In computing, failover is automatic switching to a redundant or standby computer server, system, or network upon the failure or abnormal termination of the previously active application, server, system, or network. Failover and switchover are essentially the same operation, except that failover is ...

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2
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0answers
530 views

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 ...
1
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0answers
161 views

Dell PowerConnect Link Aggregation Failover Failed

We are a small office with two Dell PowerConnect 5548 switches that, together, cover all of our servers and hosts. I had them connected using ports 47 and 48, which I placed in a LAG. Port 47 was ...
0
votes
1answer
440 views

How do I bond eth0 to failover to wlan0 after WAN connection loss?

I would like to have my monitoring box (Zenoss) notify me when the network upstream of me goes down without an actual link loss. I have had some issues with our CoLo's switches going down, but I ...
0
votes
2answers
66 views

What is optimal sql server cluster storage solution?

I have been assigned a project where sql server is running on a single server with single raid 1 volume. This setup has worked fine until hardware failure resulted in about a day worth of downtime ...
4
votes
2answers
144 views

Windows 2012 R2 Hyper-V cluster without shared hardware

I have several servers with local SATA/SAS RAID arrays. I would like to run there virtual machines with some level of automated failover - sync VM to secondary node in 1 minute interval and automated ...
1
vote
1answer
2k views

Redis/Sentinel cluster failover results in “failover-abort-not-elected master”

I have a 2 node Redis cluster set-up. [master] 192.168.56.102: Redis Master (:6379), Redis Slave (:6380), Sentinel(:26379), Sentinel#2(:26380) [rescue] 192.168.56.103: Redis Master (:6379), Redis ...
1
vote
1answer
429 views

Openvpn failover setup - Routing to clients with static ips

I have a setup with an openvpn server and many clients connected to it. All those clients have fixed ip addresses, derived from their certificate name. Behind the openvpn server, I have a management ...
0
votes
2answers
2k views

Windows Server Failover Clustering with two servers

I was going to create a Windows Server Failover Cluster, in order to set up MS SQL Server AlwaysOn Availability Groups. As a prerequisite of failover clustering, I've created and configured an ...
1
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1answer
1k views

“Applications and Services” is missing from Failover Cluster Manager

Microsoft instructions advise to use "Services and Applications" but it's missing from the Failover Cluster Manager. For example, the documentation for Test the Failover of a Clustered Service or ...
0
votes
0answers
2k views

Windows Failover Cluster - Create Cluster Wizard: error occurred while creating the cluster

I have 2 identical Windows Server 2008 R2 servers which I am trying to setup a failover cluster on. The "Validate a Configuration" passes, but the actual creation process produces an error: An error ...
3
votes
2answers
698 views

Best CNAME TTL strategy for fallover switching

I've recently been thinking about the TTL of our DNS. We have A records for our servers and then CNAME records for the customer facing names. The www.example.com CNAME points to server-01.example.com ...
3
votes
1answer
266 views

IPTABLES for multiple Public IP Addresses

Currently i have two servers Running Debian 7 with HA Active/Passive setup using Pacemaker and Corosync as follows: node1->IP->xx.xx.xx.1 node2->IP->xx.xx.xx.2 VIP(Floating IP) ...
3
votes
1answer
200 views

vSphere/ESX How to log migration event to guest Windows OS

On a vSphere/ESX environment, how to write (automated) migration events to the eventlog into the hosted Windows VM that has been migrated? So that the hosted OS is aware of the migration event, and ...
1
vote
0answers
108 views

No messages received on Queue after Failover in SQL Always On

We have an Application, which uses Service Broker to receive notifications from the SQL Server. The application works fine when we don’t have SQL Always On enabled, and when we are interacting with a ...
0
votes
1answer
640 views

Ubuntu 2 Node Cluster Postgresql 9.3 with pacemaker and Streaming Replication

I'm trying to setup a 2 Node Cluster with Postresql 9.3 and Streaming Replication. Streaming Replication is successfully configured. Master is listen up and is sending to slave. I can do failover ...
0
votes
1answer
430 views

PowerDNS - Verify that a host is up before resolving

I have twp name servers running PowerDNS as ns1 and ns2 using a master/slave-type setup, and this works well. I want to create multiple servers to provide services (i.e. web, email, etc), then have ...
0
votes
1answer
330 views

Architecting nginx for redundacy

This may be a stupid question, but after googling a while I can't find the answer or just don't know how to ask it. I have a web app running on a server named 'myserver1'. I've brought up 'myserver2' ...
0
votes
1answer
74 views

How to achieve stateful fail over when using multiple uplinks?

