Introduction

The Dbvisit Standby Archive Log Management Module fully automates the management and monitoring of the Oracle archive log space on either the primary, standby server or both. Unlike the Oracle database files location, the Oracle archive logs location needs to be monitored and managed constantly to ensure the database continues its optimal operation. If the disk space available to Oracle archive logs is used up, the whole database will "freeze" and not allow any update or insert operation.

Dbvisit Standby Archive Log Management Module includes the following options:

Alerts through email when Oracle archive logs have reached a set threshold of available disk space.
Can delete Oracle archive logs after a set number of days.
Can ensure that only x number of Oracle archive log files remain on server.
Can delete Oracle archive logs after available disk space has been used up to ensure continual database operation.
Ensures the Oracle archive logs have been sent to standby database before removing any logs.
Can integrate with Backup software to ensure logs have been backed up before removing.

Dbvisit Standby is not replacing your backup scripts or backup software. It is important that you still backup your database and archive log to different storage or a tape device.

The Dbvisit Standby Archive Log Management Module (AMM) can be used on the primary server, the standby server or on both. The Dbvisit Standby Archive Log Management Module can either be installed as part of the main Dbvisit Standby configuration or separately through the Dbvisit Standby setup menu. Configuration is always done on the primary server for both the primary server and the standby server. The AMM can be configured separately as part of the initial Dbvisit Standby setup, and can also be configured separately.

As of Dbvisit Standby 6.0.30 managing of archive log files in ASM is supported. Dbvisit Standby uses RMAN to delete logs in multiple archive destinations.

Dbvisit Standby checks if a log has been transferred to the standby server before deleting it on the primary. This check can be turned of by setting:

AMM_CHECK_TRANSFERRED=N

AMM and Multiple Standby Databases

In case of multiple standby databases, Dbvisit Standby checks if a log has been transferred to all active standby databases before deleting it on the primary.

A standby database is considered to be active if a Dbvisit process has run within the last DBV_LAST_RUN_OFFSET days to ship logs to this database from the primary.

Note the default value:

DBV_LAST_RUN_OFFSET=1

Configure AMM

image2012-1-20 11:27:47.png To configure AMM choose option 3 from the main dbvisit_setup utility:

oracle@dbvlin101[/usr/dbvisit/standby]: ./dbvisit_setup

=========================================================
Dbvisit Standby Database Technology (7.0.03.11502)
 http://www.dbvisit.com
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=>dbvisit_setup only needs to be run on the primary server.
Is this the primary server? <Yes/No> [Yes]:
=========================================================
 Dbvisit Standby Database Technology (7.0.03.11502)
 http://www.dbvisit.com
 Dbvisit Database setup
 Default values will be shown in []
 
 Options:
 1) New Dbvisit Database setup (combines options 2,3,4)
 1a) New Dbvisit RAC Instance setup (combines options 2,3,4)

 2) New Dbvisit Database configuration (DDC) file setup
 3) New Dbvisit Archive Management Module (AMM) setup
 4) New Dbvisit Database repository (DDR) setup

 5) Manage Dbvisit Database repository (DDR)
 6) Update Dbvisit Database configuration (DDC) file

 7) Create Standby Database (and template)
 8) Synchronize Standby Database

 9) Uninstall Dbvisit Database repository (DDR)
 E) Exit
=========================================================
Please enter choice :

Follow the on-screen instructions to install AMM or please see the image2012-1-20 11:31:20.png Dbvisit Standby Archive log Management Module (AMM) setup section for description of each step.

image2012-1-20 11:31:39.png Home > Setup > Update Dbvisit > Update Dbvisit Configuration. Choose the AMM settings to update and click on Save Configuration.

Dbvisit Standby AMM variables

The variables that control the Dbvisit Standby Archive Log Management Module (AMM) processing for the primary server are listed here: Primary Archive log Management Module (AMM)

The variables that control the Dbvisit Standby Archive Log Management Module (AMM) processing for the standby server are listed here: Standby Archive log Management Module (AMM)

Note

The standby server variables work exactly the same as the primary server variables. The standby server variables have the word DEST instead of SOURCE.
In normal circumstances either variable DAYS_TO_KEEP_ARCHSOURCE or NUM_ARCHSOURCE_TO_KEEP will be used, but not both.
The variables DAYS_TO_KEEP_ARCHSOURCE and NUM_ARCHSOURCE_TO_KEEP can be turned off by setting them to 0.
The variable THRESHOLD_ARCHSOURCE can be turned off by setting it to 100.

Dbvisit Standby AMM processing overview

The order of precedence in managing the log files are:

If there are log files older than DAYS_TO_KEEP_ARCHSOURCE, then delete these.
If there are more log files than NUM_ARCHSOURCE_TO_KEEP, then delete these (oldest ones first).
If there are more logs that have been backed up by RMAN at least ARCHSOURCE_BACKUP_COUNT times, then delete these.
If the THRESHOLD_ARCHSOURCE < mount point fullness criteria is met, then mark archives for deletion (oldest ones first). The number of archives marked for deletion is HOWMANY_ARCHSOURCE. The archives will only be deleted if DELETE_ARCHSOURCE=Y. After deletion of the archives, and the criteria is still met (THRESHOLD_ARCHSOURCE < mount point fullness), then mark more archives for deletion (number of archives marked for deletion will be again HOWMANY_ARCHSOURCE, and oldest ones first). This process will continue until criteria is no longer met.

