Remove bf abort handling `client_state::after_statement()`, since the
same logic already appears later in `transaction::after_statement()`.
Also, introduce `transaction::after_statement()` overload which takes
a lock.
The transaction state is set to s_ordered_commit in
ordered_commit(). However, this is too late for making the
transaction immune for BF aborts after commit order has
been established, which happens in before_commit().
Moving the state change into before_commit() would be the
right thing to do, but that would require too many fixes
to existing applications which are using the lib.
In order to make the transaction immune for BF abort
after it has been ordered to commit, introduce additional
boolean flag which is set to true at the end of before_commit()
and is taken into account in bf_abort().
Removed calls to assert() from public headers to have
full control when assertions are enabled in wsrep-lib
code regardless of parent project build configuration.
Moved methods containing assertions and non-trivial
code from headers into compilation units.
Handle the case were prepare is bf aborted after it has replicated a
fragment, and before the command finishes in
after_command_before_result() and after_command_after_result() hooks.
Assertion is_streaming() fires in transaction::adopt() when a
transaction is BF aborted, while it is in s_executing state, and it
manages to complete rollback and cleanup while the BF aborter is
executing streaming_rollback() with client_state lock is unlocked.
In this case method transaction::adopt() finds a transaction that is
no longer marked as streaming, triggering the assertion.
A condition variable and flag streaming_rollback_in_progress_ now
prevents a client thread to finish rollback, even if the BF aborter
has temporarily unlocked the client_state lock.
Remove the method as it does nothing, except for calling
`streaming_context_.clear()`. This led to a situation where we have
two ways to do the same thing, and it is annoying, if one wants to search
for all places where streaming_context is cleaned up.
* Removed transaction::p_unsafe_ member
* Changed transaction::pa_unsafe(bool) to modify flags member directly
* Modified transaction.cpp to use transaction.pa_unsafe(bool) rather than
directly changing transaction's flag
* added method mark_transaction_pa_unsafe() for client_state,
application will use this
* Added unit tests for transaction::xa_detach() and
transaction::xa_replay()
* Added unit tests for wsrep::xid
* Fixed minor issues pointed out by reviewer
This patch implments replaying for prepared XA transactions.
Replay may happen in the following cases:
1) The transaction is BF aborted in prepared state and is idle. In
that case, the transaction is handed over to rollbacker for replay.
2) The transaction is BF aborted while executing the
commit (i.e. before or after successful certification). In
which case the transaction replays itself from fragment storage.
3) The transaction is BF aborted while certifying its commit
fragment. This case is handled like replay for streaming transactions,
where the provider is directly involved and re-delivers the last
fragment.
Add support for detaching XA transactions. This is useful for handling
the case where the DBMS client has a transaction in prepared state and
disconnects. Before disconnect, the DBMS calls the newly introduced
client_state::xa_detach(), to cleanup the local transaction and
convert it to a high priority transaction. The DBMS may later attempt
to terminate the transaction through client_state::commit_by_xid() or
client_state::rollback_by_xid().
Also in this patch:
- Fix client_state::close() so that it does not rollback transactions
in prepared state
- Changed class wsrep::xid representation to hold enough information
so that DBMS can convert to its native representation
- Fix potential infinite loop in
server_state::find_streaming_applier(wsrep:xid&)
- Append SR keys on prepare fragment and make it pa_unsafe
- Handle one phase commit (simply fall back to two phase)
- Do not rollback prepared streaming clients in
server_state::close_orphaned_transactions()
If the transaction fails during replay because of certification
failure, the provider will return control to applier without
terminating the transaction and transaction remains in
s_replaying.
Fixed transaction::after_statement() to handle the state changes
correctly if certification failure is returned from replay.
Replaying was extracted to separate private method from
after_statement(). Removed transaction::after_replay() as it
seems now unnecessary and it bypassed state change sanity checks.
Allowed replaying -> committed transaction transition to handle
the situation where DBMS allocates a new context and client_state
to do the replay.
Certification keys are needed for NBO end to resolve dependencies
for the write sets which follow NBO end. Without keys the following
write sets do not detect dependency to NBO event and may start applying
too early.
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.
Force fragment replication when XA transaction is prepared, with
prepare fragment. Commit fragment happens in before_commit().
Adjusted fragment removal, which cannot happen in atomically with the
executing transaction.
- 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
Moved the check for transaction state before certification step
into separate method abort_or_interrupted() which will check the state
and adjust state and client_state error status accordingly.
Moved the check for abort_or_interrupted() to happen before
the state is changed to certifying and write set data is appended.
This makes the check atomic and reduces the probability of race
conditions. After this check we rely on provider side transaction
state management and error reporting until the certification step
is over.
Change to public API: Pass client_state mutex wrappend in unique_lock
object to client_service::interrupted() call. This way the DBMS side
has a control to the lock object in case it needs to unlock it
temporarily. The underlying mutex will always be locked when the lock
object is passed via interrupted() call.
Other: Allow server_state change from donor to connected. This may
happen if the joiner crashes during SST and the provider reports
it before the DBMS side SST mechanism detects the error.
* Adds method wsrep::transaction::streaming_step() so that there is a
single place where streaming context unit counter is udpated.
The method also checks that some data has been generated before
attempting fragment replication.
* Emit a warning if there is an attempt to replicate a fragment and
there is no data to replicate.
* 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
* 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
