Java JRE 1.5.0 performance problems with Squid proxy

[broc]

We have a Linux based proxy server running Squid & Dansguardian. This was set up by our LEA support team.

 

During a recent image refresh of our classroom PCs we upgraded Jave.

 

Now we are experiencing major performance problems with Java JRE 1.5.0_6 compared to JRE 1.4.2 when students are accessing Samlearning.

 

Under JRE 1.5.0 The Java 'coffee cup' animation takes forever to load before the Java applet starts, however under 1.4.2 it is very quick.

 

I have been able to reproduce the problem accessing other websites that use Java which suggests it is not a problem unique to Samlearning.

 

Looking at the Java console, there are significant delays (7-9secs) following every 'network: Connecting http.....' request.

 

The problem exists using either IE6 or Firefox browsers. If I tell the browser to bypass the proxy JRE 1.5.0 is almost as fast as JRE 1.4.2.

 

To me, this points to a problem with the Proxy. Any ideas or suggestions on how to resolve this? Downgrading Java back to 1.4.2 would be a short term bypass, but would be a lot of work & would still leave us with the basic problem.

 

Brian

[CyberNerd]

I dont have direct experience of this yet, but i looked it up in anticipation that we'll have the same problem with JRE updates.

 

You should check with the proxy but without the firewall.

 

http://archlinux.org/pipermail/arch/2005-November/007409.html

http://forum.java.sun.com/thread.jspa?messageID=3980773

 

Apparently, the timeout is due to the fact, that the program first tries to use ipv6 instead of ipv4. If your local ipv6 policy is set to block all ipv6 traffic, the java program waits, until the connection is timed out, and the program falls back to ipv4.

[Snuffkins]

We use a linux proxy with squid, but without the firewall and it's fine for us. I've only upgraded a couple of machines so far to test it though, but there's no problems.

[duncane]

Now we are experiencing major performance problems with Java JRE 1.5.0_6 compared to JRE 1.4.2 when students are accessing Samlearning.

 

Under JRE 1.5.0 The Java 'coffee cup' animation takes forever to load before the Java applet starts...

 

Could I ask whether you resolved this issue? We're having a similar problem with samlearning.

 

I'm going to try running an applet from a file URL, and the same applet from my website - hopefully this should narrow down where the problem is likely to be. (Or at least give me enough evidence to say it isn't the JRE itself.)

 

Sixth day on the job... I'm liking it. People actually thank you for your help - I never got that in my last job

[Wildebeaste]

We've had problems with SamLearning through a proxy - this time using Censornet (squid/dansguardian). I just put it in the list to bypass the authentication and filtering and it's okay now - as much as it will ever be

 

It helps with all of these 'educational' sites just not to bother filtering. You'll just get a 'vacancy' sign flapping in the breeze if you talk to their support.

[broc]

Now we are experiencing major performance problems with Java JRE 1.5.0_6 compared to JRE 1.4.2 when students are accessing Samlearning.

 

Under JRE 1.5.0 The Java 'coffee cup' animation takes forever to load before the Java applet starts...

 

Could I ask whether you resolved this issue? We're having a similar problem with samlearning.

 

I'm going to try running an applet from a file URL, and the same applet from my website - hopefully this should narrow down where the problem is likely to be. (Or at least give me enough evidence to say it isn't the JRE itself.)

 

Sixth day on the job... I'm liking it. People actually thank you for your help - I never got that in my last job

 

We gave up eventually. Our Proxy was built & maintained by our LEA support team. They could reproduce the problem (it affected all Java access, including Samlearning) but they were unable to find a solution. After 9 months of reminding them I gave up & downgraded Java to 1.4.2 (during summer holidays) and the problem went away. We proved that bypassing the proxy for Java fixed the problem but that was not the solution we wanted.

[Ric_]

Have the subsequent releases of Java not helpe you.... JRE 1.5.9 is the latest IIRC.

[Geoff]

Can you give me an example of a site that runs slow? I'll have a tinker here with Java/squid.

[broc]

Try this

 

http://www.samlearning.com

 

then select GCSE from left hand side, then Maths, then Algebra free sample, followed by factorising start

 

With 1.4.2 we get a grey window opens, with Java coffee cup in top left corner, followed by the student problem displayed maybe 2-4 seconds later.

 

When we last tried this on 1.5.0 the kids were tearing mouse buttons off with frustration & boredom waiting for the problem to load. it took several minutes.

