Verifying synchronization between source and target replication server

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The purpose of replication is to maintain the same level of files on the source and the target replication servers so that data can be restored from the target server if necessary. When data is replicated from the source replication server to the target replication server, you might want to verify if both the servers are synchronized. It is necessary that you understand the processes that are involved in verifying synchronization between the source and target replication server. You must also understand the ways to troubleshoot for reasons if the servers are not synchronized.

View client replication status

On the Client Replication page, you can view client replication status to verify that the client file spaces were successfully replicated to target replication servers and that the replicated data is current.

Note: The Client Replication page displays file spaces regardless of whether they were replicated by a replication storage rule or by using the REPLICATE NODE command.

To view client replication status, complete the following steps:

  1. On the Operations Center menu bar, click Clients > Client Replication.
  2. Review the information that is shown in the table. Each row of the table shows a separate file space that is replicated to a target replication server. To verify that a file space was successfully replicated and that the replicated data is current, review the information in the Status and Last Synchronized columns.

Verify data synchronization between source and target replication servers

You can verify if both servers are in sync by issuing QUERY REPLICATION command. Specify the name of the client node on the source replication server, name of the target replication server, and the parameter FORMAT=DETAILED.

To verify synchronization between the client node, NODE1 on the source replication server and the target replication server PHOENIX-DR, issue the following command:

query replication node1 server=phoenix-dr format=detailed
From the query output, you need to focus on the following fields:
Total Files To Replicate
Displays the total number of files to replicate to the target replication server. The value must be zero.
Total Files Not Replicated Due To Errors
Displays the total number of files that were not replicated because of errors. The value must be zero.
Total files Not Yet Replicated
Displays the total number of files that are not yet replicated to the target replication server. The value must be zero.

If any of the values in the fields that are mentioned is not equal to zero, it would indicate that the source and target replication servers are not in sync. For more information about QUERY REPLICATION command, see Guidelines for reducing database size by pruning the SDRC table

View information about the failed replication

The QUERY REPLICATION command output might display information on files that failed to replicate from the source replication server to the target replication server. You can obtain more details on the files that failed to replicate and the reason for the failure by issuing the QUERY REPLFAILURES command.

When you issue the command, specify the name of the client node that you want to query, the name of the target replication server, and the parameter TYPE=OBJECTS.

To obtain the list of files that failed to replicate from the client node, NODE1 on the source replication server to the target replication server PHOENIX-DR, issue the following command:

query replfailures node1 server=phoenix-dr type=objects

From the query command output you can view the names and IDs of the files that failed to replicate, the error code, and the explanation of the errors.

Check the server activity log file and other log files

To have a better understanding of the replication error, you might want to obtain detailed information about the recent server activities. Also, you might need log filestoraise a service request with IBM® Software Support.

To review the messages in the server activity log, issue the QUERY ACTLOG command.

To view additional information about the cause of the problem and to find ways to resolve it, you can refer to the following log files:
  • Web-server log files:
    • console.log
    • messages.log
  • First-failure-data-capture (FFDC) log files:
    • exception_summary_date_time.log
    • ffdc_date_time.log