Tomcat6无法连接到MySql（驱动程序尚未从服务器接收任何数据包） [英] Tomcat6 can't connect to MySql (The driver has not received any packets from the server)
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问题描述
我试图获得一个简单的DB查询示例，现在运行2天，但我仍然得到这个异常：
org.apache.jasper.JasperException：javax.servlet.ServletException：javax.servlet.jsp.JspException：无法获取连接，DataSource无效：org.apache.commons.dbcp.SQLNestedException：无法创建PoolableConnectionFactory（通信链接失败
成功发送到服务器的最后一个数据包是0毫秒前。驱动程序没有从服务器收到任何数据包。）
org.apache.jasper.servlet.JspServletWrapper.handleJspException （JspServletWrapper.java:522）
org.apache.jasper.servlet.JspServletWrapper.service（JspServletWrapper.java:398）
org.apache.jasper.servlet.JspServlet.serviceJspFile（JspServlet.java:342 ）
org.apache.jasper.servlet.JspServlet.service（JspServlet.java:267）
javax.servlet.http.HttpServlet.service（HttpServlet.java:717）
原因
javax.servlet.ServletException：javax.servlet.jsp.JspException：无法获取连接，DataSource无效：org.apache.commons.dbcp.SQLNestedException：无法创建PoolableConnectionFactory（通信链接failure
成功发送到服务器的最后一个数据包为0毫秒前。驱动程序没有收到来自服务器的任何数据包。）
org.apache.jasper.runtime.PageContextImpl.doHandlePageException（PageContextImpl.java:862）
org.apache.jasper.runtime.PageContextImpl.handlePageException （PageContextImpl.java:791）
org.apache.jsp.index_jsp._jspService（index_jsp.java:104）
org.apache.jasper.runtime.HttpJspBase.service（HttpJspBase.java:70）
javax.servlet.http.HttpServlet.service（HttpServlet.java:717）
org.apache.jasper.servlet.JspServletWrapper.service（JspServletWrapper.java:374）
org.apache.jasper .servlet.JspServlet.serviceJspFile（JspServlet.java:342）
org.apache.jasper.servlet.JspServlet.service（JspServlet.java:267）
javax.servlet.http.HttpServlet.service（HttpServlet .java：717）
根本原因
javax.servlet.jsp.JspException：无法获取连接，DataSource无效：org.apache.commons.dbcp.SQLNestedException：无法创建PoolableConnectionFactory（通信链接失败
成功发送到服务器的最后一个数据包为0毫秒前。驱动程序没有收到来自服务器的任何数据包。）
org.apache.taglibs.standard.tag.common.sql.QueryTagSupport.getConnection（QueryTagSupport.java:285）
org.apache.taglibs .standard.tag.common.sql.QueryTagSupport.doStartTag（QueryTagSupport.java:168）
org.apache.jsp.index_jsp._jspx_meth_sql_005fquery_005f0（index_jsp.java:274）
org.apache.jsp.index_jsp ._jspx_meth_c_005fotherwise_005f0（index_jsp.java:216）
org.apache.jsp.index_jsp._jspx_meth_c_005fchoose_005f0（index_jsp.java:130）
org.apache.jsp.index_jsp._jspService（index_jsp.java:93）
org.apache.jasper.runtime.HttpJspBase.service（HttpJspBase.java:70）
javax.servlet.http.HttpServlet.service（HttpServlet.java:717）
org.apache.jasper .servlet.JspServletWrapper.service（JspServletWrapper.java:374）
org.apache.jasper.servlet.JspServlet.serviceJspFile（JspServlet.java:342）
org.apache.jasper.servlet.JspServlet.service （JspServlet.java:267）
javax.servlet.http.HttpServlet.service（HttpServlet.java:717）
my web.xml如下所示：
<？xml version =1.0encoding = utf-8？>
< web-app xmlns =http://java.sun.com/xml/ns/javaee
xmlns：xsi =http://www.w3.org/2001/XMLSchema -instance
xsi：schemaLocation =http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd
version =2.5>
< resource-ref>
< description> DB连接< / description>
< res-ref-name> jdbc / testDB< / res-ref-name>
< res-type> javax.sql.DataSource< / res-type>
< res-auth>容器< / res-auth>
< / resource-ref>
< / web-app>
context.xml如下所示：
<？xml version =1.0encoding =UTF-8？>
< Context path =/ my1stAppdocBase =/ var / www / jsp / my1stAppdebug =5oadable =truecrossContext =true>