 

The problem existed with Firefox and IE6, if I recall correctly bypassing the proxy either in the Java console or at the browser level fixed the performance problem. Looking at the Java console it looked like every request sent to the proxy waits (times out?) and then gets a response. The time delay was very consistent (I think I timed it at something like 6-7 seconds even when there was no load after school).

[broc]

Have the subsequent releases of Java not helpe you.... JRE 1.5.9 is the latest IIRC.

 

I will try the latest version later today if I get a chance.

[Geoff]

Try this

 

http://www.samlearning.com

 

then select GCSE from left hand side, then Maths, then Algebra free sample, followed by factorising start

 

With 1.4.2 we get a grey window opens, with Java coffee cup in top left corner, followed by the student problem displayed maybe 2-4 seconds later.

 

When we last tried this on 1.5.0 the kids were tearing mouse buttons off with frustration & boredom waiting for the problem to load. it took several minutes.

 

The problem existed with Firefox and IE6, if I recall correctly bypassing the proxy either in the Java console or at the browser level fixed the performance problem. Looking at the Java console it looked like every request sent to the proxy waits (times out?) and then gets a response. The time delay was very consistent (I think I timed it at something like 6-7 seconds even when there was no load after school).

 

 

The Java application you mentioned is buggy. It uses the correct Java system calls to pull in some of it's class files but then appears to be hard coded to go direct for the rest. Which of course fails.

 

Here's the Squid log:

 

1165312580.181    289 127.0.0.1 TCP_MISS/200 16461 GET [url]http://www.samlearning.com/com/tpl/javastuff_p/DragDrop.class[/url] STMICHAELS\administrator DEFAULT_PARENT/proxy.lancsngfl.ac.uk application/octet-stream
1165312580.403    221 127.0.0.1 TCP_MISS/200 909 GET [url]http://www.samlearning.com/com/tpl/javastuff_p/HueFilter.class[/url] STMICHAELS\administrator DEFAULT_PARENT/proxy.lancsngfl.ac.uk application/octet-stream

 

Where you can see it's behaving. After these two class files are pulled down it hangs. Then in the console we get:

 

load: class ShowFile not found.

java.lang.ClassNotFoundException: ShowFile

at sun.applet.AppletClassLoader.findClass(Unknown Source)

at sun.plugin.security.PluginClassLoader.findClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadCode(Unknown Source)

at sun.applet.AppletPanel.createApplet(Unknown Source)

at sun.plugin.AppletViewer.createApplet(Unknown Source)

at sun.applet.AppletPanel.runLoader(Unknown Source)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)

Caused by: java.io.IOException: open HTTP connection failed.

at sun.applet.AppletClassLoader.getBytes(Unknown Source)

at sun.applet.AppletClassLoader.access$100(Unknown Source)

at sun.applet.AppletClassLoader$1.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

... 11 more

[Geoff]

ok, I've got this working now. I missed the other log entries before.

 

