Update HISTORY and bump version (#7984)

Summary:
Prepare to cut 6.18.fb branch

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7984

Reviewed By: ajkr

Differential Revision: D26557151

Pulled By: riversand963

fbshipit-source-id: 8c144c807090cdae67e6655e7a17056ce8c50bc0

HISTORY.md

@@ -1,5 +1,7 @@
 # Rocksdb Change Log
 ## Unreleased
+
+## 6.18.0 (02/19/2021)
 ### Behavior Changes
 * When retryable IO error occurs during compaction, it is mapped to soft error and set the BG error. However, auto resume is not called to clean the soft error since compaction will reschedule by itself. In this change, When retryable IO error occurs during compaction, BG error is not set. User will be informed the error via EventHelper.
 * Introduce a new trace file format for query tracing and replay and trace file version is bump up to 0.2. A payload map is added as the first portion of the payload. We will not have backward compatible issues when adding new entries to trace records. Added the iterator_upper_bound and iterator_lower_bound in Seek and SeekForPrev tracing function. Added them as the new payload member for iterator tracing.

include/rocksdb/version.h

@@ -10,7 +10,7 @@
 #include "rocksdb/rocksdb_namespace.h"
 
 #define ROCKSDB_MAJOR 6
-#define ROCKSDB_MINOR 17
+#define ROCKSDB_MINOR 18
 #define ROCKSDB_PATCH 0
 
 // Do not use these. We made the mistake of declaring macros starting with