åŽŸå› æ˜?hibernate 使用c3p0˜qžæŽ¥orcaleæ•°æ®åŽä¸ä¼šé‡Šæ”?åQ?c3p0的最大连接数ä¸?00åQŒä½†æ˜„¡„¶c3p0有BugåQŒå¯¼è‡´æ•°æ®åº“˜qžæŽ¥æ± ä¸å¤Ÿç”¨åQŒå¯¼è‡´è¿›½E‹é”æ…R€?br />åŽæ¢ProxoolåŽï¼Œè§‚察æ£å¸¸ã€?br />
下é¢è½¬å¼•å…¶å®ƒ¾|‘å‹æ–‡ç« 说明c3p0 ã€?Proxoolã€?dbcp 的区åˆ?
1
<!-- JDBC驱动½E‹åº -->
2<property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost:3306/struts?useUnicode=true&characterEncoding=GBK</property> <!-- æ•°æ®åº“用户å -->
3<property name="connection.username">root</property> <!-- æ•°æ®åº“密ç ?nbsp;-->
<!-- JDBC驱动½E‹åº --> 2
<property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost:3306/struts?useUnicode=true&characterEncoding=GBK</property> <!-- æ•°æ®åº“用户å --> 3
<property name="connection.username">root</property> <!-- æ•°æ®åº“密ç ?nbsp;-->上é¢çš„一ŒDµé…¾|®ï¼Œåœ?span class="hilite2" style="background-color: #ffffff">c3p0å’?span class="hilite1" style="background-color: #ffffff">dbcpä¸ï¼Œéƒ½æ˜¯å¿…éœ€çš„ï¼Œå› äØ“hibernateä¼šæ ¹æ®ä¸Š˜q°çš„é…ç½®æ¥ç”ŸæˆconnectionsåQŒå†äº¤ç»™c3p0æˆ?span class="hilite1" style="background-color: #ffffff">dbcp½Ž¡ç†.
1 C3P0
åªéœ€åœ¨hibernate.cfg.xmlä¸åŠ å…?
1<property name="c3p0.min_size">5</property>
2<property name="c3p0.max_size">30</property>
3<property name="c3p0.time_out">1800</property>
4<property name="c3p0.max_statement">50</property>
5
<property name="c3p0.min_size">5</property> 2
<property name="c3p0.max_size">30</property> 3
<property name="c3p0.time_out">1800</property> 4
<property name="c3p0.max_statement">50</property> 5
˜q˜æœ‰åœ¨classespathä¸åŠ å…?span class="hilite2" style="background-color: #ffffff">c3p0-0.8.4.5.jar
2 dbcp
在hibernate.cfg.xmlä¸åŠ å…?
1<property name="dbcp.maxActive">100</property>
2<property name="dbcp.whenExhaustedAction">1</property>
3<property name="dbcp.maxWait">60000</property>
4<property name="dbcp.maxIdle">10</property>
5
6<property name="dbcp.ps.maxActive">100</property>
7<property name="dbcp.ps.whenExhaustedAction">1</property>
8<property name="dbcp.ps.maxWait">60000</property>
9<property name="dbcp.ps.maxIdle">10</property>
10
<property name="dbcp.maxActive">100</property> 2
<property name="dbcp.whenExhaustedAction">1</property> 3
<property name="dbcp.maxWait">60000</property> 4
<property name="dbcp.maxIdle">10</property> 5
6
<property name="dbcp.ps.maxActive">100</property> 7
<property name="dbcp.ps.whenExhaustedAction">1</property> 8
<property name="dbcp.ps.maxWait">60000</property> 9
<property name="dbcp.ps.maxIdle">10</property> 10
˜q˜æœ‰åœ¨classespathä¸åŠ å…¥commons-pool-1.2.jar å’Œcommons-dbcp-1.2.1.jar.
