MemTableList::TrimHistory now use allocated bytes (#9020)

Summary:
Fix a bug when both max_write_buffer_size_to_maintain and max_write_buffer_number_to_maintain are 0.
The bug was introduced in 6.5.0 and  https://github.com/facebook/rocksdb/issues/5022.
Fix https://github.com/facebook/rocksdb/issues/8371

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9020

Reviewed By: pdillinger

Differential Revision: D32767084

Pulled By: ajkr

fbshipit-source-id: c401ee6e2557230e892d0fe8abb4966cbd18e85f

HISTORY.md

@@ -5,6 +5,7 @@
 * Fixed a bug in rocksdb automatic implicit prefetching which got broken because of new feature adaptive_readahead and internal prefetching got disabled when iterator moves from one file to next.
 
 ### Behavior Changes
+* MemTableList::TrimHistory now use allocated bytes when max_write_buffer_size_to_maintain > 0(default in TrasactionDB, introduced in PR#5022) Fix #8371.
 ### Public API change
 * Extend WriteBatch::AssignTimestamp and AssignTimestamps API so that both functions can accept an optional `checker` argument that performs additional checking on timestamp sizes.
 

db/db_impl/db_impl_write.cc

@@ -1661,7 +1661,7 @@ Status DBImpl::TrimMemtableHistory(WriteContext* context) {
   for (auto& cfd : cfds) {
     autovector<MemTable*> to_delete;
     bool trimmed = cfd->imm()->TrimHistory(
-        &context->memtables_to_free_, cfd->mem()->ApproximateMemoryUsage());
+        &context->memtables_to_free_, cfd->mem()->MemoryAllocatedBytes());
     if (trimmed) {
       context->superversion_context.NewSuperVersion();
       assert(context->superversion_context.new_superversion.get() != nullptr);

db/memtable.h

@@ -146,6 +146,13 @@ class MemTable {
     return approximate_memory_usage_.load(std::memory_order_relaxed);
   }
 
+  // used by MemTableListVersion::MemoryAllocatedBytesExcludingLast
+  size_t MemoryAllocatedBytes() const {
+    return table_->ApproximateMemoryUsage() + 
+           range_del_table_->ApproximateMemoryUsage() + 
+           arena_.MemoryAllocatedBytes();
+  }
+
   // Returns a vector of unique random memtable entries of size 'sample_size'.
   //
   // Note: the entries are stored in the unordered_set as length-prefixed keys,

db/memtable_list.cc

@@ -259,8 +259,8 @@ SequenceNumber MemTableListVersion::GetEarliestSequenceNumber(
 void MemTableListVersion::Add(MemTable* m, autovector<MemTable*>* to_delete) {
   assert(refs_ == 1);  // only when refs_ == 1 is MemTableListVersion mutable
   AddMemTable(m);
-
+  // m->MemoryAllocatedBytes() is added in MemoryAllocatedBytesExcludingLast
-  TrimHistory(to_delete, m->ApproximateMemoryUsage());
+  TrimHistory(to_delete, 0);
 }
 
 // Removes m from list of memtables not flushed.  Caller should NOT Unref m.
@@ -282,16 +282,16 @@ void MemTableListVersion::Remove(MemTable* m,
 }
 
 // return the total memory usage assuming the oldest flushed memtable is dropped
-size_t MemTableListVersion::ApproximateMemoryUsageExcludingLast() const {
+size_t MemTableListVersion::MemoryAllocatedBytesExcludingLast() const {
   size_t total_memtable_size = 0;
   for (auto& memtable : memlist_) {
-    total_memtable_size += memtable->ApproximateMemoryUsage();
+    total_memtable_size += memtable->MemoryAllocatedBytes();
   }
   for (auto& memtable : memlist_history_) {
-    total_memtable_size += memtable->ApproximateMemoryUsage();
+    total_memtable_size += memtable->MemoryAllocatedBytes();
   }
   if (!memlist_history_.empty()) {
-    total_memtable_size -= memlist_history_.back()->ApproximateMemoryUsage();
+    total_memtable_size -= memlist_history_.back()->MemoryAllocatedBytes();
   }
   return total_memtable_size;
 }
@@ -301,7 +301,7 @@ bool MemTableListVersion::MemtableLimitExceeded(size_t usage) {
     // calculate the total memory usage after dropping the oldest flushed
     // memtable, compare with max_write_buffer_size_to_maintain_ to decide
     // whether to trim history
-    return ApproximateMemoryUsageExcludingLast() + usage >=
+    return MemoryAllocatedBytesExcludingLast() + usage >=
            static_cast<size_t>(max_write_buffer_size_to_maintain_);
   } else if (max_write_buffer_number_to_maintain_ > 0) {
     return memlist_.size() + memlist_history_.size() >
@@ -596,9 +596,9 @@ size_t MemTableList::ApproximateUnflushedMemTablesMemoryUsage() {
 
 size_t MemTableList::ApproximateMemoryUsage() { return current_memory_usage_; }
 
-size_t MemTableList::ApproximateMemoryUsageExcludingLast() const {
+size_t MemTableList::MemoryAllocatedBytesExcludingLast() const {
   const size_t usage =
-      current_memory_usage_excluding_last_.load(std::memory_order_relaxed);
+      current_memory_allocted_bytes_excluding_last_.load(std::memory_order_relaxed);
   return usage;
 }
 
