Shared cache for multiple index services in nonrelational databases

A system comprising:

• an index storage comprising a plurality of indexes for a nonrelational database system, the index storage containing a shared index cache and a plurality of cache indexes, wherein each cache index of the plurality of cache indexes corresponds to a tenant in a plurality of tenants and the each cache index of the plurality of cache indexes further comprises an individual index specific to the corresponding tenant and a reference to the shared index cache;
• and
• one or more processors coupled with the index storage, the one or more processors configured to perform a method comprising:
• receiving from a first tenant of the plurality of tenants, a query to retrieve data from the nonrelational database system;
• accessing the index storage containing the shared index cache and the plurality of cache indexes, wherein the each cache index of the plurality of cache indexes corresponds to the tenant in the plurality of tenants and the each cache index of the plurality of cache indexes further comprises the individual index specific to the corresponding tenant and the reference to the shared index cache and
• determining that the index associated with the query is cached in the individual index cache that is specific to the first tenant when the index associated with the query is cached in the individual index cache;
• responding to a cache penetration of the individual index cache that is specific to the first tenant by determining that the index associated with the query is cached in the shared index cache, wherein the shared index cache stores indexes for the plurality of tenants, when the index associated with the query is not cached in the individual index cache that is specific to the first tenant and the index associated with the query is cached in the shared index cache;
• retrieving the result of the query based on the index in the individual index cache when the index associated with the query is stored in the individual index cache that is specific to the first tenant;
• retrieving a result of the query based on the index in the shared index cache when the index associated with the query is not stored in the individual index cache that is specific to the first tenant;
• and
• outputting the result of the query.

A computer program product comprising a computer-readable storage medium that has computer-executable instructions stored thereupon, the computer-executable instructions when executed by a processor cause the processor to perform a method comprising:

• receiving from a first tenant, a query to retrieve data from a nonrelational database system;
• accessing an index storage containing a shared index cache and a plurality of cache indexes, wherein each cache index of the plurality of cache indexes corresponds to a tenant in a plurality of tenants and the each cache index of the plurality of cache indexes further comprises an individual index specific to the corresponding tenant and a reference to the shared index cache and
• determining that the index associated with the query is cached in the individual index cache that is specific to the first tenant when the index associated with the query is cached in the individual index cache;
• responding to a cache penetration of the individual index cache that is specific to the first tenant by determining that the index associated with the query is cached in the shared index cache, wherein the shared index cache stores indexes for the plurality of tenants, when the index associated with the query is not cached in the individual index cache that is specific to the first tenant and the index associated with the query is cached in the shared index cache;
• retrieving the result of the query based on the index in the individual index cache when the index associated with the query is stored in the individual index cache that is specific to the first tenant;
• retrieving a result of the query based on the index in the shared index cache when the index associated with the query is not stored in the individual index cache that is specific to the first tenant;
• and
• outputting the result of the query.