hugegraph 数据库的初始化（二)
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图数据ku

hugegraph 数据库的初始化（二)

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图数据ku

在进行hugegrpah的使用的时候需要进行预先的初始化：
执行 com.baidu.hugegraph.cmd 中的main 进行图的初始化

private static void initGraph(String configPath) throws Exception {
        LOG.info("Init graph with config file: {}", configPath);
        HugeConfig config = new HugeConfig(configPath);
        // Forced set to false when initializing backend
        config.setProperty(CoreOptions.RAFT_MODE.name(), "false");
        HugeGraph graph = (HugeGraph) GraphFactory.open(config);

        BackendStoreSystemInfo sysInfo = graph.backendStoreSystemInfo();
        try {
            if (sysInfo.exists()) {
                LOG.info("Skip init-store due to the backend store of '{}' " +
                         "had been initialized", graph.name());
                sysInfo.checkVersion();
            } else {
                initBackend(graph); //主要是初始化后端
            }
        } finally {
            graph.close();
        }
    }

初始化后端存储：

 int retries = RETRIES;
        retry: do {
            try {
                graph.initBackend();
            } catch (Exception e) {
                String clz = e.getClass().getSimpleName();
                String message = e.getMessage();
                if (exceptions.containsKey(clz) && retries > 0) {
                    @SuppressWarnings("unchecked")
                    Collection<String> keywords = exceptions.getCollection(clz);
                    for (String keyword : keywords) {
                        if (message.contains(keyword)) {
                            LOG.info("Init failed with exception '{} : {}', " +
                                     "retry  {}...",
                                     clz, message, RETRIES - retries + 1);

                            Thread.sleep(RETRY_INTERVAL);
                            continue retry;
                        }
                    }
                }
                throw e;
            }
            break;
        } while (retries-- > 0);
    }
}

这里主要是graph.initBackend();
跟踪接口的实现我们走到StandardHugegraph

@Override
    public void initBackend() {
        this.loadSchemaStore().open(this.configuration); //schema 初始化
        this.loadSystemStore().open(this.configuration); //system 系统信息初始化
        this.loadGraphStore().open(this.configuration); //graph//图存储初始化

        LockUtil.lock(this.name, LockUtil.GRAPH_LOCK);
        try {
            this.storeProvider.init(); //存储提供者初始化
            this.storeProvider.initSystemInfo(this);//初始化系统信息
        } finally {
            LockUtil.unlock(this.name, LockUtil.GRAPH_LOCK);
            this.loadGraphStore().close();
            this.loadSystemStore().close();
            this.loadSchemaStore().close();
        }

        LOG.info("Graph '{}' has been initialized", this.name);
    }

loadSchemaStore 可以看到是通过父类调用子类的实现,这里我们看看抽象类中的实现

    private BackendStore loadSchemaStore() {
        String name = this.configuration.get(CoreOptions.STORE_SCHEMA);
        return this.storeProvider.loadSchemaStore(name);
    }
    //抽象类的实现
    public BackendStore loadSchemaStore(final String name) {
        LOG.debug("The '{}' StoreProvider load SchemaStore '{}'",
                  this.type(), name);

        this.checkOpened();
        if (!this.stores.containsKey(name)) {
            BackendStore s = this.newSchemaStore(name);
            this.stores.putIfAbsent(name, s);
        }

        BackendStore store = this.stores.get(name);
        E.checkNotNull(store, "store");
        return store;
    }

可以看到抽象类是通过名字来创建相应的schema hbase的具体实现：

    @Override
    protected BackendStore newSchemaStore(String store) {
        return new HbaseSchemaStore(this, this.namespace(), store);
    }
    public HbaseSchemaStore(BackendStoreProvider provider,
                                String namespace, String store) {
            super(provider, namespace, store);

            this.counters = new HbaseTables.Counters();

            registerTableManager(HugeType.VERTEX_LABEL,
                                 new HbaseTables.VertexLabel());
            registerTableManager(HugeType.EDGE_LABEL,
                                 new HbaseTables.EdgeLabel());
            registerTableManager(HugeType.PROPERTY_KEY,
                                 new HbaseTables.PropertyKey());
            registerTableManager(HugeType.INDEX_LABEL,
                                 new HbaseTables.IndexLabel());

            registerTableManager(HugeType.SECONDARY_INDEX,
                                 new HbaseTables.SecondaryIndex(store));
        }

可以看到HbaseSchemaStore中创建了不同的表 包括VERTEX_LABEL,EDGE_LABEL,PROPERTY_KEY,INDEX_LABEL,SECONDARY_INDEX

schemastore 加载完成之后接着加载systemStore

this.loadSystemStore().open(this.configuration);

loadSystemStore走到最后hbase的具体实现是：

public HbaseGraphStore(BackendStoreProvider provider,
                               String namespace, String store) {
            super(provider, namespace, store);

            registerTableManager(HugeType.VERTEX,
                                 new HbaseTables.Vertex(store));

            registerTableManager(HugeType.EDGE_OUT,
                                 HbaseTables.Edge.out(store));
            registerTableManager(HugeType.EDGE_IN,
                                 HbaseTables.Edge.in(store));

            registerTableManager(HugeType.SECONDARY_INDEX,
                                 new HbaseTables.SecondaryIndex(store));
            registerTableManager(HugeType.VERTEX_LABEL_INDEX,
                                 new HbaseTables.VertexLabelIndex(store));
            registerTableManager(HugeType.EDGE_LABEL_INDEX,
                                 new HbaseTables.EdgeLabelIndex(store));
            registerTableManager(HugeType.RANGE_INT_INDEX,
                                 HbaseTables.RangeIndex.rangeInt(store));
            registerTableManager(HugeType.RANGE_FLOAT_INDEX,
                                 HbaseTables.RangeIndex.rangeFloat(store));
            registerTableManager(HugeType.RANGE_LONG_INDEX,
                                 HbaseTables.RangeIndex.rangeLong(store));
            registerTableManager(HugeType.RANGE_DOUBLE_INDEX,
                                 HbaseTables.RangeIndex.rangeDouble(store));
            registerTableManager(HugeType.SEARCH_INDEX,
                                 new HbaseTables.SearchIndex(store));
            registerTableManager(HugeType.SHARD_INDEX,
                                 new HbaseTables.ShardIndex(store));
            registerTableManager(HugeType.UNIQUE_INDEX,
                                 new HbaseTables.UniqueIndex(store));
        }

关联的表如下图：
a4fab1765cfce97921cb340688e6bcb6.png

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最后编辑时间为: Apr 3, 2022 at 11:55 am

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