Apparatus and method for replicating changed-data in source database management system to target database management system in real time

• US 10,795,911 B2
• Filed: 03/01/2018
• Issued: 10/06/2020
• Est. Priority Date: 03/06/2017
• Status: Active Grant

• Current Assignee: DataStreams Corp.
• Original Assignee: DataStreams Corp.
• Inventors: Lee, WooJune
• Primary Examiner(s): Mackes, Kris E
• Assistant Examiner(s): Vuong, Cao D
• Application Number:
  US15/909,360
• Publication Number:
  US 20180253483A1
• Time in Patent Office: 950 Days
• Field of Search: None
• CPC Class Codes: G06F 11/1402 Saving, restoring, recovering or retrying
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/1734 Details of monitoring file system events, e.g. by the use of hooks, filter drivers, logs
• CPC Class Codes: G06F 16/23 Updating
• CPC Class Codes: G06F 16/2358 Change logging, detection, and notification replication G06F16/27
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: G06F 2201/80 Database-specific techniques
• CPC Class Codes: G06F 2201/855 Details of asynchronous mirroring using a journal to transfer not-yet-mirrored changes

Abstract

Provided are an apparatus and a method for replicating changed-data in a source database management system to a target database management system in real time, for minimizing the load on the source DBMS system, reducing costs for DBMS hardware configuration, and facilitating operation and failure recovery. The source server transmits the changed-data from a redo log file or an archive log file in a source DBMS area to a target server in real time, and the target server receives the changed-data transmitted from the source server to temporarily store the changed-data in a local area, and extracts the change data stored in the local area to replicate the extracted changed-data to the target DBMS, thereby implementing the apparatus for replicating the changed-data in the source database management system to the target database management system in real time.

Claims

1. A method of replicating changed-data in a source database management system to a target database management system in real time, the method comprising:

(a) confirming an existence of a synchronization target log in a source server when log file synchronization is preliminarily prepared;

(b) performing synchronization error processing when the synchronization target log is not found in the source server in step (a), or establishing a synchronization network connection between the source server and a target server through a log synchronization process when the synchronization target log exists in the source server;

(c) transmitting changed-data of a redo log file and an archive log file in a log file format from the source server to the target server;

(d) generating a synchronization network error event through network monitoring when the synchronization network connection to the target server is not established in a state that log replication is preliminarily prepared;

(e) performing the log synchronization process when the synchronization network connection to the target server is established;

(f) when the log synchronization process is normally performed in step (e), analyzing a log synchronization type in the target server and receiving the changed-data to synchronize the changed-data through a replication process when the log synchronization type is a log synchronization file; and

(g) receiving entire changed-data and storing the entire changed-data in a memory when the log synchronization type analyzed in the target server is not the log synchronization file,

wherein step (a) comprises;

(a1) setting a real application cluster (RAC) node for an Oracle replication target;

(a2) checking completion of the preliminary preparation for the replication;

(a3) creating a log replication list management table and executing synchronization for entire redo logs when the preliminary preparation for the replication is not completed;

(a4) checking a recovery time-point after the preliminary preparation for the replication is completed or after the synchronization for the entire redo logs is executed; and

(a5) setting a current time-point log file synchronization mode when it is not the recovery time-point, or setting a past time-point log file synchronization mode when the recovery time-point is confirmed, as a result of checking the recovery time-point.

2. The method of claim 1, wherein step (e) comprises (e1) entering a log synchronization mode when the synchronization network connection is established, for generating a synchronization data reception process, transferring a synchronization network object, and verifying a network authentication.

3. The method of claim 1, wherein step (f) comprises:

(f1) receiving the changed-data to synchronize the changed-data through the replication process when the log synchronization type is a redo log synchronization file after analyzing the log synchronization type;

(f2) generating an archive log when the synchronizing the changed-data is completed; and

(f3) transmitting a synchronization result to the source server via the network, and finishing the log synchronization.