< Resource name =jdbc / testDBauth =Containertype =javax.sql.DataSource
maxActive =5maxIdle =5maxWait =10000
username =userpassword =passworddriverClassName =com.mysql.jdbc.Driver
url =jdbc：mysql：// localhost：3306 / some/>
< / Context>
并且jsp文件如下所示：
<％@ page contentType =text / html％>
<％@ taglib prefix =curi =http://java.sun.com/jsp/jstl/core％>
<％@ taglib prefix =fnuri =http://java.sun.com/jsp/jstl/functions％>
<％@ taglib prefix =fmturi =http://java.sun.com/jsp/jstl/fmt％>
<％@ taglib prefix =sqluri =http://java.sun.com/jsp/jstl/sql％>
< html>
< head>
< title> DroneLootTool< / title>
< / head>
< body bgcolor =white>
< sql：query var =resdataSource =jdbc / testDB>
select name，othername
from mytable
< / sql：query>
< h2>结果< / h2>
< c：forEach var =rowitems =$ {res.rows}>
名称$ {row.name}< br />
MoreName $ {row.othername}< br />< br />
< / c：forEach>
< / body>
< / html>
- 阅读了许多论坛条目/尝试过许多不同的设置
- 在/ etc / default / tomcat6中设置TOMCAT6_SECURITY = no，因为TOMCAT6_SECURITY = yes会导致麻烦。
- 未为数据库设置skip-networking标志（设置BIND 127.0.0.1）
- 防火墙已关闭（sudo ufw disable）
- MySQL工作（用户在此skript中使用过多次测试）
-
telnet localhost 3306说
Trying :: 1 ...
尝试127.0.0.1 ...
连接到localhost。
转义字符是'^]'。
外部主机关闭的连接。
TestConnection .java生成以下输出：
me @ my-laptop：〜/ Desktop $ java -classpath'/usr/share/java/mysql.jar:./' TestConnection com.mysql.jdbc.Driver jdbc：mysql：// localhost：3306 / testDB myuser mypassword
com.mysql.jdbc .CommunicationsException：通信链路故障
发送到服务器的最后一个数据包是0毫秒前。
at com.mysql.jdbc.SQLError.createCommunicationsException（SQLError.java:1070）
at com.mysql.jdbc.ConnectionImpl.createNewIO（ConnectionImpl.java:2103）
at com.mysql .jdbc.ConnectionImpl。< init>（ConnectionImpl.java:718）
at com.mysql.jdbc.ConnectionImpl.getInstance（ConnectionImpl.java:298）
at com.mysql.jdbc.NonRegisteringDriver。 connect（NonRegisteringDriver.java:282）
在java.sql.DriverManager.getConnection（DriverManager.java:582）
在java.sql.DriverManager.getConnection（DriverManager.java:185）
在TestConnection.checkConnection（TestConnection.java:40）
在TestConnection.main（TestConnection.java:21）
导致：com.mysql.jdbc.CommunicationsException：通信链路失败
发送到服务器的最后一个数据包是0毫秒前。
at com.mysql.jdbc.SQLError.createCommunicationsException（SQLError.java:1070）
at com.mysql.jdbc.MysqlIO.readPacket（MysqlIO.java:666）
at com.mysql .jdbc.MysqlIO.doHandshake（MysqlIO.java:1069）
at com.mysql.jdbc.ConnectionImpl.createNewIO（ConnectionImpl.java:2031）
... 7更多
由于： java.io.EOFException：无法从服务器读取响应。预期读取4个字节，在连接意外丢失之前读取0个字节。
at com.mysql.jdbc.MysqlIO.readFully（MysqlIO.java:2431）
at com.mysql.jdbc.MysqlIO.readPacket（MysqlIO.java:590）
... 9更多
连接失败。
我不知道是否有差异在java驱动程序连接到DB和Perl DBI模块的方式之间，但是这个PERL skript工作
＃！/ usr / bin / perl -w
使用CGI;
使用DBI;
use strict;
print CGI :: header（）;
my $ dbh = DBI-> connect（dbi：mysql：some：localhost，user，password）;
my $ sSql =SELECT * from mytable;
my $ ppl = $ dbh-> selectall_arrayref（$ sSql）;
foreach my $ pl（@ $ ppl）
{
my @array = @ $ pl;
print @array;
}
$ dbh-> disconnect;
但我没有得到任何新的警告。
当我在日志中搜索警告时，我发现这个消息，当我重新启动tomcat，不知道是否有帮助找到问题：
Feb 2 19:50:37 tobias-laptop jsvc.exec [3129]：02.02.2010 19:50:37 org.apache.catalina.startup.HostConfig checkResources＃012INFO：取消部署上下文[/ myapp]
Feb 2 19:50:37 tobias-laptop jsvc.exec [3129]：02.02.2010 19:50:37 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads＃012SCHWERWIEGEND：一个Web应用程序似乎有启动了一个名为[MySQL Statement Cancellation Timer]的线程，但是没能阻止它。这很可能造成内存泄漏。
