Greetings; If you can, send some code that uses the connection. From that I think we can rule out an improperly handled connection. There are a few patterns to look for in connection handling that can cause this type of issue.
I had a case once where I opened two connections and only closed one of them .. it took a day or two for my connection pool to start timing out. Something like this seems like it will be in the Java code. Have a super day, John On 2/18/19, fai...@bestercapitalmedia.com <fai...@bestercapitalmedia.com> wrote: > Hi John, > > I am working in spring boot (maven) project. > I am not doing exclusive null-out of the connection feeling that spring boot > will manage it, do I still need to manage it myself? > If you want I can list the dependencies here. > > I have just added the following dependency but didn’t try yet on production > server. > <dependency> > <groupId>com.zaxxer</groupId> > <artifactId>HikariCP</artifactId> > <version>2.7.8</version> > <scope>compile</scope> > </dependency> > > Regards, > Faisal Zaidi > > -----Original Message----- > From: John Dale [mailto:jcdw...@gmail.com] > Sent: Monday, February 18, 2019 5:45 PM > To: Tomcat Users List > Subject: Re: Tomcat connection error > > I agree - release your connection, commit transaction (if you have > auto-commit set to false), and null-out your connection references. > > The analogy in c++ is you need deallocate memory. > > Java has GC in Java at a base level, but we also have some resource > reclamation at higher levels of abstraction over which GC has no purview. > Pooling (threads, connections) is an example. The connection pool needs to > reclaim its connections for reallocation to other threads. If it can't, the > application will hang waiting for connections. > > Do you have a static references to a database connection? > > The golden rule with database connections is acquire them late and release > them early. I like to create try/catch/finally blocks. In the finally > block, which executes even if there is an exception, I commit the > transaction and set connection reference to null. > > As a matter of course, I would null out and close references to > PreparedStatements and ResultSets as well (especially ResultSets). > > I'm sure you'll figure it out. > > Sincerely, > > John > > > On 2/18/19, Mark Thomas <ma...@apache.org> wrote: >> On 18/02/2019 10:24, fai...@bestercapitalmedia.com wrote: >>> Hi Ted, >>> >>> Yes, you are right. >>> I just need to restart the tomcat to get back it on. >>> There is no need to restart the mySql in my case. >>> >>> Any clue please. >> >> Sounds like a connection leak in the web application. I expect the >> connection pool includes tools to help you track that sort of problem >> down. >> >> Mark >> >> >>> >>> Faisal Zaidi >>> >>> -----Original Message----- >>> From: Ted Spradley [mailto:ted.k.sprad...@gmail.com] >>> Sent: Monday, February 18, 2019 1:52 PM >>> To: Tomcat Users List >>> Subject: Re: Tomcat connection error >>> >>> Hi Faisal, >>> >>> Your application(s) run as expected for a while, then you get the SQL >>> Connection error? Then the only way to “fix it” is to restart Tomcat? >>> At the same time are you also restarting MySQL? >>> >>> Thanks, >>> Ted >>> >>>> On Feb 18, 2019, at 02:17, Luis Rodríguez Fernández >>>> <uo67...@gmail.com> >>>> wrote: >>>> >>>> Hello Faisal, >>>> >>>> It looks like your problem is more related with your hikari >>>> connection pool than with tomcat itself. I would recommend you to >>>> double check your hikari configuration properties. Pay specially >>>> attention on how you are configuring your connection pool (minimum >>>> and maximum size, timeout, >>>> etc...) It looks like there is "something" in your application that >>>> prevents to get connections from your pool. >>>> >>>> Hope it helps, >>>> >>>> Luis >>>> >>>> >>>> >>>> >>>> >>>> >>>>> El lun., 18 feb. 2019 a las 6:33, <fai...@bestercapitalmedia.com> >>>>> escribió: >>>>> >>>>> Dear all, >>>>> >>>>> >>>>> >>>>> I am working on a project and I am facing following issue on almost >>>>> every second day. I need to restart tomcat to get it running again. >>>>> >>>>> Can someone guide me on it. Ask if you need some other insight to >>>>> look into it. >>>>> >>>>> >>>>> >>>>> 2019-02-18 04:49:35.572 WARN 20698 --- [io-4200-exec-15] >>>>> o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: >>>>> null >>>>> >>>>> 2019-02-18 04:49:35.572 ERROR 20698 --- [io-4200-exec-15] >>>>> o.h.engine.jdbc.spi.SqlExceptionHelper : HikariPool-1 - Connection >>>>> is >>>>> not >>>>> available, request timed out after 30000ms. >>>>> >>>>> 2019-02-18 04:49:35.573 WARN 20698 --- [io-4200-exec-15] >>>>> o.s.s.o.provider.endpoint.TokenEndpoint : Handling error: >>>>> InternalAuthenticationServiceException, Unable to acquire JDBC >>>>> Connection; nested exception is >>>>> org.hibernate.exception.JDBCConnectionException: Unable to acquire >>>>> JDBC Connection >>>>> >>>>> >>>>> >>>>> Server is Ubuntu (aws) >>>>> >>>>> Database is mySql >>>>> >>>>> java version "1.8.0_181" >>>>> >>>>> Java(TM) SE Runtime Environment (build 1.8.0_181-b13) >>>>> >>>>> Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode) >>>>> >>>>> >>>>> >>>>> Best Regards | Bien Cordialement | تحياتي >>>>> >>>>> Faisal Zaidi >>>>> Application Architect >>>>> >>>>> >>>>> >>>>> >>>> >>>> -- >>>> >>>> "Ever tried. Ever failed. No matter. Try Again. Fail again. Fail >>>> better." >>>> >>>> - Samuel Beckett >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >>> For additional commands, e-mail: users-h...@tomcat.apache.org >>> >>> >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >>> For additional commands, e-mail: users-h...@tomcat.apache.org >>> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: users-h...@tomcat.apache.org >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
