Hibernate启动很慢

Question

出于某种原因,我的hibernate应用程序的启动速度非常慢.(最多2分钟)我一直认为c3p0配置是完全错误的(相关问题),但研究日志显示,在建立与服务器的连接之后没有活动.此外,使用Hibernate的内置轮询功能也可以显示相同的结果.

这是日志的片段:

20:06:51,248 DEBUG BasicResourcePool:422 - decremented pending_acquires: 0
20:06:51,248 DEBUG BasicResourcePool:1644 - trace com.mchange.v2.resourcepool.BasicResourcePool@1acaf0ed [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@5f873eb2)
20:06:51,248 DEBUG BasicResourcePool:1644 - trace com.mchange.v2.resourcepool.BasicResourcePool@1acaf0ed [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@5f873eb2)
20:06:51,273 DEBUG JdbcServicesImpl:121 - Database ->
       name : PostgreSQL
    version : 9.1.6
      major : 9
      minor : 1
20:06:51,274 DEBUG JdbcServicesImpl:127 - Driver ->
       name : PostgreSQL Native Driver
    version : PostgreSQL 9.2 JDBC4 (build 1002)
      major : 9
      minor : 2
20:06:51,274 DEBUG JdbcServicesImpl:133 - JDBC version : 4.0 ##### HANGS FOR 2 MINUTES  ON THIS LINE #####
20:08:14,727  INFO Dialect:123 - HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect
20:08:14,736  INFO LobCreatorBuilder:120 - HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException
20:08:14,736 DEBUG GooGooStatementCache:297 - checkinAll(): com.mchange.v2.c3p0.stmt.GlobalMaxOnlyStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
20:08:14,736 DEBUG GooGooStatementCache:297 - checkinAll(): com.mchange.v2.c3p0.stmt.GlobalMaxOnlyStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
20:08:14,883 DEBUG BasicResourcePool:1644 - trace com.mchange.v2.resourcepool.BasicResourcePool@1acaf0ed [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@5f873eb2)
20:08:14,883 DEBUG BasicResourcePool:1644 - trace com.mchange.v2.resourcepool.BasicResourcePool@1acaf0ed [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@5f873eb2)
20:08:14,883 DEBUG GooGooStatementCache:297 - checkinAll(): com.mchange.v2.c3p0.stmt.GlobalMaxOnlyStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0

(请注意#comment#.)

我也尝试了一个较旧的Postgres JDBC驱动程序,但没有任何运气.

连接到本地数据库工作正常.立即建立连接,我可以查询数据库.这个远程数据库是一个Heroku开发实例.我也尝试了另一个遥控器.同样的结果.

我想出了我现在可以检查的想法,以摆脱这种烦恼.任何帮助将非常感激.

也许我的hibernate.cfg.xml很有帮助:

http://www.hibernate.org/dtd/hibernate-

configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="connection.driver_class">org.postgresql.Driver</property>
        <property name="connection.url"/>
        <property name="connection.default_schema"/>
        <property name="connection.username"/>
        <property name="connection.password"/> 

        <property name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>
            <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
        <property name="current_session_context_class">thread</property>            
        <property name="hibernate.c3p0.acquire_increment">3</property>
        <property name="hibernate.c3p0.min_size">3</property>
        <property name="hibernate.c3p0.max_size">10</property>
        <property name="hibernate.c3p0.timeout">300</property>
        <property name="hibernate.c3p0.max_statements">50</property>
        <property name="hibernate.c3p0.idle_test_period">3000</property>
        <property name="hibernate.c3p0.acquireRetryDelay">500</property>

        <property name="show_sql">true</property>
        <property name="format_sql">false</property>

        <property name="hbm2ddl.auto">validate</property>

        <mapping class="core.entities.Exam" />
        <mapping class="core.entities.Examination" />
        ...
    </session-factory>
</hibernate-configuration>

编辑:我试图通过日志和分析找到延迟的原因,但已广泛不成功.(虽然我在这个领域并不是那么先进.)最后我确实尝试了尝试并失败并更改了我的数据库以获取远程MySQL实例以检查是否存在任何差异.事实证明,连接几乎立即建立.

Answer 1

请参阅Hibernate Slow以获取Postgres连接

hibernate.temp.use_jdbc_metadata_defaults=false

在SessionFactory创建期间避免元数据重新加载.

Answer 2

对于Postgres,添加应用程序配置:

spring.jpa.database-platform = org.hibernate.dialect.PostgreSQLDialect
spring.jpa.properties.hibernate.temp.use_jdbc_metadata_defaults=false

如果不确定方言,第一行是必要的

结果

之前:

09:10:19.637 [main] INFO  o.h.annotations.common.Version - HCANN000001: Hibernate Commons Annotations {4.0.5.Final}
09:14:17.159 [main] INFO  org.hibernate.dialect.Dialect - HHH000400: Using dialect: org.hibernate.dialect.PostgreSQL9Dialect

~4分钟

后:

09:40:10.930 [main] INFO  o.h.annotations.common.Version - HCANN000001: Hibernate Commons Annotations {4.0.5.Final}
09:40:11.043 [main] INFO  org.hibernate.dialect.Dialect - HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect

~1分钟