java初始化C3P0连接池需要2分钟
我不明白为什么在我的Hibernate应用程序中初始化c3p0连接池需要2分钟
这是我的冬眠。cfg。xml:
<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">1</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."></property>
<property name="show_sql">true</property>
<property name="format_sql">false</property>
<property name="hbm2ddl.auto">create</property>
</session-factory>
</hibernate-configuration>
在构建会话工厂时,在我的HibernateUtil文件中设置连接设置
当测试中的第一个事务打开时,池将初始化。 连接和查询数据库之后工作正常,在开始之前,它只在下面的行上挂起一段时间。我对输出进行了一些格式化,因为我认为问题可能与此处提到的设置之一有关:
INFO: Initializing c3p0 pool...
com.mchange.v2.c3p0.PoolBackedDataSource@30670080 [
connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@ecfec4d0 [
acquireIncrement -> 1,
acquireRetryAttempts -> 30,
acquireRetryDelay -> 1000,
autoCommitOnClose -> false,
automaticTestTable -> null,
breakAfterAcquireFailure -> false,
checkoutTimeout -> 0,
connectionCustomizerClassName -> null,
connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester,
debugUnreturnedConnectionStackTraces -> false,
factoryClassLocation -> null,
forceIgnoreUnresolvedTransactions -> false,
identityToken -> I-REMOVED-THIS,
idleConnectionTestPeriod -> 3000,
initialPoolSize -> 3,
maxAdministrativeTaskTime -> 0,
maxConnectionAge -> 0,
maxIdleTime -> 300,
maxIdleTimeExcessConnections -> 0,
maxPoolSize -> 10,
maxStatements -> 50,
maxStatementsPerConnection -> 0,
minPoolSize -> 3,
nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@b17e5c65 [
description -> null,
driverClass -> null,
factoryClassLocation -> null,
identityToken -> I-REMOVED-THIS,
jdbcUrl -> jdbc:postgresql://URL-TO-MY_DB,
properties -> {user=******, password=******, default_schema=}
],
preferredTestQuery -> null,
propertyCycle -> 0,
testConnectionOnCheckin -> false,
testConnectionOnCheckout -> false,
unreturnedConnectionTimeout -> 0,
usesTraditionalReflectiveProxies -> false;
userOverrides: {}
],
dataSourceName -> null,
factoryClassLocation -> null,
identityToken -> I-REMOVED-THIS,
numHelperThreads -> 3
]
这是我第一次使用Hibernate和c3p0,我希望它在启动池时会快得多?这是我的误解吗
使用远程数据库和本地PostgreSQL实例没有区别
(编辑:这不是真的。我在比较本地和远程数据库服务器时犯了一个错误。在本地,初始化几乎是立即进行的,远程初始化大约需要2分钟。)
Edit2:Here是连接进程的日志
# 1 楼答案
设置属性Hibernate。临时雇员在会话工厂的配置中,use_jdbc_metadata_默认为false。这将指示使用元数据方言而不是连接进行休眠,这会导致启动缓慢。您还必须为驱动程序配置适当的方言