After the distribution event starts, the user interface displays the successive stages of the event in the Status field of the Jobs view table. The distribution event has the following stages:
The headings of the topics that follow include the stage designations that appear in the Status field of the Jobs view.
Note
These indicators might go by too quickly to be seen if the job is small.
When the distribution event begins, the first entry in the Status field is Running. During this phase of the process a directory labeled with the job ID and the temporary directory are created in the Workspace. Access to the Workspace is also verified.
ChanCreate appears next in the Status field, indicating that the distribution channels are being created. The core application gets the job ID, the destination group ID, and the destination group name and sends them to the group leaders. The group leaders set up the ports and addresses for the transport channels to the group members that are included in the destination group.
After the channels are established, the core application creates the assignment. An assignment consists three types of data.
When the assignment is created, the core application retrieves the original data files from the source with the directory structure specifying their location. The core application processes this data according to the specifications of the job definition with regard to such things as compression and security. For this reason, the data in the assignment is not in the same form as that in the original data files.
When the assignment is created, the core application attaches the information about the data processing specified by the job. ContentDirector agents use this information on the destination devices to interpret the assignment and unpack the data correctly.
The command buffer contains the commands that initiate the processing of the assignment on the destination devices and information about the source location of the data. The command buffer essentially "tells" the ContentDirector agents what is about to be sent in the data delivery stage and the type of processing that occurs. The command buffer is sent before the rest of the assignment and processing information
After the assignment is created, the core application tests for the availability quorum. If enough devices on the back end are online and ready to receive data, the next phase of the process begins.
After the assignment is created on the front end and the availability quorum is met, the core application sends the command buffer to the destination devices. It goes first to the transport group Leaders. The group leader, in turn, sends it to those transport group members that are part of the destination group.
Before the rest of the assignment is sent, the group leaders report their success rates to the core application. Based on these reports, the core application tests for the commit quorum. If the quorum is met, the core application embarks on the next step in the process.
After the core application sends the command buffer, the assignment data files with their accompanying processing information are pushed to the group leaders, which send it to the group members.
When a ContentDirector agent (on the group member) receives an assignment, it runs the commands in the command buffer. This initiates the assignment processing, which includes such things as verifying the integrity of the data, unencryption, decompression, parsing, and so on.
When the processing is completed, the group leader is notified by the group member, and the group leader sends a report to the core application. The core application tests for the commit quorum. If the commit quorum is met, the commit process occurs. The result is that the files in the temporary directory are now in the Shadow directory, and all temporary directories are removed. Finally, the distribution event is designated as Completed in the user interface.
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Part No. 210-00073
File: distrco4.htm
Last updated: 10/25/01 16:10:28