Fix failures caused by the destorying order of singleton objects.
4.5.0 (2/5/2016)
Public API Changes
Add a new perf context level between kEnableCount and kEnableTime. Level 2 now does not include timers for mutexes.
Statistics of mutex operation durations will not be measured by default. If you want to have them enabled, you need to set Statistics::stats_level_ to kAll.
DBOptions::delete_scheduler and NewDeleteScheduler() are removed, please use DBOptions::sst_file_manager and NewSstFileManager() instead
New Features
ldb tool now supports operations to non-default column families.
Add kPersistedTier to ReadTier. This option allows Get and MultiGet to read only the persited data and skip mem-tables if writes were done with disableWAL = true.
Add DBOptions::sst_file_manager. Use NewSstFileManager() in include/rocksdb/sst_file_manager.h to create a SstFileManager that can be used to track the total size of SST files and control the SST files deletion rate.
4.4.0 (1/14/2016)
Public API Changes
Change names in CompactionPri and add a new one.
Deprecate options.soft_rate_limit and add options.soft_pending_compaction_bytes_limit.
If options.max_write_buffer_number > 3, writes will be slowed down when writing to the last write buffer to delay a full stop.
Introduce CompactionJobInfo::compaction_reason, this field include the reason to trigger the compaction.
After slow down is triggered, if estimated pending compaction bytes keep increasing, slowdown more.
Increase default options.delayed_write_rate to 2MB/s.
Added a new parameter --path to ldb tool. --path accepts the name of either MANIFEST, SST or a WAL file. Either --db or --path can be used when calling ldb.
4.3.0 (12/8/2015)
New Features
CompactionFilter has new member function called IgnoreSnapshots which allows CompactionFilter to be called even if there are snapshots later than the key.
RocksDB will now persist options under the same directory as the RocksDB database on successful DB::Open, CreateColumnFamily, DropColumnFamily, and SetOptions.
Introduce LoadLatestOptions() in rocksdb/utilities/options_util.h. This function can construct the latest DBOptions / ColumnFamilyOptions used by the specified RocksDB intance.
Introduce CheckOptionsCompatibility() in rocksdb/utilities/options_util.h. This function checks whether the input set of options is able to open the specified DB successfully.
Public API Changes
When options.db_write_buffer_size triggers, only the column family with the largest column family size will be flushed, not all the column families.
