storage: disable alerts for non vshard replicas

Before this patch vshard throwed alerts for replicas, which are not in
its config. E.g. disconnected CDC replica caused `UNREACHABLE_REPLICA`
alert. This patch fixes it by skipping unknown replicas.

Closes tarantool#493

NO_DOC=bugfix

Author: mrForza

test/storage-luatest/persistent_names_test.lua

@@ -136,3 +136,32 @@ test_group.test_no_unreachable_replica_alert = function(g)
     asserts:assert_server_no_alerts(g.replica_2_a)
     persistent_names_restore(g, names)
 end
+
+--
+-- gh-493: vshard should not show alerts for replicas, which are not in the
+-- vshard's config.
+--
+test_group.test_alerts_for_named_replica = function(g)
+    t.run_only_if(vutil.feature.persistent_names)
+
+    local named_replica = server:new({
+        alias = 'named_replica_with_name_identification',
+        box_cfg = {
+            replication = g.replica_1_a.net_box_uri,
+            instance_name = 'named_replica'
+        }
+    })
+
+    named_replica:start()
+    named_replica:wait_for_vclock_of(g.replica_1_a)
+    asserts:assert_server_no_alerts(g.replica_1_a)
+    local instance_id = named_replica:instance_id()
+
+    named_replica:stop()
+    asserts:assert_server_no_alerts(g.replica_1_a)
+
+    named_replica:drop()
+    g.replica_1_a:exec(function(id)
+        box.space._cluster:delete(id)
+    end, {instance_id})
+end

test/storage-luatest/storage_1_test.lua

@@ -1,6 +1,8 @@
 local t = require('luatest')
 local vtest = require('test.luatest_helpers.vtest')
 local vutil = require('vshard.util')
+local server = require('test.luatest_helpers.server')
+local asserts = require('test.luatest_helpers.asserts')
 
 local group_config = {{engine = 'memtx'}, {engine = 'vinyl'}}
 
@@ -588,3 +590,47 @@ test_group.test_moved_buckets_various_statuses = function(g)
         _G.bucket_gc_continue()
     end)
 end
+
+--
+-- gh-493: vshard should not show alerts for replicas, which are not
+-- in the vshard's config.
+--
+local function test_alerts_for_non_vshard_config_template(replicaset, replica)
+    replica:start()
+    replica:wait_for_vclock_of(replicaset.replica_1_a)
+    asserts:assert_server_no_alerts(replicaset.replica_1_a)
+    local id = replica:instance_id()
+
+    replica:stop()
+    asserts:assert_server_no_alerts(replicaset.replica_1_a)
+
+    replica:drop()
+    replicaset.replica_1_a:exec(function(id)
+        box.space._cluster:delete(id)
+    end, {id})
+end
+
+test_group.test_alerts_for_unnamed_replica = function(g)
+    local non_config_replica = server:new({
+        alias = 'non_config_replica',
+        box_cfg = {
+            replication = g.replica_1_a.net_box_uri,
+        }
+    })
+
+    test_alerts_for_non_vshard_config_template(g, non_config_replica)
+end
+
+test_group.test_alerts_for_named_replica = function(g)
+    t.run_only_if(vutil.feature.persistent_names)
+
+    local non_config_replica = server:new({
+        alias = 'non_config_replica',
+        box_cfg = {
+            replication = g.replica_1_a.net_box_uri,
+            instance_name = 'named_replica'
+        }
+    })
+
+    test_alerts_for_non_vshard_config_template(g, non_config_replica)
+end

vshard/storage/init.lua

@@ -4003,7 +4003,10 @@ local function storage_info(opts)
         local id = box.info.id
         for _, replica in pairs(box.info.replication) do
             -- Alerts for other replicas.
-            if id ~= replica.id then
+            if id ~= replica.id and (
+                M.this_replicaset.replicas[replica.name] ~= nil or
+                M.this_replicaset.replicas[replica.uuid] ~= nil
+            ) then
                 replica_count = replica_count + 1
                 if replica.downstream == nil or
                    replica.downstream.vclock == nil then