Ignore disappeared projections on start

src/Storages/MergeTree/IMergeTreeDataPart.cpp

@@ -72,6 +72,7 @@ namespace ErrorCodes
     extern const int BAD_TTL_FILE;
     extern const int NOT_IMPLEMENTED;
     extern const int NO_SUCH_COLUMN_IN_TABLE;
+    extern const int FILE_DOESNT_EXIST;
 }
 
 
@@ -749,8 +750,16 @@ void IMergeTreeDataPart::loadColumnsChecksumsIndexes(bool require_columns_checks
                 /// Probably there is something wrong with files of this part.
                 /// So it can be helpful to add to the error message some information about those files.
                 String files_in_part;
+
                 for (auto it = getDataPartStorage().iterate(); it->isValid(); it->next())
-                    files_in_part += fmt::format("{}{} ({} bytes)", (files_in_part.empty() ? "" : ", "), it->name(), getDataPartStorage().getFileSize(it->name()));
+                {
+                    std::string file_info;
+                    if (!getDataPartStorage().isDirectory(it->name()))
+                        file_info = fmt::format(" ({} bytes)", getDataPartStorage().getFileSize(it->name()));
+
+                    files_in_part += fmt::format("{}{}{}", (files_in_part.empty() ? "" : ", "), it->name(), file_info);
+
+                }
                 if (!files_in_part.empty())
                     e->addMessage("Part contains files: {}", files_in_part);
                 if (isEmpty())
@@ -2141,7 +2150,27 @@ void IMergeTreeDataPart::checkConsistencyBase() const
             }
         }
 
-        checksums.checkSizes(getDataPartStorage());
+        const auto & data_part_storage = getDataPartStorage();
+        for (const auto & [filename, checksum] : checksums.files)
+        {
+            try
+            {
+                checksum.checkSize(data_part_storage, filename);
+            }
+            catch (const Exception & ex)
+            {
+                /// For projection parts check will mark them broken in loadProjections
+                if (!parent_part && filename.ends_with(".proj"))
+                {
+                    std::string projection_name = fs::path(filename).stem();
+                    LOG_INFO(storage.log, "Projection {} doesn't exist on start for part {}, marking it as broken", projection_name, name);
+                    if (hasProjection(projection_name))
+                        markProjectionPartAsBroken(projection_name, ex.message(), ex.code());
+                }
+                else
+                    throw;
+            }
+        }
     }
     else
     {

src/Storages/MergeTree/MergeTreeDataPartChecksum.cpp

@@ -100,12 +100,6 @@ void MergeTreeDataPartChecksums::checkEqual(const MergeTreeDataPartChecksums & r
     }
 }
 
-void MergeTreeDataPartChecksums::checkSizes(const IDataPartStorage & storage) const
-{
-    for (const auto & [name, checksum] : files)
-        checksum.checkSize(storage, name);
-}
-
 UInt64 MergeTreeDataPartChecksums::getTotalSizeOnDisk() const
 {
     UInt64 res = 0;

src/Storages/MergeTree/MergeTreeDataPartChecksum.h

@@ -65,9 +65,6 @@ struct MergeTreeDataPartChecksums
 
     static bool isBadChecksumsErrorCode(int code);
 
-    /// Checks that the directory contains all the needed files of the correct size. Does not check the checksum.
-    void checkSizes(const IDataPartStorage & storage) const;
-
     /// Returns false if the checksum is too old.
     bool read(ReadBuffer & in);
     /// Assume that header with version (the first line) is read

tests/integration/test_broken_projections/test.py

@@ -4,6 +4,7 @@ import logging
 import string
 import random
 from helpers.cluster import ClickHouseCluster
+from multiprocessing.dummy import Pool
 
 cluster = ClickHouseCluster(__file__)
 
@@ -18,6 +19,12 @@ def cluster():
             stay_alive=True,
             with_zookeeper=True,
         )
+        cluster.add_instance(
+            "node_restart",
+            main_configs=["config.d/dont_start_broken.xml"],
+            stay_alive=True,
+            with_zookeeper=True,
+        )
 
         logging.info("Starting cluster...")
         cluster.start()
@@ -632,6 +639,49 @@ def test_broken_on_start(cluster):
     check(node, table_name, 0)
 
 
+def test_disappeared_projection_on_start(cluster):
+    node = cluster.instances["node_restart"]
+
+    table_name = "test_disapperead_projection"
+    create_table(node, table_name, 1)
+
+    node.query(f"SYSTEM STOP MERGES {table_name}")
+
+    insert(node, table_name, 0, 5)
+    insert(node, table_name, 5, 5)
+    insert(node, table_name, 10, 5)
+    insert(node, table_name, 15, 5)
+
+    assert ["all_0_0_0", "all_1_1_0", "all_2_2_0", "all_3_3_0"] == get_parts(
+        node, table_name
+    )
+
+    def drop_projection():
+        node.query(
+            f"ALTER TABLE {table_name} DROP PROJECTION proj2",
+            settings={"mutations_sync": "0"},
+        )
+
+    p = Pool(2)
+    p.apply_async(drop_projection)
+
+    for i in range(30):
+        create_query = node.query(f"SHOW CREATE TABLE {table_name}")
+        if "proj2" not in create_query:
+            break
+        time.sleep(0.5)
+
+    assert "proj2" not in create_query
+
+    # Remove 'proj2' for part all_2_2_0
+    break_projection(node, table_name, "proj2", "all_2_2_0", "part")
+
+    node.restart_clickhouse()
+
+    # proj2 is not broken, it doesn't exist, but ok
+    check(node, table_name, 0, expect_broken_part="proj2", do_check_command=0)
+
+
 def test_mutation_with_broken_projection(cluster):
     node = cluster.instances["node"]