I have multiple ISP lines over which I am load balancing the network traffic on my linux machine having multiple interfaces ( eth0, eth1 ,eth2, eth3) . This I am doing by creating the routing tables ...
0
votes
1answer
356 views

High CPU consumption of Apache in Win2008 R2 cluster

I Have 2 Win2008 servers running in a failover cluster, I have also installed Apache 2.2 and assigned it as a generic service for the cluster. The setup is designed to cater (at max) 76 clients. When ...
1
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0answers
277 views

IP Resource Errors While Building a Windows Failover Cluster on Azure

I have setup a failover cluster in Microsoft Azure on four VMs. I have two nodes in one subnet/region, one node in another subnet/region and a final node in a third subnet/region. The cluster passed ...
1
vote
0answers
128 views

Apache ReverseProxy sets upstream server to error when it returns an error page

We are using an Apache LoadBalancer/ReverseProxy to provide a failover for our web servers. Currently we are experiencing the following problem: A webservice call returns an error with HTTP status ...
0
votes
0answers
34 views

MSSQL High Availability Advice Required

I'm looking to implement a high availability SQL installation using MSSQL2012 or 2014 and there is 1 part of this I'm not sure about. I plan to have a SQL cluster at site a, and a secondary SQL ...
0
votes
1answer
18 views

Restart failed processes on available machine

I'm working on a system that has about 50 processes distributed across about 4 different machines. The architecture allows for any process to run on any machine, but only allows each process to run on ...
-1
votes
1answer
69 views

Rapid failover from one data center to another when the first goes down?

I'm building a global CDN and have a DNS service that will direct customers to the closest server. However I need rapid failover if one of the data centers e.g. Germany goes down users need to be ...
0
votes
1answer
34 views

Hot-spare using Pound

I currently have a server deployment in which Pound is being used as a reverse proxy (HTTPS -> HTTP) in front of a single server instance. I'd like to add a second instance on a different host that ...
0
votes
1answer
305 views

How can I create redundant EC2 instances when also using EBS?

I am searching for a host for a web application that must interact with a few terabytes worth of files. One solution I'm considering is to host the application on Amazon EC2 with multiple EBS ...
1
vote
1answer
476 views

PHP - Memcached - Libmemcached - Handle cache server outage

I am working on ensuring our app degrades gracefully in case of a complete cache outage, which is highly unlikely, as we have minimum of at least 3 cache nodes to add to the cache pool, by way of ...
1
vote
0answers
223 views

ASA failover mode switching from Active/Active to Active/Standby

We have two ASAs with failover set to Active/Active. This seems to work fine for everything we do except using VPN connections. It seems whenever the primary ASA fails over that all VPN connections ...
1
vote
1answer
1k views

RTMP Proxy Server

I have an application which uses both HTTP (content data) and RTMP (video streams) for communications. An nginx server is configured for load balancing and proxying incoming client requests. It works ...
0
votes
2answers
572 views

Keepalived loses VIP upon power cycle of master

I have two servers running Keepalived 1.2.7 with hostnames left and right. Here are the configs: # keepalived.conf on left vrrp_instance VI_1 { state MASTER interface eth1 ...
0
votes
1answer
57 views

Apache loadbalancing - how to get reported about server fault

I am a newbie about load balancing so sorry if the question is trivial. I set up a basic load balancing using one server as a load balancer (planning to add at least one more with heartbeat) and for ...
0
votes
1answer
1k views

Mongodb replica failures to resolve DNS when primary DNS is stopped while secondary DNS is operational

I have setup mongod replica consisted of 3 nodes + 1 delayed hidden node + arbiter. I have setup DNS: primary and secondary internal DNS (bind) servers, so that I can reference nodes by normal FQDN ...
2
votes
1answer
178 views

What are the options for a HA system?

I'm looking into creating a HA Linux machine for my client's website. What are the main options I have, or a place/article where I can find out more? I would LOVE if it was a single-image, too, so ...
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votes
1answer
92 views

Is MOSIX the easiest way to build a redundant system?

