US 7,890,457 B2Granted

Transactionally consistent database workload replay

AssigneeOracle International Corporation

InventorsKarl Dias, Leonidas Galanis, Jonathan Klein, Venkateshwaran Venkataramani, Yujun Wang

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Abstract

A method and apparatus for capturing database system workload and replaying that workload in a database system is provided. According to one aspect, in order to subject a test database system to the same workload to which the production database system actually would be subjected, a database server in the production system captures and records workload that the database server receives from external entities. This captured workload is processed. Processes external to a database server in the test database system send the processed workload to that database server. As a result, the test database system is subjected to the same workload to which the production database system originally was subjected. The foregoing technique permits a database administrator to determine how the production database system will fare if the difference that is present in the test database system is introduced into the production database system.

Claims20

Dependent claims

A computer-implemented method comprising steps of:

concurrently replaying, relative to a replay database, a first transaction and a second transaction that previously executed concurrently relative to an initial database that is separate from the replay database;
wherein concurrently replaying the multiple database transactions comprises:
determining that the first transaction was committed relative to the initial database prior to a commitment, relative to the initial database, of the second transaction;
and
in response to determining that the first transaction was committed relative to the initial database prior to the commitment of the second transaction relative to the initial database, delaying execution of a command of the second transaction relative to the replay database until after commitment of the first transaction relative to the replay database;
wherein the first transaction comprises two or more first commands and ends with a first COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more first commands to be made permanent relative to the replay database;
wherein the effects of execution the two or more first commands are not permanent relative to the replay database until the first COMMIT instruction has been executed;
wherein the second transaction comprises two or more second commands and ends with a second COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more second commands to be made permanent relative to the replay database;
wherein the effects of execution of the two or more second commands are not permanent relative to the replay database until the second COMMIT instruction has been executed;
wherein delaying execution of the command of the second transaction relative to the replay database until after commitment of the first transaction relative to the replay database comprises ensuring that the first COMMIT instruction is executed prior to execution of the command of the second transaction;
wherein at least one command of the second transaction was executed relative to the initial database before execution of the first commit instruction of the first transaction, but after another command of the first transaction;
wherein execution is not delayed for the at least one command of the second transaction;
wherein the at least one command of the second transaction is executed before the other command of the first transaction during replay;
wherein the steps are performed by one or more computing devices.

11 more elements

A computer-implemented method comprising steps of:

processing a first database transaction concurrently with a second database transaction relative to an initial database;
wherein the first database transaction obtains a lock on an item;
wherein the second database transaction includes a command that affects the item;
wherein, during processing of the second database transaction, (a) execution of the command within the second database transaction is delayed until said lock is released, and (b) after the lock is released, the second database transaction obtains said lock on said item and executes said command;
determining a particular value that indicates a state of the initial database that existed when the second database transaction obtained the lock, wherein the state of the initial database changes as commands are committed to the initial database;
and
storing the particular value in association with the command;
reading the command and the particular value from a repository;
determining, based at least in part on a comparison between (a) a current value that reflects a current state of a replay database that is separate from the initial database and (b) the particular value, a target value that the current value needs to reach before the command can be executed relative to the replay database;
and
executing the command relative to the replay database only after the current value has reached the target value;
wherein at least one command of the second transaction was executed relative to the initial database after another command of the first transaction;
wherein execution is not delayed for the at least one command of the second transaction;
and
wherein the at least one command of the second transaction is executed before the other command of the first transaction during replay;
wherein the steps are performed by one or more computing devices.

13 more elements

A computer-implemented method comprising steps of:

determining that a first transaction did not commit relative to an initial database prior to a start of a second transaction relative to the initial database;
in response to determining that the first transaction did not commit relative to the initial database prior to the start of the second transaction relative to the initial database, ensuring that the second transaction starts relative to the replay database prior to a commitment of the first transaction relative to the replay database;
wherein said initial database is separate from said replay database;
wherein the first transaction comprises two or more first commands and ends with a first COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more first commands to be made permanent relative to the replay database;
wherein the effects of execution the two or more first commands are not permanent relative to the replay database until the first COMMIT instruction has been executed;
wherein the second transaction comprises two or more second commands and ends with a second COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more second commands to be made permanent relative to the replay database;
wherein the effects of execution of the two or more second commands are not permanent relative to the replay database until the second COMMIT instruction has been executed;
wherein at least one command of the second transaction was executed relative to the initial database before execution of the first commit instruction of the first transaction, but after another command of the first transaction;
wherein execution is not delayed for the at least one command of the second transaction;
and
wherein the at least one command of the second transaction is executed before the other command of the first transaction during replay;
wherein the steps are performed by one or more computing devices.

