Forum LAMS for Tech-Heads - General Forum: LAMS blank page issue

By: Ernie Ghiglione

[ Reply | Forward ]

Hi Lachlan,

Have a look at the LAMS log files. They will give you clues about what went wrong.

I haven't seen LAMS returning blank pages before, so I'm also keen to find out.

To find the log files go to the directory where you install LAMS and see the following dir: jboss-4.0.2/server/default/log. In there look for the server.log and the lams.log files. Please zip these two files and upload them here so we can have a look.

Thanks,

Ernie

Posted by Ernie Ghiglione

By: Lachlan Hockings

[ Reply | Forward ]

Hi Ernie,

The server.log file for the 23rd March only shows entries from around 1:07pm onwards, which is after I had restarted the lams2 service and everything had returned to normal.

Attached is the lams.log files for that time period, I beleive the issue surfaced around 12:45pm.

The log file seems quite detailed, I hope you are able to make sense of it.
Thanks.

Posted by Lachlan Hockings

By: Lachlan Hockings

[ Reply | Forward ]

Please note the file attached above IS a zip file, for some reason when I click on it, it tries to download it as a .log1 file so you may need to rename the extension.

Posted by Lachlan Hockings

By: Ernie Ghiglione

[ Reply | Forward ]

Hi Lachlan,

I can't seem to find anything obvious on these logs as to why LAMS would return just blank pages. Not so sure how that occurred.

However, I did find some other errors:

2011-03-23 12:50:05,019 [TP-Processor16:] ERROR org.lamsfoundation.lams.util.HttpUrlConnectionUtil - A problem has occurred w
hile connecting to the tools export url http://learning.xavierllandilo.catholic.edu.au/lams/tool/lavote11/exportPortfolio?mod
e=teacher&toolContentID=256&offline=false&directoryName=lamstmp_000000002eb18276012ee06781fe0283_export/Activity288
2011-03-23 12:50:05,058 [TP-Processor16:] ERROR org.lamsfoundation.lams.learning.export.service.ExportPortfolioService - A pr
oblem has occurred while connecting to the tool's export url. The export url may be invalid or may not exist
2

It seems that you are not able to export sequences. Can you please confirm if that's the case?

Can you try exporting a sequence that does not contain a Vote activity please? Let me know if that works.

Also, your Jabber server doesn't seem to be working though.

Thanks,

Ernie

Posted by Ernie Ghiglione

By: Lachlan Hockings

[ Reply | Forward ]

Ernie,

The blank page issue has not occured again, perhaps it was a once off glitch.

However you are correct in that we cannot export sequences. And yes Jabber is not running, I will be looking at that later.

Regarding the exporting, any ideas?

Posted by Lachlan Hockings

By: Ernie Ghiglione

[ Reply | Forward ]

Hi Lachlan,

I've just came across something that might be able to shed some light into the issue regarding blank pages.

Recently I've had a LAMS server that was experiencing some heavy usage and it ran out of memory.

Using JAVA_OPTS you can specifically assign the amount of RAM memory you want a java application to use.

In your run.conf file in your jboss-4.0.2/bin directory, you'll find a line that starts with JAVA_OPTS = "...."

Can you please paste this line here?

I believe you might have experience a similar issue, so if you increase the memory allocation to LAMS, that will prevent this from happening.

Thansk,

Ernie

Posted by Ernie Ghiglione

By: Lachlan Hockings

[ Reply | Forward ]

JAVA_OPTS="-server -Xms128m -Xmx128m"

What should we set it to? Our server has 16gb of ram so we have plenty of spare.

Posted by Lachlan Hockings

By: Ernie Ghiglione

[ Reply | Forward ]

> JAVA_OPTS="-server -Xms128m -Xmx128m"

Woow.. that's very very bad! LAMS would run out of memory very quickly. I'm almost certain this was the problem with blank pages now.

For production, I would suggest a minimum this:

JAVA_OPTS="-server -Xms256m -Xmx2048m -XX:MaxPermSize=256m"

After this, you won't have any problems even with 500 concurrent users.

Thanks,

Ernie

Posted by Ernie Ghiglione

By: Ernie Ghiglione

[ Reply | Forward ]

> 2011-03-23 12:50:05,019 [TP-Processor16:] ERROR org.lamsfoundation.lams.util.HttpUrlConnectionUtil - A problem has occurred w
> hile connecting to the tools export url http://learning.xavierllandilo.catholic.edu.au/lams/tool/lavote11/exportPortfolio?mod
> e=teacher&toolContentID=256&offline=false&directoryName=lamstmp_000000002eb18276012ee06781fe0283_export/Activity288
> 2011-03-23 12:50:05,058 [TP-Processor16:] ERROR org.lamsfoundation.lams.learning.export.service.ExportPortfolioService - A pr
> oblem has occurred while connecting to the tool's export url. The export url may be invalid or may not exist

LAMS is trying to make www calls to itself so it can get the output from the tools to export the sequence.

