[Tarantool-patches] [PATCH v8 3/6] limbo: gather promote tracking into a separate structure
Cyrill Gorcunov
gorcunov at gmail.com
Mon Jul 26 18:34:49 MSK 2021
It is needed to introduce ordered promote related data
modifications in next patch.
Part-of #6036
Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>
---
src/box/box.cc | 12 +++++++----
src/box/txn_limbo.c | 24 ++++++++++++++--------
src/box/txn_limbo.h | 49 ++++++++++++++++++++++++++++-----------------
3 files changed, 55 insertions(+), 30 deletions(-)
diff --git a/src/box/box.cc b/src/box/box.cc
index fb58f981d..b356508f0 100644
--- a/src/box/box.cc
+++ b/src/box/box.cc
@@ -1565,7 +1565,8 @@ box_run_elections(void)
static int
box_check_promote_term_intact(uint64_t promote_term)
{
- if (txn_limbo.promote_greatest_term != promote_term) {
+ const struct txn_limbo_terms *tr = &txn_limbo.terms;
+ if (tr->terms_max != promote_term) {
diag_set(ClientError, ER_INTERFERING_PROMOTE,
txn_limbo.owner_id);
return -1;
@@ -1577,7 +1578,8 @@ box_check_promote_term_intact(uint64_t promote_term)
static int
box_trigger_elections(void)
{
- uint64_t promote_term = txn_limbo.promote_greatest_term;
+ const struct txn_limbo_terms *tr = &txn_limbo.terms;
+ uint64_t promote_term = tr->terms_max;
raft_new_term(box_raft());
if (box_raft_wait_term_persisted() < 0)
return -1;
@@ -1588,7 +1590,8 @@ box_trigger_elections(void)
static int
box_try_wait_confirm(double timeout)
{
- uint64_t promote_term = txn_limbo.promote_greatest_term;
+ const struct txn_limbo_terms *tr = &txn_limbo.terms;
+ uint64_t promote_term = tr->terms_max;
txn_limbo_wait_empty(&txn_limbo, timeout);
return box_check_promote_term_intact(promote_term);
}
@@ -1604,7 +1607,8 @@ box_wait_limbo_acked(void)
if (txn_limbo_is_empty(&txn_limbo))
return txn_limbo.confirmed_lsn;
- uint64_t promote_term = txn_limbo.promote_greatest_term;
+ const struct txn_limbo_terms *tr = &txn_limbo.terms;
+ uint64_t promote_term = tr->terms_max;
int quorum = replication_synchro_quorum;
struct txn_limbo_entry *last_entry;
last_entry = txn_limbo_last_synchro_entry(&txn_limbo);
diff --git a/src/box/txn_limbo.c b/src/box/txn_limbo.c
index 570f77c46..53c86f34e 100644
--- a/src/box/txn_limbo.c
+++ b/src/box/txn_limbo.c
@@ -37,6 +37,13 @@
struct txn_limbo txn_limbo;
+static void
+txn_limbo_terms_create(struct txn_limbo_terms *tr)
+{
+ vclock_create(&tr->terms_map);
+ tr->terms_max = 0;
+}
+
static inline void
txn_limbo_create(struct txn_limbo *limbo)
{
@@ -45,8 +52,7 @@ txn_limbo_create(struct txn_limbo *limbo)
limbo->owner_id = REPLICA_ID_NIL;
fiber_cond_create(&limbo->wait_cond);
vclock_create(&limbo->vclock);
- vclock_create(&limbo->promote_term_map);
- limbo->promote_greatest_term = 0;
+ txn_limbo_terms_create(&limbo->terms);
limbo->confirmed_lsn = 0;
limbo->rollback_count = 0;
limbo->is_in_rollback = false;
@@ -305,10 +311,11 @@ void
txn_limbo_checkpoint(const struct txn_limbo *limbo,
struct synchro_request *req)
{
+ const struct txn_limbo_terms *tr = &limbo->terms;
req->type = IPROTO_PROMOTE;
req->replica_id = limbo->owner_id;
req->lsn = limbo->confirmed_lsn;
- req->term = limbo->promote_greatest_term;
+ req->term = tr->terms_max;
}
static void
@@ -726,20 +733,21 @@ txn_limbo_wait_empty(struct txn_limbo *limbo, double timeout)
void
txn_limbo_process(struct txn_limbo *limbo, const struct synchro_request *req)
{
+ struct txn_limbo_terms *tr = &limbo->terms;
uint64_t term = req->term;
uint32_t origin = req->origin_id;
if (txn_limbo_replica_term(limbo, origin) < term) {
- vclock_follow(&limbo->promote_term_map, origin, term);
- if (term > limbo->promote_greatest_term)
- limbo->promote_greatest_term = term;
