Methods, apparatuses, and devices for lease transfer between master and slave replicas

A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform one or more operations for replica lease transfer, comprising:

• locally starting to calculate, by a master replicator, an initial master replica lease;
• sending a lease establishment message to a plurality of slave replicators;
• locally starting to calculate, by the slave replicators after receiving the lease establishment message, corresponding leases at the slave replicators;
• sending lease establishment success responses to the master replicator;
• determining, by the master replicator in response to receiving the lease establishment success responses from a majority of the slave replicators, that a local master replica lease of the master replicator takes effect;
• sending, by the master replicator before a local current master replica lease of the master replicator expires in response to a determination that that a master replica transfer needs to be performed, a transfer preparation message to a target replicator in the plurality of slave replicators;
• locally starting and calculating, by the target replicator after receiving the transfer preparation message, a new master replica lease at the target replicator;
• returning a readiness response to the master replicator;
• sending, by the master replicator after receiving the readiness response, a lease extension message to remaining slave replicators to extend local corresponding leases of the remaining slave replicators;
• terminating, by the master replicator after receiving lease extension success responses returned by a majority of the slave replicators, the local master replica lease of the master replicator in advance, and sending a transfer confirmation message to the target replicator;
• and
• validating, by the target replicator after receiving the transfer confirmation message, the new master replica lease to make the target replicator a new master replicator.

A computer-implemented system, comprising:

• one or more computers;
• and
• one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform one or more operations for replica lease transfer, comprising:
• locally starting to calculate, by a master replicator, an initial master replica lease;
• sending a lease establishment message to a plurality of slave replicators;
• locally starting to calculate, by the slave replicators after receiving the lease establishment message, corresponding leases at the slave replicators;
• sending lease establishment success responses to the master replicator;
• determining, by the master replicator in response to receiving the lease establishment success responses from a majority of the slave replicators, that a local master replica lease of the master replicator takes effect;
• sending, by the master replicator before a local current master replica lease of the master replicator expires in response to a determination that that a master replica transfer needs to be performed, a transfer preparation message to a target replicator in the plurality of slave replicators;
• locally starting and calculating, by the target replicator after receiving the transfer preparation message, a new master replica lease at the target replicator;
• returning a readiness response to the master replicator;
• sending, by the master replicator after receiving the readiness response, a lease extension message to remaining slave replicators to extend local corresponding leases of the remaining slave replicators;
• terminating, by the master replicator after receiving lease extension success responses returned by a majority of the slave replicators, the local master replica lease of the master replicator in advance, and sending a transfer confirmation message to the target replicator;
• and
• validating, by the target replicator after receiving the transfer confirmation message, the new master replica lease to make the target replicator a new master replicator.