RE: [Javaserver-perl] RE: Perl process hangs on new Java(...) call
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RE: [Javaserver-perl] RE: Perl process hangs on new Java(...) call
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From: Mark E. T. <ma...@zz...> - 2004-10-29 22:15:28
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Cool. JavaServer will attempt to instantiate a new class every time - unless pooling is implemented in the underlying class a new one will be created. You probably want a pooling mechanism for this kind of thing as JavaServer does not provide one... Mark > I found the problem, and indeed it's not in the JavaServer code! > > Using perl alarms helped me to isolate what was hanging. Regarding the > large # of threads, closing the Oracle connection really helped! > > > I have a quick question regarding JavaServer. > > In one of my Java classes being created, I am using an Oracle JDBC > client via a non-static Oracle connection instance variable. > > In subsequent class creations of the same class, is the object being > newly instantiated or is there a pooled object being reused? > Additionally, do I need to implement any synchronization methods around > methods that make use of the connection for example? > > Thanks very much again. > > > Jordan > > > > -----Original Message----- > From: jav...@li... > [mailto:jav...@li...] On Behalf Of > ma...@zz... > Sent: Thursday, October 14, 2004 10:08 AM > To: Jordan Redner > Cc: jav...@li... > Subject: Re: [Javaserver-perl] RE: Perl process hangs on new Java(...) > call > > Wow that's a lotta threads in not so much memory. Yah try to socket > timeout but a more fundamental problem is JavaServer hanging - prolly > running out of memory - look a 'top' next time that happens & see what > the Java process is doing... > M > > On Thu, Oct 14, 2004 at 09:48:24AM -0700, Jordan Redner wrote: >> It's hard to reproduce. It seems to happen when the machine is under >> high CPU load. >> >> The JavaServer typically does have a lot of threads and does run for >> long periods of time. I just checked a production machine and there > are >> 133 threads (ps -ef on Linux) total memory is 151 MB. >> >> Thinking about putting a socket timeout in Java.pm... even though it's >> running on localhost, what do you think? >> >> >> >> Jordan >> >> >> -----Original Message----- >> From: ma...@zz... [mailto:ma...@zz...] >> Sent: Thursday, October 14, 2004 8:29 AM >> To: Jordan Redner >> Cc: jav...@li... >> Subject: Re: [Javaserver-perl] RE: Perl process hangs on new Java(...) >> call >> >> Can you telnet to 127.0.0.1 port 2000? >> Then try: >> >> #!perl >> >> use IO::Socket; >> my $socket = IO::Socket::INET->new >> ( >> PeerAddr => '127.0.0.1', >> PeerPort => 2000, >> ); >> >> & see if that hangs. >> Does it hang all of the time or only sometimes? Maybe it's the >> JavaServer >> process itself that's hanging. Hm. If only sometimes is it after >> JavaServer >> has been running for a while w/lots of objects? >> I don't think upgrading to 4.7 will help - it's better handling for > Java >> protected fields. >> M >> >> >> On Thu, Oct 14, 2004 at 08:03:30AM -0700, Jordan Redner wrote: >> > Thanks so much for the fast response. >> > >> > Server port is always 127.0.0.1 >> > >> > OS is a couple years old. >> > >> > Mandrake: Linux sj7 2.4.19-16mdkenterprise #1 SMP Fri Sep 20 > 17:34:59 >> > CEST 2002 i686 >> > >> > Perl version 5.8.0 >> > >> > >> > >> > Do you think upgrading from 4.6 to 4.7 will help? Are there any >> > synchronization issues which were fixed or anything like that? When > I >> > read "better handling of private/protected fields/functions...", I >> > wasn't sure of what this meant internally. JavaServer runs on > several >> > production machines, otherwise I'd just go ahead and try it. >> > >> > My next step is to install a timeout parm. in the socket constructor >> > inside Java.pm. What are your thoughts on this?? >> > >> > >> > Thanks for your help. >> > >> > >> > >> > Jordan >> > >> > >> > -----Original Message----- >> > From: ma...@zz... [mailto:ma...@zz...] >> > Sent: Wednesday, October 13, 2004 9:33 PM >> > To: Jordan Redner >> > Cc: jav...@li... >> > Subject: Re: Perl process hangs on new Java(...) call >> > >> > The only interesting thing the Java.pm constructor does that may > cause >> > it to hang is trying to connect to the remove JavaServer java > process. >> > Try to telnet to port 2000 of your JavaServer machine from the > machine >> > running the perl code to ensure you can make a connection between > the >> > two. >> > Of course you'll want to make sure you're running compatible version >> > of Java.pm & JavaServer (the major version numbers match). >> > Perhaps your DNS is screwey & your JavaServer host is not be > resolved? >> > As to why it stays hung - which operating system are you running on? >> > If perl is 'hung' in a system call (socket connect) perhaps the >> > signal