[Tarantool-patches] [PATCH v2 02/19] replication: introduce replication_synchro_* cfg options

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Synchronous transactions are supposed to be replicated on a
specified number of replicas before committed on master. The
number of replicas can be specified using
replication_synchro_quorum option. It is 1 by default, so sync
transactions work like asynchronous when not configured anyhow.
1 means successful WAL write on master is enough for commit.

When replication_synchro_quorum is greater than 1, an instance has to
wait for the specified number of replicas to  reply with success. If
enough replies aren't collected during replication_synchro_timeout,
the instance rolls back the tx in question.

Part of #4844
Part of #5073
---
 src/box/box.cc                  | 53 +++++++++++++++++++++++++++++++++
 src/box/box.h                   |  2 ++
 src/box/lua/cfg.cc              | 18 +++++++++++
 src/box/lua/load_cfg.lua        | 10 +++++++
 src/box/replication.cc          |  2 ++
 src/box/replication.h           | 12 ++++++++
 test/app-tap/init_script.result |  2 ++
 test/box/admin.result           |  4 +++
 test/box/cfg.result             |  8 +++++
 9 files changed, 111 insertions(+)

diff --git a/src/box/box.cc b/src/box/box.cc
index 871b0d976..0821ea0a3 100644
--- a/src/box/box.cc
+++ b/src/box/box.cc
@@ -476,6 +476,31 @@ box_check_replication_sync_lag(void)
 	return lag;
 }
 
+static int
+box_check_replication_synchro_quorum(void)
+{
+	int quorum = cfg_geti("replication_synchro_quorum");
+	if (quorum <= 0 || quorum > VCLOCK_MAX) {
+		diag_set(ClientError, ER_CFG, "replication_synchro_quorum",
+			 "the value must be greater than zero and less than "
+			 "maximal number of replicas");
+		return -1;
+	}
+	return quorum;
+}
+
+static double
+box_check_replication_synchro_timeout(void)
+{
+	double timeout = cfg_getd("replication_synchro_timeout");
+	if (timeout <= 0) {
+		diag_set(ClientError, ER_CFG, "replication_synchro_timeout",
+			 "the value must be greater than zero");
+		return -1;
+	}
+	return timeout;
+}
+
 static double
 box_check_replication_sync_timeout(void)
 {
@@ -658,6 +683,10 @@ box_check_config()
 	box_check_replication_connect_timeout();
 	box_check_replication_connect_quorum();
 	box_check_replication_sync_lag();
+	if (box_check_replication_synchro_quorum() < 0)
+		diag_raise();
+	if (box_check_replication_synchro_timeout() < 0)
+		diag_raise();
 	box_check_replication_sync_timeout();
 	box_check_readahead(cfg_geti("readahead"));
 	box_check_checkpoint_count(cfg_geti("checkpoint_count"));
@@ -777,6 +806,26 @@ box_set_replication_sync_lag(void)
 	replication_sync_lag = box_check_replication_sync_lag();
 }
 
+int
+box_set_replication_synchro_quorum(void)
+{
+	int value = box_check_replication_synchro_quorum();
+	if (value < 0)
+		return -1;
+	replication_synchro_quorum = value;
+	return 0;
+}
+
+int
+box_set_replication_synchro_timeout(void)
+{
+	double value = box_check_replication_synchro_timeout();
+	if (value < 0)
+		return -1;
+	replication_synchro_timeout = value;
+	return 0;
+}
+
 void
 box_set_replication_sync_timeout(void)
 {
@@ -2417,6 +2466,10 @@ box_cfg_xc(void)
 	box_set_replication_connect_timeout();
 	box_set_replication_connect_quorum();
 	box_set_replication_sync_lag();
+	if (box_set_replication_synchro_quorum() != 0)
+		diag_raise();
+	if (box_set_replication_synchro_timeout() != 0)
+		diag_raise();
 	box_set_replication_sync_timeout();
 	box_set_replication_skip_conflict();
 	box_set_replication_anon();
diff --git a/src/box/box.h b/src/box/box.h
index 557542a83..f9789154e 100644
--- a/src/box/box.h
+++ b/src/box/box.h
@@ -243,6 +243,8 @@ void box_set_replication_timeout(void);
 void box_set_replication_connect_timeout(void);
 void box_set_replication_connect_quorum(void);
 void box_set_replication_sync_lag(void);
+int box_set_replication_synchro_quorum(void);
+int box_set_replication_synchro_timeout(void);
 void box_set_replication_sync_timeout(void);
 void box_set_replication_skip_conflict(void);
 void box_set_replication_anon(void);
diff --git a/src/box/lua/cfg.cc b/src/box/lua/cfg.cc
index a5b15e527..d481155cd 100644
--- a/src/box/lua/cfg.cc
+++ b/src/box/lua/cfg.cc
@@ -313,6 +313,22 @@ lbox_cfg_set_replication_sync_lag(struct lua_State *L)
 	return 0;
 }
 