4. A method of replicating changed-data in a source database management system to a target database management system in real time, the method comprising:

(a) confirming an existence of a synchronization target log in a source server when log file synchronization is preliminarily prepared;

(b) performing synchronization error processing when the synchronization target log is not found in the source server in step (a), or establishing a synchronization network connection between the source server and a target server through a log synchronization process when the synchronization target log exists in the source server;

(c) transmitting changed-data of a redo log file and an archive log file in a log file format from the source server to the target server;

(d) generating a synchronization network error event through network monitoring when the synchronization network connection to the target server is not established in a state that log replication is preliminarily prepared;

(e) performing the log synchronization process when the synchronization network connection to the target server is established;

(f) when the log synchronization process is normally performed in step (e), analyzing a log synchronization type in the target server and receiving the changed-data to synchronize the changed-data through a replication process when the log synchronization type is a log synchronization file; and

(g) receiving entire changed-data and storing the entire changed-data in a memory when the log synchronization type analyzed in the target server is not the log synchronization file,

wherein step (b) comprises;

(b1) confirming whether the synchronization target log is found;

(b2) transmitting confidential reporting system (CRS) control monitoring data to the target server and checking a status of the synchronization network when the synchronization target log is not found;

(b3) going to step (b1) when a synchronization error does not occur, as a result of checking the status of the synchronization network, or confirming whether there is a retry when the synchronization error occurs, as a result of checking the status of the synchronization network;

(b4) reporting the error when there is no retry in step (b3) and finishing the log synchronization, or resetting a synchronization time-point when the retry occurs and going to step (b1); and

(b5) entering a log synchronization mode to create a synchronization thread, analyzing the synchronization log type, and executing the synchronization network connection when the synchronization target log is found.

5. A method of replicating changed-data in a source database management system to a target database management system in real time, the method comprising:

(a) confirming an existence of a synchronization target log in a source server when log file synchronization is preliminarily prepared;

(b) performing synchronization error processing when the synchronization target log is not found in the source server in step (a), or establishing a synchronization network connection between the source server and a target server through a log synchronization process when the synchronization target log exists in the source server;

(c) transmitting changed-data of a redo log file and an archive log file in a log file format from the source server to the target server;

(d) generating a synchronization network error event through network monitoring when the synchronization network connection to the target server is not established in a state that log replication is preliminarily prepared;

(e) performing the log synchronization process when the synchronization network connection to the target server is established;

(f) when the log synchronization process is normally performed in step (e), analyzing a log synchronization type in the target server and receiving the changed-data to synchronize the changed-data through a replication process when the log synchronization type is a log synchronization file; and

(g) receiving entire changed-data and storing the entire changed-data in a memory when the log synchronization type analyzed in the target server is not the log synchronization file,

wherein step (c) comprises;

(c1) confirming whether a log file to be transmitted to the target server is the redo log file;

(c2) confirming existence of a changed-data block when the log file to be transmitted to the target server is the redo log file, and transmitting the changed-data block to the target server when the changed-data block exists;

(c3) transmitting an event of archive log generation when the transmission of the redo log file is completed;

(c4) analyzing an archive log to measure and transmit a changed archive log data block when the log file transmitted to the target server is not the redo log file;

(c5) completing the archive log generation after the archive log data block is transmitted; and

(c6) after the redo log file and the archive log file are transmitted from the target server, generating an error event when a response message is not received, or generating a success event and finishing the log synchronization when the response message is received.

6. A method of replicating changed-data in a source database management system to a target database management system in real time, the method comprising:

(a) confirming an existence of a synchronization target log in a source server when log file synchronization is preliminarily prepared;

(b) performing synchronization error processing when the synchronization target log is not found in the source server in step (a), or establishing a synchronization network connection between the source server and a target server through a log synchronization process when the synchronization target log exists in the source server;

(c) transmitting changed-data of a redo log file and an archive log file in a log file format from the source server to the target server;

(d) generating a synchronization network error event through network monitoring when the synchronization network connection to the target server is not established in a state that log replication is preliminarily prepared;

(e) performing the log synchronization process when the synchronization network connection to the target server is established;

(f) when the log synchronization process is normally performed in step (e), analyzing a log synchronization type in the target server and receiving the changed-data to synchronize the changed-data through a replication process when the log synchronization type is a log synchronization file; and

(g) receiving entire changed-data and storing the entire changed-data in a memory when the log synchronization type analyzed in the target server is not the log synchronization file,

wherein step (d) comprises;

(d1) checking a state of preliminary preparation for log synchronization, creating a log replication repository when the preliminary preparation is not completed, checking whether a redo replication initially occurs, and generating a server socket when the redo replication initially occurs;

(d2) checking a state of establishing the synchronization network connection, transmitting monitoring data to the source server when the synchronization network connection is not established; and

(d3) receiving a response state of the source server, and going to step (d2) when the response state is not an error state, or generating an error event and finishing the log synchronization when the response state is an error state.