neo4j - 启动嵌入式 Neo4j HA Slave 时出现索引创建错误

Question

我正在尝试创建一个运行嵌入式 Neo4J HA 服务器的 Java 应用程序集群，但在启动任何从属服务器时出现错误

Caused by: org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement CREATE INDEX ON :`DeviceNode`(`deviceType`); nested exception is org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement CREATE INDEX ON :`DeviceNode`(`deviceType`); nested exception is org.neo4j.cypher.CypherExecutionException: Modifying the database schema can only be done on the master server, this server is a slave. Please issue schema modification commands directly to the master.
        at org.springframework.data.neo4j.support.query.CypherQueryEngine.query(CypherQueryEngine.java:56) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.support.schema.SchemaIndexProvider.createIndex(SchemaIndexProvider.java:36) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.support.mapping.EntityIndexCreator$1.doWithPersistentProperty(EntityIndexCreator.java:45) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.support.mapping.EntityIndexCreator$1.doWithPersistentProperty(EntityIndexCreator.java:41) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:261) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.support.mapping.EntityIndexCreator.ensureEntityIndexes(EntityIndexCreator.java:41) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.support.mapping.Neo4jMappingContext.updateStoredEntityType(Neo4jMappingContext.java:77) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.support.mapping.Neo4jMappingContext.addPersistentEntity(Neo4jMappingContext.java:71) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.support.mapping.Neo4jMappingContext.addPersistentEntity(Neo4jMappingContext.java:49) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:170) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:139) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:65) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.repository.query.CypherQueryBuilder.<init>(CypherQueryBuilder.java:37) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.repository.query.CypherQueryCreator.create(CypherQueryCreator.java:72) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.repository.query.CypherQueryCreator.create(CypherQueryCreator.java:35) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.repository.query.parser.AbstractQueryCreator.createCriteria(AbstractQueryCreator.java:109) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:88) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:73) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.repository.query.DerivedCypherRepositoryQuery.<init>(DerivedCypherRepositoryQuery.java:59) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.repository.query.GraphQueryMethod.createQuery(GraphQueryMethod.java:146) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.repository.GraphRepositoryFactory$1.resolveQuery(GraphRepositoryFactory.java:113) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:304) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:161) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:224) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:210) ~[spring-data-commons-1.7.0.RELEASE.jar:na]
        at org.springframework.data.neo4j.repository.GraphRepositoryFactoryBean.afterPropertiesSet(GraphRepositoryFactoryBean.java:69) ~[spring-data-neo4j-3.0.0.RELEASE.jar:na]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1571) ~[spring-beans-3.2.8.RELEASE.jar:3.2.8.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1509) ~[spring-beans-3.2.8.RELEASE.jar:3.2.8.RELEASE]
        ... 38 common frames omitted

最重要的一点似乎是修改数据库模式只能在主服务器上完成，这个服务器是从服务器。请直接向 master 发出模式修改命令。我相信索引是在存储库接口(interface)被 SDN 解析时创建的。

我是不是在某个地方做了一些疯狂的事情，我可以告诉奴隶们稍微退后一步，从最终会到达那里的主人那里拉出他们的模式吗？我相信我的配置是相当标准的:

<util:map id="config">
    <entry key="org.neo4j.server.database.mode" value="HA"/>

    <entry key="enable_remote_shell" value="true"/> 
    <entry key="ha.server_id" value="1"/>
    <entry key="ha.initial_hosts" value="neo1:5001,neo2:5001,neo3:5001"/>
    <entry key="ha.allow_init_cluster" value="true"/>
    <entry key="ha.cluster_join_timeout" value="60s"/>
    <entry key="ha.slave_only" value="false"/>
</util:map>

<bean id="graphDbFactory" class="org.neo4j.graphdb.factory.HighlyAvailableGraphDatabaseFactory"/>

<bean id="graphDbBuilder" factory-bean="graphDbFactory" factory-method="newHighlyAvailableDatabaseBuilder">
    <constructor-arg value="#{neoloc}"/>
</bean>

<bean id="graphDbBuilderFinal" factory-bean="graphDbBuilder" factory-method="setConfig">
    <constructor-arg ref="config"/>
</bean>

<bean id="graphDatabaseService" factory-bean="graphDbBuilderFinal" factory-method="newGraphDatabase" destroy-method="shutdown" />

