diff --git a/changelogs/unreleased/gh-10087-update-quorum-in-on_commit-trigger.md b/changelogs/unreleased/gh-10087-update-quorum-in-on_commit-trigger.md
new file mode 100644
index 0000000000000000000000000000000000000000..615f97386687945b185c4c7acb4fd98542c19d0b
--- /dev/null
+++ b/changelogs/unreleased/gh-10087-update-quorum-in-on_commit-trigger.md
@@ -0,0 +1,7 @@
+## bugfix/replication
+
+* Fixed the inability to add a new replica to the replicaset if the user has
+ manually made space `_cluster` synchronous. Now the synchronous replication
+ quorum is updated after the `_cluster` change is confirmed by a quorum rather
+ than immediately after persisting the configuration change in the WAL
+ (gh-10087).
diff --git a/src/box/alter.cc b/src/box/alter.cc
index e135ea14767ed6517e6a36b41d6d48d0b9235d3d..36f97e720254e1068c7ae0c8226af3a777d4310c 100644
--- a/src/box/alter.cc
+++ b/src/box/alter.cc
@@ -4128,6 +4128,15 @@ on_replace_cluster_clear_id(struct trigger *trigger, void * /* event */)
return 0;
}
+/** Update the synchronous replication quorum. */
+static int
+on_replace_cluster_update_quorum(struct trigger * /* trigger */,
+ void * /* event */)
+{
+ box_update_replication_synchro_quorum();
+ return 0;
+}
+
/**
* A trigger invoked on replace in the space _cluster,
* which contains cluster configuration.
@@ -4203,6 +4212,15 @@ on_replace_dd_cluster(struct trigger *trigger, void *event)
diag_set(ClientError, ER_UNSUPPORTED, "Tarantool", msg);
return -1;
}
+ /*
+ * Update the quorum only after commit. Otherwise the replica
+ * would have to ack its own insertion.
+ */
+ struct trigger *on_commit = txn_alter_trigger_new(
+ on_replace_cluster_update_quorum, NULL);
+ if (on_commit == NULL)
+ return -1;
+ txn_stmt_on_commit(stmt, on_commit);
struct trigger *on_rollback = txn_alter_trigger_new(
on_replace_cluster_clear_id, NULL);
if (on_rollback == NULL)
diff --git a/src/box/replication.cc b/src/box/replication.cc
index 5730569a4cfc28255e6241d9e60683848b77ac25..5b7c76afd4f69e86f7281039fc56d29399b7b014 100644
--- a/src/box/replication.cc
+++ b/src/box/replication.cc
@@ -360,7 +360,6 @@ replica_set_id(struct replica *replica, uint32_t replica_id)
say_info("assigned id %d to replica %s",
replica->id, tt_uuid_str(&replica->uuid));
replica->anon = false;
- box_update_replication_synchro_quorum();
box_broadcast_ballot();
}
diff --git a/test/replication-luatest/gh_10087_update_quorum_in_on_commit_trigger_test.lua b/test/replication-luatest/gh_10087_update_quorum_in_on_commit_trigger_test.lua
new file mode 100644
index 0000000000000000000000000000000000000000..7fc1ed70b331239b1e2fa35b36226e69d6130342
--- /dev/null
+++ b/test/replication-luatest/gh_10087_update_quorum_in_on_commit_trigger_test.lua
@@ -0,0 +1,94 @@
+local t = require('luatest')
+local replica_set = require('luatest.replica_set')
+local server = require('luatest.server')
+
+local g_one_member_cluster = t.group('one_member_cluster')
+local g_three_member_cluster = t.group('three_member_cluster')
+
+g_one_member_cluster.before_all(function(cg)
+ cg.master = server:new{alias = 'master'}
+ cg.master:start()
+ -- Make `_cluster` space synchronous.
+ cg.master:exec(function()
+ box.ctl.promote()
+ box.space._cluster:alter{is_sync = true}
+ end)
+end)
+
+-- Test that synchronous insertion into 1-member cluster works properly.
+g_one_member_cluster.test_insertion = function(cg)
+ cg.replica = server:new{alias = 'replica', box_cfg = {
+ replication = cg.master.net_box_uri,
+ }}
+ cg.replica:start()
+ cg.master:wait_for_downstream_to(cg.replica)
+ cg.replica:exec(function()
+ t.assert_not_equals(box.space._cluster:get{box.info.id}, nil)
+ end)
+end
+
+g_one_member_cluster.after_all(function(cg)
+ cg.master:drop()
+ if cg.replica ~= nil then
+ cg.replica:drop()
+ end
+end)
+
+g_three_member_cluster.before_all(function(cg)
+ cg.replica_set = replica_set:new{}
+ cg.master = cg.replica_set:build_and_add_server{alias = 'master'}
+ cg.master:start()
+ cg.replica_to_be_disabled =
+ cg.replica_set:build_and_add_server{alias = 'to_be_disabled',
+ box_cfg = {
+ replication = {
+ cg.master.net_box_uri,
+ server.build_listen_uri('replica', cg.replica_set.id),
+ },
+ }}
+ cg.replica = cg.replica_set:build_and_add_server{alias = 'replica',
+ box_cfg = {
+ replication = {
+ cg.master.net_box_uri,
+ server.build_listen_uri('to_be_disabled', cg.replica_set.id),
+ },
+ }}
+ cg.replica_set:start()
+
+ -- Make `_cluster` space synchronous.
+ cg.master:exec(function()
+ box.ctl.promote()
+ box.space._cluster:alter{is_sync = true}
+ end)
+
+ cg.master:wait_for_downstream_to(cg.replica_to_be_disabled)
+ cg.master:wait_for_downstream_to(cg.replica)
+end)
+
+-- Test that synchronous insertion into 3-member cluster with 1 disabled node
+-- works properly.
+g_three_member_cluster.test_insertion = function(cg)
+ cg.replica_to_be_disabled:exec(function()
+ box.cfg{replication = ''}
+ end)
+ cg.replica_to_be_added =
+ cg.replica_set:build_and_add_server{alias = 'to_be_added',
+ box_cfg = {
+ replication = {
+ cg.master.net_box_uri,
+ server.build_listen_uri('to_be_disabled', cg.replica_set.id),
+ server.build_listen_uri('replica', cg.replica_set.id),
+ },
+ replication_sync_timeout = 0,
+ }}
+ cg.replica_to_be_added:start()
+ cg.master:wait_for_downstream_to(cg.replica)
+ cg.master:wait_for_downstream_to(cg.replica_to_be_added)
+ cg.replica_to_be_added:exec(function()
+ t.assert_not_equals(box.space._cluster:get{box.info.id}, nil)
+ end)
+end
+
+g_three_member_cluster.after_all(function(cg)
+ cg.replica_set:drop()
+end)