2006.12.5 9:32:29 administrator 10.81.104.16 [url]http://jdl.sun.com/webapps/getjava/BrowserRedirect?locale=en&host=www.java.com[/url]  GET 0 0  1 302 text/html itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:32:33 administrator 10.81.104.16 [url]http://sunglobal.112.2o7.net/b/ss/sunglobal,sunjava/1/G.5-PD-R/s91802383674092?[/url][AQB]&ndh=1&t=5/11/2006%209%3A32%3A32%202%200&pageName=javac%3ADownload%3AWindowsAuto%3AWin_DownloadLatest&ch=javac%3ADownload&events=event13&products=%3Benglish&h1=javac%3Ajavac%3ADownload&c2=javac%3A&c19=en_javac%3ADownload%3AWindowsAuto%3AWin_DownloadLatest&c20=Download_Help_Pages&c21=NoAds&pid=javac%3AHomepage&pidt=1&oid=http%3A//jdl.sun.com/webapps/getjava/BrowserRedirect%3Flocale%3Den%26host%3Dwww.java.com&ot=A&oi=91&g=http%3A//www.java.com/en/download/windows_ie.jsp&r=http%3A//www.java.com/en/&s=1024x768&c=32&j=1.3&v=Y&k=Y&bw=1024&bh=603&ct=lan&hp=N&[AQE]  GET 0 0  1 302 text/plain itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:32:36 administrator 10.81.104.16 [url]http://java.sun.com/update/1.5.0/jinstall-1_5_0_09-windows-i586-jc.cab[/url] *DENIED* Banned extension: .cab GET 0 0 Banned extension. 1 403 text/html itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:32:36 administrator 10.81.104.16 [url]http://javadl-esd.sun.com/update/1.5.0/jinstall-1_5_0_09-windows-i586-jc.cab[/url] *DENIED* Banned extension: .cab GET 0 0 Banned extension. 1 403 text/plain itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:33:36 administrator 10.81.104.16 [url]http://java.sun.com/update/1.5.0/jinstall-1_5_0_09-windows-i586-jc.cab[/url] *DENIED* Banned extension: .cab GET 0 0 Banned extension. 1 403 text/html itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:33:36 administrator 10.81.104.16 [url]http://javadl-esd.sun.com/update/1.5.0/jinstall-1_5_0_09-windows-i586-jc.cab[/url] *DENIED* Banned extension: .cab GET 0 0 Banned extension. 1 403 text/plain itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:33:40 administrator 10.81.104.16 [url]http://java.sun.com/update/1.5.0/1.5.0_09-b03.xml[/url]  GET 0 0  1 302 text/html itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:33:41 administrator 10.81.104.16 [url]http://jdl.sun.com/webapps/download/GetFile/1.5.0_09-b03/windows-i586//jre1.5.0_09.msi[/url] *DENIED* Banned extension: .msi GET 0 0 Banned extension. 1 403 text/html itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:33:42 administrator 10.81.104.16 [url]http://jdl.sun.com/webapps/download/AutoDL?BundleId=10752[/url]  GET 0 0  1 302 text/html itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:33:42 administrator 10.81.104.16 [url]http://sdlc1g.sun.com/servlet/BridgeServlet/main_products/SDLC//ESD28/JSCDL/jdk/1.5.0_09_b03/jre/jre1.5.0_09.msi?ActionId=verify&TicketId=c1h7Ow9GOekz%2Bw%3D%3D&TicketServerUrl=X6Z71ReeUlpCSwpDMklTkxnjO5ECxhgJGglUASUDBdNZvmDESZ4pAhgSQQZcAhjNUas%3D&GroupName=5PoE[/url]  GET 0 0  1 302 text/html itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk
2006.12.5 9:33:43 administrator 10.81.104.16 [url]http://sdlc-esd.sun.com/ESD28/JSCDL/jdk/1.5.0_09_b03/jre/jre1.5.0_09.msi?AuthParam=1165311342_96a1b64fc5ae5c857c1d2640b6526d84&TUrl=X6Z71ReeUlpCSwpDMklTkxnjO5ECxhgJGglUASUDBdNZvmDESZ4pAhgSQQZcAhjNUas=&TicketId=c1h7Ow9GOekz+w==&GroupName=JSC&BHost=sdlc1g.sun.com&FilePath=/ESD28/JSCDL/jdk/1.5.0_09_b03/jre/jre1.5.0_09.msi&File=jre1.5.0_09.msi[/url] *DENIED* Banned extension: .msi GET 0 0 Banned extension. 1 403 text/plain itsuitepc19.st-michaels-ce23.lancsngfl.ac.uk

 

It looks like that running the java app requires downloading of extra components from sun. My proxy disallows .cab and .msi file downloads. So I had to whitelist sun.com as an ok download site. As soon as I did that the applet sprung into life.

 

Does your proxy filter on filetype?

[duncane]

I'm going to try running an applet from a file URL, and the same applet from my website - hopefully this should narrow down where the problem is likely to be. (Or at least give me enough evidence to say it isn't the JRE itself.)

 

I've tried running a single class applet (to keep it simple) from a file, and from a website. The same applet runs almost instantaneously from the file, and takes about 6-7 seconds via the network and shows the halo'ed coffee-cup. The network isn't that slow

 

As soon as I did that the applet sprung into life.

 

When you say 'sprung into life', do you mean it worked, or it worked without any objectionable delay?

 

Cheers.

[Geoff]

When you say 'sprung into life', do you mean it worked, or it worked without any objectionable delay?

 

The page loaded instantly as it was cached. I then got a java logo and 'loading' bar. After about 3 sec I was in the java application.

