Abstract: User data is shared among servers or server farms, referred to transaction nodes. A user is assigned to one of multiple transaction nodes as its home when the user enrolls in a web-based service. Each transaction nodes maintains records of the users assigned to it, including blocks which are formed when a specified number of new users are assigned. A block hash value is computed based on row hash values, where one row is provided for each user. A transaction node advertises its block identifiers when there is a changed full or partial block, or at other times, to allow other transaction nodes to request a block they do not have. Changed blocks can also be advertised with their recomputed block hash value. Advertisements can be provided to transaction nodes actively accepting new users, and to a subset of transaction nodes which are deactivated and not accepting new users.

Abstract: User data is shared among servers or server farms, referred to transaction nodes. A user is assigned to one of multiple transaction nodes as its home when the user enrolls in a web-based service. Each transaction nodes maintains records of the users assigned to it, including blocks which are formed when a specified number of new users are assigned. A block hash value is computed based on row hash values, where one row is provided for each user. A transaction node advertises its block identifiers when there is a changed full or partial block, or at other times, to allow other transaction nodes to request a block they do not have. Changed blocks can also be advertised with their recomputed block hash value. Advertisements can be provided to transaction nodes actively accepting new users, and to a subset of transaction nodes which are deactivated and not accepting new users.