+static int
+lbox_cfg_set_replication_synchro_quorum(struct lua_State *L)
+{
+	if (box_set_replication_synchro_quorum() != 0)
+		luaT_error(L);
+	return 0;
+}
+
+static int
+lbox_cfg_set_replication_synchro_timeout(struct lua_State *L)
+{
+	if (box_set_replication_synchro_timeout() != 0)
+		luaT_error(L);
+	return 0;
+}
+
 static int
 lbox_cfg_set_replication_sync_timeout(struct lua_State *L)
 {
@@ -370,6 +386,8 @@ box_lua_cfg_init(struct lua_State *L)
 		{"cfg_set_replication_connect_quorum", lbox_cfg_set_replication_connect_quorum},
 		{"cfg_set_replication_connect_timeout", lbox_cfg_set_replication_connect_timeout},
 		{"cfg_set_replication_sync_lag", lbox_cfg_set_replication_sync_lag},
+		{"cfg_set_replication_synchro_quorum", lbox_cfg_set_replication_synchro_quorum},
+		{"cfg_set_replication_synchro_timeout", lbox_cfg_set_replication_synchro_timeout},
 		{"cfg_set_replication_sync_timeout", lbox_cfg_set_replication_sync_timeout},
 		{"cfg_set_replication_skip_conflict", lbox_cfg_set_replication_skip_conflict},
 		{"cfg_set_replication_anon", lbox_cfg_set_replication_anon},
diff --git a/src/box/lua/load_cfg.lua b/src/box/lua/load_cfg.lua
index f2f2df6f8..a7f03c7d6 100644
--- a/src/box/lua/load_cfg.lua
+++ b/src/box/lua/load_cfg.lua
@@ -89,6 +89,8 @@ local default_cfg = {
     replication_timeout = 1,
     replication_sync_lag = 10,
     replication_sync_timeout = 300,
+    replication_synchro_quorum = 1,
+    replication_synchro_timeout = 5,
     replication_connect_timeout = 30,
     replication_connect_quorum = nil, -- connect all
     replication_skip_conflict = false,
@@ -164,6 +166,8 @@ local template_cfg = {
     replication_timeout = 'number',
     replication_sync_lag = 'number',
     replication_sync_timeout = 'number',
+    replication_synchro_quorum = 'number',
+    replication_synchro_timeout = 'number',
     replication_connect_timeout = 'number',
     replication_connect_quorum = 'number',
     replication_skip_conflict = 'boolean',
@@ -280,6 +284,8 @@ local dynamic_cfg = {
     replication_connect_quorum = private.cfg_set_replication_connect_quorum,
     replication_sync_lag    = private.cfg_set_replication_sync_lag,
     replication_sync_timeout = private.cfg_set_replication_sync_timeout,
+    replication_synchro_quorum = private.cfg_set_replication_synchro_quorum,
+    replication_synchro_timeout = private.cfg_set_replication_synchro_timeout,
     replication_skip_conflict = private.cfg_set_replication_skip_conflict,
     replication_anon        = private.cfg_set_replication_anon,
     instance_uuid           = check_instance_uuid,
@@ -313,6 +319,8 @@ local dynamic_cfg_order = {
     replication_timeout     = 150,
     replication_sync_lag    = 150,
     replication_sync_timeout    = 150,
+    replication_synchro_quorum  = 150,
+    replication_synchro_timeout = 150,
     replication_connect_timeout = 150,
     replication_connect_quorum  = 150,
     replication             = 200,
@@ -348,6 +356,8 @@ local dynamic_cfg_skip_at_load = {
     replication_connect_quorum = true,
     replication_sync_lag    = true,
     replication_sync_timeout = true,
+    replication_synchro_quorum = true,
+    replication_synchro_timeout = true,
     replication_skip_conflict = true,
     replication_anon        = true,
     wal_dir_rescan_delay    = true,
diff --git a/src/box/replication.cc b/src/box/replication.cc
index 273a7cb66..01e9e876a 100644
--- a/src/box/replication.cc
+++ b/src/box/replication.cc
@@ -51,6 +51,8 @@ double replication_timeout = 1.0; /* seconds */
 double replication_connect_timeout = 30.0; /* seconds */
 int replication_connect_quorum = REPLICATION_CONNECT_QUORUM_ALL;
 double replication_sync_lag = 10.0; /* seconds */
+int replication_synchro_quorum = 1;
+double replication_synchro_timeout = 5.0; /* seconds */
 double replication_sync_timeout = 300.0; /* seconds */
 bool replication_skip_conflict = false;
 bool replication_anon = false;
diff --git a/src/box/replication.h b/src/box/replication.h
index 93a25c8a7..a081870f9 100644
--- a/src/box/replication.h
+++ b/src/box/replication.h
@@ -125,6 +125,18 @@ extern int replication_connect_quorum;
  */
 extern double replication_sync_lag;
 
