java example Hibernate慢慢收購Postgres連接




postgresql-version jdbc jar (4)

我修好了=)我真的不得不找到這個答案。 基本上,它歸結為加載元數據和JDBC驅動程序。 它正在加載ALL META DATA,包括sql列和其他各種構造旁邊的註釋,這些註釋不需要操作。 我不知道為什麼默認情況下這是打開的,但除非你明確需要,否則你應該關閉此功能:

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

即時連接吧!

我能找到的唯一信息是代碼:

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

我很難調試這個問題。 每當我嘗試與postgres建立連接時,都需要一分鐘。 建立連接後,一切都很好。 我已經嘗試禁用所有映射而不加載任何映射,但仍然需要很長時間才能獲取。 我也試過禁用驗證,沒有區別。 當我使用簡單的簡單JDBC連接時,它是瞬間的。 Hibernate正在做一些花費大量時間的事情,我似乎無法縮小範圍。 任何輸入都非常感謝!

Postgres驅動程序:

postgresql-9.1-901.jdbc4.jar

配置設置:

<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>

代碼中的其他設置:

    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");

這是發生延遲的代碼段:

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;
    }

這是日誌結果:

[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

我已經對此進行了一些研究,逐步完成了調試器。 我的類路徑中沒有所有源代碼,但我仍然可以看到變量。 留下一分鐘等待,Hibernate正在查詢pg_catalog.pg_type表:

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

這是一個截圖:


我還必須啟用hibernate.jdbc.use_get_generated_keys,否則身份生成策略會拋出異常。 在根據從DB收到的元數據自動啟用之前。 所以我的整個解決方案是將以下兩行添加到persistence.xml:

<property name="hibernate.jdbc.use_get_generated_keys" value="true" />
<property name="hibernate.temp.use_jdbc_metadata_defaults" value="false" />






connection