How to setup a synchronously Mirrored Database - Revision history

Konstantinos Kontogiannis at 14:48, 6 November 2014

2014-11-06T14:48:58Z

Konstantinos Kontogiannis at 14:48, 6 November 2014

2014-11-06T14:48:45Z

Konstantinos Kontogiannis at 14:48, 6 November 2014

2014-11-06T14:48:21Z

Konstantinos Kontogiannis: /* Setup in Synchronous Mode */

2014-11-06T10:16:09Z

‎Setup in Synchronous Mode

Konstantinos Kontogiannis: /* Setup in Synchronous Mode */

2014-11-06T10:15:18Z

‎Setup in Synchronous Mode

Konstantinos Kontogiannis: /* Setup in Synchronous Mode */

2014-11-06T10:14:39Z

‎Setup in Synchronous Mode

Konstantinos Kontogiannis: /* Setup in Synchronous Mode */

2014-11-06T10:14:08Z

‎Setup in Synchronous Mode

Konstantinos Kontogiannis: /* Setup in Synchronous Mode */

2014-11-06T10:13:38Z

‎Setup in Synchronous Mode

Konstantinos Kontogiannis: /* Setup in Synchronous Mode */

2014-11-06T10:12:45Z

‎Setup in Synchronous Mode

Konstantinos Kontogiannis: /* Setup in Synchronous Mode */

2014-11-06T10:12:04Z

‎Setup in Synchronous Mode

@@ Line 12: / Line 12: @@
 * '''Synchronous Mirroring''': A third server ("Witness") monitors the state of the main server. If the Principal should fail, the Witness will switch over to the Mirror, which will hereby become the Principal. Moreover, the Witness checks whether all transactions have been completed on the Mirror, too. Thus it is ensured that no data loss will occur. However, the performance will be slightly lower than with asynchronous mirroring.
- '''Be aware that High Availability with guaranteed data loss prevention is  possible only with synchronous mirroring.'''
+'''Be aware that High Availability with guaranteed data loss prevention is  possible only with synchronous mirroring.'''
 * '''Asynchronous Mirroring''': There is no Witness, and the switchover to the mirror server is done by "Forced Service", i. e., by the DLS.

@@ Line 12: / Line 12: @@
 * '''Synchronous Mirroring''': A third server ("Witness") monitors the state of the main server. If the Principal should fail, the Witness will switch over to the Mirror, which will hereby become the Principal. Moreover, the Witness checks whether all transactions have been completed on the Mirror, too. Thus it is ensured that no data loss will occur. However, the performance will be slightly lower than with asynchronous mirroring.
-'''Be aware that High Availability with guaranteed data loss prevention is  possible only with synchronous mirroring.'''
+ '''Be aware that High Availability with guaranteed data loss prevention is  possible only with synchronous mirroring.'''
 * '''Asynchronous Mirroring''': There is no Witness, and the switchover to the mirror server is done by "Forced Service", i. e., by the DLS.

@@ Line 10: / Line 10: @@
 For database mirroring, two models are supported:
-* '''Synchronous Mirroring''': A third server ("Witness") monitors the state of the main server. If the Principal should fail, the Witness will switch over to the Mirror, which will hereby become the Principal. Moreover, the Witness checks whether all transactions have been completed on the Mirror, too. Thus it is ensured that no data loss will occur. However, the performance will be slightly lower than with asynchronous mirroring. '''Be aware that High Availability with guaranteed data loss prevention is  possible only with synchronous mirroring.'''
+* '''Synchronous Mirroring''': A third server ("Witness") monitors the state of the main server. If the Principal should fail, the Witness will switch over to the Mirror, which will hereby become the Principal. Moreover, the Witness checks whether all transactions have been completed on the Mirror, too. Thus it is ensured that no data loss will occur. However, the performance will be slightly lower than with asynchronous mirroring.
 * '''Asynchronous Mirroring''': There is no Witness, and the switchover to the mirror server is done by "Forced Service", i. e., by the DLS.

← Older revision		Revision as of 10:16, 6 November 2014
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	'''Be aware that if Mirroring has been executed in the past then the script cannot run successfully.'''		'''Be aware that if Mirroring has been executed in the past then the script cannot run successfully.'''
		+

	12. Start Mirroring from SQL Management Studio. Make sure you configure security with Witness server too.If mirroring was uninstalled (e.g. due to a db restore or a DLS upgrade) and is to be installed again, make sure that only the DLS database in the Mirror SQL server is deleted (via SQL Mgmnt Studio.		12. Start Mirroring from SQL Management Studio. Make sure you configure security with Witness server too.If mirroring was uninstalled (e.g. due to a db restore or a DLS upgrade) and is to be installed again, make sure that only the DLS database in the Mirror SQL server is deleted (via SQL Mgmnt Studio.

