Newest java Questions

Q&A for system and network administrators

Jetty Crashes After Let's Encrypt Certificate Import

I'm using an application that comes bundled with Java 1.8.0_77-b03 and Jetty 9.3.3.v20150827. Everything works great until I import my Let's Encrypt certificate into the Jetty JKS. Once I do that, ...

Adding IPv6 support in Client-server application. Is it common to have IPv4 stack disabled at OS level in “Pure IPv6” production servers?

OS in considerations : Windows Server 2008+ We are adding IPv6 support in a complex client-server network application. Server opens many ports for listening, and different types of clients connect ...

Tomcat 8.5 can't load @WebServlet annotations

I want to transfer my web application from tomcat7 / java7 to tomcat 8.5 / java8. My application consists of a directory with some JSP files & WEB-INF folder which contains my application's web....

Which type of server do I need for my Java application to run a couple of thousand times daily? [duplicate]

I'm very new to this so please keep that in mind. :) I have a Java application (a simulator) that uses almost 50% of my CPU. This is when I run the program in the most efficient way. It takes about ...

Can't access jboss remotely despite of proper binding of IP address in standalone.xml file

I am using JBOSS EAP 7. I start it using the command sh standalone.sh -b 0.0.0.0 Following is my IP config when not binding explicitly from command line. <interfaces> <interface ...

WebLogic T3 protocol in OSI model and it's relation to HTTP?

I'd like to figure out which level of osi model is represented by WebLogic Server T3 protocol and it's relationship to http protocol (one is build over another; one is used instead of another...) ...

PHP and JAVA ec2 configuration guideline [duplicate]

We are group of people who deploy the application on PHP and JAVA. Before this, we have faced many issues related to security. For example, we keep uploading files through WinSCP which need 755 ...

Jasper login page not loading

I'm wondering whether something needs to be in user tomcat's environment. I'm not going to run tomcat as root. BTW, does anyone use the installer or is everyone just downloading the war file and ...

Does anyone know how to scan through a Java Keystore and remove all the expired certificates?

I have in the past made a list of all the alias's that were expired and then made a forloop in CMD to then go through and remove all of them but I was wondering if anyone knew of a perl script or ...

Cassandra tmpdir change location

Cassandra is failing to start if /tmp is set as noexec, which is pretty much default these days: java.lang.NoClassDefFoundError: Could not initialize class com.sun.jna.Native at org.apache....

Logstash multiline codec for Java stacktraces

The logstash documentation indicates that you can collapse the multiple indented lines in a Java stacktrace log entry into a single event using the multiline codec: https://www.elastic.co/guide/en/...

Could not find or load main class org.apache.catalina.util.ServerInfo

I am about to install OpenEMM on Ubuntu 16.04 and have installed previously successfully on Ubuntu 14.04. Now I am facing the problem, that somehow OpenEMM can not see tomcat running. I followed the ...

How to improve availability of a old legacy java application in AWS

I have a old java application running on an AWS EC2 but a couple of times per week the application is very slow or down and I have to restart the system which is very bad for our clients. It's an old ...

IBM WebSphere SDK Java Technology Edition Version 8.0 for Liberty install error using IBM Installation Manager on CentOS6.8

The "packages" in the error below means that result of ./imcl listInstalledPackagescommand? If the question above is correct, I should install one of liberty package using "IIM" right? ERROR that ...

Unable to connect to MySQL Cluster with ClusterJ

Database server machine MySQL cluster is installed on single machine. On database server I have created user: mysqlcluster. This user does not have admin privileges. I have downloaded generic Linux ...

Can swapped memory be read directly by java?

When the kernel swaps stuff to disk, can this data be subsequently read by the process directly from swap? or it must absolutely be put back into physical ram (thus generating si so activity in vmstat)...

