High availability and automated recovery in scale-out distributed database system

A method comprising:

• configuring a plurality of spare computers that does not contain a plurality of participating computers;
• receiving, by a database management system (DBMS), a query of a database;
• generating, from said query of the database, a first offload query plan that contains:
• a first logical identifier of a first failed computer of the plurality of participating computers, and
• a second logical identifier of a second failed computer of the plurality of participating computers;
• first sending, by the DBMS, said first offload query plan and a respective first portion of the database to each computer of the plurality of participating computers;
• first detecting that said first failed computer failed after said first sending said first offload query plan;
• second sending, in response to said first detecting that the first failed computer failed, said first offload query plan and said respective first portion of the database of said first failed computer to a replacement computer of the plurality of spare computers;
• second detecting that said second failed computer failed after said second sending said first offload query plan;
• in response to said second detecting that the second failed computer failed:
• a) detecting said plurality of spare computers is empty;
• b) regenerating, from said query, a second offload query plan that does not contain said second logical identifier of said second failed computer;
• c) repartitioning the database into a plurality of second portions;
• and
• d) third sending said second offload query plan and a respective second portion of the plurality of second portions to each computer of the plurality of participating computers that has not failed;
• receiving, by the DBMS, results of successful distributed execution of said second offload query plan that include a result from the replacement computer.

One or more non-transitory computer-readable media storing instructions that, when executed by one or more processors, cause:

• configuring a plurality of spare computers that does not contain a plurality of participating computers;
• receiving, by a database management system (DBMS), a query of a database;
• generating, from the query of the database, an offload query plan;
• sending, by the DBMS, said offload query plan and a respective portion of the database to each computer of the plurality of participating computers;
• detecting that a failed computer of the plurality of participating computers failed after said sending said offload query plan;
• in response to said detecting that the failed computer failed:
• reassigning a logical identifier of the failed computer to a replacement computer of the plurality of spare computers, and
• sending said offload query plan and said respective portion of the database of said failed computer to the replacement computer;
• receiving, by the DBMS, results of successful distributed execution of said offload query plan that include a result from the replacement computer.

One or more non-transitory computer-readable media storing instructions that, when executed by one or more processors, cause:

• configuring a plurality of spare computers that does not contain a plurality of participating computers;
• receiving, by a database management system (DBMS), a query of a database;
• generating, from said query of the database, a first offload query plan that contains:
• a first logical identifier of a first failed computer of the plurality of participating computers, and
• a second logical identifier of a second failed computer of the plurality of participating computers;
• first sending, by the DBMS, said first offload query plan and a respective first portion of the database to each computer of the plurality of participating computers;
• first detecting that said first failed computer failed after said first sending said first offload query plan;
• second sending, in response to said first detecting that the first failed computer failed, said first offload query plan and said respective first portion of the database of said first failed computer to a replacement computer of the plurality of spare computers;
• second detecting that said second failed computer failed after said second sending said first offload query plan;
• in response to said second detecting that the second failed computer failed:
• a) detecting said plurality of spare computers is empty;
• b) regenerating, from said query, a second offload query plan that does not contain said second logical identifier of said second failed computer;
• c) repartitioning the database into a plurality of second portions;
• and
• d) third sending said second offload query plan and a respective second portion of the plurality of second portions to each computer of the plurality of participating computers that has not failed;
• receiving, by the DBMS, results of successful distributed execution of said second offload query plan that include a result from the replacement computer.