Use correct sequence number when creating memtable

Summary:
copied from: 5ebfd2623a

Opening existing RocksDB attempts recovery from log files, which uses
wrong sequence number to create the memtable. This is a regression
introduced in change a400336.

This change includes a test demonstrating the problem, without the fix
the test fails with "Operation failed. Try again.: Transaction could not
check for conflicts for operation at SequenceNumber 1 as the MemTable
only contains changes newer than SequenceNumber 2.  Increasing the value
of the max_write_buffer_number_to_maintain option could reduce the
frequency of this error"

This change is a joint effort by Peter 'Stig' Edwards thatsafunnyname
and me.
Closes https://github.com/facebook/rocksdb/pull/1458

Differential Revision: D4143791

Pulled By: reidHoruff

fbshipit-source-id: 5a25033

db/db_impl.cc

@@ -1721,7 +1721,7 @@ Status DBImpl::RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
           flushed = true;
 
           cfd->CreateNewMemtable(*cfd->GetLatestMutableCFOptions(),
-                                 *next_sequence);
+                                 versions_->LastSequence());
         }
       }
 

utilities/transactions/optimistic_transaction_test.cc

@@ -34,14 +34,24 @@ class OptimisticTransactionTest : public testing::Test {
     dbname = test::TmpDir() + "/optimistic_transaction_testdb";
 
     DestroyDB(dbname, options);
-    Status s = OptimisticTransactionDB::Open(options, dbname, &txn_db);
-    assert(s.ok());
-    db = txn_db->GetBaseDB();
+    Open();
   }
   ~OptimisticTransactionTest() {
     delete txn_db;
     DestroyDB(dbname, options);
   }
+
+  void Reopen() {
+    delete txn_db;
+    Open();
+  }
+
+private:
+  void Open() {
+    Status s = OptimisticTransactionDB::Open(options, dbname, &txn_db);
+    assert(s.ok());
+    db = txn_db->GetBaseDB();
+  }
 };
 
 TEST_F(OptimisticTransactionTest, SuccessTest) {
@@ -1338,6 +1348,33 @@ TEST_F(OptimisticTransactionTest, OptimisticTransactionStressTest) {
   ASSERT_OK(s);
 }
 
+TEST_F(OptimisticTransactionTest, SequenceNumberAfterRecoverTest) {
+  WriteOptions write_options;
+  OptimisticTransactionOptions transaction_options;
+
+  Transaction* transaction(txn_db->BeginTransaction(write_options, transaction_options));
+  Status s = transaction->Put("foo", "val");
+  ASSERT_OK(s);
+  s = transaction->Put("foo2", "val");
+  ASSERT_OK(s);
+  s = transaction->Put("foo3", "val");
+  ASSERT_OK(s);
+  s = transaction->Commit();
+  ASSERT_OK(s);
+  delete transaction;
+
+  Reopen();
+  transaction = txn_db->BeginTransaction(write_options, transaction_options);
+  s = transaction->Put("bar", "val");
+  ASSERT_OK(s);
+  s = transaction->Put("bar2", "val");
+  ASSERT_OK(s);
+  s = transaction->Commit();
+  ASSERT_OK(s);
+
+  delete transaction;
+}
+
 }  // namespace rocksdb
 
 int main(int argc, char** argv) {