public static void initOptions()

in hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStdSessions.java [446:627]


    public static void initOptions(HugeConfig conf,
                                   DBOptionsInterface<?> db,
                                   MutableDBOptionsInterface<?> mdb,
                                   ColumnFamilyOptionsInterface<?> cf,
                                   MutableColumnFamilyOptionsInterface<?> mcf) {
        final boolean optimize = conf.get(RocksDBOptions.OPTIMIZE_MODE);

        if (db != null) {
            /*
             * Set true then the database will be created if it is missing.
             * should we use options.setCreateMissingColumnFamilies()?
             */
            db.setCreateIfMissing(true);
            db.setWriteDbidToManifest(true);
            db.setAvoidUnnecessaryBlockingIO(true);

            // Optimize RocksDB
            if (optimize) {
                int processors = CoreOptions.CPUS;
                db.setIncreaseParallelism(Math.max(processors / 2, 1));

                db.setAllowConcurrentMemtableWrite(true);
                db.setEnableWriteThreadAdaptiveYield(true);
            }
            db.setInfoLogLevel(InfoLogLevel.valueOf(
                    conf.get(RocksDBOptions.LOG_LEVEL) + "_LEVEL"));

            db.setMaxSubcompactions(conf.get(RocksDBOptions.MAX_SUB_COMPACTIONS));

            db.setAllowMmapWrites(conf.get(RocksDBOptions.ALLOW_MMAP_WRITES));
            db.setAllowMmapReads(conf.get(RocksDBOptions.ALLOW_MMAP_READS));

            db.setUseDirectReads(conf.get(RocksDBOptions.USE_DIRECT_READS));
            db.setUseDirectIoForFlushAndCompaction(
                    conf.get(RocksDBOptions.USE_DIRECT_READS_WRITES_FC));

            db.setUseFsync(conf.get(RocksDBOptions.USE_FSYNC));

            db.setAtomicFlush(conf.get(RocksDBOptions.ATOMIC_FLUSH));

            db.setMaxManifestFileSize(conf.get(RocksDBOptions.MAX_MANIFEST_FILE_SIZE));

            db.setSkipStatsUpdateOnDbOpen(conf.get(RocksDBOptions.SKIP_STATS_UPDATE_ON_DB_OPEN));
            db.setSkipCheckingSstFileSizesOnDbOpen(
                    conf.get(RocksDBOptions.SKIP_CHECK_SIZE_ON_DB_OPEN));

            db.setMaxFileOpeningThreads(conf.get(RocksDBOptions.MAX_FILE_OPENING_THREADS));

            db.setDbWriteBufferSize(conf.get(RocksDBOptions.DB_MEMTABLE_SIZE));

            db.setLogReadaheadSize(conf.get(RocksDBOptions.LOG_READAHEAD_SIZE));

            // A global cache for table-level rows
            long cacheCapacity = conf.get(RocksDBOptions.ROW_CACHE_CAPACITY);
            if (cacheCapacity > 0) {
                db.setRowCache(new LRUCache(cacheCapacity));
            }
        }

        if (mdb != null) {
            /*
             * Migrate to max_background_jobs option
             * https://github.com/facebook/rocksdb/wiki/Thread-Pool
             * https://github.com/facebook/rocksdb/pull/2205/files
             */
            mdb.setMaxBackgroundJobs(conf.get(RocksDBOptions.MAX_BG_JOBS));

            mdb.setDelayedWriteRate(conf.get(RocksDBOptions.DELAYED_WRITE_RATE));

            mdb.setMaxOpenFiles(conf.get(RocksDBOptions.MAX_OPEN_FILES));

            mdb.setMaxTotalWalSize(conf.get(RocksDBOptions.MAX_TOTAL_WAL_SIZE));

            mdb.setBytesPerSync(conf.get(RocksDBOptions.BYTES_PER_SYNC));
            mdb.setWalBytesPerSync(conf.get(RocksDBOptions.WAL_BYTES_PER_SYNC));
            mdb.setStrictBytesPerSync(conf.get(RocksDBOptions.STRICT_BYTES_PER_SYNC));

            mdb.setCompactionReadaheadSize(conf.get(RocksDBOptions.COMPACTION_READAHEAD_SIZE));

            mdb.setDeleteObsoleteFilesPeriodMicros(
                    1000000 * conf.get(RocksDBOptions.DELETE_OBSOLETE_FILE_PERIOD));
        }

        if (cf != null) {
            if (optimize) {
                // Optimize RocksDB
                cf.optimizeLevelStyleCompaction();
                cf.optimizeUniversalStyleCompaction();
            }

            int numLevels = conf.get(RocksDBOptions.NUM_LEVELS);
            List<CompressionType> compressions = conf.get(RocksDBOptions.LEVELS_COMPRESSIONS);
            E.checkArgument(compressions.isEmpty() || compressions.size() == numLevels,
                            "Elements number of '%s' must be 0 or " +
                            "be the same as '%s', but got %s != %s",
                            RocksDBOptions.LEVELS_COMPRESSIONS.name(),
                            RocksDBOptions.NUM_LEVELS.name(), compressions.size(), numLevels);

