PageStorage: Fix entry.tag after full gc && add more debug message

dbms/src/Storages/DeltaMerge/DeltaMergeStore.cpp

@@ -34,6 +34,7 @@
 #include <Storages/Page/V2/VersionSet/PageEntriesVersionSetWithDelta.h>
 #include <Storages/PathPool.h>
 #include <Storages/Transaction/TMTContext.h>
+#include <common/logger_useful.h>
 
 #include <atomic>
 #include <ext/scope_guard.h>
@@ -1137,9 +1138,11 @@ BlockInputStreams DeltaMergeStore::readRaw(const Context & db_context,
     }
 
     fiu_do_on(FailPoints::force_slow_page_storage_snapshot_release, {
-        std::thread thread_hold_snapshots([tasks]() {
+        std::thread thread_hold_snapshots([this, tasks]() {
+            LOG_FMT_WARNING(log, "failpoint force_slow_page_storage_snapshot_release begin");
             std::this_thread::sleep_for(std::chrono::seconds(5 * 60));
             (void)tasks;
+            LOG_FMT_WARNING(log, "failpoint force_slow_page_storage_snapshot_release end");
         });
         thread_hold_snapshots.detach();
     });

dbms/src/Storages/Page/PageUtil.h

@@ -281,7 +281,7 @@ void readFile(T & file,
     }
 
     if (unlikely(bytes_read != expected_bytes))
-        throw DB::TiFlashException(fmt::format("No enough data in file {}, read bytes: {} , expected bytes: {}", file->getFileName(), bytes_read, expected_bytes),
+        throw DB::TiFlashException(fmt::format("No enough data in file {}, read bytes: {}, expected bytes: {}, offset: {}", file->getFileName(), bytes_read, expected_bytes, offset),
                                    Errors::PageStorage::FileSizeNotMatch);
 }
 

dbms/src/Storages/Page/V2/tests/gtest_page_util.cpp

@@ -17,6 +17,7 @@
 #include <Poco/Logger.h>
 #include <Storages/Page/PageUtil.h>
 #include <TestUtils/TiFlashTestBasic.h>
+#include <common/logger_useful.h>
 
 namespace DB
 {
@@ -30,6 +31,7 @@ namespace tests
 static const std::string FileName = "page_util_test";
 
 TEST(PageUtilsTest, ReadWriteFile)
+try
 {
     ::remove(FileName.c_str());
 
@@ -52,6 +54,7 @@ TEST(PageUtilsTest, ReadWriteFile)
 
     ::remove(FileName.c_str());
 }
+CATCH
 
 TEST(PageUtilsTest, FileNotExists)
 {

dbms/src/Storages/Page/V3/BlobStore.cpp

@@ -14,6 +14,7 @@
 
 #include <Common/Checksum.h>
 #include <Common/CurrentMetrics.h>
+#include <Common/Exception.h>
 #include <Common/FailPoint.h>
 #include <Common/Logger.h>
 #include <Common/ProfileEvents.h>
@@ -555,7 +556,7 @@ void BlobStore::read(PageIDAndEntriesV3 & entries, const PageHandler & handler,
 
     for (const auto & [page_id_v3, entry] : entries)
     {
-        auto blob_file = read(entry.file_id, entry.offset, data_buf, entry.size, read_limiter);
+        auto blob_file = read(page_id_v3, entry.file_id, entry.offset, data_buf, entry.size, read_limiter);
 
         if constexpr (BLOBSTORE_CHECKSUM_ON_READ)
         {
@@ -635,7 +636,7 @@ PageMap BlobStore::read(FieldReadInfos & to_read, const ReadLimiterPtr & read_li
             // TODO: Continuously fields can read by one system call.
             const auto [beg_offset, end_offset] = entry.getFieldOffsets(field_index);
             const auto size_to_read = end_offset - beg_offset;
-            auto blob_file = read(entry.file_id, entry.offset + beg_offset, write_offset, size_to_read, read_limiter);
+            auto blob_file = read(page_id_v3, entry.file_id, entry.offset + beg_offset, write_offset, size_to_read, read_limiter);
             fields_offset_in_page.emplace(field_index, read_size_this_entry);
 
