Dynamic application layout is the capability to move thecomponents of a distributed program among different hosts during theexecution of the application. This capability is essential forlarge-scale applications since it allows to adapt them to changes inresource availability which are common in wide-area environments. TheFarGo system introduces a model for programming the layout ofdistributed applications separately from their basic logic, by attachingrelocation semantics to inter-component references, and by using abuilt-in monitoring support for making relocation decisions. Dynamiclayout policies are encoded within the application using a special APIor externally using a high-level scripting language. This paper presentsthe design of the runtime environment that realizes the model
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