the bottleneck, so we aim to
organise the shared objects in such a way that congestion is minimized.
First we present schemes that are efficient w.r.t. information about read-and write-frequencies. The main part of the talk
will deal with online, dynamic, redundant data mamnagement strategies that have good competitive ratio, i.e., that are efficient
compared to an optimal dynamic ofine strategy that is constructed using full knowledge of the dynamic access pattern. Especially
the case of memory restrictions in the processors will be discussed.