Cherry-pick: Wal debug 6.29.tikv (tikv#2)

Signed-off-by: Qi Xu <[email protected]>
Co-authored-by: Qi Xu <[email protected]>

db/db_impl/db_impl.cc

@@ -1471,13 +1471,19 @@ void DBImpl::MarkLogsSynced(uint64_t up_to, bool synced_dir,
   for (auto it = logs_.begin(); it != logs_.end() && it->number <= up_to;) {
     auto& wal = *it;
     assert(wal.IsSyncing());
-
+    ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                   "Synced log %" PRIu64 " from logs_\n", wal.number);
     if (logs_.size() > 1) {
       if (immutable_db_options_.track_and_verify_wals_in_manifest &&
           wal.GetPreSyncSize() > 0) {
         synced_wals->AddWal(wal.number, WalMetadata(wal.GetPreSyncSize()));
       }
-      logs_to_free_.push_back(wal.ReleaseWriter());
+      auto writer = wal.ReleaseWriter();
+      ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                     "deleting log %" PRIu64
+                     " from logs_. Last Seq number of the WAL is %" PRIu64 "\n",
+                     wal.number, writer->GetLastSequence());
+      logs_to_free_.push_back(writer);
       it = logs_.erase(it);
     } else {
       wal.FinishSync();
@@ -1491,12 +1497,19 @@ void DBImpl::MarkLogsSynced(uint64_t up_to, bool synced_dir,
 
 void DBImpl::MarkLogsNotSynced(uint64_t up_to) {
   log_write_mutex_.AssertHeld();
+  uint64_t min_wal = 0;
   for (auto it = logs_.begin(); it != logs_.end() && it->number <= up_to;
        ++it) {
     auto& wal = *it;
+    if (min_wal == 0) {
+      min_wal = it->number;
+    }
     wal.FinishSync();
   }
   log_sync_cv_.SignalAll();
+  ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                 "MarkLogsNotSynced from %" PRIu64 " to %" PRIu64 "\n", min_wal,
+                 up_to);
 }
 
 SequenceNumber DBImpl::GetLatestSequenceNumber() const {

db/db_impl/db_impl.h

@@ -1822,7 +1822,7 @@ class DBImpl : public DB {
 
   IOStatus WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer,
                       uint64_t* log_used, uint64_t* log_size,
-                      LogFileNumberSize& log_file_number_size);
+                      LogFileNumberSize& log_file_number_size, int caller_id);
 
   IOStatus WriteToWAL(const WriteThread::WriteGroup& write_group,
                       log::Writer* log_writer, uint64_t* log_used,

db/db_impl/db_impl_files.cc

@@ -293,6 +293,8 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
                        earliest.number);
         log_recycle_files_.push_back(earliest.number);
       } else {
+        ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                       "deleting WAL log %" PRIu64 "\n", earliest.number);
         job_context->log_delete_files.push_back(earliest.number);
       }
       if (job_context->size_log_to_delete == 0) {
@@ -317,7 +319,12 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
         // logs_ could have changed while we were waiting.
         continue;
       }
-      logs_to_free_.push_back(log.ReleaseWriter());
+      auto writer = log.ReleaseWriter();
+      ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                     "deleting log %" PRIu64
+                     " from logs_, last seq number of WAL %" PRIu64 "\n",
+                     log.number, writer->GetLastSequence());
+      logs_to_free_.push_back(writer);
       logs_.pop_front();
     }
     // Current log cannot be obsolete.
@@ -491,6 +498,10 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
   // Close WALs before trying to delete them.
   for (const auto w : state.logs_to_free) {
     // TODO: maybe check the return value of Close.
+    ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                   "Close log %" PRIu64
+                   " from logs_, last Seq number in WAL %" PRIu64 "\n",
+                   w->get_log_number(), w->GetLastSequence());
     auto s = w->Close();
     s.PermitUncheckedError();
   }