3 proxool
ç”׃ºŽæ•°æ®åº“connection在较长时间没有访问下会自动æ–å¼€˜qžæŽ¥åQŒå¯¼è‡´æµè§ˆå‡ºé”™ï¼Œå¢žåŠ proxool作äØ“æ•°æ®åº“pool。它有自动连接功能ã€?br />1)ã€ä»Žhttp://proxool.sourceforge...下è²proxoolåQŒé‡Šæ”¾proxool.jar到WEB-INF/lib
2)ã€åœ¨hibernate.cfg.xmlä¸å¢žåŠ ：
1<property name="hibernate.proxool.pool_alias">dbpool</property>
2<property name="hibernate.proxool.xml">proxool.xml</property>
3<property name="connection.provider_class">org.hibernate.connection.ProxoolConnectionProvider</property>
4
<property name="hibernate.proxool.pool_alias">dbpool</property> 2
<property name="hibernate.proxool.xml">proxool.xml</property> 3
<property name="connection.provider_class">org.hibernate.connection.ProxoolConnectionProvider</property> 4
3)ã€åœ¨ä¸Žhibernate.cfg.xmlåŒçñ”目录åQˆsrcæ ¹ç›®å½•ä¸‹åQ‰å¢žåŠ proxool.xmlæ–‡äšgåQ?br />
1<?xml version="1.0" encoding="utf-8"?>
2<!-- the proxool configuration can be embedded within your own application's.
3 Anything outside the "proxool" tag is ignored. -->
4<something-else-entirely>
5 <proxool>
6 <alias>dbpool</alias>
7 <!--proxoolåªèƒ½½Ž¡ç†ç”Þp‡ªå·×ƒñ”生的˜qžæŽ¥-->
8 <driver-url>
9 jdbc:mysql://127.0.0.1:3306/wlsh?characterEncoding=GBK&useUnicode=true&autoReconnect=true </driver-url>
10 <driver-class>com.mysql.jdbc.Driver</driver-class>
11 <driver-properties>
12 <property name="user" value="root" />
13 <property name="password" value="123456" />
14 </driver-properties>
15 <!-- proxool自动侦察å„个˜qžæŽ¥çŠ¶æ€çš„æ—‰™—´é—´éš”(毫秒),侦察到空闲的˜qžæŽ¥ž®±é©¬ä¸Šå›žæ”?‘…时的销æ¯?/span>-->
16 <house-keeping-sleep-time>90000</house-keeping-sleep-time>
17 <!-- 最ž®‘ä¿æŒçš„½Iºé—²˜qžæŽ¥æ•?/span>-->
18 <prototype-count>5</prototype-count>
19 <!-- å…许最大连接数,‘…过了这个连接，å†æœ‰è¯äh±‚æ—Óž¼Œž®±æŽ’在队列丽{‰å€™ï¼Œæœ€å¤§çš„½{‰å¾…è¯äh±‚æ•°ç”±maximum-new-connections军_®š-->
20 <maximum-connection-count>100</maximum-connection-count>
21 <!-- 最ž®è¿žæŽ¥æ•°-->
22 <minimum-connection-count>10</minimum-connection-count>
23 </proxool>
24</something-else-entirely>
25
<?xml version="1.0" encoding="utf-8"?> 2
<!-- the proxool configuration can be embedded within your own application's. 3
Anything outside the "proxool" tag is ignored. --> 4
<something-else-entirely> 5
<proxool> 6
<alias>dbpool</alias> 7
<!--proxoolåªèƒ½½Ž¡ç†ç”Þp‡ªå·×ƒñ”生的˜qžæŽ¥--> 8
<driver-url> 9
jdbc:mysql://127.0.0.1:3306/wlsh?characterEncoding=GBK&useUnicode=true&autoReconnect=true </driver-url> 10
<driver-class>com.mysql.jdbc.Driver</driver-class> 11
<driver-properties> 12
<property name="user" value="root" /> 13
<property name="password" value="123456" /> 14
