Mirroring DMSII Audit Files
Introduction to Mirroring
Note
Mirroring is available as an additional Enterprise Server component and requires special licensing. Contact your sales representative for details.
After you have loaded a dump of a DMSII database to a secondary MCP host computer, you can propagate or "mirror" Audit Files
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An operator closes the audit file with the mixnumber SM AUDIT CLOSE command.
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The audit file reaches the file size set in its DASDL.
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There is an I/O error on the audit file.
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There is not enough disk space for this audit file.
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The database update level changes due to database definition changes
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A Databridge accessory closed the file in preparation for the fixup phase after extracting records from a DMSII database.
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The current audit file could not be found.
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A file reorganization was executed to modify the DMSII structure.
from the primary computer through Enterprise Server to the secondary computer using audit file mirroring. After an audit file has been mirrored, you can use the standard DMSII recovery techniques to recover through the audit file and apply the changes to the secondary database. Because the audit files are first mirrored to the Enterprise Server environment, they are available even if the primary system is unusable. Mirroring in near real-time ensures that very few updates are lost in the case of a primary system failure. There are two ways to mirror audit files for a configured source: from the Databridge Enterprise graphical interface and from the command line. This procedure uses the graphical interface. The command line lets you specify a range of audit file numbers to be mirrored. For more information about mirroring audit files using the command line, see Command-Line Options.
To mirror audit files
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In the right pane of the Databridge Enterprise window, right-click a base source and click Properties.
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In the Base Source Properties dialog box, click [Audit Mirror].
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In the Audit Mirroring Properties Dialog Box, select the appropriate settings, and then click [OK] twice to close the Audit Mirroring Properties and the Base Source Properties dialog boxes.
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Click [Save] to record your new configuration.
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To mirror audit files for a configured source, right-click the Enterprise Server source, and select Start mirroring audit files.
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To configure the secondary Databridge host, load the sample CONTROL file
Timestamps
- INDEPENDENTRANS option
- AFN for the current audit file and ABSN for the current audit block
- Data set pack names
- Audit file pack name
- Database user code
(DATA/AUDITMIRROR/SAMPLE/CONTROL) and save a copy as DATA/AUDITMIRROR/databasename/CONTROL.
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In the sample control file, modify the parameters described in the following table to reflect your installation. (See the sample configuration file in this section.)
Parameter Description SOURCE SOURCE name in Enterprise Server AT Hostname or IP address of the Enterprise Server computer PORT Port number where the DBDirector service listens (for example, 5100) AUDIT "targetPath" on "pack" For targetPath and pack, type the directory path and pack on the secondary system where DBAuditMirror will write audit files it receives from Enterprise Server. The mirrored audit file will be created under the usercode that runs DBAuditMirror. RETRY num
SECONDSNumber of seconds to pause between retry attempts. MAXWAIT maxwait
Maximum wait for additional audit updates before quitting. If maxwait is set to FOREVER, the host will retry indefinitely. -
On the secondary system, start DBAuditMirror
START WFL/DATABRIDGE/AUDITMIRROR("databasename" [, ["logicaldbname"] [, startAFN[, endAFN]]])
where databasename is the name of the secondary database. Optionally, you can include a logical database name as a second parameter, and can specify a starting and ending audit file number range as third and fourth parameters. If you want to specify a starting AFN but not a logical database name, include the comma where the logical database name would go and immediately follow it with another comma before the startAFN. For example:
START WFL/DATABRIDGE/AUDITMIRROR ("(MIRROR)BANKDB", , 21, 25)
For additional details, view WFL/DATABRIDGE/AUDITMIRROR.
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Secondary database: The replicated database. The replicated database is the database that usually resides on the client machine and contains records cloned from the DMSII database. The replicated database is updated periodically with changes made to the primary (original) DMSII database. The periodic update (or tracking process) is explained later in this section. Compare this to the primary database.
Audit Mirroring Properties Dialog Box
Getting there
- In the right pane of the Databridge Enterprise window, right-click a base source and click Properties.
- In the Base Source Properties dialog box, click [Audit Mirror].
The options are as follows:
Mirroring parent directory (enables audit file mirroring) | Target directory for mirrored Audit Files
. This can be a local path, or a network path described in UNC format. (For example: \server\share\directory.) The mirrored audit files will be stored in the sourcename subdirectory of the parent directory specified here. For example, if the source is named BANKDB and the parent directory is D:\Databridge\Mirror, then the mirrored audit files will be stored in the D:\Databridge\Mirror\BANKDB subdirectory. Placing the mirrored audit files near the secondary system rather than on a local drive of the Enterprise Server computer is strongly recommended. That way, if the network connection fails between the Enterprise Server computer and the DBAuditMirror computer, DBAuditMirror can continue mirroring all available audit files. |
Read mirrored files as user | Enter the Windows account and password that Enterprise Server will use when running the batch file, reading mirrored audit files, and so on. |
Password | Enter the password for the Windows account specified in the previous box. |
After mirroring an audit file to the secondary host, run | Optionally, you may specify a batch file or application to run after mirroring each audit file to the secondary MCP system. This batch file might remove the mirrored file from the audit mirroring directory. Enterprise Server includes a sample file FinishMirrored.cmd in the Enterprise Server directory that removes the mirrored file after it is mirrored to the secondary system (using DBAuditMirror). This file contains information about parameters available to any batch file specified in this option. |
Wait for audit to mirror | From the menu, specify the wait and retry rules that Enterprise Server follows when mirroring. If you select Wait forever, set a value for Seconds between retries. If you select Wait max seconds, set values for Max seconds and Seconds between retries. |
Sample Audit Mirror Configuration File
%-----------------------------------------------------------------------
%
% Copyright 2024 Rocket Software, Inc. or its affiliates.
%
% Module: DATA/AUDITMIRROR/SAMPLE/CONTROL
%
% Project: Databridge
%
% Description: Databridge Audit Mirror Sample Parameter File
%
% Copyright 2024 Rocket Software, Inc. or its affiliates.
%
%-----------------------------------------------------------------------
% How to locate the DBEnterprise SOURCE ...
SOURCE <sourcename> % SOURCE name in DBEnterprise
AT "<host/ipaddress>" % DBEnterprise's host
PORT <portnumber> % DBEnterprise's port number, e.g. 11367
% example:
% source BANKDB at "WINSERVER" port 11367
% Where to write the audit files ...
AUDIT ["<prefix>"] ON "<mirroredauditfamily>"
[ JOB "<finishedauditwfl>" ]
% The default <prefix> is <dbname>/MIRRORED and the
% default <mirroredauditfamily> is DISK (subject to
% FAMILY substitution).
%
% If you are running the DBAuditMirror program on the
% same system as the primary database be sure at least
% one of the following is true:
%
% <prefix> is not <dbname>
%
% <mirroredauditfamily> is not the original audit
% family
%
% otherwise you will overwrite the primary database's
% audit files.
%
% DBAuditMirror will start the <finishedauditwfl> job
% after successfully mirroring an audit file.
% example:
% audit "BANKDB/MIRRORED" on "ALTPACK"
% job "WFL/DATABRIDGE/FINISHMIRRORED"
% When waiting for an audit file ...
RETRY <retrysecs> SECONDS % seconds delay between retries
% example: retry 10 seconds
MAXWAIT <waitsecs> SECONDS % max total seconds to wait
% MAXWAIT FOREVER % keep retrying indefinitely
% MAXWAIT DONTWAIT % don't retry at all
% example: maxwait 60 seconds