This section describes problems that can occur during the export phase of synchronization.
syncreplica –export can fail with the following warning message:
Multiutil: Error: 'family' database has exported oplog entries originating from replica 'site' through oplog-ID oplog-ID. The next oplog-ID to be exported is oplog-ID; it should be oplog-ID. A gap in oplog entries may indicate missing oplog entries.
(For more information about oplog entries, see The Operation Log.)
This error occurs when the sending replica’s epoch number matrix does not match its set of oplog entries. For example:
This discrepancy may be an expected condition. For example, when you change the synchronization pattern for a family, replicas that have not communicated with each other in the past start exchanging update packets. Synchronizing two replicas (syncreplica –export followed by syncreplica –import) updates epoch number matrix rows for the sending and receiving replicas, but it does not revise the row for any other replica. If two replicas rarely (or never) send updates to each other directly, the relevant rows in their epoch number matrices are out of date (possibly consisting of all zeros). This is not a problem, as long as the replicas receive operations indirectly, for example, through a hub replica.
In this case, you must inform sydney about the true state of buenosaires, information that sydney has not received through the standard synchronization mechanism. This information enables sydney to determine which oplog entries to send to buenosaires.
This situation may also occur if you remove oplog entries with the scruboplog command before they are sent to other replicas. You must make sure that you have synchronized the replicas in a family before you scrub oplogs at any of the replicas. See Scrubbing Parameters for Replicas.
Problems with packet delivery are recoverable errors. In many cases, the MultiSite automatic-retry capability recovers from errors.
A replica-creation or update packet submitted to the store-and-forward facility for transport to one or more other hosts is accompanied by a shipping order file. (A logical packet can include multiple physical packets, each with its own shipping order.) The shipping order typically has an expiration time, determined by one of the following:
Any number of delivery attempts may take place before the shipping order expires.
You can receive the following message during export if you specify the sending replica as a destination:
If the sending replica is the only replica you specified, the syncreplica –export command fails. If you specified other replicas, this message is printed as a warning, and the syncreplica –export command continues its processing.