Memory-aware real-time scheduling for distributed query processing

A method comprising:

• for each query of a plurality of queries:
• determining a memory reservation for said each query;
• adding the memory reservation to a set of memory reservations;
• in response to determining that a total of the set of memory reservations might exceed currently available memory, identifying, from among the plurality of queries, based on one or more criteria, one or more queries to prioritize;
• assigning the one or more queries to a prioritized status;
• scheduling, for execution, only queries that have a prioritized status;
• wherein the method is performed by one or more computing devices.

A method comprising:

• while a plurality of queries are executing concurrently, determining that a particular query, of the plurality of queries, failed due to an out-of-memory (OOM) error;
• in response to determining that the particular query failed due to an OOM error:
• waiting for the other queries in the plurality of queries to finish executing;
• preventing new queries from executing;
• in response to determining that no query is executing and while preventing new queries from executing, causing the particular query to be executed again;
• wherein the method is performed by one or more computing devices.