<neo4j:config graphDatabaseService="graphDatabaseService"/>
<neo4j:repositories base-package="com.clarifimedia.data.repository"></neo4j:repositories>

<tx:annotation-driven transaction-manager="transactionManager"/>

<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
    <property name="converters">
        <set>
            <bean class="com.clarifimedia.data.converter.DateTimeToLongConverter"/>
            <bean class="com.clarifimedia.data.converter.LongToDateTimeConverter"/>
        </set>
    </property>
</bean>

配置值实际上是从 JNDI 中读取的，但我在上面进行了硬编码，因为加载 #{xyz} 不会那么方便。

版本
neo4j-2.0.1
neo4j-ha-2.0.1
spring-data-neo4j-3.0.0.RELEASE
spring-general-stuff-3.2.8.RELEASE

[编辑、切线、错误？]
我试图通过破坏网络来启动三个孤立的 master，目的是修复网络并查看是否发生了选举。但是在启动时，webapp 由于 TimeoutException 而无法启动。

Caused by: java.util.concurrent.TimeoutException: null
        at org.neo4j.cluster.statemachine.StateMachineProxyFactory$ResponseFuture.get(StateMachineProxyFactory.java:300) ~[neo4j-cluster-2.0.1.jar:2.0.1]
        at org.neo4j.cluster.client.ClusterJoin.joinByConfig(ClusterJoin.java:158) ~[neo4j-cluster-2.0.1.jar:2.0.1]
        at org.neo4j.cluster.client.ClusterJoin.start(ClusterJoin.java:91) ~[neo4j-cluster-2.0.1.jar:2.0.1]
        at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.start(LifeSupport.java:503) ~[neo4j-kernel-2.0.1.jar:2.0.1]

ClusterJoin 捕获 InterruptedException 和 ExecutionException，但不捕获 StateMachineProxyFactory$ResponseFuture 抛出的 TimeoutException。考虑到 ClusterJoin 类中的 while(true)，我认为这是一个错误，或者我不知何故混合了 jar 文件(尽管这两个类都在 neo4j-cluster-2.0.1 中)。

Answer 1

我有一个解决方法。请注意，我使用 spring Java 配置，但通过 XML 配置它应该没什么大不了的。

创建两个扩展标准 sdn 类的类，第一个添加一个方法来检查当前 jvm 是否以 neo 作为 master 运行:

public class OurDelegatingGraphDatabase extends DelegatingGraphDatabase {

    public OurDelegatingGraphDatabase(GraphDatabaseService delegate) {
        super(delegate);
    }

    public boolean isMaster(){
        if (delegate instanceof HighlyAvailableGraphDatabase){
            HighlyAvailableGraphDatabase highlyAvailableGraphDatabase = (HighlyAvailableGraphDatabase) delegate;
            return highlyAvailableGraphDatabase.isMaster();
        }
        return true;
    }
}

然后是一个自定义的 SchemaIndexProvider，它只在 master 上做索引(单模式也被认为是 master):

public class HACheckingSchemaIndexProvider extends SchemaIndexProvider {

    private OurDelegatingGraphDatabase graphDatabase;

    public HACheckingSchemaIndexProvider(GraphDatabase gd) {
        super(gd);
        if (gd instanceof OurDelegatingGraphDatabase){
            this.graphDatabase = (OurDelegatingGraphDatabase) gd;
        } else {
            throw new IllegalStateException("OurDelegatingGraphDatabase was not configured");
        }
    }

    @Override
    public void createIndex(Neo4jPersistentProperty property) {
        if (!graphDatabase.isMaster()){
            return;
        }
        super.createIndex(property);
    }

    @Override
    public void createIndex(String label, String prop, boolean unique) {
        if (!graphDatabase.isMaster()){
            return;
        }
        super.createIndex(label, prop, unique);
    }
}

然后使用spring配置这些:

@Configuration
//..whatever else config you have
public class Neo4jConfig extends Neo4jConfiguration {

//other config stuf..

    @Bean
    @Autowired
    @DependsOn("graphDatabaseService")
    public GraphDatabase graphDatabase() {
        return new OurDelegatingGraphDatabase(getGraphDatabaseService());
    }

    @Bean
    @Override
    public SchemaIndexProvider schemaIndexProvider() throws Exception {
        return new HACheckingSchemaIndexProvider(graphDatabase());
    }