9 more elements

A non-transitory computer-readable storage medium that stores instructions which, when executed by one or more processors, cause the one of more processors to perform steps comprising:

concurrently replaying, relative to a replay database, a first transaction and a second transaction that previously executed concurrently relative to an initial database that is separate from the replay database;
wherein concurrently replaying the multiple database transactions comprises:
determining that the first transaction was committed relative to the initial database prior to a commitment, relative to the initial database, of the second transaction;
and
in response to determining that the first transaction was committed relative to the initial database prior to the commitment of the second transaction relative to the initial database, delaying execution of a command of the second transaction relative to the replay database until after commitment of the first transaction relative to the replay database;
wherein the first transaction comprises two or more first commands and ends with a first COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more first commands to be made permanent relative to the replay database;
wherein the effects of execution the two or more first commands are not permanent relative to the replay database until the first COMMIT instruction has been executed;
wherein the second transaction comprises two or more second commands and ends with a second COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more second commands to be made permanent relative to the replay database;
wherein the effects of execution of the two or more second commands are not permanent relative to the replay database until the second COMMIT instruction has been executed;
wherein delaying execution of the command of the second transaction relative to the replay database until after commitment of the first transaction relative to the replay database comprises ensuring that the first COMMIT instruction is executed prior to execution of the command of the second transaction;
wherein at least one command of the second transaction was executed relative to the initial database before execution of the first commit instruction of the first transaction, but after another command of the first transaction;
wherein execution is not delayed for the at least one command of the second transaction;
wherein the at least one command of the second transaction is executed before the other command of the first transaction during replay.

10 more elements

A non-transitory computer-readable storage medium that stores instructions which, when executed by one or more processors, cause the one of more processors to perform steps comprising:

processing a first database transaction concurrently with a second database transaction relative to an initial database;
wherein the first database transaction obtains a lock on an item;
wherein the second database transaction includes a command that affects the item;
wherein, during processing of the second database transaction, (a) execution of a command within the second database transaction is delayed until said lock is released, and (b) after the lock is released, the second database transaction obtains said lock on said item and executes said command;
determining a particular value that indicates a state of the initial database that existed when the second database transaction obtained the lock, wherein the state of the initial database changes as commands are committed to the initial database;
and
storing the particular value in association with the command;
reading the command and the particular value from a repository;
determining, based at least in part on a comparison between (a) a current value that reflects a current state of a replay database that is separate from the initial database and (b) the particular value, a target value that the current value needs to reach before the command can be executed relative to the replay database;
and
executing the command relative to the replay database only after the current value has reached the target value;
wherein at least one command of the second transaction was executed relative to the initial database after another command of the first transaction;
wherein execution is not delayed for the at least one command of the second transaction;
and
wherein the at least one command of the second transaction is executed before the other command of the first transaction during replay.

12 more elements

A non-transitory computer-readable storage medium that stores instructions which, when executed by one or more processors, cause the one of more processors to perform steps comprising:

determining that a first transaction did not commit relative to an initial database prior to a start of a second transaction relative to the initial database;
in response to determining that the first transaction did not commit relative to the initial database prior to the start of the second transaction relative to the initial database, ensuring that the second transaction starts relative to the replay database prior to a commitment of the first transaction relative to the replay database;
wherein said initial database is separate from said replay database;
wherein the first transaction comprises two or more first commands and ends with a first COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more first commands to be made permanent relative to the replay database;
wherein the effects of execution the two or more first commands are not permanent relative to the replay database until the first COMMIT instruction has been executed;
wherein the second transaction comprises two or more second commands and ends with a second COMMIT instruction, which, when executed by a database server, causes effects of execution of the two or more second commands to be made permanent relative to the replay database;
wherein the effects of execution of the two or more second commands are not permanent relative to the replay database until the second COMMIT instruction has been executed;
wherein at least one command of the second transaction was executed relative to the initial database before execution of the first commit instruction of the first transaction, but after another command of the first transaction;
wherein execution is not delayed for the at least one command of the second transaction;
and
wherein the at least one command of the second transaction is executed before the other command of the first transaction during replay.

8 more elements

Dependencies are inferred from the claim text.