- High priority interface method to apply NBO begin, separate from
apply_toi() in order to avoid implementation to force interpreting
ws_meta flags.
- Method to put client_state into NBO mode when applying NBO begin.
The client_state will process in m_local mode.
- Unit tests for applying NBO
- Implemented calls to enter and leave NBO phase one and two
- Extended client_state mode checking to include m_nbo
- Changed client_state state and mode change sanity checks to
print a warning and assert() instead of throwing exceptions
to be more graceful in release builds.
Remove methods `is_xa()`, `is_xa_prepare()`, and `xid()` from
client_service interface. Instead, transactions are explicitly
assigned their xid, through at start of XA.
* Add method `restore_prepared_transaction` to `client_state` class
which restores a transaction state from storage given its xid.
* Add method `commit_or_rollback_by_xid` to terminate prepared XA
transactions by xid.
* Make sure that transactions in prepared state are not rolled back
when their master fails/partitions away.
next_fragment is called outside the scope of a high_priority_switch,
and we may be in a different thread context then the streaming applier
was created in
Added a wsrep::thread_service interface to allow application to
inject instrumented thread, mutex and condition variable implementation
for provider.
The interface is defined in include/wsrep/thread_service.hpp.
Sample implementation is provided in dbsim/db_threads.[h|c]pp.
This patch will also clean up some remaining dependencies to
wsrep-API compilation units so that the dependency to wsrep-API
is header only. This will extending the provider support to
later wsrep-API versions.
Sanity checks to detect concurrency bugs were assuming a threading
model where each client state would always be processed within
single thread of execution. This however may be too strong assumption
if the application uses some kind of thread pooling.
This patch relaxes those assumptions by removing current_thread_id_
from client_state and relaxing assertions against owning_thread_id_.
This patch also adds a new method
wait_rollback_complete_and_acquire_ownership() into
client_state. This method is idempotent and can be used to gain
control to client_state before before_command() is called.
The method will wait until possible background rollback process is
over and marks the state to s_exec to protect the state against
new background rollbacks.
Other fixes/improvements:
- High priority globals state is restored after discarding streaming.
- Allowed server_state transition donor -> synced.
- Client state method store_globals() was renamed to acquire_ownership()
to better describe the intent. Method store_globals() was left for
backwards compatibility and marked deprecated.
- populate and pass real error description buffer to provider in case
of applying error
- return 0 from server_state::on_apply() if error voting confirmed
consistency
- remove fragments and rollback after fragment applying failure
- always release streaming applier on commit or rollback
Storing information that background rollbacker in ongoing in client state has_rollback_
This can be used for detecting if there is ongoing background rollback,
and client should keep waiting in before_command() entry to avoid conflicts
in accessing client state during background rollbacking.
transaction::bf_abort() is modified to set has_rollback_ flag when
backgroung rollbacking has been assigned for the client
sync_rollback_complete() method has been modified to reset the backround
rollbacker flag
* Check fragment removal error code in prepare phase. It is possible
that the transaction gets BF aborted during fragment removal.
* Mark fragment certified in certify_fragment() even if the provider
returns cert failed error. With current wsrep-API error codes
it may not be possible to distinquish certification failure
and BF abort during fragment replication. This may also be a
provider bug. As a result rollback fragment may sometimes be
replicated when it would not be necessary.
* Added server_id into transaction in order to be able to stop
streaming applier during high priority BF abort
* Added missing commit fragment applying
* Don't clear fragments for replaying SR transaction
The write set handle and meta data are needed for SR transactions
where the commit context is not known when the transaction starts.
The passed handle and meta data can be set through client_state
prepare_for_ordering() call before performing commit.
The intended purpose for local mode was local storage access without
entering replication hooks. However, the same can be achieved with
high priority mode. Removed replicating mode and use local instead to
denote locally processing clients.
quite useful as there might not be enough information for it
after the statement has been processed. Better to handle retrying
on DBMS side. Also removed after_statement_result enumeration and
return plain int from after_statement().
of background rollback. The separate call is necessary as all of
the resources may not have been released before the execution
reaches after_rollback() call and background rollbacker needs
to notify the client thread after all is complete.
The interface method can be used to notify the DBMS implementation
about state changes in well defined order. The call will be done
under server_state mutex protection.
* Added after applying call for high priority threads in order to
avoid client mode complexity in after_statement() call and
make high prio transaction cleanup possible
* Mask connection failed error with deadlock error if provider
returns connection failed and the transaction was BF aborted
* Pass condition variable for client_state
* Notify all cond waiters when changing the transcation status to
aborted
* Wait for aborting transaction state aborted in before_command
Depending on the DBMS client session allocation strategy the
client id may or may not be available when the client_session
is constructed, therefore there should be a method to assign
an id after construction. Close/cleanup methods were added to
clean up open transactions appropriately.
