The first step in handling START_MEREQ
is to
ensure that no local checkpoint is currently taking place;
otherwise, it is necessary to wait until it is completed. The
next step is to copy all distribution information from the
master DBDIH
to the starting
DBDIH
. After this, all metadata is
synchronized in DBDICT
(see
Section 6.5.21, “System Restart Handling in Phase 4”).
After blocking local checkpoints, and then synchronizing distribution information and metadata information, global checkpoints are blocked.
The next step is to integrate the starting node in the global checkpoint protocol, local checkpoint protocol, and all other distributed protocols. As part of this the node status is also updated.
After completing this step the global checkpoint protocol is
permitted to start again, the START_MECONF
signal is sent to indicate to the starting node that the next
phase may proceed.