Sync Point

The value known as the Sync Point reflects not only the current state of the database, but also provides information on the entire history of changes to the database, since each new Sync Point value takes into account both the GUID of the current transaction and that of the last transaction.

All the HSMs in a Replication Domain at a given time must have the same value for the Sync Point. If any of them differ, this is a serious sign of inconsistency between the bases, and new Write transactions cannot be carried out until consistency is restored in the pool. Note that in an environment with a high volume of write operations, the Sync Point will be changing very quickly.

Along with the Sync Point value (16 hexadecimal characters), a 04-digit summary called SPVV(Sync Point Verification Value) is displayed, the purpose of which is merely to allow easier comparison; each Sync Point corresponds to an SPVV, so two different SPVVs would already indicate different Sync Points.

Sync Point

In routine HSM operation, there should be no occurrences of differences in the Sync Point. The most common situation is when configuring the Domain with manual addition of nodes, and the operator forgets to reset the base synchronization on one of them. When configuring a Domain with automatic discovery, the synchronization reset is automatic.

In the case of a pool with nodes displaying different Sync Points, the operator must restore base consistency by resetting the synchronization in the Database Live Sync option in the replication menu. It is important to choose the node where the operation will be carried out, as this node will have its base entirely reset, and it is up to the operator to decide which of the nodes has the base that should be preserved and which should be overwritten, noting that it is on the node where the operation is being carried out that the base is overwritten.