heartbeat listener

Listener I understand him this way, he is the realization of an observer pattern: When we configure Listener in Web. XML, it is the observer queue that puts an observer into the viewer, and the observer responds accordingly when the observed person triggers the registration event. The specific implementation in Jsp/servlet is to register Listener in Web. XML, whi

Listener (22 web basic learning notes) and listener learning notes1. Listener A listener is an object that is used to listen for and process events or state changes on other objects. When the Monitored Objects occur, they take corresponding actions immediately. The listener

Provide Zstack communityContent IntroductionHeartbeat is an open source program that delivers cluster infrastructure capacity-including cluster members and messaging-to client servers. Hearbeat plays a key role in the High Availability server infrastructure. We often need to combine heartbeat with cluster resource managers such as pacemaker (CRM) to achieve full high availability settings. In today's tutorial, however, we will demonstrate how to easil

Recently, colleagues have reflected that in the process of monitoring the master-slave replication delay using pt-heartbeat, if master down, Pt-heartbeat will fail to connect, but will try again. It's understandable, after all, from the user's point of view, I hope pt-heartbeat can keep retrying until you reconnect to the database. However, they found that repea

The HA cluster model is as follows: the external vip address is 192.168.2.1, the active web host name node1 and the backup web host name node2. when the master web is dead, the web page in the backup status changes to the master status immediately. To achieve high availability. (Ignore storage) Node1 Configuration 1. Configure host name and IP address 2. Edit the hosts file so that the master and slave nodes can parse each other. 192.168.2.100 node1.server1.com 192.168.2.200 node2.server2.c

Centos + heartbeat + mysql configuration 1: install two linux (rh4.5-32-bit) systems and disable the firewall. selinux is set to disable, and two NICs are required for each computer. The two computers are node1 and node2www. 2cto. the IP addresses of comnode1 are :----... centos + heartbeat + mysql configuration 1: install two linux (rh4.5-32-bit) systems and disable the firewall. selinux is set to disable,

://mirrors.zju.edu.cn/epel/6/i386/epel-release-6-8.noarch.rpm# Yum Install heartbeat cluster-glue resource-agents pacemaker httpd3, Node1 configuration Heartbeat# Copy config file to/etc/ha.d/# cp-p/usr/share/doc/heartbeat-3.0.4/{ha.cf,authkeys,haresources}/etc/ha.d/# Configure generate Communication key# OpenSSL Rand-base64 20Trli5dr/yhoe59kj4yyognpvmdi=# Vim/et

Environment Description: This environment consists of two MySQL databases and heartbeat, one IPFor 192.168.10.197, one for 192.168.10.198, external service VIPTo 192.168.10.200Note: Heartbeat itself is not able to do services can not be automatically switched, so with the combinationAdditional scripts are available, the Moniter script mentioned in this article is to implement aWhen the MySQL service is not

Tags: hostInstallation environment: Centos 6.4, Httpd2.4,mysql5.5,heartbeat v2 Two machines Node1 and Node2 are provided, name resolution is added to the/etc/hosts file, and the host name is the same as the node name, that is, the name of the uname-n must be the same as the name defined by the hosts. # IP HOSTNAME ALIAS 10.204.80.79 node1.mylinux.com Node1 10.204.80.80 node2.mylinux.com Node2 Establish SSH trust between the two servers #ssh-kegen–t rs

listeners use more in javaweb development, and the following is a common application of the Listener (Listener) in developmentI. Statistics of the current number of people onlineIn Javaweb application development, sometimes we need to count the number of users currently online, so we can use listener technology to implement this feature. 1 package Me.gacl.web.lis

Servlet Listener: A special class defined in the servlet specification that listens for creation and destruction events for domain objects such as ServletContext, HttpSession, and ServletRequest in Web applications. and listening for events in which the properties in these domain objects have been modified.Serveltcontextlistener interface: It is used to listen for ServletContext object creation and destruction events.When the ServletContext object is

I. Deployment environment: Server version: centos6.5 Active/standby mode: VIP: 192.168.3.30 (on the master) VIP: 192.168.3.32 (on backup) Host network parameters: Interface Master Backup Description Eth1 192.168.3.23 192.168.3.24 Intranet management IP Address Eth2 192.168.5.23 192.168.5.24 Heartbeat line Eth3 192.168.2.23 192.168.2.24 Internet (for temporary file download)

Listener Listener Preface: wrote an article about filter: http://tianweili.github.io/blog/2015/01/26/java-filter/, now another listener, Filter and listener are often used in projects, and clever use can achieve a multiplier effect. So summarize the usage of the two. Original link: http://tianweili.github.io/blog/2015

After the client is connected to the server, what will happen next? What should I do if the connection is closed? I do not need to reconnect. How can I know that the other party is alive? What is the impact of force disconnection on the other? Next, answer the following questions one by one. [Client] Reconnect task: if the session is closed, you can try to reconnect the task, for example, increasing the number of reconnection tasks. The specific connection process is no different from

Listener is a servlet listener that can listen to client requests and server operations. Procedure for defining the listener class 1) To make a Class A listener class, you must implement the listener interface and interface implementation methods, Common listening interface

Tags: sharing DRBD resourcesFirst, the reason analysis1, the current structure analysis diagram:650) this.width=650; "Src=" Http://s3.51cto.com/wyfs02/M02/89/B5/wKioL1gasQ6i4sKMAAU4ouVcKQE537.png-wh_500x0-wm_3 -wmp_4-s_2563946043.png "title=" Dd1.png "alt=" Wkiol1gasq6i4skmaau4ouvckqe537.png-wh_50 "/>2. Cause analysisBecause the platform business network is not stable, the heartbeat of DRBD points to the Gateway guide, in the network problems caused b

Host Planning:The highly available server installs the V2 version of Heartbeat, while the two nodes are installed with MySQL, the runtime only one node can run MySQL, the other node is standby, and the backend has an NFS shared storage, which provides a shared directory for storing data for the database.The IP address is set to:ha1:172.16.103.1ha2:172.16.103.2nfs:172.16.103.3Experimental process:First, prepare Server for NFS# mkdir-pv/nfs/shared# Grou

CentOS6.6 install heartbeat for High Availability I recently learned about the High Availability Technology in linux under the guidance of a teacher, using the heartbeat software to achieve high availability of Server clusters. Below I will record the problems and some personal opinions I encountered during my studies and tests, for the reference of the majority of bloggers. My level may not be enough. Plea

Centos + heartbeat + mysql configuration 1: install two linux (rh4.5-32-bit) systems and disable the firewall. selinux is set to disable, and two NICs are required for each computer. The IP addresses of node1 and node2 www.2cto.com node1 on the two computers are respectively: -------------------------------- eth0: 192.168.18.33 eth1: 10.0.0.3 (Heartbeat address) and node2 respectively: ---------------------

Heartbeat error: attempted replay attack, heartbeatattempted Two lvs servers are configured for heartbeat hot backup. However, an error is reported after the configuration is started: Jan 28 15:50:22 usvr-211 heartbeat: [2266]: ERROR: should_drop_message: attempted replay attack [usvr-210]? [Gen = 1418354318, curgen = 1418354319]Jan 28 15:50:24 usvr-211