Comments on: Solving Common ELB Problems with a Sanity Test

By: shlomo

shlomo — Sun, 03 Oct 2010 00:18:57 +0000

@Raj,

Thanks for reporting this. I’ve created Issue 2 for this issue, and I fixed the problem and uploaded a new jar.

Please try again.

By: Raj

Raj — Tue, 28 Sep 2010 19:43:17 +0000

I am getting the NoClassDefFoundError error. can you help please?

./elb-sanity-test
JUnit version 4.5
.E
Time: 0.003
There was 1 failure:
1) initializationError(shlomo.ec2.elb.ELBSanityTest)
java.lang.NoClassDefFoundError: com/xerox/amazonws/ec2/EC2Exception
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
at java.lang.Class.getMethod0(Class.java:2670)
at java.lang.Class.getMethod(Class.java:1603)
at org.junit.internal.builders.SuiteMethodBuilder.hasSuiteMethod(SuiteMethodBuilder.java:20)
at org.junit.internal.builders.SuiteMethodBuilder.runnerForClass(SuiteMethodBuilder.java:13)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:29)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
at org.junit.runners.model.RunnerBuilder.runners(RunnerBuilder.java:93)
at org.junit.runners.model.RunnerBuilder.runners(RunnerBuilder.java:84)
at org.junit.runners.Suite.(Suite.java:66)
at org.junit.runner.Request.classes(Request.java:68)
at org.junit.runner.JUnitCore.run(JUnitCore.java:107)
at org.junit.runner.JUnitCore.runMain(JUnitCore.java:88)
at org.junit.runner.JUnitCore.runMainAndExit(JUnitCore.java:54)
at org.junit.runner.JUnitCore.main(JUnitCore.java:46)
Caused by: java.lang.ClassNotFoundException: com.xerox.amazonws.ec2.EC2Exception
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
… 17 more

FAILURES!!!
Tests run: 1, Failures: 1

By: shlomo

shlomo — Thu, 24 Dec 2009 05:27:22 +0000

@Logan Green,

There's no API to modify the listeners of an ELB. So you'll need to create a new ELB with both HTTP:80 and TCP:443 listeners specified at creation time.

By: Logan Green

Logan Green — Thu, 24 Dec 2009 05:17:51 +0000

Is it possible to edit a load balancer to forward additional ports? For example we launched our aws ELB forwarding port 80, and now we want to add https support and forward 443 as well. Do I need to create a new ELB or can I edit my existing one?

By: Prabhakar

Prabhakar — Tue, 15 Sep 2009 22:15:43 +0000

Excellent post! Very useful tips on what to look for while debugging ELBs. We just integrated this approach into our management UI – http://vimeo.com/6592989

thanks!

By: Ken

Ken — Tue, 15 Sep 2009 20:58:33 +0000

Very useful post! I just saw that Ylastic integrated your sanity check approach into their dashboard. Nice!

I wanted to share a problem I had recently. Because of some current ELB issues, it is possible to cause an ELB to get into an inconsistent state by terminating one of its instances without first deregistering it from the ELB. See the thread Mysterious "server=0" content returned by ELB on the AWS forums.

Also, if you are trying to read client IP addresses on a server behind an ELB, see my blog post: Amazon ELB - Capturing Client IP Address