What are the implications of the “live” option as the only one available for activation in Sharep (4302338)

What are the implications of the “live” option as the only one available for activation in Sharep

What are the implications of the “live” option as the only one available for activation in Shareplex 7.6 and up?

General information.

In prior versions of Shareplex the default activation needed downtime on source tables and if the downtime was not available, then there was a “live” option that could be used. In case of latter, it was expected that since users keep making changes to the source table, some tables may go out of sync unless this option was used for first time sync and activation in conjunction with reconcile command. Since there is only “live” option available with Shareplex 7.6, one may run into out of sync if the users keep accessing source tables while activation is running, unless one activates as a part of first time sync and uses the reconcile command to eliminate duplicates from Post queues. So the onus lies on the part of users in ensuring that the tables that are being activated are not accessed on source database for the duration of activation. Another side effect will be that the activation will keep revisiting the tables it is not able to lock to lock them (and in the process it will appear to be hung though it is not) and will eventually time out if it is not successful. The timeout is determined by the setting of the parameter SP_OCF_LOCK_WAIT_TIME.

Here is a chronology of the options available in “activate config” command that would shed some light on the options “live” and “nolock”: In versions of Shareplex prior to 7.6.1, the default behavior of the command “activate config” without specifying any option was to lock a table to bring it in replication and if for any reason a table could not be locked, then the activation would fail. There was a “live” option which would allow the activation process to move to the next table and so on and revisit the table(s) that failed to lock earlier so as to lock them. This iteration would go on till all tables could be locked and successfully activated or the activation would fail if it took a time which exceeded the value of the parameter SP_OCF_LOCK_WAIT_TIME. Starting with SharePlex 7.6.1 there is no “live” option needed to be specified as all activation occur in “live” mode and there are no option available for the command. Starting with SharePlex 7.6.3, there is a “nolock” option in replication that allows a table to be inducted into replication without having to wait to lock it. Of course this comes at an increased complexity of partial transactions replicated for such tables which can potentially result in out of sync. See article 134680 for details.