From 854eb76a8c8533779da7eaf21bef6266d9cca6aa Mon Sep 17 00:00:00 2001
From: Changyu Bi <102700264+cbi42@users.noreply.github.com>
Date: Mon, 10 Jul 2023 15:52:38 -0700
Subject: [PATCH] Improve error message when an SST file in MANIFEST is not
 found (#11573)

Summary:
I got the following error message when an SST file is recorded in MANIFEST but is missing from the db folder.
It's confusing in two ways:
1. The part about file "./074837.ldb" which RocksDB will attempt to open only after ./074837.sst is not found.
2. The last part about "No such file or directory in file ./MANIFEST-074507" sounds like `074837.ldb` is not found in manifest.

```
ldb --hex --db=. get some_key

Failed: Corruption: Corruption: IO error: No such file or directory: While open a file for random read: ./074837.ldb: No such file or directory in file ./MANIFEST-074507
```

Improving the error message a little bit:

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11573

Test Plan:
run the same command after this PR
```
Failed: Corruption: Corruption: IO error: No such file or directory: While open a file for random read: ./074837.sst: No such file or directory  The file ./MANIFEST-074507 may be corrupted.
```

Reviewed By: ajkr

Differential Revision: D47192056

Pulled By: cbi42

fbshipit-source-id: 06863f376cc4455803cffb2250c41399b4c39467
---
 db/table_cache.cc          | 14 +++++++++-----
 db/version_edit_handler.cc |  3 ++-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/db/table_cache.cc b/db/table_cache.cc
index 0bbec70e1d..00224fd818 100644
--- a/db/table_cache.cc
+++ b/db/table_cache.cc
@@ -111,13 +111,17 @@ Status TableCache::GetTableReader(
     RecordTick(ioptions_.stats, NO_FILE_OPENS);
   } else if (s.IsPathNotFound()) {
     fname = Rocks2LevelTableFileName(fname);
-    s = PrepareIOFromReadOptions(ro, ioptions_.clock, fopts.io_options);
-    if (s.ok()) {
-      s = ioptions_.fs->NewRandomAccessFile(fname, file_options, &file,
-                                            nullptr);
+    // If this file is also not found, we want to use the error message
+    // that contains the table file name which is less confusing.
+    Status temp_s =
+        PrepareIOFromReadOptions(ro, ioptions_.clock, fopts.io_options);
+    if (temp_s.ok()) {
+      temp_s = ioptions_.fs->NewRandomAccessFile(fname, file_options, &file,
+                                                 nullptr);
     }
-    if (s.ok()) {
+    if (temp_s.ok()) {
       RecordTick(ioptions_.stats, NO_FILE_OPENS);
+      s = temp_s;
     }
   }
 
diff --git a/db/version_edit_handler.cc b/db/version_edit_handler.cc
index 965213b586..732723996a 100644
--- a/db/version_edit_handler.cc
+++ b/db/version_edit_handler.cc
@@ -86,7 +86,8 @@ void VersionEditHandlerBase::Iterate(log::Reader& reader,
         message << ' ';
       }
       // append the filename to the corruption message
-      message << "in file " << reader.file()->file_name();
+      message << " The file " << reader.file()->file_name()
+              << " may be corrupted.";
       // overwrite the status with the extended status
       s = Status(s.code(), s.subcode(), s.severity(), message.str());
     }