Capturing And Restoring Database Session State

A computer-implemented method comprising steps of:

• determining that a database session in a first database server has reached a transaction boundary;
• in response to determining that said database session has reached a transaction boundary, capturing a session state of said database session;
• after capturing said session state, capturing a workload that is processed in said database session by said first database server;
• recreating, based on said session state, said database session in a second database server that is separate from said first database server;
• and
• replaying at least a portion of said workload in said recreated database session in said second database server.

A computer-implemented method comprising:

• synchronizing multiple sessions at a transaction boundary during a capture process and a restore process while making no change to a database state of a database during the capture and restore process;
• and
• ensuring transactional consistency between concurrently executing transactions during the capture process and the restore process by performing steps comprising:
• a coordinator session marking a particular session with a suspend option;
• suspending one or more user sessions once the one or more user sessions reach both a capture boundary of a particular transaction and a current call boundary, and when capture criteria are met;
• after each selected session of a plurality of selected sessions reaches the capture boundary and each selected session of the plurality of selected sessions is suspended, the coordinator session initiating capture of each selected session of the plurality of suspended sessions, thereby aligning captured session states of each selected session of the plurality of selected sessions to a particular database system change number;
• maintaining the particular session in a suspended state after the particular session captures a session state of the particular session, until all the selected sessions of the plurality of selected sessions are done with a capture process and until the coordinator resumes workload;
• restoring each selected session of the plurality of sessions during the restore process after each selected session of the plurality of sessions has stabilized;
• suspending a restored version of the particular session after the restore process, until all of the selected sessions of the plurality of selected sessions are done restoring;
• wherein, throughout the capture process and the restore process, no change is made to the database state of the database;
• serializing session states of each selected session of the plurality of selected sessions to external storage;
• wherein no change needs to be committed in the database during the capture process and the restore process.

A non-transitory computer-readable medium storing one or more sequences of instructions which, when executed by one or more processors, cause performing steps comprising of:

• determining that a database session in a first database server has reached a transaction boundary;
• in response to determining that said database session has reached a transaction boundary, capturing a session state of said database session;
• after capturing said session state, capturing a workload that is processed in said database session by said first database server;
• recreating, based on said session state, said database session in a second database server that is separate from said first database server;
• and
• replaying at least a portion of said workload in said recreated database session in said second database server.