Hibernate速度慢，无法获取Postgres连接

Z时代
2024-01-10
分类：问答

我在调试此问题时非常困难。每当我尝试与postgres建立连接时，都需要花费一分钟的时间。建立连接后，一切正常。我尝试禁用所有映射并且不加载任何映射，但是仍然需要花费很长时间来获取连接。我也尝试过禁用验证，没有区别。当我使用简单的简单JDBC连接时，它是瞬时的。Hibernate所做的事情需要花费大量时间，而我似乎无法缩小范围。任何输入，不胜感激！

Postgres驱动程序：

postgresql-9.1-901.jdbc4.jar

配置设置：

<hibernate-configuration>
    <session-factory>
    <!-- properties -->
        <property name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="connection.driver_class">org.postgresql.Driver</property>
        <property name="connection.url">jdbc:postgresql://xxxx.com:5432/xxxxx</property>
        <property name="connection.username">xxxxxxx</property>
        <property name="connection.password">xxxxxxx</property>
    </session-factory>
</hibernate-configuration>

代码中的其他设置：

    config.setProperty("hibernate.hbm2ddl.auto", hbm2ddlMode);
    //config.setProperty("hibernate.cache.use_query_cache", "true");
    config.setProperty("hibernate.cache.use_second_level_cache", "true");
    //config.setProperty("hibernate.cache.region.factory_class", "net.sf.ehcache.hibernate.EhCacheRegionFactory");
    config.setProperty("hibernate.cache.provider_class", "org.hibernate.cache.EhCacheProvider");
    //config.setProperty("hibernate.cache.provider_class", "org.hibernate.cache.NoCacheProvider");
    config.setProperty("hibernate.jdbc.fetch_size", "100");
    config.setProperty("hibernate.jdbc.batch_size", "30");
    config.setProperty("hibernate.jdbc.use_scrollable_resultset", "true");
    config.setProperty("hibernate.connection.provider_class", "org.hibernate.connection.C3P0ConnectionProvider");
    config.setProperty("hibernate.c3p0.acquire_increment", "1");
    config.setProperty("hibernate.c3p0.idle_test_period", "0");
    config.setProperty("hibernate.c3p0.min_size", "1");
    config.setProperty("hibernate.c3p0.max_size", "2");
    config.setProperty("hibernate.c3p0.timeout", "0");
    config.setProperty("javax.persistence.validation.mode", "none");

这是发生延迟的代码段：

private SessionFactory buildSessionFactory() throws Exception {
        ServiceRegistry serviceRegistry  = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
            //Building session takes a whole minute without mappings!!!
        sessionFactory = config.buildSessionFactory(serviceRegistry);
        validateConnection();
        return sessionFactory;
    }

