Problem:
========
- Currently mariabackup have to reread the pages in case they are
modified by server concurrently. But while reading the undo
tablespace, mariabackup failed to do reread the page in case of
error.
Fix:
===
Mariabackup --backup functionality should have retry logic
while reading the undo tablespaces.
InnoDB startup was discovering undo tablespaces in a dirty way.
It was reading a possibly stale copy of the TRX_SYS page before
processing any redo log records.
srv_start(): Do not call buf_pool_invalidate(). Invoke
trx_rseg_get_n_undo_tablespaces() after the recovery has been initiated.
recv_recovery_from_checkpoint_start(): Assert that the buffer pool is
empty. This used to be guaranteed by the buf_pool_invalidate() call.
trx_rseg_get_n_undo_tablespaces(): Move to the calling compilation unit,
and reimplement in a simpler way.
srv_undo_tablespace_create(): Remove the constant parameter
size=SRV_UNDO_TABLESPACE_SIZE_IN_PAGES.
srv_undo_tablespace_open(): Reimplement in a cleaner way, with
more robust error handling.
srv_all_undo_tablespaces_open(): Split from srv_undo_tablespaces_init().
srv_undo_tablespaces_init(): Read all "undo001","undo002" tablespace
files directly, without consulting the TRX_SYS page via calling
trx_rseg_get_n_undo_tablespaces().
This is joint work with Thirunarayanan Balathandayuthapani.
