Linux

After the CentOS system is installed, it cannot be immediately used in the production environment. It usually needs to be optimized by our O & M personnel. Here are some basic optimization operations for Linux system installation. Note: This

If you have multiple SSH hosts that need to be managed, it is difficult to directly input 'ssh user @ ip' each time. Although we can [add it '~ /. Ssh/config'] [c] is in the configuration file, but you must manually edit it. [Storm] [s] makes this

Devstack is a set of scripts used to quickly deploy the openstack development environment for developers and configure the network environment. The entire process is scripted and one-click installation. It is also the preferred script for learning

Use the php script in cacti to query the disk usage of the database in mysql. Today, I first wrote a php script, but I haven't written it for a long time. It's so painful. Fortunately, we have finished six hours in history and hope it can be

I recently learned Java Network Programming and saw a simple example, but implemented a Web access function. Of course, it cannot be compared with Web servers such as Tomcat and Weblogic, however, it shows the implementation of the most basic Web

Hadoop configuration error Summary 1: INFO ipc. Client: Retrying connect to server: localhost/127.0.0.1: 12200. Already tried 0 time (s ). RunXimo @ Ubuntu :~ $ Hadoop fs-ls 14/01/08 22:01:41 INFO ipc. Client: Retrying connect to server: localhost/12

I. PrefaceII. Introduction to cronologIii. cronolog featuresIv. Installing cronologV. Use cronologVi. Summary of cronologNote: For CentOS 6.4 x86_64 and cronolog 1.6.2, download http://cronolog.org/download/index.html. I. PrefaceAs we all know, by

The DHCP server is suddenly needed for a small project today. Here is a brief introduction! I use CentOS as the DHCP server. First, you need to install DHCP through yum. This is very simple and will not be detailed here. After installation, run the

Before analyzing the consistency of HDFS, we must solve several problems of HDFS client behavior. 1. Why does HDFS not support simultaneous Writing of one file by multiple writers, that is, concurrent writing is not supported?First, let's talk about

When a Hadoop-common-2.2.0.jar package is introduced for secondary development, such as reading and writing HDFS files, the first run reports an error. Java. io. IOException: No FileSystem for scheme: hdfsAt org. apache. hadoop. fs. FileSystem.

I. Overview The Reverse Proxy method is to use a Proxy server to accept connection requests from the Internet and then forward the requests to the server on the internal network; return the result obtained from the server to the Client Requesting

ISCSI technology is a SCSI instruction set that is developed by IBM and used by hardware devices to run on the upper layer of the IP protocol, this command set allows you to run the SCSI protocol on an IP network so that it can select routes on high-

The scenario is as follows: OS: Ubuntu 12.04 LTS x86_64; Nagios version 3.2.3; Nagiosql version 3.2.0; Pnp4nagios version 0.6.13; Virtual Machine, quad-core, 1.5 memory; Mode: passive monitoring Number of monitored hosts: 169 Number of monitoring

To work with website tests, you have been frequently adding virtual hosts, namely cp, Configuration modification, and service restart!Fortunately, I wrote a script for adding a virtual host to Nginx, which is easy to add. It is much easier to add

I. Main Server Load balancer Technologies 1. Cisco Ethernet channel (network balancing) 2. WindowsNLB Technology 3. LinuxLVS Technology 4. Server Load balancer (Server Load balancer) such as F5) Ii. Redundancy Technology 1. CsicoHSRP Hot Backup

When oozie is used to manage mapreduce workflows for the first time, the following exception occurs: Java. io. IOException: Type mismatch in key from map: expected org. apache. Hadoop. io. LongWritable, recieved org. apache. hadoop. io. Text At org.

System: CentOS; this method can also be used in general Linux systems. Situation description: Today, the email server cannot send or receive emails, and the connection to the server cannot be enabled. At first, the df thought that the disk space

Network Structure Description:1 Nginx (front-end) + 2 tomcat (backend) Environment:Company intranet (network segment: 192.168.1.0/24), the server is also allocated Intranet ip: 192.168.1.4 (tentative); Two backend tomcat: 192.168.1.31/189The website

Use apt-cache search to find the required software package nameFor example:# Sudo apt-cache serach java6Openjdk-6-jdk-OpenJDK Development Kit (JDK)Openjdk-6-jre-OpenJDK Java runtime, using Hotspot JITOpenjdk-6-jre-headless-OpenJDK Java runtime,

Directory Nginx + uWSGI getting startedStartError TestSummaryReference StartMake sure that the software package is installed: Apt-get install uwsgi-plugin-python nginx brief introduction: Nginx is an http server, which is similar to apache, lighttpd,