ERR_CONNECTION_TIMED_OUT after setting up a load balancer on Amazon Web Services

I have a site set up on AWS using Spring Boot on port 5000. I was able to connect to the site fine using HTTP only. I want to set up HTTPS using Amazon's Certificate Manager to deploy an SSL ...

How to fix java.lang.ClassNotFoundException: solr.VelocityResponseWriter?

I am trying to get Solr 3.6.2 example to work but there seem to be an issue with velocity library not found FROM java:7-alpine ENV SOLR_VERSION=3.6.2 ENV SOLR=apache-solr-$SOLR_VERSION RUN mkdir /opt ...

Can GlassFish or Payara be configured to specify server preferred order of cipher suites?

I would like to prioritize cipher suites so I can implement perfect forward secrecy. I am not sure if this is feasible in GlassFish or Payara. We are currently running Payara Server 4.1.1.154.

Why can't I get JMX to run with Tomcat8 through CATALINA_OPTS?

According to https://tomcat.apache.org/tomcat-8.0-doc/monitoring.html#Introduction I should be able to active JMX by setting some env variables on CATALINA_OPTS. I've done this: export CATALINA_OPTS="...

How to start java application on boot

I have a server with Centos 6. I've installed an configured everything so my server application runs smoothly, however if there is any unexpected reboots I have to manually start an SSH session and ...

Shibboleth Could not locate Java.exe Please check the value for JAVA_HOME [closed]

I am trying to install Shibboleth for development on my local copy of windows 10. I am on the first step and stuck. After downloading the shibboleth identity provider I am not able to install as I ...

Jboss EAP 6.2 AvailableCount in connection pool decresing

1.We have a J2EE application using Servlets & JSPs running on Jboss EAP-6.2, and using SQL server database. 2.Everything was fine on UAT system where users count was 20 but when we moved the same ...

nginx proxy pass removing header SM_USER from java spring rest client request

We are using nginx as a proxy for a java application (both in docker containers, but that's probably not relevant). When we try to reach the java application via a rest client a specific header, ...

Correct directory for my own jar applications, and their configuration

I coded a Java application (in this case an Apache Camel application) that I package as a jar file. It's an executable program (not a library). I am wondering where is the appropriate place for such ...

Protect my database password from developers

We have an application that uses a database at my workplace. Currently, it's using a username password to authenticate (though we could use trusted IPs connections). We don't want to use trust because ...

How to disable JRE upgrade popups?

We have a business need to freeze our Windows 7 user desktops at JRE 8.66. I'd like to disable this popup from happening: I've already tried removing the Java updated from startup, and adding the ...

Execute JSP files in IIS7 and Tomcat6

I want to execute JSP files in on Windows Server having IIS7, Tomcat6 and Java 1.6 installed. Already Installed: Java 1.6 IIS7 Tomcat6 BonCode Apache Tomcat AJP 1.3 Connector Current scenario: I am ...

Authorization required to install jzos batch launcher

We are trying to install the JZOS Batch Launcher. The function consists of three pieces: a load module that must be put into a z/OS PDSE, a sample start proc that can be tailored and put into an ...

Cannot install openjdk-8-jre-headless on Debian Jessie

This Friday I saw that I had 2 held back packages for some reason when I ran apt-get upgrade, so naturally I did what any inexperienced sysadmin would do and uninstalled the packages in the hopes that ...

How to restart java app managed by systemd on OutOfMemory errors

I have the java app (on top of Spring Boot framework) installed as systemd service. [Unit] Description=${module_name}-service Requires=network.target After=syslog.target [Service] User=${user_name} ...

How can I check if my ElasticSearch process is using compressed oops?

I'd like to figure out if I need to tune my currently-running ElasticSearch cluster. How do I check if a running HotSpot process is using compressed oops or not?

Java cacerts file source

Bit of a random question - our enterprise uses a bunch of internal certificate authorities. As a result, we have automation in place to automatically add these CAs to both the default linux cacerts ...

Why won't my keystore type change?

