Ticket 564 - Is ldbm_txn_ruv_modify_context still required
Ticket 47358 introduces backend optimizations using a configuration switch.
By default all optimisation are disabled.
One optimisation is related to changelog and DB RUV being written back to disk in the same txn with the same value.
This is a consequence of bug fix 543633. Although the write back of the DB RUV brings a little overhead
it is not strictly required. In fact since 633168, changelog RUV is in sync with the data store. So
changelog RUV and DB RUV have the same values.
This fix enables by default the ticket 47358 optimization BACKEND_OPT_NO_RUV_UPDATE that does
not compute/update the database RUV.
Two consequences of this are:
1. In case of disordely shutdown (crash) and after recovery, we need to rebuild the DB RUV
2. Provide a mechanism to monitor replication status, as DB ruv would be late compare
to the current update status
1. is achieve using the changelog RUV (in sync with the data store) to rebuild the database RUV.
2. was done with ticket https://fedorahosted.org/389/ticket/47350https://fedorahosted.org/389/ticket/564
Reviewed by: Rich, Ludwig (thanks to you both !)
Platforms tested: fedora 17
Flag Day: no
Doc impact: no