Multicasting data from a remote source to a plurality of data processing machines which report missing data to a local site master

摘要

A data package is transmitted from a source to a plurality of data processing machines, spread over a plurality of sites, by means of a multicast. At each site, a local data processing machine is designated as a site master. The other local data processing machines report missing data portions to the site master and the site master consolidates reports of missing data portions and requests missing data portions from the source. The source then transmits the missing data portions to the plurality of data processing machines by means of a further multicast. If the site master receives a report of missing data that the site master has stored locally in a cache, the site master provides that missing data to the local machines by means of a site multicast. Also disclosed is an election process for designating one of the plurality of data processing machines as a site master.