Can your server make calls out on port 80? Maybe a firewall rule preventing this?

The other thing could be that LAMS isn't able to resolve the domain name?

Thanks,

Ernie

Posted by Ernie Ghiglione

By: Lachlan Hockings

[ Reply | Forward ]

Hi Ernie,

Thanks for your ongoing help regarding our issues.

We tried disabling the firewall completely and still have our exporting issue.

When browsing to
http://learning.xavierllandilo.catholic.edu.au/lams/tool/lavote11/exportPortfolio?mod

we get a long error message:

java.lang.IllegalArgumentException: directoryName is required 'null'
java.lang.IllegalArgumentException: directoryName is required 'null' at org.lamsfoundation.lams.util.WebUtil.checkObject(WebUtil.java:107) at org.lamsfoundation.lams.util.WebUtil.readStrParam(WebUtil.java:238) at org.lamsfoundation.lams.util.WebUtil.readStrParam(WebUtil.java:227) at org.lamsfoundation.lams.web.servlet.AbstractExportPortfolioServlet.doGet(AbstractExportPortfolioServlet.java:105) at javax.servlet.http.HttpServlet.service(HttpServlet.java:697) at javax.servlet.http.HttpServlet.service(HttpServlet.java:810) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.lamsfoundation.lams.web.filter.LocaleFilter.doFilterInternal(LocaleFilter.java:142) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:77) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:174) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:77) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.lamsfoundation.lams.web.session.SystemSessionFilter.doFilter(SystemSessionFilter.java:71) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:39) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:153) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:59) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) at org.lamsfoundation.lams.integration.security.SingleSignOn.invoke(SingleSignOn.java:121) at org.lamsfoundation.lams.integration.security.LoginRequestValve.invoke(LoginRequestValve.java:67) at org.apache.catalina.valves.FastCommonAccessLogValve.invoke(FastCommonAccessLogValve.java:481) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:307) at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:385) at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:748) at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:678) at org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:871) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) at java.lang.Thread.run(Thread.java:619)

Posted by Lachlan Hockings

By: Lachlan Hockings

[ Reply | Forward ]

Just thought I would add as well,

If we choose to export as IMS it works fine, however they cannot be re imported into LAMS.


Also, we tried exporting on our internal test server running the same version of LAMS, and it worked fine. The differences between our live server and our test one are:
1: Live server is 64bit, where as our test server is 32bit. (Both running CentOS)

2: We access the test server directly via it's IP, where as our live server is through our domain, with all traffic routed via an external firewall. I wonder if this is perhaps playing a part, however why would exporting via ISM work but not normal LAMS format?

Posted by Lachlan Hockings

By: Ernie Ghiglione

[ Reply | Forward ]

Lachlan,

On the sysadmin menu, go to the Edit configuration settings and see what are the directories you have set up for:

* Temporary Files Directory
* Content Repository Directory
* Flash Dump Files Directory

See if these directories exist in the file system and if the user you are using to run LAMS has write permissions on them.

Thanks,

Ernie

Posted by Ernie Ghiglione

By: Lachlan Hockings

[ Reply | Forward ]

Ernie,

These directories exist and have correct permissions. I don't understand why we can export in one format but not the other.

Anything else we can try?

Posted by Lachlan Hockings

By: Ernie Ghiglione

[ Reply | Forward ]

Hmmm...

Can you from the shell ping or resolve the learning.xavierllandilo.catholic.edu.au domain?

Ernie

Posted by Ernie Ghiglione

By: Lachlan Hockings

[ Reply | Forward ]

Ernie,

Yes we can.

I should point out however that our server is not directly connected to the web, it's traffic is routed through a central server at another location, so when you browse to learning.xavierllandilo.catholic.edu.au the request is then redirected to our internal server IP.

Sounds like that could be an issue?

Posted by Lachlan Hockings

By: Ernie Ghiglione

[ Reply | Forward ]

Hi Lachlan,

Yes, I'm pretty certain that would be the issue.

Is this just port forwarding or a proxy?

If this is a proxy, have a look at this options you can set in run.conf:

http://info4tech.wordpress.com/2007/05/04/java-http-proxy-settings/

Thanks,

Ernie

Posted by Ernie Ghiglione

By: Lachlan Hockings

[ Reply | Forward ]

That did it!

Thanks for all your help Ernie, exporting now works.
I added
JAVA_OPTS="-Dhttp.proxyHost=ourproxyip ..."

to our run.conf and it fixed our issue.

Thanks again.

Posted by Lachlan Hockings