Issue using Wildfly 9.02 - Help Requested

[verbixlp]

Hi,

we have an issue using Wildfly 9.02. I write you for any suggestion on
this issue.

Our application is based on EJB call and it’s composed by two modules;
one is a web application an the other one is a java web start application.

Actual configuration below:

• Linux Redhat 7.3
• Wildfly 9.02
• Java 1.7
• EJB 3.2
• Postgresql 9.2
• Hibernate 4 with annotation
• 12 Cpu
• 16 Gb of memory for the JVM

The application is used to perform quiz exams; the actors are the
examiner and the candidates; every 30 seconds the candidate application saves
the given answers.

The examiner

In the situation of 80 consecutive candidates who complete the examinations the
system collapses.



This application has been migrated from an environment where it is regularly
run with 1 Gb of memory. Below is the previous configuration

• Linux Redhat 5.11
• JBoss 4.2.3
• Java 1.5
• EJB 1.0
• Postgresql 9.2
• Hibernate 2
• 8 cpu
• 1 Gb of memory for the JVM

Waiting for your kind answer, best regards

Thanks in advance for help.

[claudio4j]

Hi, we are happy to help you if you provide full error messages. There are lots of scenarios why your system is going down, it may be the application, database, configurations, etc.

[verbixlp]

Hi Claudio,
I am collecting the information you need.
I will send you as soon as possible.
Thank you
With best regards

[verbixlp]

Hi Claudio,
yesterday we did a simulation with 1 candidate only through the creation of a java program (EjbTest.java, Runner.java), which performs the same calls that are made while conducting a real exam.
I therefore attach the following files:

EjbTest.java, Runner.java
standalone.conf
standalone.xml
threaddump-1507744868934.tdump
server.log.20171011-part

This test was carried out in a test environment whose configuration is that reported in the attached files.
With this configuration if we try to test with 5 candidates the system collapses.

In the Exercise environment we notice an excessive amount of memory compared to the old application server. I mean that in the same situation as 80 contemporary candidates, the old application server uses 1 Gb of memory, the new 12 Gb.
This is in the Exercise configuration.

We also notice an excessive compilation activity by the application server.
Do you feel normal? We do not have any evidence in the old system.

It seems that already during the launch of 1 candidate the system allocates a lot of memory.
The data required is not excessive during the exam.
The candidate saves 1 string of few bytes, which contains the given answers.
Clearly to do this, the candidate calls an EJB.

I hope you can help us in identifying the problem.
We are at your complete disposal if you need further information.
Even if we have to make tests that you will find fit to analyze the problem.

Thank you very much for your availability.

Best regards

Luigi