杭州观建设计网站,哈尔滨中小企业网站制作,如何在网站上做404页面,排版设计问题一#xff1a;数据源连接不足当TongWeb数据源连接用完时#xff0c;除了监控中看到连接占用高以外#xff0c;日志中会有如下提示信息。2023-02-14 10:24:43 [WARN] - com.tongweb.web.jdbc.pool.PoolExhaustedException: [TW-0.0.0.0-8088-3] Timeout: Pool empty. Una…问题一数据源连接不足 当TongWeb数据源连接用完时除了监控中看到连接占用高以外日志中会有如下提示信息。2023-02-14 10:24:43 [WARN] - com.tongweb.web.jdbc.pool.PoolExhaustedException: [TW-0.0.0.0-8088-3] Timeout: Pool empty. Unable to fetch a connection in 30 seconds, none available[size:10; busy:10; idle:0; lastwait:786].2023-02-14 10:24:43 [WARN] - at com.tongweb.web.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:660)2023-02-14 10:24:43 [WARN] - at com.tongweb.web.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:171)2023-02-14 10:24:43 [WARN] - at com.tongweb.web.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:117)2023-02-14 10:24:43 [WARN] - at com.tong.TestServlet.testDB(TestServlet.java:61)2023-02-14 10:24:43 [WARN] - at com.tong.TestServlet.doGet(TestServlet.java:38)2023-02-14 10:24:43 [WARN] - at javax.servlet.http.HttpServlet.service(HttpServlet.java:503)2023-02-14 10:24:43 [WARN] - at javax.servlet.http.HttpServlet.service(HttpServlet.java:590)造成这一问题的原因有两个数据源的最大连接数 设置过小无法满足并发需求适当调大最大连接数即可。但不可超过数据库可用的连接数数据库设置的最大连接数-其它系统已用的连接数。应用存在连接泄露或SQL执行时间过长导致连接耗光。在接下来的说明中介绍分析方法。问题二应用存在连接泄露的情况 针对应用存在连接泄露的情况可以开启TongWeb的连接泄漏检查“泄漏时记录日志”。可以从堆栈检查出应用哪里打开Connection而没有close()。2023-02-14 10:53:27 [WARN] - Connection leak detected, PooledConnection[com.mysql.cj.jdbc.ConnectionImpl4c9438e4]:java.lang.Exceptionat com.tongweb.web.jdbc.pool.ConnectionPool.getThreadDump(ConnectionPool.java:102)at com.tongweb.web.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:747)at com.tongweb.web.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:610)at com.tongweb.web.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:171)at com.tongweb.web.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:117)at com.tong.TestServlet.testDB(TestServlet.java:61) #检查这部分代码并修改at com.tong.TestServlet.doGet(TestServlet.java:38)at javax.servlet.http.HttpServlet.service(HttpServlet.java:503)at javax.servlet.http.HttpServlet.service(HttpServlet.java:590) 若应用不能修改代码则可以再开启泄漏时关闭连接, 将在达到“泄漏判定时间”后强制回收连接。注意“泄漏判定时间”要大于正常的SQL执行时间。问题三应用存在未关闭的statement,导致数据库游标不足的情况 针对应用存在未关闭的statement,导致数据库游标不足的情况可开启跟踪语句。这样在connection.close()时会关闭相应的statement。 若想修改应用代码关闭statement可开启跟踪未关闭堆栈,从中可看到哪里没有关闭。如下2023-02-14 11:09:30 [WARN] - Statement created, but was not closed at: java.lang.Throwable: Statement created at stackat com.tongweb.web.jdbc.pool.interceptor.StatementFinalizer$StatementEntry.init(StatementFinalizer.java:92)at com.tongweb.web.jdbc.pool.interceptor.StatementFinalizer.createStatement(StatementFinalizer.java:31)at com.tongweb.web.jdbc.pool.interceptor.AbstractCreateStatementInterceptor.invoke(AbstractCreateStatementInterceptor.java:57)at com.tongweb.web.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:90)at com.tongweb.web.jdbc.pool.interceptor.AbstractCreateStatementInterceptor.invoke(AbstractCreateStatementInterceptor.java:55)at com.tongweb.web.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:90)at com.tongweb.web.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:60)at com.sun.proxy.$Proxy38.prepareStatement(Unknown Source)at com.tong.TestServlet.testDB(TestServlet.java:66)at com.tong.TestServlet.doGet(TestServlet.java:38)问题四连接有效性验证无SQL配置 TongWeb8数据源会看到没有配SQL语句 连接验证不再配SQL语句而是通过connection.isValid(timeout) API来验证(TongWeb7也是有这功能的)开启验证日志后若验证失败会有如下日志输出。2022-06-07 13:55:45 [ERROR] - isValid() returned false.2022-06-07 13:55:45 [ERROR] - isValid() returned false.2022-06-07 13:55:45 [ERROR] - isValid() returned false.问题五慢SQL的检查 若怀疑有慢SQL可以开启慢SQL监视。可以在监控和日志中看到慢的SQL。2023-02-14 14:16:57 [WARN] - Slow Query Report SQLselect * from test01,testd where test01.test01testd.test01 and test01.test01 like %b6%; time9075 ms;获取慢SQL后可进行优化或进行SQL超时设置这取决于JDBC驱动支持API Statement.setQueryTimeout(int timeout)Failed Query Report SQLselect * from test01,testd where test01.test01testd.test01 and test01.test01 like %b6%; time5024 ms;com.mysql.cj.jdbc.exceptions.MySQLTimeoutException: Statement cancelled due to timeout or client request at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:113) at com.mysql.cj.jdbc.StatementImpl.checkCancelTimeout(StatementImpl.java:2189) at com.mysql.cj.protocol.a.NativeProtocol.sendQueryPacket(NativeProtocol.java:1033) at com.mysql.cj.protocol.a.NativeProtocol.sendQueryString(NativeProtocol.java:897) at com.mysql.cj.NativeSession.execSQL(NativeSession.java:1073) at com.mysql.cj.jdbc.StatementImpl.executeQuery(StatementImpl.java:1166) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.tongweb.web.jdbc.pool.interceptor.AbstractQueryReport$StatementProxy.invoke(AbstractQueryReport.java:219) at com.sun.proxy.$Proxy41.executeQuery(Unknown Source) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.tongweb.web.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:97) at com.sun.proxy.$Proxy41.executeQuery(Unknown Source) at com.tong.TestServlet.testDB(TestServlet.java:67)at com.tong.TestServlet.doGet(TestServlet.java:38)问题六采用 java:comp/env/jdbc/testdb方式引用数据源 (1) 配置数据源jdbc/testdb2代码 dataSource (DataSource) initialContext.lookup(java:comp/env/jdbc/testdb);3应用web.xml中配如下内容resource-refdescriptionjdbc/testdb/descriptionres-ref-namejdbc/testdb/res-ref-nameres-typejavax.sql.DataSource/res-typeres-authContainer/res-auth
/resource-ref
