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Questions tagged [high-availability]

High availability is an architectural consideration often involving degrees of redundancy to insure availability in case of system or component failure.

High availability is an architectural consideration often involving degrees of redundancy to insure availability in case of system or component failure. Highly available systems are commonly implemented in situations where the risk outweighs the cost.

Best practices such as change control, standardized procedures, and monitoring can also enable high availability.

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How to health check Squid server with ELB?

I wanted to have an HA forward proxy solution using Squid, and I am trying to use the Squid servers behind ELB solution on page 41. However, my forward proxy service is a service meant to forwarding traffic to an internal network (back to my corp…
chen
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"live" mirror of HA VM cluster?

I'm reading about HA techniques in virtualization but all solutions I see work more or less just like more specialized VRRP - when host gets down, VM is booted up on another virtualization host. If storage is shared (eg. iSCSI) then "the same" VM…
Lapsio
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How to suppress a Heartbeat resource from starting in failover data center?

I have a pair of CentOS Linux servers in each datacenter. They have failover within each datacenter, managed by heartbeat and DRBD (I know these are outdated tools, but they are stable, so there's no desire to change them). They also have the…
Bill Karwin
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Complete High Availability System

I'm in the process of configuring a LAMP server but want to make sure it'll be ready for expansion for the future. Here's my current setup.. Two physical windows servers clustered with Hyper-V Two virtual machines, one for Apache and another for…
royjr
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Is it possible to look up distances between AWS data centers?

My company is negotiating with a customer who has requirements for a minimum distance between data centers. Namely they require redundant storage in data centers more than 3 km apart. Is it possible to ensure this by using two different AZs in one…
EagleBeak
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What is the definition of High Availability?

As far as my understanding goes the availability of a service or system is defined as: (Time resource was available - Time resource was unavailable) / Total Time My questions are: Is describing a system/service as "Highly Available" a standard…
Aditya K
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POST of large file is timing out, when running through ARR

When POST'ing a large file through ARR, the request times out after 120 seconds. The client recieves error code 502 Bad Gateway. I have configured the "proxy timeout" of the web farm to be 600 seconds. I have also configured the Connection time-out…
Thomas M. H.
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Replicating a linux web server

I'm planning on replicating a web server for high availability purposes. The server is running as a Ubuntu 15.04 virtual machine in Hyper-V and has MariaDB 10.0, Apache 2.4 and PHP-FPM 5.6 installed. The 2nd virtual machine will start as a direct…
gijs007
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DRBD + corosync + pacemaker - Servers won't connect after failover

I got 2 servers configured with drbd, corosync with pacemaker. It is all working fine, primary server gets secondary if it fails, and secondary gets primary. But if the 1st server comes up again after the failover, drbd won't connect back again and…
Jockel
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VMware FT, App HA: What happens if vCenter Server is offline?

I am interested in the two features named "Fault Tolerance" and "App High Availability" which are part of some VMware products. As far as I understand the vCenter Server instance is needed to perform administrative tasks. Therefore, a crash of the…
C-Otto
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Should VMware HA Admission Control be enabled for small (2/3-host) clusters?

Take the following common scenario... A basic vSphere cluster running two or three hosts, shared storage and a token set of virtual machines under Essentials Plus or greater licensing. Should HA Admission Control be enabled on such a small setup?…
ewwhite
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VMware vSphere DRS affinity rules for more than 2 guests

I've received a request to add disaffinity/anti-affinity rules on a set of virtual machines in a VMware HA/DRS cluster running VMware vSphere 4.1. The client has four hosts and wants to keep certain virtual machines from running on the same host in…
ewwhite
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mount.ocfs2: Transport endpoint is not connected while mounting...?

I have replaced a dead node that was running in dual-primary mode with OCFS2. All the steps work: /proc/drbd version: 8.3.13 (api:88/proto:86-96) GIT-hash: 83ca112086600faacab2f157bc5a9324f7bd7f77 build by mockbuild@builder10.centos.org, 2012-05-07…
quanta
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How stable is the VMWare vCenter Server OVF and is there a better way to get HA features?

I am considering pruchasing Vsphere solely for the HA feature, however, in order to do this, I will also need vCenter Server. I am not keen on purchasing a copy of Windows especially for this and have seen the vSphere server OVF which is available…
wil
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Using LVS (Linux Virtual Server) for doing DNS HA

I have been trying to create an LVS DNS HA using CentOS 6.x: Piranha GUI to configure the DNS Pulse is the HA heart of CentOS LB IPTables to configure marks on the packets since DNS uses TCP and UDP 53 After several days, I find that I can not…
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