Method for mirroring a log file by threshold driven synchronization

A computer program product for mirroring log data from a primary storage subsystem to a secondary storage subsystem, comprising:

• a non-transitory computer usable medium having computer usable code embodied therewith, the computer program product comprising;
• computer usable code configured for initiating a transaction;
• computer usable code configured for determining a value of the transaction;
• computer usable code configured for adding the value of the transaction to a cumulative value of transaction values since a most recent synchronous mirroring;
• computer usable code configured for asynchronously mirroring of said log data when the cumulative value does not exceed a damage threshold;
• computer usable code configured for synchronously mirroring said log data when the cumulative value exceeds the damage threshold;
• wherein the cumulative value is determined by incrementing a counter according to the value of the transaction;
• wherein said counter is reset after performing the synchronous mirroring.

A method of mirroring database transaction log data from a primary storage subsystem to a secondary storage subsystem, the method comprising:

• initializing a damage counter;
• initiating several transactions;
• upon initiating each transaction, determining a value of the transaction;
• upon determining the value of each transaction, updating the damage counter based on the value of the transaction to a cumulative value of the transactions processed after a most recent synchronous mirroring;
• and
• performing a synchronous mirroring of said log data when a value of said damage counter is greater than a damage threshold;
• wherein the cumulative value is determined by incrementing a counter according to the value of the transaction;
• wherein said counter is reset after performing the synchronous mirroring.

A method of mirroring database transaction log data from a primary storage subsystem to a secondary storage subsystem, the method comprising:

• initiating a transaction;
• determining whether a physical data threshold is reached;
• performing an asynchronous mirroring of said log data when the physical data threshold is not yet reached;
• and
• performing a synchronous mirroring of said log data when said physical dam threshold is reached;
• wherein the cumulative value is determined by incrementing a counter according to the value of the transaction;
• wherein said counter is reset after performing the synchronous mirroring.