[tarantool-patches] [PATCH v2 1/2] Journal transaction boundaries
vdavydov.dev at gmail.com
Mon Jan 28 16:00:53 MSK 2019
On Tue, Jan 22, 2019 at 01:57:36PM +0300, Georgy Kirichenko wrote:
> Append txn_id, txn_replica_id and txn_last to xrow_header structure.
> txn_replica_id identifies replica where transaction was started and
> txn_id identifies transaction id on that replica. As transaction id
> a lsn of the first row in this transaction is used.
> txn_last set to true if it is the last row in a transaction, so we
> could commit transaction with last row or use additional NOP requests
> with txn_last = true ans valid txn_id and txn_replica_id.
> For replication all local changes moved to xrows array tail to form
> a separate transaction (like autonomous transaction) because it is not
> possible to replicate such transaction back to it's creator.
> As encoding/deconding rules assumed:
> 1. txn_replica_id is encoded only if it is not equal with replica
> id. This might have point because of replication trigger
> 2. txn_id and txn_last are encoded only for multi-row transaction.
> So if we do not have txn_id in a xstream then this means that it
> is a single row transaction.
> This rules provides compatibility with previous xlog handling.
> Needed for: 2798
> src/box/iproto_constants.h | 3 ++
> src/box/wal.c | 36 +++++++++++++++-
> src/box/xrow.c | 38 +++++++++++++++++
> src/box/xrow.h | 5 ++-
> test/unit/xrow.cc | 3 ++
> test/vinyl/errinj_stat.result | 8 ++--
> test/vinyl/layout.result | 24 +++++------
> test/vinyl/stat.result | 78 +++++++++++++++++------------------
Also, forgot to say that this patch lacks a test case. We should
probably check that transaction boundaries are written using the
xlog reader module.
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