Feb 2 19:50:37 tobias-laptop jsvc.exec [3129]：02.02.2010 19:50:37 org.apache.catalina.startup.HostConfig deployDescriptor＃012INFO：部署配置描述符myapp.xml
解决方案
事实证明，我通过运行三个mysqld实例来摧毁服务器，所以杀死不必要的解决我的问题：
me @ ubuntu：〜$ ps aux | grep mysql
mysql 8149 0.1 0.4 280484 26008？ Ssl 13:24 0:00 / usr / sbin / mysqld
me 8256 0.0 0.0 4392 836 pts / 3 S + 13:24 0:00 grep --color = auto mysql
root 26569 0.0 0.0 5952 1856 ？ S 10:44 0:00 sudo / usr / sbin / mysqld --skip-grant-tables --skip-networking
mysql 26570 0.1 0.6 323528 41936？ Sl 10:44 0:15 / usr / sbin / mysqld --skip-grant-tables --skip-networking
me @ ubuntu：〜$ sudo kill 26570
i'm running an Apache Tomcat 6.0.20 / MySQL 5.1.37-lubuntu / sun-java6-jdk /sun-java6-jre / sun-java6-bin on my local machine using Ubuntu 9.10 as OS. I'm trying to get a simple DB-query example running for 2 days now, but i still get this Exception:
org.apache.jasper.JasperException: javax.servlet.ServletException: javax.servlet.jsp.JspException: Unable to get connection, DataSource invalid: "org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)"
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:522)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:398)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
javax.servlet.ServletException: javax.servlet.jsp.JspException: Unable to get connection, DataSource invalid: "org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)"
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:862)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:791)
org.apache.jsp.index_jsp._jspService(index_jsp.java:104)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
javax.servlet.jsp.JspException: Unable to get connection, DataSource invalid: "org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)"
org.apache.taglibs.standard.tag.common.sql.QueryTagSupport.getConnection(QueryTagSupport.java:285)
org.apache.taglibs.standard.tag.common.sql.QueryTagSupport.doStartTag(QueryTagSupport.java:168)
org.apache.jsp.index_jsp._jspx_meth_sql_005fquery_005f0(index_jsp.java:274)
org.apache.jsp.index_jsp._jspx_meth_c_005fotherwise_005f0(index_jsp.java:216)
org.apache.jsp.index_jsp._jspx_meth_c_005fchoose_005f0(index_jsp.java:130)
org.apache.jsp.index_jsp._jspService(index_jsp.java:93)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
my web.xml looks like this :
<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/testDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
</web-app>
the context.xml looks like this :
<?xml version="1.0" encoding="UTF-8"?>
<Context path="/my1stApp" docBase="/var/www/jsp/my1stApp" debug="5" reloadable="true" crossContext="true">
<Resource name="jdbc/testDB" auth="Container" type="javax.sql.DataSource"
maxActive="5" maxIdle="5" maxWait="10000"
username="user" password="password" driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/some"/>
</Context>
and the jsp file looks like this:
<%@ page contentType="text/html" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql" %>
<html>
<head>
<title>DroneLootTool</title>
</head>
<body bgcolor="white">
<sql:query var="res" dataSource="jdbc/testDB">
select name, othername
from mytable
</sql:query>
<h2>Results</h2>
<c:forEach var="row" items="${res.rows}">
Name ${row.name}<br/>
MoreName ${row.othername}<br/><br/>