[Inglebob]

With regard to the Samlearning problem;

 

We've installed jre 1.6 and tested it (all okay)

All IE 7 security looks okay, everthing allowed and the site trusted.

No firewall software or similar running.

 

When the samlearning site is loaded the console complains of the following:

 

java.lang.ClassFormatError: Incompatible magic value 218774632 in class file HueFilter

at java.lang.ClassLoader.defineClass1(Native Method)

at java.lang.ClassLoader.defineClass(Unknown Source)

at java.security.SecureClassLoader.defineClass(Unknown Source)

at sun.applet.AppletClassLoader.findClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClassInternal(Unknown Source)

at ShowFile.start(ShowFile.java:286)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)

 

This is the same no matter what exercise is loaded.

[Womble]

We are also having problems with Java and Sam Learning...

 

If we run the test on Java Tester - Home Page going through the proxy, the java applet tries to load...but after about 10seconds gives up and a red cross is displayed.

 

The actual java console displays the following...

 

Java Plug-in 1.6.0_05

Using JRE version 1.6.0_05 Java HotSpot™ Client VM

User home directory = C:\Documents and Settings\test123

 

 

----------------------------------------------------

c: clear console window

f: finalize objects on finalization queue

g: garbage collect

h: display this help message

l: dump classloader list

m: print memory usage

o: trigger logging

p: reload proxy configuration

q: hide console

r: reload policy configuration

s: dump system and deployment properties

t: dump thread list

v: dump thread stack

x: clear classloader cache

0-5: set trace level to

----------------------------------------------------

 

load: class JavaVersionDisplayApplet.class not found.

java.lang.ClassNotFoundException: JavaVersionDisplayApplet.class

at sun.applet.AppletClassLoader.findClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadCode(Unknown Source)

at sun.applet.AppletPanel.createApplet(Unknown Source)

at sun.plugin.AppletViewer.createApplet(Unknown Source)

at sun.applet.AppletPanel.runLoader(Unknown Source)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)

 

If we run the test on Java Tester - Home Page going out through the LEA, the java applet loads, and all is well....

 

Then if we change the IE proxy settings back to our proxy, everything works fine...

 

Log off, log back onto the machine, the problem restarts all over again...

 

Have looked at the settings on the proxy, there is nothing obvious on there...

 

Has anyone got any ideas what could be causing the problem? I'm running out of ideas...

[roty80]

We use a linux proxy with squid, but without the firewall and it's fine for us. I've only upgraded a couple of machines so far to test it though, but there's no problems.

 

Same here. On Samlearning.com it can take 2-3 minutes for the java applet to load, if at all (at which point the students are sick of waiting and have clicked refresh a dozen times and restarted their machines, which just makes it take longer). Tried IE6, IE7, Firefox, tried to set Java to go through our ADSL line instead and tried many different versions of Java without any improvement. When we removed the linux proxy Samlearning worked almost instantly with every version of Java we tried.

 

We are talking about getting a hardware firewall instead anyway as our network administrator prefers them, but it is still annoying the students and staff in the meantime.

[Geoff]

disabling requring ntlm auth for the sam learning site worked for me.

[bjohnny42]

I'm not a Linux user, or any of the software you mention but we've had terrible trouble with slow Java loads (Mostly WebJetadmin). The following worked for us and may be of some use.

 

Right click on Java icon in taskbar,

Open Control Panel,

General Tab,

Temporary File Settings,

Remove the tick on Keep Temporary Files on My Computer.

Close and restart your browser.

[mee]

With regard to the Samlearning problem;

 

java.lang.ClassFormatError: Incompatible magic value 218774632 in class file HueFilter

 

Hi All,

 

Apologies for resurrecting an old thread!

 

I was wondering if anyone found a solution to this? We have exactly the same issue here. Like most schools in Lincolnshire, we use the NetSweeper proxy - which is hosted at the LEA/NetLinc - so don't have local control other than to block/unblock websites etc. The problem occurs on all Java applets - even the test applet at java.com. If I use our old proxy (Symantec Web Security) which we still have installed but disabled, it works fine.

 

I've whitelisted samlearning.com/co.uk and sun.com and java.com incase Java is trying to 'phone home' - no joy. I've tried setting the proxy manually in Java Control Panel.

 

I know Java is working fine at a neighbouring school who also use NetSweeper.

 

Any ideas? Will be logging a call with Mouchel but don't hold out much hope!!

 

Thanks.