这是日志结果：

[main] 2012-04-09 10:40:32,823 110391 INFO C3P0ConnectionProvider - HHH000046: Connection properties: {user=hgaidb_test, password=****} [main] 2012-04-09 10:40:32,823 110391 INFO C3P0ConnectionProvider - HHH000006: Autocommit mode: false [main] 2012-04-09 10:40:34,100 111668 DEBUG JdbcServicesImpl - Database -> name : PostgreSQL version : 8.3.3 major : 8 minor : 3 [main] 2012-04-09 10:40:34,101 111669 DEBUG JdbcServicesImpl - Driver -> name : PostgreSQL Native Driver version : PostgreSQL 9.1 JDBC4 (build 901) major : 9 minor : 1 ******************************************************************************* // 1 MINUTE DELAY ******************************************************************************* [main] 2012-04-09 10:40:34,102 111670 DEBUG JdbcServicesImpl - JDBC version : 4. 0 [main] 2012-04-09 10:41:21,632 159200 INFO Dialect - HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect ******************************************************************************* [main] 2012-04-09 10:41:21,669 159237 INFO LobCreatorBuilder - HHH000424: Disab ling contextual LOB creation as createClob() method threw error : java.lang.refl ect.InvocationTargetException [main] 2012-04-09 10:41:21,814 159382 DEBUG SettingsFactory - Automatic flush du ring beforeCompletion(): disabled [main] 2012-04-09 10:41:21,814 159382 DEBUG SettingsFactory - Automatic session close at end of transaction: disabled [main] 2012-04-09 10:41:21,815 159383 DEBUG SettingsFactory - JDBC batch size: 3 0 [main] 2012-04-09 10:41:21,816 159384 DEBUG SettingsFactory - JDBC batch updates for versioned data: disabled [main] 2012-04-09 10:41:21,816 159384 DEBUG SettingsFactory - Scrollable result sets: enabled [main] 2012-04-09 10:41:21,817 159385 DEBUG SettingsFactory - Wrap result sets: disabled [main] 2012-04-09 10:41:21,818 159386 DEBUG SettingsFactory - JDBC3 getGenerated Keys(): enabled [main] 2012-04-09 10:41:21,818 159386 DEBUG SettingsFactory - JDBC result set fe tch size: 100 [main] 2012-04-09 10:41:21,819 159387 DEBUG SettingsFactory - Connection release mode: auto [main] 2012-04-09 10:41:21,819 159387 INFO TransactionFactoryInitiator - HHH000 399: Using default transaction strategy (direct JDBC transactions) [main] 2012-04-09 10:41:21,844 159412 DEBUG SettingsFactory - Default batch fetc h size: 1 [main] 2012-04-09 10:41:21,844 159412 DEBUG SettingsFactory - Generate SQL with comments: disabled [main] 2012-04-09 10:41:21,845 159413 DEBUG SettingsFactory - Order SQL updates by primary key: disabled [main] 2012-04-09 10:41:21,846 159414 DEBUG SettingsFactory - Order SQL inserts for batching: disabled [main] 2012-04-09 10:41:21,846 159414 DEBUG SettingsFactory - Query translator: org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory [main] 2012-04-09 10:41:21,867 159435 INFO ASTQueryTranslatorFactory - HHH00039 7: Using ASTQueryTranslatorFactory [main] 2012-04-09 10:41:21,867 159435 DEBUG SettingsFactory - Query language sub stitutions: {} [main] 2012-04-09 10:41:21,867 159435 DEBUG SettingsFactory - JPA-QL strict comp liance: disabled [main] 2012-04-09 10:41:21,868 159436 DEBUG SettingsFactory - Second-level cache : enabled [main] 2012-04-09 10:41:21,868 159436 DEBUG SettingsFactory - Query cache: disab led [main] 2012-04-09 10:41:21,869 159437 DEBUG SettingsFactory - Cache region facto ry : org.hibernate.cache.internal.NoCachingRegionFactory [main] 2012-04-09 10:41:21,872 159440 DEBUG SettingsFactory - org.hibernate.cach e.internal.NoCachingRegionFactory did not provide constructor accepting java.uti l.Properties; attempting no-arg constructor. [main] 2012-04-09 10:41:21,873 159441 DEBUG SettingsFactory - Optimize cache for minimal puts: disabled [main] 2012-04-09 10:41:21,873 159441 DEBUG SettingsFactory - Structured second- level cache entries: disabled [main] 2012-04-09 10:41:21,873 159441 DEBUG SettingsFactory - Statistics: disabl ed [main] 2012-04-09 10:41:21,874 159442 DEBUG SettingsFactory - Deleted entity syn thetic identifier rollback: disabled [main] 2012-04-09 10:41:21,874 159442 DEBUG SettingsFactory - Default entity-mod e: pojo [main] 2012-04-09 10:41:21,875 159443 DEBUG SettingsFactory - Named query checki ng : enabled [main] 2012-04-09 10:41:21,875 159443 DEBUG SettingsFactory - Check Nullability in Core (should be disabled when Bean Validation is on): enabled [main] 2012-04-09 10:41:21,876 159444 DEBUG SettingsFactory - multi-tenancy stra tegy : NONE

我对此进行了更多的研究，逐步调试器。我的类路径中没有所有源代码，但仍然可以看到变量。等待一分钟后，Hibernate正在查询pg_catalog.pg_type表：

[SELECT typname FROM pg_catalog.pg_type WHERE oid = , ]

回答：

我修复了它=）我真的必须扎根寻找这个问题的答案。基本上，它涉及到加载元数据和JDBC驱动程序。它正在加载所有元数据，包括sql列旁边的注释和其他各种构造，这些都是操作所不需要的。我不知道为什么默认情况下会启用此功能，但是除非明确需要，否则您应该关闭此功能：

config.setProperty("hibernate.temp.use_jdbc_metadata_defaults","false");

立即连接！

我可以找到的唯一信息是在代码中：

107 // 'hibernate.temp.use_jdbc_metadata_defaults' is a temporary magic value. 108 // The need for it is intended to be alleviated with future development, thus it is 109 // not defined as an Environment constant... 110 // 111 // it is used to control whether we should consult the JDBC metadata to determine 112 // certain Settings default values; it is useful to *not* do this when the database 113 // may not be available (mainly in tools usage). 114 boolean useJdbcMetadata = ConfigurationHelper.getBoolean( "hibernate.temp.use_jdbc_metadata_defaults", configValues, true );

http://grepcode.com/file/repo1.maven.org/maven2/org.hibernate/hibernate-core/4.1.1.Final/org/hibernate/engine/jdbc/internal/JdbcServicesImpl.java#JdbcServicesImpl

以上是 Hibernate速度慢，无法获取Postgres连接的全部内容，来源链接： utcz.com/qa/409704.html

Hibernate速度慢，无法获取Postgres连接

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