</c:forEach>
</body>
</html>
- read lots of forum entries / tried lots of different settings (always changed back to original settings when it didnt' work)
- set TOMCAT6_SECURITY=no in /etc/default/tomcat6 because TOMCAT6_SECURITY=yes was causing trouble too
- the skip-networking flag is not set for the DB (BIND 127.0.0.1 is set)
- firewall is swiched off (sudo ufw disable)
- MySQL works (tested several times with user used in this skript)
telnet localhost 3306 says
Trying ::1... Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. Connection closed by foreign host.
The TestConnection.java produced the following output:
me@my-laptop:~/Desktop$ java -classpath '/usr/share/java/mysql.jar:./' TestConnection com.mysql.jdbc.Driver jdbc:mysql://localhost:3306/testDB myuser mypassword
com.mysql.jdbc.CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2103)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:298)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at TestConnection.checkConnection(TestConnection.java:40)
at TestConnection.main(TestConnection.java:21)
Caused by: com.mysql.jdbc.CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:666)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1069)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2031)
... 7 more
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2431)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:590)
... 9 more
Connection failed.
i don't know if there is a difference between the way the java driver connects to the DB and the Perl DBI module does, but this PERL skript works
#!/usr/bin/perl -w
use CGI;
use DBI;
use strict;
print CGI::header();
my $dbh = DBI->connect("dbi:mysql:some:localhost", "user", "password");
my $sSql = "SELECT * from mytable";
my $ppl = $dbh->selectall_arrayref( $sSql );
foreach my $pl (@$ppl)
{
my @array = @$pl;
print @array;
}
$dbh->disconnect;
enabled --log-warnings on the mysql, but i didn't get any new warnings. When i was searching the logs for warnings i found this messages when i restart the tomcat, don't know if it helps to find the problem :
Feb 2 19:50:37 tobias-laptop jsvc.exec[3129]: 02.02.2010 19:50:37 org.apache.catalina.startup.HostConfig checkResources#012INFO: Undeploying context [/myapp]
Feb 2 19:50:37 tobias-laptop jsvc.exec[3129]: 02.02.2010 19:50:37 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads#012SCHWERWIEGEND: A web application appears to have started a thread named [MySQL Statement Cancellation Timer] but has failed to stop it. This is very likely to create a memory leak.
Feb 2 19:50:37 tobias-laptop jsvc.exec[3129]: 02.02.2010 19:50:37 org.apache.catalina.startup.HostConfig deployDescriptor#012INFO: Deploying configuration descriptor myapp.xml
解决方案
I had the same issue.
It turns out I messed up the server by running three mysqld instances, so kill the unwanted resolved my issue:
me@ubuntu:~$ ps aux | grep mysql
mysql 8149 0.1 0.4 280484 26008 ? Ssl 13:24 0:00 /usr/sbin/mysqld
me 8256 0.0 0.0 4392 836 pts/3 S+ 13:24 0:00 grep --color=auto mysql
root 26569 0.0 0.0 5952 1856 ? S 10:44 0:00 sudo /usr/sbin/mysqld --skip-grant-tables --skip-networking
mysql 26570 0.1 0.6 323528 41936 ? Sl 10:44 0:15 /usr/sbin/mysqld --skip-grant-tables --skip-networking
me@ubuntu:~$ sudo kill 26570
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