休眠缓慢获取Postgres连接 [英] Hibernate Slow to Acquire Postgres Connection

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本文介绍了休眠缓慢获取Postgres连接的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我有一个很难调试这个问题。每当我尝试与postgres建立连接，需要一分钟。连接建立后，一切都很好。我试图禁用所有的映射，不加载任何，但仍然连接需要很长时间才能获得。我也试过禁用验证，没有什么区别。当我使用一个简单的简单JDBC连接时，它是瞬间的。 Hibernate正在做一些需要大量时间的东西，我似乎不能把它缩小。非常感谢任何输入。

I'm having a really difficult time debugging this problem. Whenever I try to establish a connection with postgres, it takes a whole minute. After the connection is established, everything is fine. I've tried disabling all the mappings and not loading any, but still the connection takes a long time to aquire. I've also tried disabling validation, no difference. When I use a simple a simple JDBC connection, it's instantaneous. Hibernate is doing something which takes considerable amount of time and I can't seem to narrow it down. Any input is greatly appreciated!

Postgres驱动程序：

Postgres Driver:

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");

这里是发生延迟的代码段：

Here's the segment of code where the delay occurs:

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;
    }

以下是日志结果：

[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

我做了一些更多的研究这，通过调试器。我没有在我的类路径中的所有源，但我仍然可以看到变量。 Durring一分钟等待，Hibernate正在查询pg_catalog.pg_type表：

I've done a little more research on this, stepping through the debugger. I don't have all the source in my classpath, but i can still see the variables. Durring that one minute wait, Hibernate is querying the pg_catalog.pg_type table:

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

这是屏幕截图：

img src =https://i.stack.imgur.com/DKiBX.jpgalt =DebugWindow>

推荐答案

我固定它=）我真的不得不根除了找到这一个答案。基本上，它来到加载元数据和JDBC驱动程序。它加载所有元数据，包括旁边sql列和其他各种构造，不需要操作的注释。我不知道为什么这是默认开启，但你应该肯定打开这个功能，除非你明确需要它：

I fixed it =) I really had to root around to find the answer for this one. Basically, it comes down to loading metadata and the JDBC driver. It's loading ALL META DATA, including comments beside sql columns and other various constructs, which are not needed for operation. I don't know why this is on by default but you should definitely turn this feature off unless you explicitly need it:

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

立即连线！

info我可以在代码中找到：

The only info I could find on this is in code:

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

这篇关于休眠缓慢获取Postgres连接的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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