@@ -609,8 +609,8 @@ bool MemTableList::HasHistory() const {
 
 void MemTableList::UpdateCachedValuesFromMemTableListVersion() {
   const size_t total_memtable_size =
-      current_->ApproximateMemoryUsageExcludingLast();
+      current_->MemoryAllocatedBytesExcludingLast();
-  current_memory_usage_excluding_last_.store(total_memtable_size,
+  current_memory_allocted_bytes_excluding_last_.store(total_memtable_size,
                                              std::memory_order_relaxed);
 
   const bool has_history = current_->HasHistory();

db/memtable_list.h

@@ -168,7 +168,7 @@ class MemTableListVersion {
   // excluding the last MemTable in memlist_history_. The reason for excluding
   // the last MemTable is to see if dropping the last MemTable will keep total
   // memory usage above or equal to max_write_buffer_size_to_maintain_
-  size_t ApproximateMemoryUsageExcludingLast() const;
+  size_t MemoryAllocatedBytesExcludingLast() const;
 
   // Whether this version contains flushed memtables that are only kept around
   // for transaction conflict checking.
@@ -221,7 +221,7 @@ class MemTableList {
         commit_in_progress_(false),
         flush_requested_(false),
         current_memory_usage_(0),
-        current_memory_usage_excluding_last_(0),
+        current_memory_allocted_bytes_excluding_last_(0),
         current_has_history_(false) {
     current_->Ref();
   }
@@ -281,13 +281,13 @@ class MemTableList {
   // Returns an estimate of the number of bytes of data in use.
   size_t ApproximateMemoryUsage();
 
-  // Returns the cached current_memory_usage_excluding_last_ value.
+  // Returns the cached current_memory_allocted_bytes_excluding_last_ value.
-  size_t ApproximateMemoryUsageExcludingLast() const;
+  size_t MemoryAllocatedBytesExcludingLast() const;
 
   // Returns the cached current_has_history_ value.
   bool HasHistory() const;
 
-  // Updates current_memory_usage_excluding_last_ and current_has_history_
+  // Updates current_memory_allocted_bytes_excluding_last_ and current_has_history_
   // from MemTableListVersion. Must be called whenever InstallNewVersion is
   // called.
   void UpdateCachedValuesFromMemTableListVersion();
@@ -430,8 +430,8 @@ class MemTableList {
   // The current memory usage.
   size_t current_memory_usage_;
 
-  // Cached value of current_->ApproximateMemoryUsageExcludingLast().
+  // Cached value of current_->MemoryAllocatedBytesExcludingLast().
-  std::atomic<size_t> current_memory_usage_excluding_last_;
+  std::atomic<size_t> current_memory_allocted_bytes_excluding_last_;
 
   // Cached value of current_->HasHistory().
   std::atomic<bool> current_has_history_;

db/memtable_list_test.cc

@@ -344,7 +344,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {
   // Create MemTableList
   int min_write_buffer_number_to_merge = 2;
   int max_write_buffer_number_to_maintain = 2;
-  int64_t max_write_buffer_size_to_maintain = 2000;
+  int64_t max_write_buffer_size_to_maintain = 2 * Arena::kInlineSize;
   MemTableList list(min_write_buffer_number_to_merge,
                     max_write_buffer_number_to_maintain,
                     max_write_buffer_size_to_maintain);

db/write_batch.cc

@@ -1986,8 +1986,8 @@ class MemTableInserter : public WriteBatch::Handler {
           const MemTable* const mem = cfd->mem();
           assert(mem);
 
-          if (mem->ApproximateMemoryUsageFast() +
+          if (mem->MemoryAllocatedBytes() +
-                      imm->ApproximateMemoryUsageExcludingLast() >=
+                      imm->MemoryAllocatedBytesExcludingLast() >=
                   size_to_maintain &&
               imm->MarkTrimHistoryNeeded()) {
             trim_history_scheduler_->ScheduleWork(cfd);

utilities/transactions/optimistic_transaction_test.cc

@@ -37,7 +37,7 @@ class OptimisticTransactionTest
   OptimisticTransactionTest() {
     options.create_if_missing = true;
     options.max_write_buffer_number = 2;
-    options.max_write_buffer_size_to_maintain = 1600;
+    options.max_write_buffer_size_to_maintain = 2 * Arena::kInlineSize;
     options.merge_operator.reset(new TestPutOperator());
     dbname = test::PerThreadDBPath("optimistic_transaction_testdb");
 
@@ -318,7 +318,6 @@ TEST_P(OptimisticTransactionTest, CheckKeySkipOldMemtable) {
   const int kAttemptImmMemTable = 1;
   for (int attempt = kAttemptHistoryMemtable; attempt <= kAttemptImmMemTable;
        attempt++) {
-    options.max_write_buffer_number_to_maintain = 3;
     Reopen();
 
     WriteOptions write_options;