Do not write retriable errors for Replicated mutate/merge into error log

src/Storages/MergeTree/ReplicatedMergeMutateTaskBase.cpp

@@ -69,11 +69,11 @@ bool ReplicatedMergeMutateTaskBase::executeStep()
             else
                 tryLogCurrentException(log, __PRETTY_FUNCTION__);
 
-            /** This exception will be written to the queue element, and it can be looked up using `system.replication_queue` table.
-                 * The thread that performs this action will sleep a few seconds after the exception.
-                 * See `queue.processEntry` function.
-                 */
-            throw;
+            /// This exception will be written to the queue element, and it can be looked up using `system.replication_queue` table.
+            /// The thread that performs this action will sleep a few seconds after the exception.
+            /// See `queue.processEntry` function.
+            if (!retryable_error)
+                throw;
         }
         catch (...)
         {

tests/queries/0_stateless/02903_rmt_retriable_merge_exception.reference

@@ -0,0 +1 @@
+Information	1

tests/queries/0_stateless/02903_rmt_retriable_merge_exception.sql

@@ -0,0 +1,32 @@
+-- Test that retriable errors during merges/mutations
+-- (i.e. "No active replica has part X or covering part")
+-- does not appears as errors (level=Error), only as info message (level=Information).
+
+drop table if exists rmt1;
+drop table if exists rmt2;
+
+create table rmt1 (key Int) engine=ReplicatedMergeTree('/clickhouse/{database}', '1') order by key settings always_fetch_merged_part=1;
+create table rmt2 (key Int) engine=ReplicatedMergeTree('/clickhouse/{database}', '2') order by key settings always_fetch_merged_part=0;
+
+insert into rmt1 values (1);
+insert into rmt1 values (2);
+
+system stop pulling replication log rmt2;
+optimize table rmt1 final settings alter_sync=0;
+
+select sleep(3) format Null;
+system start pulling replication log rmt2;
+
+system flush logs;
+with
+    (select uuid from system.tables where database = currentDatabase() and table = 'rmt1') as uuid_
+select
+    level, count() > 0
+from system.text_log
+where
+    event_date >= yesterday() and event_time >= now() - 60 and
+    (
+        (logger_name = 'MergeTreeBackgroundExecutor' and message like '%{' || uuid_::String || '::all_0_1_1}%No active replica has part all_0_1_1 or covering part%') or
+        (logger_name = uuid_::String || '::all_0_1_1 (MergeFromLogEntryTask)' and message like '%No active replica has part all_0_1_1 or covering part%')
+    )
+group by level;