</driver-properties> 15
<!-- proxool自动侦察å„个˜qžæŽ¥çŠ¶æ€çš„æ—‰™—´é—´éš”(毫秒),侦察到空闲的˜qžæŽ¥ž®±é©¬ä¸Šå›žæ”?‘…时的销æ¯?/span>--> 16
<house-keeping-sleep-time>90000</house-keeping-sleep-time> 17
<!-- 最ž®‘ä¿æŒçš„½Iºé—²˜qžæŽ¥æ•?/span>--> 18
<prototype-count>5</prototype-count> 19
<!-- å…许最大连接数,‘…过了这个连接，å†æœ‰è¯äh±‚æ—Óž¼Œž®±æŽ’在队列丽{‰å€™ï¼Œæœ€å¤§çš„½{‰å¾…è¯äh±‚æ•°ç”±maximum-new-connections军_®š--> 20
<maximum-connection-count>100</maximum-connection-count> 21
<!-- 最ž®è¿žæŽ¥æ•°--> 22
<minimum-connection-count>10</minimum-connection-count> 23
</proxool> 24
</something-else-entirely> 25
于在hibernate3.0ä¸ï¼Œå·²ç»ä¸å†æ”¯æŒdbcp了，hibernate的作者在hibernate.orgä¸ï¼Œæ˜Žç¡®æŒ‡å‡ºåœ¨å®žè·µä¸å‘现dbcpæœ?BUG,在æŸäº›ç§æƒ…会产生很多½Iø™¿žæŽ¥ä¸èƒ½é‡Šæ”¾ï¼Œæ‰€ä»¥æŠ›å¼ƒäº†å¯¹dbcp的支æŒã€‚至于c3p0åQŒæœ‰è¯„论说它的算法ä¸æ˜¯æœ€ä¼˜çš„åQŒå› 为网上查资料得知åQšæœ‰¾|‘å‹åšäº†ä¸€ä¸ªå®žéªŒï¼Œåœ¨åŒä¸€™å¹ç›®ä¸åˆ†åˆ«ç”¨äº†å‡ 个常用的˜qžæŽ¥æ± ，然压¹‹è¯•å…¶æ€§èƒ½åQŒå‘现c3p0å 用资æºæ¯”较大，效率也ä¸é«˜ã€‚所以，åŸÞZºŽä¸Šè¿°åŽŸå› åQŒproxoolä¸å°‘行家推è使用åQŒè€Œä¸”æš‚æ—¶æ¥è¯´åQŒæ˜¯è´Ÿé¢è¯„äh是最ž®‘的一个。在三星ä¸ä¹Ÿæœ‰é¡¹ç›®æ˜¯ç”¨proxool的。从性能和出错率æ¥è¯´åQŒproxool½E微比å‰ä¸¤ç§å¥½äº›ã€‚C3P0åQŒç¨³å®šæ€§ä¼¼ä¹Žä¸é”™ï¼Œåœ¨è¿™æ–šw¢ä¼ég¹Žæœ‰å¾ˆå¥½çš„å£ç¢‘。至于性能åQŒåº”该ä¸æ˜¯æœ€å¥½çš„åQŒç®—是ä¸è§„ä¸çŸ©çš„¾cÕdž‹ã€?
　　Proxool的壼„‘似乎很好，ä¸å¤§è§åˆ°è´Ÿé¢çš„评ä»øP¼Œä»Žå®˜æ–¹èµ„料上æ¥çœ‹åQŒæœ‰è®¸å¤šæœ‰ç”¨çš„特性和特点åQŒä¹Ÿæ˜¯è®¸å¤šäh推èçš„ã€?br />
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org.hibernate.exception.JDBCConnectionException: could not execute query at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) 
. Caused by: com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: No operations allowed after connection closed.Connection was implicitly closed due to underlying exception/error: ** BEGIN NESTED EXCEPTION ** com.mysql.jdbc.CommunicationsException MESSAGE: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.net.SocketException MESSAGE: Broken pipe STACKTRACE: java.net.SocketException: Broken pipe at java.net.SocketOutputStream.socketWrite0(Native Method) ** END NESTED EXCEPTION ** 查看了Mysql的文档，以åŠConnector/J的文档以åŠåœ¨¾U¿è¯´æ˜Žå‘玎ͼŒå‡ºçŽ°˜q™ç§å¼‚å¸¸çš„åŽŸå› æ˜¯åQ?/p>
MysqlæœåŠ¡å™¨é»˜è®¤çš„“wait_timeout”æ˜?ž®æ—¶åQŒä¹Ÿž®±æ˜¯è¯´ä¸€ä¸ªconnection½Iºé—²‘…过8个å°æ—Óž¼ŒMysqlž®†è‡ªåŠ¨æ–开该connection。这ž®±æ˜¯é—®é¢˜çš„所在，在C3P0 poolsä¸çš„connections如果½Iºé—²‘…过8ž®æ—¶åQŒMysqlž®†å…¶æ–å¼€åQŒè€ŒC3P0òq¶ä¸çŸ¥é“该connectionå·²ç»å¤±æ•ˆåQŒå¦‚果这时有Clientè¯äh±‚connectionåQŒC3P0ž®†è¯¥å¤±æ•ˆçš„Connectionæä¾›¾l™ClientåQŒå°†ä¼šé€ æˆä¸Šé¢çš„异常ã€?/p>
解决的方法有3¿U：
- å¢žåŠ wait_timeout的时间ã€?
