Right now, the default is to keep the old backup behavior, i.e., do NOT use
backup workers. Specifically, if BackupType is not set (or is set to default),
the master will not recruit backup workers and will not add pseudo locality for
backup workers.
The StartFullBackupTaskFunc is updated to check if backup worker is enabled.
Only when it is not enabled, starting a backup will wait on all backup workers
to be started.
The backup task may be restarted multiple times so the started key for the
backup task may already be set. In this case, the wait on watch should be
skipped.
TaskBucket::keepRunning() needs to be called in backup transactions to be sure
that the task has not been cancelled. If so, the task is cancelled. Otherwise,
the task can continue run, causing multiple runs of the same task.
Another subtle issue is that the beginVersion is persisted on backupStartedKey.
So while reading it back from that key, we should set task's beginVersion with
the value persisted earlier.
This wait is to make sure that backup workers are already saving mutations so
that no mutations are missed. The idea is that the CLI sets a "backupStartedKey"
in the database and waits for allWorkerStarted() key of the backup to be set.
Backup workers monitor the changes to the "backupStartedKey" and start logging
mutations. Additionally, backup worker for Tag(-2,0) monitors all other workers
have started (checking their saved progress version is larger than the backup's
start version), and then sets the allWorkerStarted() key for the backup.
aborting a DR without the —cleanup flag will still attempt to cleanup for 30 seconds before giving up
added a cleanup command to fdbbackup which can remove mutations from orphaned DRs which were stopped without the —cleanup flag
Because the current restore has defined RestoreConfig, windows linker complains.
This commit rename the RestoreConfig used in FastRestore as RestoreConfigFR.
1) Use the runRYWTransaction for simple DB access
2) Replace some printf with TraceEvent
3) Remove printf not used in debugging
4) Avoid wait inside the condition in loop-choose-when for
the core routine of restore worker, loader and applier.
5) Rename Restore.actor.cpp to RestoreWorker.actor.cpp since
the file only has functionalities related to restore worker.
Passed correctness test
We used fprintf(stderr,) to make sure the message is flushed out.
When we run correctness, we should comment the unnecessary stderr
to avoid false positive errors.
When two struct have the same name but never used in the same scope,
the compiler will NOT report any error in compilation, but
the program will arbitrarily choose one of the struct at the linker time,
and experience weird error in running time. The runtime error is caused by the
corrrupted memory when we assign a struct content to a different struct type.
Evan Tschannen