- Bloom filter
Compression scheme used by the Replica Location Service (RLS) that is intended to reduce the size of soft state updates between Local Replica Catalogs (LRCs) and Replica Location Index (RLI) servers. A Bloom filter is a bit map that summarizes the contents of a Local Replica Catalog (LRC). An LRC constructs the bit map by applying a series of hash functions to each logical name registered in the LRC and setting the corresponding bits.
- Local Replica Catalog (LRC)
Stores mappings between logical names for data items and the target names (often the physical locations) of replicas of those items. Clients query the LRC to discover replicas associated with a logical name. Also may associate attributes with logical or target names. Each LRC periodically sends information about its logical name mappings to one or more RLIs.
- logical file name
A unique identifier for the contents of a file.
- logical name
A unique identifier for the contents of a data item.
- Replica Location Index (RLI)
Collects information about the logical name mappings stored in one or more Local Replica Catalogs (LRCs) and answers queries about those mappings. Each RLI periodically receives updates from one or more LRCs that summarize their contents.
- Replica Location Service (RLS)
A distributed registry that keeps track of where replicas exist on physical storage systems. The job of the RLS is to maintain associations, or mappings, between logical names for data objects and one or more target or physical names for replicas. Users or services register data items in the RLS and query RLS servers to find replicas. (RLS)
- RLS attribute
Descriptive information that may be associated with a logical or target name mapping registered in a Local Replica Catalog (LRC). Clients can query the LRC to discover logical names or target names that have specified RLS attributes.