1. A method, implemented at a computer system that includes one or more processors and a primary application that operates at least in part on a first network node and that includes a primary application cache on the first network node, the primary application having an associated secondary application that operates at least in part on a second network node and that includes a secondary application cache on the second network node, for at least partially replicating the primary application cache in the secondary application cache, the method comprising: identifying a plurality of cache portions that have been added to the primary application cache; identifying a plurality of identifiers that are each associated with one of the plurality of cache portions; and transferring the plurality of identifiers to the second network node, which is configured to: in response to receiving the plurality of identifiers associated with a plurality of cache portions in the primary application cache, retrieve one or more cache portions that each correspond to one of the plurality of received identifiers, wherein the one or more cache portions are retrieved from a storage node that is shared by the first network node and the second network node; and cache the at least one cache portion in the secondary application cache.