Linux/ Centos7/ Tech Info

Problem: If we deploy our application (*.war) on a customer's infrastructure, all texts in graphs are broken. The very same montioring of the application works when deployed in our local infrastructure. All "plain" texts are rendered corretly. Only graphs are affected The problem seems to be environment specific I've no clue what we need to do/install/change on the customers environment to be able to have proper texts in graphs again. When we first installed the application the graphs worked. Our customers administrators have updated the system / installed patches since then but cannot tell what they've done exactly. I've never seen java melody showing broken graphs before. Broken Dashboard: Betriebssystem: | Linux, 3.10.0-693.2.2.el7.x86_64 , amd64/64 (16 Kerne) Java: | Java(TM) SE Runtime Environment, 1.8.0_111-b14 JVM: | Java HotSpot(TM) 64-Bit Server VM, 25.111-b14, mixed mode Server: | Apache Tomcat/8.0.36 Same Application works fine i...

 How To Share Data Between the Docker Container and the Host Introduction In general, Docker containers are ephemeral, running just as long as it takes for the command issued in the container to complete. By default, any data created inside the container is only available from within the container and only while the container is running. Docker volumes can be used to share files between a host system and the Docker container. For example, let's say you wanted to use the official Docker Nginx image and keep a permanent copy of Nginx's log files to analyze later. By default, the  nginx  Docker image will log to the  /var/log/nginx  directory  inside  the Docker Nginx container. Normally it's not reachable from the host filesystem. In this tutorial, we'll explore how to make data from inside the container accessible on the host machine. Prerequisites To follow this article, you will need an Ubuntu 18.04 server with the following: A no...

How to Add a Static TCP/IP Route to the Windows Routing Table In some specific types of environments, you might find it useful to add a static route to the routing table in Windows. Here’s how to go about it. RELATED:   How to Use Traceroute to Identify Network Problems A routing table dictates where all packets go when they leave a system—whether that system is a physical router or a PC. Most routers—including the one built into your Windows PC—use some form of dynamic routing, where the router is capable of selecting the best place to forward packets based on information it gets from other routers. You can see it at work if you use the  traceroute command  to watch the connections a packet makes as it reaches it’s final destination. Most routers also allow you to add a static route (one that doesn’t get dynamically updated) if you want to always forward certain traffic to a specific router or gateway. Why? Well, most people using Windows in t...

Understanding the dm-multipath Configuration file /etc/multipath.conf The main configuration file for DM-Multipath is  /etc/multipath.conf . This file is not created by the initial installation of the RPM package. However, the following file is installed in the  /usr/share/doc/device-mapper-multipath-[version]  directory: multipath.conf  – Basic configuration file with some examples for DM-Multipath. This file is used to create the /etc/multipath.conf file. Sample /etc/multipath.conf file The multipath.conf file contains the following sections, and each section contains one or more attributes or subsections. Section Description defaults Defines the default settings for DM-Multipath. These settings can be overwritten by the devices and multipaths sections. blacklist Defines the devices to be excluded from the multipath topology discovery. Devices that are blacklisted are not grouped into a multipath device. blacklist_exceptions Defines the devices to ...

Enabling File format for upload at ROCKET CHAT application/msword   - for .doc application/vnd.openxmlformats-officedocument.wordprocessingml.document   - for .docx application/vnd.ms-excel   - for xls application/vnd.openxmlformats-officedocument.spreadsheetml.sheet   - for .xlsx application/vnd.ms-powerpoint   - for .ppt application/vnd.openxmlformats-officedocument.presentationml.presentation   - for .pptx image/*,audio/*,video/*,application/zip,application/x-rar-compressed,application/pdf,text/plain,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document,application/vnd.ms-excel,application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

Increase disk size for an EC2 instance in AWS While using Amazon Web Services (AWS) you may find that, when using one of the Amazon Machine Images (AMIs) provided, you may run out of disk space. There does not appear to be any way to “resize” an Elastic Block Store (EBS) volume; however, you can create a new one based on an existing snapshot and replace the current drive with a larger one. I have provided the instructions for doing so below. Log into the AWS Management Console Make sure that the Instance that you wish to change is not currently running Navigate to Elastic Block Store > Volumes Check the box next to the Volume that needs more space Click the More… drop down list and select Create Snapshot Enter a Name and a Description Navigate to Elastic Block Store > Snapshots Monitor the progress of the Snapshot for completion Once complete, navigate back to Elastic Block Store > Volumes Click Create Volume Enter the desired size for the ne...

RHEL / Centos Linux 7: Change and Set Hostname Command last updated  January 6, 2018   in  Categories CentOS ,  Linux ,  RedHat and Friends I ‘m a new RHEL (Red Hat Linux) and/or CentOS Linux 7 server user. How can I change the hostname in CentOS 7 using a command line option? On a CentOS Linux 7 server you can use any one of the following tool to manage hostnames:[donotprint][/donotprint] hostnamectl command  : Control the system hostname. This is recommended method. nmtui command  : Control the system hostname using text user interface (TUI). nmcli command  : Control the system hostname using CLI part of NetworkManager. Types of hostnames The hostname can be configured as follows Static host name  assigned by sysadmin. For example, “server1”, “wwwbox2”, or “server42.cyberciti.biz”. Transient/dynamic host name  assigned by DHCP or mDNS server at run time. Pretty host name  assigned by sysadmin/end-users and...