- å‡å°‘Connection poolsä¸connectionçš„lifetimeã€?
- ‹¹‹è¯•Connection poolsä¸connection的有效性ã€?
当然最好的办法是åŒæ—¶ç»¼åˆä‹É用上˜q?¿U方法，下颞®±DBCPå’ŒC3P0分别åšä¸€è¯´æ˜ŽåQŒå‡è®¾wait_timeout为默认的8ž®æ—¶
DBCPå¢žåŠ ä»¥ä¸‹é…置信æ¯:
//set to 'SELECT 1' validationQuery = "SELECT 1" //set to 'true' testWhileIdle = "true" //some positive integer timeBetweenEvictionRunsMillis = 3600000 //set to something smaller than 'wait_timeout' minEvictableIdleTimeMillis = 18000000 //if you don't mind a hit for every getConnection(), set to "true" testOnBorrow = "true" C3P0å¢žåŠ ä»¥ä¸‹é…置信æ¯:
//获å–connnection时测试是å¦æœ‰æ•?nbsp;testConnectionOnCheckin = true //自动‹¹‹è¯•çš„tableå称automaticTestTable=C3P0TestTable//set to something much less than wait_timeout, prevents connections from going stale idleConnectionTestPeriod = 18000 //set to something slightly less than wait_timeout, preventing 'stale' connections from being handed out maxIdleTime = 25000 //if you can take the performance 'hit', set to "true" testConnectionOnCheckout = true 更多的酾|®ä¿¡æ¯å¤§å®¶å¯ä»¥æŸ¥çœ‹C3P0文档åQŒConnector/J文档åQŒä»¥åŠDBCP的文档ã€?
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| RDBMS | 方言 |
|---|---|
| DB2 | org.hibernate.dialect.DB2Dialect |
| DB2 AS/400 | org.hibernate.dialect.DB2400Dialect |
| DB2 OS390 | org.hibernate.dialect.DB2390Dialect |
| PostgreSQL | org.hibernate.dialect.PostgreSQLDialect |
| MySQL | org.hibernate.dialect.MySQLDialect |
| MySQL with InnoDB | org.hibernate.dialect.MySQLInnoDBDialect |
| MySQL with MyISAM | org.hibernate.dialect.MySQLMyISAMDialect |
| Oracle (any version) | org.hibernate.dialect.OracleDialect |
| Oracle 9i/10g | org.hibernate.dialect.Oracle9Dialect |
| Sybase | org.hibernate.dialect.SybaseDialect |
| Sybase Anywhere | org.hibernate.dialect.SybaseAnywhereDialect |
| Microsoft SQL Server | org.hibernate.dialect.SQLServerDialect |
| SAP DB | org.hibernate.dialect.SAPDBDialect |
| Informix | org.hibernate.dialect.InformixDialect |
| HypersonicSQL | org.hibernate.dialect.HSQLDialect |
| Ingres | org.hibernate.dialect.IngresDialect |
| Progress | org.hibernate.dialect.ProgressDialect |
| Mckoi SQL | org.hibernate.dialect.MckoiDialect |
| Interbase | org.hibernate.dialect.InterbaseDialect |
| Pointbase | org.hibernate.dialect.PointbaseDialect |
| FrontBase | org.hibernate.dialect.FrontbaseDialect |
| Firebird | org.hibernate.dialect.FirebirdDialect |
]]>