I struggled with this issue for a long period, at the end I reached a good point: I started using database connection pools [1]. Actually you should wait until the mysql connection dies (it should be after 8 hours of db inactivity ), but you could change the connect-timeout=seconds [2] in order to achieve the before mentioned scenario.
[1] http://commons.apache.org/dbcp/ [2] http://dev.mysql.com/doc/refman/5.5/en/mysql-options.html Here my context.xml is: <Context override="true" reloadable="false" unpackWARs="true" autoDeploy="true" liveDeploy="false" allowLinking="true"> <!-- maxActive=10 Don't set this any higher than max_connections on your MySQL server, usually this should be a 10 or a few 10's of connections, not hundreds or thousands --> <!-- maxIdle=5 You don't want to many idle connections hanging around if you can avoid it, only enough to soak up a spike in the load --> <!-- validationQuery=select 1 Don't use autoReconnect=true, it's going away eventually and it's a crutch for older connection pools that couldn't test connections. You need to decide whether your application is supposed to deal with SQLExceptions (hint, it should), and how much of a performance penalty you're willing to pay to ensure 'freshness' of the connection --> <!-- testOnBorrow=true The most conservative approach is to test connections before they're given to your application. For most applications this is okay, the query used above is very small and takes no real server resources to process, other than the time used to traverse the network. If you have a high-load application you'll need to rely on something else. --> <!-- testWhileIdle=true Otherwise, or in addition to testOnBorrow, you can test while connections are sitting idle --> <!-- timeBetweenEvictionRunsMillis=10000 You have to set this value, otherwise even though you've asked connections to be tested while idle, the idle evicter thread will never run --> <!-- minEvictableIdleTimeMillis=60000 Don't allow connections to hang out idle too long, never longer than what wait_timeout is set to on the server...A few minutes or even fraction of a minute is sometimes okay here, it depends on your application and how much spikey load it will see --> <!-- maxWait Maximum time to wait for a dB connection to become available in ms, in this example 10 seconds. An Exception is thrown if this timeout is exceeded. Set to -1 to wait indefinitely. --> <!-- removeAbandoned=true A database connection pool creates and manages a pool of connections to a database. Recycling and reusing already existing connections to a dB is more efficient than opening a new connection. There is one problem with connection pooling. A web application has to explicetely close ResultSet's, Statement's, and Connection's. Failure of a web application to close these resources can result in them never being available again for reuse, a db connection pool "leak". This can eventually result in your web application db connections failing if there are no more available connections. There is a solution to this problem. The Jakarta-Commons DBCP can be configured to track and recover these abandoned dB connections. Not only can it recover them, but also generate a stack trace for the code which opened these resources and never closed them. --> <!-- removeAbandonedTimeout="60" Use the removeAbandonedTimeout attribute to set the number of seconds a dB connection has been idle before it is considered abandoned. --> <!-- logAbandoned=true The logAbandoned attribute can be set to true if you want DBCP to log a stack trace of the code which abandoned the dB connection resources. --> <Resource type="javax.sql.DataSource" name="jdbc/${CONTEXT_NAME}" password="PASSWORD" driverClassName="org.gjt.mm.mysql.Driver" username="${USERNAME}" url="jdbc:mysql://localhost/${DB_NAME}?zeroDateTimeBehavior=convertToNull" auth="Container" factory="org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory" maxActive="20" maxIdle="5" validationQuery="select 1" testOnBorrow="true" testWhileIdle="true" timeBetweenEvictionRunsMillis="10000" minEvictableIdleTimeMillis="60000" maxWait="5000" removeAbandoned="true" removeAbandonedTimeout="60" logAbandoned="true" /> </Context> On 1 March 2011 07:09, abhishek jain <abhishek.netj...@gmail.com> wrote: > hi, > this didnt solved, i created a file c3po.properties with the mentioned > property and it didnt solved. > also i have to wait a day for the error message, is there a way where i can > reduce this time during test? > > > thanks > abhi > > On Sat, Feb 26, 2011 at 12:32 AM, Burton Rhodes <burtonrho...@gmail.com>wrote: > >> I recall having a similiar issue when moving to MySQL from MSSQL. I >> solved it by adding c3po.properties file to the classpath with the >> text below. It kept the connection alive with the database. >> >> # This property corresponds to the query run defined by the >> "hibernate.c3p0.idle_test_period" value >> c3p0.preferredTestQuery = SELECT 1; >> >> On Fri, Feb 25, 2011 at 12:53 AM, Jerson John <jer...@cprvision.com> >> wrote: >> > Hi, >> > >> > Yup I faced this problem before and flush to Hibernate group.They have >> > suggested me some solution based on my mapping xml fle....Why don't u >> send >> > me that mapping xml and let me compare with mine.....Actually Even though >> it >> > look like Server error,its more to do with hibernate ....Please feel free >> to >> > currect me if my assumption is wrong >> > >> > Many Thanks and Regards, >> > >> > Jerson >> > >> > >> > -----Original Message----- >> > From: abhishek jain [mailto:abhishek.netj...@gmail.com] >> > Sent: Friday, February 25, 2011 2:31 PM >> > To: Struts Users Mailing List >> > Subject: Exception in hibernate3 >> > >> > hi, >> > I am not sure if i am ringing the correct list, but i am sure people here >> > must have encountered this problem. I am new to hibernate and when i ran >> the >> > code on server it was fine , strangely next day it keep on giving this >> error >> > till i restart tomcat. >> > >> > The last packet successfully received from the server was 54,880,316 >> > milliseconds ago. The last packet sent successfully to the server was >> > 54,880,317 milliseconds ago. is longer than the server configured value >> of >> > 'wait_timeout'. You should consider either expiring and/or testing >> > connection validity before use in your application, increasing the server >> > configured values for client timeouts, or using the Connector/J >> connection >> > property 'autoReconnect=true' to avoid this problem. >> > >> > I have searched a lot on net and added the following properties on >> > hibernate.cfg.xml, as people there were suggesting this,but of no use. >> > <!-- Sessions and transactions --> >> > <!-- Use the C3P0 connection pool provider --> >> > <property name="hibernate.c3p0.min_size">5</property> >> > <property name="hibernate.c3p0.max_size">20</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="current_session_context_class">thread</property> >> > >> > >> > >> > Pl. help me. >> > I have used hibernate3 with myeclipse as the development environment, and >> am >> > using mysql 5.x and centos (Linux) with Tomcat 5.x >> > -- >> > -- Maurizio Cucchiara --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@struts.apache.org For additional commands, e-mail: user-h...@struts.apache.org