+ vclock_follow(&tr->terms_map, origin, term);
+ if (term > tr->terms_max)
+ tr->terms_max = term;
} else if (iproto_type_is_promote_request(req->type) &&
- limbo->promote_greatest_term > 1) {
+ tr->terms_max > 1) {
/* PROMOTE for outdated term. Ignore. */
say_info("RAFT: ignoring %s request from instance "
"id %u for term %llu. Greatest term seen "
"before (%llu) is bigger.",
iproto_type_name(req->type), origin, (long long)term,
- (long long)limbo->promote_greatest_term);
+ (long long)tr->terms_max);
return;
}
diff --git a/src/box/txn_limbo.h b/src/box/txn_limbo.h
index 53e52f676..dc980bf7c 100644
--- a/src/box/txn_limbo.h
+++ b/src/box/txn_limbo.h
@@ -75,6 +75,31 @@ txn_limbo_entry_is_complete(const struct txn_limbo_entry *e)
return e->is_commit || e->is_rollback;
}
+/**
+ * Keep state of promote requests to handle split-brain
+ * situation and other errors.
+ */
+struct txn_limbo_terms {
+ /**
+ * Latest terms received with PROMOTE entries from remote instances.
+ * Limbo uses them to filter out the transactions coming not from the
+ * limbo owner, but so outdated that they are rolled back everywhere
+ * except outdated nodes.
+ */
+ struct vclock terms_map;
+ /**
+ * The biggest PROMOTE term seen by the instance and persisted in WAL.
+ * It is related to raft term, but not the same. Synchronous replication
+ * represented by the limbo is interested only in the won elections
+ * ended with PROMOTE request.
+ * It means the limbo's term might be smaller than the raft term, while
+ * there are ongoing elections, or the leader is already known and this
+ * instance hasn't read its PROMOTE request yet. During other times the
+ * limbo and raft are in sync and the terms are the same.
+ */
+ uint64_t terms_max;
+};
+
/**
* Limbo is a place where transactions are stored, which are
* finished, but not committed nor rolled back. These are
@@ -130,23 +155,9 @@ struct txn_limbo {
*/
struct vclock vclock;
/**
- * Latest terms received with PROMOTE entries from remote instances.
- * Limbo uses them to filter out the transactions coming not from the
- * limbo owner, but so outdated that they are rolled back everywhere
- * except outdated nodes.
- */
- struct vclock promote_term_map;
- /**
- * The biggest PROMOTE term seen by the instance and persisted in WAL.
- * It is related to raft term, but not the same. Synchronous replication
- * represented by the limbo is interested only in the won elections
- * ended with PROMOTE request.
- * It means the limbo's term might be smaller than the raft term, while
- * there are ongoing elections, or the leader is already known and this
- * instance hasn't read its PROMOTE request yet. During other times the
- * limbo and raft are in sync and the terms are the same.
+ * Track promote requests.
*/
- uint64_t promote_greatest_term;
+ struct txn_limbo_terms terms;
/**
* Maximal LSN gathered quorum and either already confirmed in WAL, or
* whose confirmation is in progress right now. Any attempt to confirm
@@ -218,7 +229,8 @@ txn_limbo_last_entry(struct txn_limbo *limbo)
static inline uint64_t
txn_limbo_replica_term(const struct txn_limbo *limbo, uint32_t replica_id)
{
- return vclock_get(&limbo->promote_term_map, replica_id);
+ const struct txn_limbo_terms *tr = &limbo->terms;
+ return vclock_get(&tr->terms_map, replica_id);
}
/**
@@ -229,8 +241,9 @@ static inline bool
txn_limbo_is_replica_outdated(const struct txn_limbo *limbo,
uint32_t replica_id)
{
+ const struct txn_limbo_terms *tr = &limbo->terms;
return txn_limbo_replica_term(limbo, replica_id) <
- limbo->promote_greatest_term;
+ tr->terms_max;
}
/**
--
2.31.1
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