Method for creating consistency snapshot for distributed application, apparatus, and distributed system

A method for creating a consistency snapshot for a distributed application in a distributed system, the distributed system comprising a control node and a plurality of execution nodes, each execution node being associated with an application instance of the distributed application, the plurality of execution nodes comprising a source execution node, an intermediate execution node, and a leaf execution node, the method comprising:

• sending, by the control node, a snapshot event to the source execution node;
• receiving, by the source execution node, the snapshot event sent by the control node;
• generating, by the source execution node, a single-point snapshot of an application instance associated with the source execution node;
• and
• sending, by the source execution node, a snapshot event to a child node of the source execution node;
• sequentially receiving, by the intermediate execution node, snapshot events separately sent by at least two parent nodes of the intermediate execution node;
• generating, by the intermediate execution node, a single-point snapshot of an application instance associated with the intermediate execution node after receiving a first snapshot event;
• recording, by the intermediate execution node, a log of a task when executing the task triggered by another parent node of the intermediate execution node different from a parent node sending the first snapshot event;
• stopping, by the intermediate execution node, recording a log of a task triggered by the parent node each time one snapshot event sent by a parent node of the intermediate execution node is received subsequently;
• and
• sending, by the intermediate execution node, a snapshot event to a child node of the intermediate execution node after confirming that snapshot events sent by all parent nodes of the intermediate execution node are received;
• and
• sequentially receiving, by the leaf execution node, snapshot events separately sent by at least two parent nodes of the leaf execution node;
• generating, by the leaf execution node, a single-point snapshot of an application instance associated with the leaf execution node after receiving a first snapshot event;
• recording, by the leaf execution node, a log of a task when executing the task triggered by another parent node of the leaf execution node different from a parent node sending the first snapshot event;
• and
• stopping, by the leaf execution node, recording a log of a task triggered by the sender of the currently received snapshot event each time one snapshot event sent by a parent node of the leaf execution node is received subsequently.

A physical server cluster, comprising:

• a first physical server comprises a first processor and a first memory, the first memory stores a first instruction, and the first processor executes the first instruction to send a snapshot event to the source execution node;
• a second physical server comprises a second processor and a second memory, the second memory stores a second instruction, and the second processor executes the second instruction to receive the snapshot event sent by the control node, generate a single-point snapshot of an application instance associated with the source execution node, and send a snapshot event to a child node of the source execution node;
• a third physical server comprises a third processor and a third memory, the third memory stores a third instruction, and the third processor executes the third instruction to sequentially receive snapshot events separately sent by at least two parent nodes of the intermediate execution node;
• generate a single-point snapshot of an application instance associated with the intermediate execution node after receiving a first snapshot event;
• record a log of a task when executing the task triggered by another parent node, of the intermediate execution node, different from a parent node sending the first snapshot event;
• each time one snapshot event sent by a parent node of the intermediate execution node is received subsequently, stop recording a log of a task triggered by the parent node;
• and send a snapshot event to a child node of the intermediate execution node after confirming that snapshot events sent by all parent nodes of the intermediate execution node are received;
• and
• a fourth physical server comprises a fourth processor and a fourth memory, the fourth memory stores a fourth instruction, and the fourth processor executes the fourth instruction to sequentially receive snapshot events separately sent by at least two parent nodes of the leaf execution node;
• generate a single-point snapshot of an application instance associated with the leaf execution node after receiving a first snapshot event;
• record a log of a task when executing the task triggered by another parent node, of the leaf execution node, different from a parent node sending the first snapshot event;
• and each time one snapshot event sent by a parent node of the leaf execution node is received subsequently, stop recording a log of a task triggered by the sender of the currently received snapshot event.