I created a PKCS12 keystore with the command below: openssl pkcs12 -export -in fullchain.pem -inkey privkey.pem -out example.cert -name test I was getting certificate_unknown errors since I renewed ...

IPMI:ProLiant DL320e Gen8 Server, ILO4 IPMI Over lan testing Verax System's IPMI Java Library

I'm testing IPMI Using Verax System's IPMI Java Library. Server model is ProLiant DL320e Gen8 Server and ILO4 in lib, there is a method which name is getAvailableCipherSuites and this do not work, ...

Deploy Java app to Azure over https behind proxy

New to Azure, I'm looking for a good way of deploying our apps. The situation is that we build our Java apps inside our network using Jenkins. Each successful build should be automatically published ...

Why multiple instances on single server is better than single intance on single server?

Want to understand why cluster with multiple instances on single server is better than single instance on single server. Assuming linux server with 16GB RAM and for java application.

Jenkins Master with High CPU Usage

I have a Jenkins master that takes around 600% of CPU usage. It causes load average of 50 and makes Jenkins crash several times. I tried to remove several plugins and clean the workspace in order to ...

Importing Solr Cores from one old Solr to another

I have old version of Solr on one server. i have 4 Cores in it. I have installed new fresh solr on new server. I have physically moved the old core directories as well, to new server Cores directory, ...

WAS not processing request hence web are not available

I'm newbie for supporting WAS(Websphere Application Server), currently I'm having issue with my WAS, my WAS was installed under AIX under 2 servers/nodes. While investigating it, I found in our ...

Session issue on Load balancing URL Apache Web Server + Tomcat 7.0.54

I'm facing the session issue on the load balancing URL, the session is not getting created but it works fine when I use the Tomcat URL directly. Controller: @RequestMapping(value = "/...

Can't start tomcat as service in redhat

I'm new to Linux but having spent a whole day I Installed Java and Tomcat. My goal is to host an App with this Linux box. I know it all works fine from my windows based machine, but it is my laptop so ...

Keytool frequently uses up all server resources

On our RHEL servers, keytool now and then eats up all available resources. This seems independent on the Java version. PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command 14103 root 20 ...

Solaris Nags About “process.max-stack-size” while running “Java Processes”

I have a server running Solaris 10. It reports using 10% of total memory using prstat. I 've ran process using Java 1.7.0_80 in 64-bit mode. The problem is that System always nags about process.max-...

how to allow one specific application to access command-prompt?

is there a workaround to allow only one specific application to access command prompt (java application) in a disabled command prompt active directory environment without enabling command prompt for ...

Mobicents Tomcat Servlet - /bin/java: No such file or directory /usr/java/jdk1.8.0_60/jre

I'm trying to run an instance of Mobicents with Tomcat embedded (on a Redhat 7 64bit machine) but I'm running into a startup issue. Whenever I run the /bin/startup.sh file of mobicents it fails to ...

Glassfish 4.1 How to change URL for webservice WSDL and Tester

I am using GlassFish 4.1 as my development Java EE server for a simple webservice. Everything works fine except GlassFish is using server name in links on the "Web Service Test Links" and "View WSDL" ...

How-to monitor keep-alive usage in Tomcat 8?

it seems that the Access Log Valve(s) of Tomcat do not allow the equivalent of LogFormat %k of Apache. How can I detect in running production which clients are using HTTP Keep-Alive requests and ...

Java OpenCV failure results in AWS Maxed ReadOps

I am using AWS to host some pretty heavy computer vision processing and have run into a problem that is very hard to diagnose. The image processing infrastructure is configured as a worker instance ...

TOMCAT : SPNEGO CONFIGURATION ERROR

I have troubles with SPNEGO TOMCAT 7 configuration: I follow this guide for setup: spnego-tomcat-config Here is my krb5.conf [libdefaults] default_realm=lctr.corp default_keytab_name="C:/tomcat/...
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