            cf.setNumLevels(numLevels);
            cf.setCompactionStyle(conf.get(RocksDBOptions.COMPACTION_STYLE));

            cf.setBottommostCompressionType(conf.get(RocksDBOptions.BOTTOMMOST_COMPRESSION));
            if (!compressions.isEmpty()) {
                cf.setCompressionPerLevel(compressions);
            }

            cf.setMinWriteBufferNumberToMerge(conf.get(RocksDBOptions.MIN_MEMTABLES_TO_MERGE));
            cf.setMaxWriteBufferNumberToMaintain(
                    conf.get(RocksDBOptions.MAX_MEMTABLES_TO_MAINTAIN));

            cf.setInplaceUpdateSupport(conf.get(RocksDBOptions.MEMTABLE_INPLACE_UPDATE_SUPPORT));

            cf.setLevelCompactionDynamicLevelBytes(conf.get(RocksDBOptions.DYNAMIC_LEVEL_BYTES));

            cf.setOptimizeFiltersForHits(conf.get(RocksDBOptions.BLOOM_FILTERS_SKIP_LAST_LEVEL));

            cf.setTableFormatConfig(initTableConfig(conf));

            // CappedPrefixExtractor uses the first N bytes
            int prefixLength = conf.get(RocksDBOptions.PREFIX_EXTRACTOR_CAPPED);
            if (prefixLength > 0) {
                cf.useCappedPrefixExtractor(prefixLength);
            }

            // https://github.com/facebook/rocksdb/tree/master/utilities/merge_operators
            cf.setMergeOperatorName("uint64add"); // uint64add/stringappend
        }

        if (mcf != null) {
            mcf.setCompressionType(conf.get(RocksDBOptions.COMPRESSION));

            mcf.setWriteBufferSize(conf.get(RocksDBOptions.MEMTABLE_SIZE));
            mcf.setMaxWriteBufferNumber(conf.get(RocksDBOptions.MAX_MEMTABLES));

            mcf.setMaxBytesForLevelBase(conf.get(RocksDBOptions.MAX_LEVEL1_BYTES));
            mcf.setMaxBytesForLevelMultiplier(conf.get(RocksDBOptions.MAX_LEVEL_BYTES_MULTIPLIER));

            mcf.setTargetFileSizeBase(conf.get(RocksDBOptions.TARGET_FILE_SIZE_BASE));
            mcf.setTargetFileSizeMultiplier(conf.get(RocksDBOptions.TARGET_FILE_SIZE_MULTIPLIER));

            mcf.setLevel0FileNumCompactionTrigger(
                    conf.get(RocksDBOptions.LEVEL0_COMPACTION_TRIGGER));
            mcf.setLevel0SlowdownWritesTrigger(
                    conf.get(RocksDBOptions.LEVEL0_SLOWDOWN_WRITES_TRIGGER));
            mcf.setLevel0StopWritesTrigger(conf.get(RocksDBOptions.LEVEL0_STOP_WRITES_TRIGGER));

            mcf.setSoftPendingCompactionBytesLimit(
                    conf.get(RocksDBOptions.SOFT_PENDING_COMPACTION_LIMIT));
            mcf.setHardPendingCompactionBytesLimit(
                    conf.get(RocksDBOptions.HARD_PENDING_COMPACTION_LIMIT));

            /*
             * TODO: also set memtable options:
             * memtable_insert_with_hint_prefix_extractor
             * The reason why use option name `memtable_bloom_size_ratio`:
             * https://github.com/facebook/rocksdb/pull/9453/files
             * #diff-cde52d1fcbcce2bc6aae27838f1d3e7e9e469ccad8aaf8f2695f939e279d7501R369
             */
            mcf.setMemtablePrefixBloomSizeRatio(
                    conf.get(RocksDBOptions.MEMTABLE_BLOOM_SIZE_RATIO));
            mcf.setMemtableWholeKeyFiltering(
                    conf.get(RocksDBOptions.MEMTABLE_BLOOM_WHOLE_KEY_FILTERING));
            mcf.setMemtableHugePageSize(conf.get(RocksDBOptions.MEMTABL_BLOOM_HUGE_PAGE_SIZE));

            boolean bulkload = conf.get(RocksDBOptions.BULKLOAD_MODE);
            if (bulkload) {
                // Disable automatic compaction
                mcf.setDisableAutoCompactions(true);

                int trigger = Integer.MAX_VALUE;
                mcf.setLevel0FileNumCompactionTrigger(trigger);
                mcf.setLevel0SlowdownWritesTrigger(trigger);
                mcf.setLevel0StopWritesTrigger(trigger);

                long limit = Long.MAX_VALUE;
                mcf.setSoftPendingCompactionBytesLimit(limit);
                mcf.setHardPendingCompactionBytesLimit(limit);

                //cf.setMemTableConfig(new VectorMemTableConfig());
            }
        }
    }