[PATCH v2 1/3] vinyl: make tx_manager_abort_writers_for_ddl more thorough
Vladimir Davydov
vdavydov.dev at gmail.com
Thu Mar 28 18:52:27 MSK 2019
We need to abort all transactions writing to an altered space when
a new index is built. Currently, we use the write set to look up such
transactions, but it isn't quite correct, because a transaction could
yield on disk read before inserting a statement into the write set.
To address this problem, this patch adds vy_tx->last_lsm, which points
to the primary index of the space affected by the last prepared
transaction. Now, tx_manager_abort_writers_for_ddl will look not only
at the write set, but also at this variable to check if it needs to
abort a transaction.
Needed for #3420
---
src/box/vinyl.c | 4 +++-
src/box/vy_tx.c | 8 ++++++--
src/box/vy_tx.h | 15 ++++++++++++++-
3 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/src/box/vinyl.c b/src/box/vinyl.c
index 3ef43e18..24f900cb 100644
--- a/src/box/vinyl.c
+++ b/src/box/vinyl.c
@@ -2433,8 +2433,10 @@ vinyl_engine_begin_statement(struct engine *engine, struct txn *txn)
(void)engine;
struct vy_tx *tx = txn->engine_tx;
struct txn_stmt *stmt = txn_current_stmt(txn);
+ struct index *pk = space_index(stmt->space, 0);
assert(tx != NULL);
- return vy_tx_begin_statement(tx, &stmt->engine_savepoint);
+ return vy_tx_begin_statement(tx, pk != NULL ? vy_lsm(pk) : NULL,
+ &stmt->engine_savepoint);
}
static void
diff --git a/src/box/vy_tx.c b/src/box/vy_tx.c
index 1b8224f4..889e094e 100644
--- a/src/box/vy_tx.c
+++ b/src/box/vy_tx.c
@@ -322,6 +322,7 @@ vy_tx_read_set_free_cb(vy_tx_read_set_t *read_set,
void
vy_tx_create(struct tx_manager *xm, struct vy_tx *tx)
{
+ tx->last_lsm = NULL;
stailq_create(&tx->log);
write_set_new(&tx->write_set);
tx->write_set_version = 0;
@@ -869,13 +870,14 @@ vy_tx_rollback(struct vy_tx *tx)
}
int
-vy_tx_begin_statement(struct vy_tx *tx, void **savepoint)
+vy_tx_begin_statement(struct vy_tx *tx, struct vy_lsm *lsm, void **savepoint)
{
if (tx->state == VINYL_TX_ABORT) {
diag_set(ClientError, ER_TRANSACTION_CONFLICT);
return -1;
}
assert(tx->state == VINYL_TX_READY);
+ tx->last_lsm = lsm;
if (stailq_empty(&tx->log))
rlist_add_entry(&tx->xm->writers, tx, in_writers);
*savepoint = stailq_last(&tx->log);
@@ -1112,7 +1114,9 @@ tx_manager_abort_writers_for_ddl(struct tx_manager *xm, struct vy_lsm *lsm)
{
struct vy_tx *tx;
rlist_foreach_entry(tx, &xm->writers, in_writers) {
- if (tx->state == VINYL_TX_READY &&
+ if (tx->state != VINYL_TX_READY)
+ continue;
+ if (tx->last_lsm == lsm ||
write_set_search_key(&tx->write_set, lsm,
lsm->env->empty_key) != NULL)
vy_tx_abort(tx);
diff --git a/src/box/vy_tx.h b/src/box/vy_tx.h
index aaa31bee..1767b509 100644
--- a/src/box/vy_tx.h
+++ b/src/box/vy_tx.h
@@ -140,6 +140,16 @@ struct vy_tx {
/** Transaction manager. */
struct tx_manager *xm;
/**
+ * Pointer to the primary index LSM tree of the space
+ * affected by the last prepared statement.
+ *
+ * We need it so that we can abort a transaction on DDL
+ * even if it hasn't inserted anything into the write set
+ * yet (e.g. yielded on unique check) and therefore would
+ * otherwise be ignored by tx_manager_abort_writers_for_ddl.
+ */
+ struct vy_lsm *last_lsm;
+ /**
* In memory transaction log. Contains both reads
* and writes.
*/
@@ -325,9 +335,12 @@ vy_tx_rollback(struct vy_tx *tx);
* Return the save point corresponding to the current
* transaction state. The transaction can be rolled back
* to a save point with vy_tx_rollback_statement().
+ *
+ * @lsm is supposed to point to the LSM tree corresponding
+ * to the primary index of the affected space.
*/
int
-vy_tx_begin_statement(struct vy_tx *tx, void **savepoint);
+vy_tx_begin_statement(struct vy_tx *tx, struct vy_lsm *lsm, void **savepoint);
/**
* Rollback a transaction statement.
--
2.11.0
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