使用Cassandra的Spring Boot和Spring数据：在数据库连接失败时继续

Question

我对Cassandra使用Spring Boot和Spring数据。在应用程序启动时，spring建立到数据库的连接，以设置模式并初始化spring数据存储库。如果数据库不可用，应用程序将无法启动。

我希望，应用程序只是记录一个错误并启动。当然，我不能再使用存储库了，但是其他独立于数据库的服务（rest控制器等）应该可以工作。在执行器健康检查中看到卡桑德拉倒下也很好。

@Configuration
public class CustomCassandraConfiguration extends CassandraAutoConfiguration {
    @Bean
    public DriverConfigLoaderBuilderCustomizer driverConfigLoaderBuilderCustomizer() {
        return builder -> builder.withBoolean(DefaultDriverOption.RECONNECT_ON_INIT, true);
    }
}

@Configuration
public class CustomCassandraAutoConfiguration extends CassandraAutoConfiguration {
private final Logger logger = LoggerFactory.getLogger(getClass());

@Override
@Bean
public CqlSession cassandraSession(CqlSessionBuilder cqlSessionBuilder) {
    try {
        return super.cassandraSession(cqlSessionBuilder);
    } catch (AllNodesFailedException e) {
        logger.error("Failed to establish the database connection", e);
    }
    return new DatabaseNotConnectedFakeCqlSession();
}

@Bean
public CassandraReactiveHealthIndicator cassandraHealthIndicator(ReactiveCassandraOperations r, CqlSession session) {
    if (session instanceof DatabaseNotConnectedFakeCqlSession) {
        return new CassandraReactiveHealthIndicator(r) {
            @Override
            protected Mono<Health> doHealthCheck(Health.Builder builder) {
                return Mono.just(builder.down().withDetail("connection", "was not available on startup").build());
            }
        };
    }
    return new CassandraReactiveHealthIndicator(r);
}
}

@Configuration
public class CustomCassandraDataAutoConfiguration extends CassandraDataAutoConfiguration {

public CustomCassandraDataAutoConfiguration(CqlSession session) {
    super(session);
}

@Bean
public SessionFactoryFactoryBean cassandraSessionFactory(CqlSession session, Environment environment, CassandraConverter converter) {
    SessionFactoryFactoryBean sessionFactoryFactoryBean = super.cassandraSessionFactory(environment, converter);

    // Disable schema action if database is not available
    if (session instanceof DatabaseNotConnectedFakeCqlSession) {
        sessionFactoryFactoryBean.setSchemaAction(SchemaAction.NONE);
    }
    return sessionFactoryFactoryBean;
}
}

DatabaseNotConnectedFakeCqlSession（假会话实现）

public class DatabaseNotConnectedFakeCqlSession implements CqlSession {
   
@Override
public String getName() {
    return null;
}

   
@Override
public Metadata getMetadata() {
    return null;
}

@Override
public boolean isSchemaMetadataEnabled() {
    return false;
}

   
@Override
public CompletionStage<Metadata> setSchemaMetadataEnabled( Boolean newValue) {
    return null;
}

   
@Override
public CompletionStage<Metadata> refreshSchemaAsync() {
    return null;
}

   
@Override
public CompletionStage<Boolean> checkSchemaAgreementAsync() {
    return null;
}

   
@Override
public DriverContext getContext() {
    return new DefaultDriverContext(new DefaultDriverConfigLoader(), ProgrammaticArguments.builder().build());
}

   
@Override
public Optional<CqlIdentifier> getKeyspace() {
    return Optional.empty();
}

   
@Override
public Optional<Metrics> getMetrics() {
    return Optional.empty();
}


@Override
public <RequestT extends Request, ResultT> ResultT execute( RequestT request, GenericType<ResultT> resultType) {
    return null;
}


@Override
public CompletionStage<Void> closeFuture() {
    return null;
}

   
@Override
public CompletionStage<Void> closeAsync() {
    return null;
}

   
@Override
public CompletionStage<Void> forceCloseAsync() {
    return null;
}

@Override
public Metadata refreshSchema() {
    return null;
}
}

有什么建议吗？

Answer 1

[编辑]我昨晚已经在内部联系了DataStax车手团队，adutra已经做出了回应，所以我撤回了我的回应。