             if constexpr (BLOBSTORE_CHECKSUM_ON_READ)
@@ -732,7 +733,7 @@ PageMap BlobStore::read(PageIDAndEntriesV3 & entries, const ReadLimiterPtr & rea
     PageMap page_map;
     for (const auto & [page_id_v3, entry] : entries)
     {
-        auto blob_file = read(entry.file_id, entry.offset, pos, entry.size, read_limiter);
+        auto blob_file = read(page_id_v3, entry.file_id, entry.offset, pos, entry.size, read_limiter);
 
         if constexpr (BLOBSTORE_CHECKSUM_ON_READ)
         {
@@ -797,7 +798,7 @@ Page BlobStore::read(const PageIDAndEntryV3 & id_entry, const ReadLimiterPtr & r
         free(p, buf_size);
     });
 
-    auto blob_file = read(entry.file_id, entry.offset, data_buf, buf_size, read_limiter);
+    auto blob_file = read(page_id_v3, entry.file_id, entry.offset, data_buf, buf_size, read_limiter);
     if constexpr (BLOBSTORE_CHECKSUM_ON_READ)
     {
         ChecksumClass digest;
@@ -824,11 +825,20 @@ Page BlobStore::read(const PageIDAndEntryV3 & id_entry, const ReadLimiterPtr & r
     return page;
 }
 
-BlobFilePtr BlobStore::read(BlobFileId blob_id, BlobFileOffset offset, char * buffers, size_t size, const ReadLimiterPtr & read_limiter, bool background)
+BlobFilePtr BlobStore::read(const PageIdV3Internal & page_id_v3, BlobFileId blob_id, BlobFileOffset offset, char * buffers, size_t size, const ReadLimiterPtr & read_limiter, bool background)
 {
     assert(buffers != nullptr);
-    auto blob_file = getBlobFile(blob_id);
-    blob_file->read(buffers, offset, size, read_limiter, background);
+    BlobFilePtr blob_file = getBlobFile(blob_id);
+    try
+    {
+        blob_file->read(buffers, offset, size, read_limiter, background);
+    }
+    catch (DB::Exception & e)
+    {
+        // add debug message
+        e.addMessage(fmt::format("(error while reading page data [page_id={}] [blob_id={}] [offset={}] [size={}] [background={}])", page_id_v3, blob_id, offset, size, background));
+        e.rethrow();
+    }
     return blob_file;
 }
 
@@ -1117,21 +1127,15 @@ PageEntriesEdit BlobStore::gc(std::map<BlobFileId, PageIdAndVersionedEntries> &
                 std::tie(blobfile_id, file_offset_beg) = getPosFromStats(next_alloc_size);
             }
 
-            PageEntryV3 new_entry;
-
-            read(file_id, entry.offset, data_pos, entry.size, read_limiter, /*background*/ true);
-
-            // No need do crc again, crc won't be changed.
-            new_entry.checksum = entry.checksum;
-
-            // Need copy the field_offsets
-            new_entry.field_offsets = entry.field_offsets;
-
-            // Entry size won't be changed.
-            new_entry.size = entry.size;
+            // Read the data into buffer by old entry
+            read(page_id, file_id, entry.offset, data_pos, entry.size, read_limiter, /*background*/ true);
 
+            // Most vars of the entry is not changed, but the file id and offset
+            // need to be updated.
+            PageEntryV3 new_entry = entry;
             new_entry.file_id = blobfile_id;
             new_entry.offset = file_offset_beg + offset_in_data;
+            new_entry.padded_size = 0; // reset padded size to be zero
 
             offset_in_data += new_entry.size;
             data_pos += new_entry.size;

dbms/src/Storages/Page/V3/BlobStore.h

@@ -296,7 +296,7 @@ class BlobStore : private Allocator<false>
 
     PageEntriesEdit handleLargeWrite(DB::WriteBatch & wb, const WriteLimiterPtr & write_limiter = nullptr);
 