@@ Line 107: / Line 107: @@
-. In the main screen of Microsoft SQL Server Management Studio, you can monitor the database mirroring by '''Database Mirroring Monitor'''.It is also possible to switch off the mirroring during operation ('''Remove Mirroring''').
+. In the main screen of Microsoft SQL Server Management Studio, you can monitor the database mirroring by '''Database Mirroring Monitor'''. It is also possible to switch off the mirroring during operation ('''Remove Mirroring''').
-Unless the two database files (DLSdb.bak, DLSdbLog.bak) from \Share folder  of Principal server are deleted (after Mirroring removal), Mirroring cannot be re-configured.
+Unless the two database files (DLSdb.bak, DLSdbLog.bak) from '''\Share''' folder  of Principal server are deleted (after Mirroring removal), Mirroring cannot be re-configured.
 == Setup in Asynchronous Mode ==

@@ Line 108: / Line 108: @@
 . In the main screen of Microsoft SQL Server Management Studio, you can monitor the database mirroring by '''Database Mirroring Monitor'''.It is also possible to switch off the mirroring during operation ('''Remove Mirroring''').
-'''Unless the two database files (DLSdb.bak, DLSdbLog.bak) from '''\Share''' folder of Principal server are deleted (after Mirroring removal), Mirroring cannot be re-configured.'''
+'''Unless the two database files (DLSdb.bak, DLSdbLog.bak) from \Share folder of Principal server are deleted (after Mirroring removal), Mirroring cannot be re-configured.'''
 == Setup in Asynchronous Mode ==

← Older revision		Revision as of 10:12, 6 November 2014
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	If any 'old' database was left over in the mirror, mirroring installation will fail.		If any 'old' database was left over in the mirror, mirroring installation will fail.
		+

	13. In the main screen of Microsoft SQL Server Management Studio, you can monitor the database mirroring by '''Database Mirroring Monitor'''.It is also possible to switch off the mirroring during operation ('''Remove Mirroring''').		13. In the main screen of Microsoft SQL Server Management Studio, you can monitor the database mirroring by '''Database Mirroring Monitor'''.It is also possible to switch off the mirroring during operation ('''Remove Mirroring''').

@@ Line 58: / Line 58: @@
 . Select '''DLSdb''' in '''Microsoft SQL Server Management Studio''' and configure '''Full Recovery''' model.
 . It is recommended to set an unlimited file size in the Files submenu by selecting unrestricted growth for DLSdb and DLSlog.
 . Enter the Witness and Mirror databases as you did in step 1.
 Create the "endpoints" for database mirroring by executing the following commands at the Principal server and the Mirror server:
- - 2220 as TCP listener port
+  - 2220 as TCP listener port
- - PARTNER role
+  - PARTNER role
- - Use Windows Authentication (WINDOWS NEGOTIATE)
+  - Use Windows Authentication (WINDOWS NEGOTIATE)
@@ Line 82: / Line 80: @@
-. Now, generate a backup of the DLS database on the Principal server under ’Share’ folder:
+. Now, generate a backup of the DLS database on the Principal server under ’Share’ folder.
-  '''Before executing the following query make sure that the 'Share' folder is empty. Any existing backup file in this folder will prevent script from running.'''
+  '''Before executing the following query make sure that the 'Share' folder is empty.
-. Using the filenames of the previous step, start the database recovery in Mirror \ DBData folder.
+. Prepare for database recovery at the Mirror server. Restore the files only of the db backup taken previously in the Principal server. In that way you get the logical and physical names of the backup files.
 . On the Principal, under ‘Share’ folder, generate a backup of the initial transaction protocol.
@@ Line 98: / Line 98: @@
    <DLS installation directory>\Tomcat5\webapps\DeploymentService\database\dbinstaller\mssql\DlsDb
   '''Be aware that if Mirroring has been executed in the past then the script cannot run successfully.'''
-. Start Mirroring from SQL Management Studio. Make sure you configure security with Witness server too.
+. Start Mirroring from SQL Management Studio. Make sure you configure security with Witness server too.If mirroring was uninstalled (e.g. due to a db restore or a DLS upgrade) and   is to be installed again, make sure that only the DLS database in the Mirror SQL server is deleted (via SQL Mgmnt Studio.
   If any 'old' database was left over in the mirror, mirroring installation will fail.
 . In the main screen of Microsoft SQL Server Management Studio, you can monitor the database mirroring by '''Database Mirroring Monitor'''.It is also possible to switch off the mirroring during operation ('''Remove Mirroring''').
-'''Unless the two database files (DLSdb.bak, DLSdbLog.bak) from \Share folder of
+'''Unless the two database files (DLSdb.bak, DLSdbLog.bak) from '''\Share''' folder of Principal server are deleted (after Mirroring removal), Mirroring cannot be re-configured.'''
 == Setup in Asynchronous Mode ==