db/db_impl/db_impl_open.cc

@@ -1735,7 +1735,7 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
         assert(log_writer->get_log_number() == log_file_number_size.number);
         impl->mutex_.AssertHeld();
         s = impl->WriteToWAL(empty_batch, log_writer, &log_used, &log_size,
-                             log_file_number_size);
+                             log_file_number_size, 0);
         if (s.ok()) {
           // Need to fsync, otherwise it might get lost after a power reset.
           s = impl->FlushWAL(false);

db/db_impl/db_impl_write.cc

@@ -1412,10 +1412,23 @@ WriteBatch* DBImpl::MergeBatch(const WriteThread::WriteGroup& write_group,
 IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
                             log::Writer* log_writer, uint64_t* log_used,
                             uint64_t* log_size,
-                            LogFileNumberSize& log_file_number_size) {
+                            LogFileNumberSize& log_file_number_size,
+                            int caller_id) {
   assert(log_size != nullptr);
-
+  if (log_writer->file()->GetFileSize() == 0) {
+    ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                   "Start writing to WAL: [%" PRIu64 " ]",
+                   log_writer->get_log_number());
+  }
+  if (log_writer->get_log_number() != logs_.back().number) {
+    ROCKS_LOG_INFO(
+        immutable_db_options_.info_log,
+        "Not writing to latest WAL: [%" PRIu64 ", %" PRIu64 "] CallerId: %d",
+        log_writer->get_log_number(), logs_.back().number, caller_id);
+  }
   Slice log_entry = WriteBatchInternal::Contents(&merged_batch);
+  SequenceNumber seq = WriteBatchInternal::Sequence(&merged_batch);
+  log_writer->SetLastSequence(seq);
   *log_size = log_entry.size();
   // When two_write_queues_ WriteToWAL has to be protected from concurretn calls
   // from the two queues anyway and log_write_mutex_ is already held. Otherwise
@@ -1468,7 +1481,7 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
 
   uint64_t log_size;
   io_s = WriteToWAL(*merged_batch, log_writer, log_used, &log_size,
-                    log_file_number_size);
+                    log_file_number_size, 1);
   if (to_be_cached_state) {
     cached_recoverable_state_ = *to_be_cached_state;
     cached_recoverable_state_empty_ = false;
@@ -1530,6 +1543,7 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
     stats->AddDBStats(InternalStats::kIntStatsWriteWithWal, write_with_wal);
     RecordTick(stats_, WRITE_WITH_WAL, write_with_wal);
   }
+
   return io_s;
 }
 
@@ -1569,7 +1583,7 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
 
   uint64_t log_size;
   io_s = WriteToWAL(*merged_batch, log_writer, log_used, &log_size,
-                    log_file_number_size);
+                    log_file_number_size, 2);
   if (to_be_cached_state) {
     cached_recoverable_state_ = *to_be_cached_state;
     cached_recoverable_state_empty_ = false;

db/log_writer.cc

@@ -29,6 +29,7 @@ Writer::Writer(std::unique_ptr<WritableFileWriter>&& dest, uint64_t log_number,
     char t = static_cast<char>(i);
     type_crc_[i] = crc32c::Value(&t, 1);
   }
+  last_seq_ = 0;
 }
 
 Writer::~Writer() {

db/log_writer.h

@@ -15,6 +15,7 @@
 #include "rocksdb/io_status.h"
 #include "rocksdb/slice.h"
 #include "rocksdb/status.h"
+#include "rocksdb/types.h"
 
 namespace ROCKSDB_NAMESPACE {
 
@@ -92,11 +93,16 @@ class Writer {
 
   bool TEST_BufferIsEmpty();
 
+  void SetLastSequence(SequenceNumber seq) { last_seq_ = seq; }
+
+  SequenceNumber GetLastSequence() const { return last_seq_; }
+
  private:
   std::unique_ptr<WritableFileWriter> dest_;
   size_t block_offset_;       // Current offset in block
   uint64_t log_number_;
   bool recycle_log_files_;
+  SequenceNumber last_seq_;
 
   // crc32c values for all supported record types.  These are
   // pre-computed to reduce the overhead of computing the crc of the