never gets sent. >> > Lemmie know how it goes - we'll get it figured out. >> > Mark >> > >> > PS there is a mailing list at sourceforge that you should join (very >> low >> > traffic) for questions such as these: >> > http://lists.sourceforge.net/lists/listinfo/javaserver-perl >> > >> > >> > On Wed, Oct 13, 2004 at 05:23:47PM -0700, Jordan Redner wrote: >> > > Hi, I hope you can help. I'm using your product as a way to > migrate >> > > some code from Perl to Java so it's a pretty key piece to our >> > strategy. >> > > >> > > >> > > >> > > >> > > Even though we put in alarms, we still end up with hung perl >> > processes. >> > > The processes seem to be hung on the line below that is bold, or >> when >> > it >> > > calls out to >> > > >> > > $java = new Java(host => $perlJavaHost, >> > > >> > > port => $perlJavaPort, >> > > >> > > event_port => -1, >> > > >> > > use_tied_arrays => 1 >> > > >> > > ); >> > > >> > > >> > > >> > > Do you have any idea what we can do to solve this problem? Was > this >> a >> > > known problem. The javaServer itself is very stable. This is the >> > only >> > > problem we know about. Is there a way to specify a timeout in the >> > > connection request? >> > > >> > > >> > > >> > > Thanks so much in advance for any help you can provide. >> > > >> > > >> > > >> > > >> > > >> > > sub getJava { >> > > >> > > my ($perlJavaHost,$perlJavaPort,$javaServerRunner,$timeout) > >> @_; >> > > >> > > >> > > >> > > my $java; >> > > >> > > >> > > >> > > my $retries = 0; >> > > >> > > >> > > >> > > while ($retries < 2) { >> > > >> > > >> > > >> > > $retries ++; >> > > >> > > >> > > >> > > ## -- reset the timer for timeout before the eval > block >> > > >> > > alarm 0; >> > > >> > > >> > > >> > > eval { >> > > >> > > local $SIG{ALRM} = sub { >> > > >> > > ## -- Signal handler to catch the ALRM signal >> > > >> > > ## -- log the timeout error and continue next >> > iteration >> > > >> > > lib::perl::Infra::Log::Print("-- Timedout on the >> > > JavaServer trying to get a Java object instance --"); >> > > >> > > next; >> > > >> > > }; >> > > >> > > >> > > >> > > lib::perl::Infra::Log::Print("-- Setting JavaServer >> alarm >> > > to: $timeout --"); >> > > >> > > >> > > >> > > alarm $timeout; >> > > >> > > >> > > >> > > $java = new Java(host => $perlJavaHost, >> > > >> > > port => $perlJavaPort, >> > > >> > > event_port => -1, >> > > >> > > use_tied_arrays => 1 >> > > >> > > ); >> > > >> > > >> > > >> > > lib::perl::Infra::Log::Print("-- Successfully obtained > a >> > > Java object --"); >> > > >> > > >> > > >> > > ## -- reset the timer for timeout >> > > >> > > alarm 0; >> > > >> > > }; >> > > >> > > >> > > >> > > if (defined $java) { >> > > >> > > return $java; >> > > >> > > } else { >> > > >> > > my $err = ""; >> > > >> > > if ($@) { $err = $@; } >> > > >> > > >> > > >> > > if ($main::gLogger){ >> > > >> > > $err = "JavaUtil.pm" . "," . "Failed obtaining Java >> > object, >> > > retry count=$retries " . "\n$err"; >> > > >> > > $main::gLogger->Log("ERROR",$err); >> > > >> > > } else { >> > > >> > > $err = "Failed obtaining Java object, retry >> count=$retries >> > " >> > > . "\n$err"; >> > > >> > > lib::perl::Infra::Log::Print ($err); >> > > >> > > } >> > > >> > > >> > > >> > > restartJavaServer($javaServerRunner); >> > > >> > > sleep 5; >> > > >> > > } >> > > >> > > } >> > > >> > > >> > > >> > > return(undef); >> > > >> > > >> > > >> > > } >> > > >> > > >> > > >> > > >> > > >> > > >> > > >> > > Jordan >> > > >> > > >> > > >> > >> > >> > >> > ------------------------------------------------------- >> > This SF.net email is sponsored by: IT Product Guide on >> ITManagersJournal >> > Use IT products in your business? Tell us what you think of them. > Give >> us >> > Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find > out >> more >> > http://productguide.itmanagersjournal.com/guidepromo.tmpl >> > _______________________________________________ >> > Javaserver-perl mailing list >> > Jav...@li... >> > https://lists.sourceforge.net/lists/listinfo/javaserver-perl >> > > > ------------------------------------------------------- > This SF.net email is sponsored by: IT Product Guide on ITManagersJournal > Use IT products in your business? Tell us what you think of them. Give > us > Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out > more > http://productguide.itmanagersjournal.com/guidepromo.tmpl > _______________________________________________ > Javaserver-perl mailing list > Jav...@li... > https://lists.sourceforge.net/lists/listinfo/javaserver-perl > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: > Sybase ASE Linux Express Edition - download now for FREE > LinuxWorld Reader's Choice Award Winner for best database on Linux. > http://ads.osdn.com/?ad_idU88&alloc_id065&op=click > _______________________________________________ > Javaserver-perl mailing list > Jav...@li... > https://lists.sourceforge.net/lists/listinfo/javaserver-perl > |