If DELETE_ARCHSOURCE=N, then only a warning email will be sent. No archives will be deleted when the THRESHOLD_ARCHSOURCE < mount point fullness criteria is met.Setting variable DELETE_ARCHSOURCE=N has no influence over DAYS_TO_KEEP_ARCHSOURCE and NUM_ARCHSOURCE_TO_KEEP. These will still delete archive files when their criteria are met.

Dbvisit Standby AMM log file

The Dbvisit Standby Archive Log Management Module (AMM) produces a separate log file to the Dbvisit Standby database processing. The log file can be found in the same location as Dbvisit Standby database log file. The log file is called <DDC>_arch_management.log. The location is determined by the LOGDIR and LOGDIR_DR settings in the DDC file.

Backup software and AMM

To use the Dbvisit Standby Archive log Management Module together with Backup software that backs up the archive logs, the post-processing option of Dbvisit Standby can be used. The post-processing option of Dbvisit Standby runs after Dbvisit Standby has executed, but before the Archive Management Module executes. This ensures that the archive logs have been backed up before they are removed by the Dbvisit Standby Archive log Management Module. The post-processing option can be called either on the primary or on the standby server or both.

On the primary server:

The sequence of events on the primary server is:

Dbvisit Standby pre-processing
Dbvisit Standby transfers the archive logs
Dbvisit Standby post-processing (Backup software can be scheduled here)
Dbvisit Standby Archive log Management Module.

On the standby server:

The sequence of events on the standby server is:

Dbvisit Standby pre-processing
Dbvisit Standby applies the archive logs
Dbvisit Standby post-processing (Backup software can be scheduled here)
Dbvisit Standby Archive log Management Module.

The Backup software can be scheduled as part of the post-processing option. If the Backup software fails, the return code can be trapped and passed back to Dbvisit Standby. This means Dbvisit Standby will alert with a notification and will stop processing. This ensures that the Dbvisit Standby Archive log Management Module will not be executed, and that archive logs will not be deleted before they are backed up.

For more information about post-processing see the Pre- and post-processing section.

Primary AMM Configuration Variables

This section provides an overview of the variables that can be configured for the AMM module with regards to the Primary Database.

Variables are sorted alphabetically in the table below

Variable Name	Meaning
ARCHSOURCE_BACKUP_COUNT	Specify the number of times an archive log has to be backed up by RMAN before Dbvisit Standby deletes it from the primary server. To disable this setting, set to 0 which is the default value. Example: ARCHSOURCE_BACKUP_COUNT = 0
ARCHSOURCE_MANAGEMENT	Specify if the AMM module to manage the archive log files are turned on or off on the primary server. Possible Values: Yes (default) Enable the AMM module on primary server. No Disable the AMM module on primary server. Example: ARCHSOURCE_MANAGEMENT= Yes
DAYS_TO_KEEP_ARCHSOURCE	Specify the number of days to keep the Oracle log files on the primary server. If this value (in days) are reached, the log files will be removed from the server. To disable this setting, set to 0, if you are not sure, set to 7. Make sure you have sufficient disk space to store the archive logs. See also the ARCHDEST parameter under the standby server variable section for more detail Example: DAYS_TO_KEEP_ARCHSOURCE = 7
DELETE_ARCHSOURCE	Specify if archive log files should be deleted once the percentage threshold (THRESHOLD_ARCHSOURCE) on the primary server is reached. Once the threshold is reached oldest archive log files are deleted first. There is no verification that these log files have been backed up. Dbvisit Standby does not perform backups, this should be configured outside the Dbvisit Standby product. Possible Values: Yes Let Dbvisit Standby delete archive log files once percentage threshold is met. No Dbvisit Standby will only alert when percentage threshold is met (no archive log files will be deleted). If you are not sure, set to No. Example: DELETE_ARCHSOURCE = No This setting has no influence whether (archive) log files are deleted for DAYS_TO_KEEP_ARCHSOURCE or NUM_ARCHSOURCE_TO_KEEP. These settings will delete (archive) log files once the percentage threshold is met.
FRA_THRESHOLD_ARCHSOURCE	Specifies the threshold in percentage (%) of how much FRA (flash/fast recovery area) space may be taken up by the archive log files on disk before an alert is triggered on the primary server. A value of 80 means at 80% FRA space threshold is reached, an alert will be triggered. Please specify threshold as an integer. Example: FRA_ THRESHOLD_ARCHSOURCE = 80
NUM_ARCHSOURCE_TO_KEEP	Specifies the number of archive log files to keep on the primary server. Log files greater than this number will be removed (oldest first). To disable this setting, set to 0. If you are not sure, set to 0 (disable). Example: NUM_ARCHSOURCE_TO_KEEP = 0
THRESHOLD_ARCHSOURCE	Specifies the threshold in percentage (%) of how much disk space may be taken up by the archive log files on disk before an alert is triggered on the primary server. A value of 80 means at 80% space threshold is reached, an alert will be triggered. Please specify threshold as an integer. Example: THRESHOLD_ARCHSOURCE = 80

Standby AMM Configuration Variables

This section provides an overview of the variables that can be configured for the AMM module with regards to the Standby Database.

Please see Archive log Management Module (AMM) for more information on AMM.