+/**
+ * Minimal number of replicas which should ACK a synchronous
+ * transaction to be able to confirm it and commit.
+ */
+extern int replication_synchro_quorum;
+
+/**
+ * Time in seconds which the master node is able to wait for ACKs
+ * for a synchronous transaction until it is rolled back.
+ */
+extern double replication_synchro_timeout;
+
 /**
  * Max time to wait for appliers to synchronize before entering
  * the orphan mode.
diff --git a/test/app-tap/init_script.result b/test/app-tap/init_script.result
index 7c4454285..857f0c95f 100644
--- a/test/app-tap/init_script.result
+++ b/test/app-tap/init_script.result
@@ -30,6 +30,8 @@ replication_connect_timeout:30
 replication_skip_conflict:false
 replication_sync_lag:10
 replication_sync_timeout:300
+replication_synchro_quorum:1
+replication_synchro_timeout:5
 replication_timeout:1
 slab_alloc_factor:1.05
 sql_cache_size:5242880
diff --git a/test/box/admin.result b/test/box/admin.result
index d94da8c5d..ab3e80a97 100644
--- a/test/box/admin.result
+++ b/test/box/admin.result
@@ -81,6 +81,10 @@ cfg_filter(box.cfg)
     - 10
   - - replication_sync_timeout
     - 300
+  - - replication_synchro_quorum
+    - 1
+  - - replication_synchro_timeout
+    - 5
   - - replication_timeout
     - 1
   - - slab_alloc_factor
diff --git a/test/box/cfg.result b/test/box/cfg.result
index b41d54599..bdd210b09 100644
--- a/test/box/cfg.result
+++ b/test/box/cfg.result
@@ -69,6 +69,10 @@ cfg_filter(box.cfg)
  |     - 10
  |   - - replication_sync_timeout
  |     - 300
+ |   - - replication_synchro_quorum
+ |     - 1
+ |   - - replication_synchro_timeout
+ |     - 5
  |   - - replication_timeout
  |     - 1
  |   - - slab_alloc_factor
@@ -172,6 +176,10 @@ cfg_filter(box.cfg)
  |     - 10
  |   - - replication_sync_timeout
  |     - 300
+ |   - - replication_synchro_quorum
+ |     - 1
+ |   - - replication_synchro_timeout
+ |     - 5
  |   - - replication_timeout
  |     - 1
  |   - - slab_alloc_factor
-- 
2.21.1 (Apple Git-122.3)