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Description
Replicator provides the possibility to set priority to the CAB files. The feature is specifically designed for low low bandwidth network to avoid sending/receiving huge CAB files. The following priority levels are available:
High priority files contain the metadata or critical information.
Low priority cab files contain all the data.
In this respect, Adonis Replicator covers the following:
Identify those replication task fields that should be added into the low priority CAB files.
Identify the bandwidth thresholds that allow sending low priority files and any files (low and high), stop using a satellite connection to send low priority files and send any file.
Identify the maximum response time to check a satellite connection.
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To set up the bandwidth options, first, run Adonis Replicator. Within the application, navigate to Settings and click the Settings Wizard button. This opens the following dialog:
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In the dialog, make sure that the Mail system field is set to FTP and click Next to proceed. The dialog appears:
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Within the dialog, click the Satellite / Bandwidth button. Clicking the command makes the Satellite and bandwidth options dialog appears:
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You can specify your preferences regarding the following points:
When a satellite connection to the Internet is used
allow the transfer of any files. If selected, either low or high priority files can be sent/received.
forbid the transfer of low priority files. If selected, low priority files cannot be sent/received.
forbid the transfer of any files. If selected, either low or high priority files cannot be sent/received.
Bandwidth thresholds
Stop transfer of low priority files when bandwidth is less than (KB/s). In the field, set the bandwidth limit (KB/s) for sending/receiving low priority files.
Stop transfer of any files when bandwidth is less than (KB/s). In the field, set the bandwidth limit (KB/s) for sending/receiving any files.
If the the Bandwidth thresholds options contain non-zero values, Replicator measures the bandwidth when downloading the first files.
Advanced settings
Minimum server response time via a satellite connection (milliseconds). In the field, specify the minimum time the server may respond.
Duration of bandwidth measurement process (milliseconds). In the field, how long the measurement of bandwidth can take.
Click OK to save the changes.
Define Low Priority Fields
To define low priority fields, first, run Adonis Personnel Manager. Within the application, navigate to the Setup ribbon tab > Adonis Replicator > View -1 > Replication Tasks:
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In the list of tasks, proceed as described below:
Select the task containing the fields that you want to be exported in the low priority CAB file.
In the Low Priority Fields column, double-click the cell where a low priority field is to be added. When the Browse
button appears, click it to view the list of fields to be added:
In the Select Values
dialogdialogue, select the fields to be added as low priority fields. To select all the fields, click Tag All at the bottom of the
dialogdialogue. To clear the selection, click Untag All at the bottom of the
dialogdialogue.
Click OK to apply the selection.
As a result, the affected cell in the Replication Tasks grid Tasks appears as yellow-highlighted:
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There is another way you can use to add low priority fields. Simply, enter LowPriorityFields='VALUE' where VALUE is a field name to be added with low priority and ImportTableName=' PW001OLEDOCS ' in the replication tasks table.
The LowPriorityFields value must not contain:
primary key fields
foreign key fields
fields used in a unique constraint
fields that do not allow nulls
Workflow
This section covers the workflow of Replicator in respect of low priority files at all the application phases. Based on the satellite and bandwidth options defined (see Setting Up Replicator), the application may have different procedures.
Receive phase
In case either either the option Forbid transfer of low priority files or Forbid transfer of any files option is is selected, Replicator calculates server response time and compares it with the value entered in the Minimum server response via a satellite connection field. Based on Based on the specified option and calculated values of time response, Replicator starts downloading high priority files downloading high priority files (files without ~1 at the end of their names). Only Only when all the high priority files are received, Replicator starts transmitting low priority files transmitting low priority files (if allowed by the options).
The bandwidth is measured a fixed period of time specified in the Duration of the bandwidth measurement process (milliseconds) field. In case a file a file is small and, therefore, it is downloaded faster than the period ends, the calculated value is discarded and Replicator makes a new attempt to measure the bandwidth value while downloading the next file.
When the bandwidth is calculated, Replicator compares its value with the values in the fields. If the bandwidth appears to be lower than the threshold value, Replicator immediately stops downloading the current file and the Receive phase the Receive phase is terminated. In this case, Replicator adds a corresponding notification to the log file. Next Next time when Replicator starts and goes to the Receive phasethe Receive phase, it will continue downloading the file that has not been downloaded completely.
Import Phase
Replicator primarily imports high priority files and then low priority files primarily imports high priority files and then low priority files.
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Import of low priority files is not supported by former versions of Replicator, therefore, it will raise an error message. |
Export Phase
For any tasks containing low priority fields, Replicator splits the result set of these tasks into low priority and high priority CAB files.
High priority files priority files keep their usual names, while low priority files are identified while low priority files are identified with ~1 at the end of the file name.
Example: low priority 35~1~40~1234~135~1~40~1234~1.cab high priority: 35~1~40~1234.cab
Send Phase
Replicator The replicator measures the bandwidth and response time. Based on Based on the result of these measurements and the options set, Replicator start sending the CAB files. High High priority files are primarily sent, followed by low priority based on the results of the bandwidth and response measurements. High High priority files are always prioritized over low priority files even if they have been created in the previous replicator session.Fields added to Database
Below, you can find the fields that Replicator automatically adds to the database:
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Field
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Table
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Field meaning
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LastFileNrLowPr (int)
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repl_Channel
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A number of the low priority file that has been recently exported.
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PriorityNr
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repl_Channel_Log
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Priority of a file: 0 stands for a high priority file; 1 is used for a low priority file.
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PriorityNr
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repl_Channel_Task_Log
Replicating Large Files
CAB files can become very large when exporting a database and all scanned documents. To avoid using large files, Replicator allows splitting the files into multiple CAB files. To do this, add the add the TOP (x) statement to the replication task select statement.
Let us consider the example of the of the replication task exporting the scanned documents PW001OLEDOCS:
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SELECT TOP(1000) * FROM dbo.PW001OLEDOCS WHERE repl_ModifiedDate >= #LR# AND repl_ModifiedBySite <> #DSN# |
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As a result, the CAB files will only contain 1000 PW001OLEDOCS records in each cab file. If If PW001OLEDOCS contains 4500 records, Replicator will create 5 CAB files instead of 1, each containing 1000 PW001OLEDOCS records except for the last cab file that contains only 500 records.