I'm trying to figure out the easiest way to build a server with HA. I looked into Linux-HA, Heartbeat, Mesos. I then found MOSIX. I don't know if it's a thing from the past that no one uses, but ...
0
votes
1answer
476 views

Can HAProxy reconnect a websocket to another backend server transparently?

I'm new to HAProxy so this might have an obvious answer but I wasn't able to find it. Consider this setup: two backend web applications; one HAProxy in front of the web applications; many clients ...
1
vote
0answers
316 views

Keepalived configurations

I installed keepalived on two firewalls to provide fail over. I'm not sure if the following configurations are correct (see configurations below). Sometimes I have problems to reach the websites ...
0
votes
1answer
322 views

Hosting self hosted WebAPI in Windows Failover Cluster

I've got a windows service that is self-hosting the Asp.Net WebAPI. This works great and I can send GET requests successfully. However I am also trying to host this service in a Windows 2012 ...
2
votes
1answer
49 views

Website failover across internet connections

Requirement For a network having 4 static IP internet leased line connections linked to hosting a website. What are the current strategies one can apply to ensure high availability in case of ...
1
vote
1answer
2k views

pfSense failover and OpenVPN site-to-site

I have two pfSense Clusters, and am trying to connect them with an OpenVPN site-to-site VPN. Initially, the client was a single pfSense system, and all was well. Now that one system is a cluster, and ...
0
votes
1answer
584 views

Active-passive xenserver bond availibility after stacked switch failure

Citrix documentation for Xenserver recommends that when physicals NICs participating in an active-passive bond, need to be connected to different switches, the switches must be stacked.. Would the ...
8
votes
5answers
1k views

Hot spare host vs cold spare host?

We have several hosts where we have an identical hot spare host, which is patched and updated so it is very close to have to same software and config. In case of failure the network cable is switched ...
0
votes
1answer
91 views

Supporting writes on bind9 failover

I want to set up a redundant DNS based on Bind9, including failover for write operations. I have DHCP dynamically update DNS based on client hostnames, and I need this functionality to continue to ...
0
votes
3answers
4k views

XenServer HA (failover VM's) without shared storage

In the university from Uruguay where I work, we have 2 IBM BladeCenter S with 4 server blades each one. Each blade have XenServer 6.2 installed and working. Our idea is have each BladeCenter in ...
1
vote
1answer
2k views

Apache mod_proxy_balancer + Tomcat load balancing - Should not redirect until web applications are ready

I am using apache2 mod_proxy and mod_proxy_balancer to balance the load to 4 seperate tomcat8 instances on different servers. I am using different AJP ports for each tomcat instance and using jvmRoute ...
0
votes
1answer
341 views

Redirect PowerDNS on Failure

I've been searching around, but cannot seem to find an answer so I apologize if this has been asked here before. I had two PowerDNS servers - ns1 and ns2 (which are in different datacenters). Both ...
0
votes
1answer
2k views

HDFS' ZKFC service unable to start

CDH4's ZooKeeper Failover Controller (ZKFC) has been installed. Starting the ZKFC service: [vagrant@localhost ~]$ sudo service hadoop-hdfs-zkfc start Starting Hadoop zkfc: ...
0
votes
3answers
73 views

One domain hiding two servers

For our SaaS web-app we have two identical servers in two geographically separated data centers. FOO_1 is the production server and does real-time (MySQL master-slave) replication to its backup ...
1
vote
1answer
355 views

How to make Nginx fire 504 immediately if server is not available?

I have Nginx set up as a load balancer with cookie-based stickiness. The logic is: If the cookie is NOT there, use round-robbing to choose a server from cluster. If the cookie is there, go to the ...
1
vote
2answers
490 views

Windows Server 2008 DNS Forwarder Failover

When setting up and testing DNS forwarders I am finding that if the primary is unreachable 2008 will still try it for every query before trying the secondary. The default timeout before querying the ...
1
vote
1answer
931 views

DFS Replication Manager on Failover Cluster Nodes

I currently have a VM architecture setup for high availability / manageability. The one point of failure is that I have a single windows 2008 machine that runs DFS replication across the servers in my ...