-    BlobFilePtr read(BlobFileId blob_id, BlobFileOffset offset, char * buffers, size_t size, const ReadLimiterPtr & read_limiter = nullptr, bool background = false);
+    BlobFilePtr read(const PageIdV3Internal & page_id_v3, BlobFileId blob_id, BlobFileOffset offset, char * buffers, size_t size, const ReadLimiterPtr & read_limiter = nullptr, bool background = false);
 
     /**
      *  Ask BlobStats to get a span from BlobStat.

dbms/src/Storages/Page/V3/tests/gtest_blob_store.cpp

@@ -534,7 +534,8 @@ TEST_F(BlobStoreTest, testWriteRead)
         ASSERT_EQ(record.entry.file_id, 1);
 
         // Read directly from the file
-        blob_store.read(record.entry.file_id,
+        blob_store.read(buildV3Id(TEST_NAMESPACE_ID, page_id),
+                        record.entry.file_id,
                         record.entry.offset,
                         c_buff_read + index * buff_size,
                         record.entry.size,
@@ -634,7 +635,8 @@ TEST_F(BlobStoreTest, testWriteReadWithIOLimiter)
         {
             for (const auto & record : edits[i].getRecords())
             {
-                blob_store.read(record.entry.file_id,
+                blob_store.read(buildV3Id(TEST_NAMESPACE_ID, page_id),
+                                record.entry.file_id,
                                 record.entry.offset,
                                 c_buff_read + i * buff_size,
                                 record.entry.size,
@@ -812,7 +814,8 @@ TEST_F(BlobStoreTest, testFeildOffsetWriteRead)
         ASSERT_EQ(check_field_sizes, offsets);
 
         // Read
-        blob_store.read(record.entry.file_id,
+        blob_store.read(buildV3Id(TEST_NAMESPACE_ID, page_id),
+                        record.entry.file_id,
                         record.entry.offset,
                         c_buff_read + index * buff_size,
                         record.entry.size,

dbms/src/Storages/Page/V3/tests/gtest_page_storage.cpp

@@ -1441,6 +1441,55 @@ try
 }
 CATCH
 
+TEST_F(PageStorageTest, EntryTagAfterFullGC)
+try
+{
+    {
+        PageStorage::Config config;
+        config.blob_heavy_gc_valid_rate = 1.0; /// always run full gc
+        page_storage = reopenWithConfig(config);
+    }
+
+    const size_t buf_sz = 1024;
+    char c_buff[buf_sz];
+
+    for (size_t i = 0; i < buf_sz; ++i)
+    {
+        c_buff[i] = i % 0xff;
+    }
+
+    PageId page_id = 120;
+    UInt64 tag = 12345;
+    {
+        WriteBatch batch;
+        batch.putPage(page_id, tag, std::make_shared<ReadBufferFromMemory>(c_buff, buf_sz), buf_sz, {});
+        page_storage->write(std::move(batch));
+    }
+
+    {
+        auto entry = page_storage->getEntry(page_id);
+        ASSERT_EQ(entry.tag, tag);
+        auto page = page_storage->read(page_id);
+        for (size_t i = 0; i < buf_sz; ++i)
+        {
+            EXPECT_EQ(*(page.data.begin() + i), static_cast<char>(i % 0xff));
+        }
+    }
+
+    auto done_full_gc = page_storage->gc();
+    EXPECT_TRUE(done_full_gc);
+
+    {
+        auto entry = page_storage->getEntry(page_id);
+        ASSERT_EQ(entry.tag, tag);
+        auto page = page_storage->read(page_id);
+        for (size_t i = 0; i < buf_sz; ++i)
+        {
+            EXPECT_EQ(*(page.data.begin() + i), static_cast<char>(i % 0xff));
+        }
+    }
+}
+CATCH
 
 } // namespace PS::V3::tests
 } // namespace DB