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

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225 views

Fault-tolerant network access to redundant storage in a heterogeneous environment (including Windows)?

We are facing a design "challenge" where we are required to set up a storage solution with the following properties: What we need HA a scalable storage backend offline/disconnected operation on ...
1
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1answer
123 views

Remus or alternatives

Is it possible to set up Remus to act as a high availability server across 3 locations. Has anyone set up something like that. That is A would be main site, which would have an HA set up at B, and C ...
1
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3answers
74 views

If my DNS is a VM with HA do I need a secondary?

Same question would apply to mail server - if I have these running as VMs with failover / HA do I need to run a secondary / backup for either? This is a relatively small site (< 50 machines) so ...
1
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1answer
116 views

Best PostgreSQL HA strategy for 99% read scenario?

I'm in the process of building out a new PostgreSQL (9.3) environment in which traffic hovers around 99% read. We'll have 2 very powerful machines, connected via 1Gb ethernet. With the multitude of ...
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2answers
1k views

Is it possible to balance load between multiple Nginx load balancers without using a hardware load balancer?

I plan to balance load between my app servers using a separate Nginx server as a software load balancer. But actually, it's because a load balancer in front of the app servers allows me to update an ...
1
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2answers
177 views

Any software/proxy that can do SMTP failover?

I'm using a monitoring software that sends out email to my ISP's mail server (SMTP Server). But sometimes, the ISP's mail server goes down, or takes too long to respond, I would like to find out if ...
1
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1answer
546 views

GlusterFS as elastic file storage?

Is there any way to run GlusterFS in a replicated mode, but with the ability to dynamically scale the volume up and down? Say you have 3 servers all running glusterd. your Gluster volume would have ...
12
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1answer
2k views

Replicating beanstalkd for High Availability

Title says it all. Does anyone know of a way to replicate beanstalkd such that if a beanstalk server went down, others slaves could take over? Here's one approach I thought of: I could make ...
0
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2answers
43 views

DNS failover in virtual network

I have read some articles here and on other websites about the drawbacks of using DNS to implement high availability services. This is mostly due to the fact that configuring DNS to work efficiently ...
1
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1answer
390 views

Solr Replication without using zookeeper

The application that I am currently working on does not need real time indexing. I am using Solr as the indexing engine and I want to setup a High Availability Solr cluster with 2 replica nodes. Seems ...
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6answers
262 views

Use two website hostings for better availability

I have two VPS servers from two different hosting companies. I want to make some fallback to second VPS if first is not available (preferably automatic). I understand that if I have a single ...
0
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1answer
83 views

How to install pulse during RHEL 5.9 install

I am desperately trying to install pulse on a rhel5.9 machine. I have tried googling all over but all I get are instruction on how to configure pulse/piranha on an already installed box. I have ...
3
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2answers
2k views

Keepalived over GRE tunnel for failover on VPS environment

I'm running an application on Linode. Their network does not support multicasting. Many tools used for failover (keepalived, spread/wackamole, hearbeat) require multicast to work (as far as I know). ...
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2answers
417 views

Using DRBD with 100mbit uplink

we are planing to use drbd to sync two servers (different hardware) to get kind of HA in case the master server dies. The servers are hosted physically in the same datacenter (Hetzner in germany) and ...
0
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1answer
66 views

Off-site HA server

I understand that this is a little too broad question, but I hope I can get some guidelines here. I have a CentOS 5 server with cPanel on it. It is extremely important not to have downtime, but ...
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2answers
60 views

What software should I use for fault tolerence/high availability for 2 servers [closed]

What are some of the industry standard enterprise software to allow fail-over or swap-over between 2 servers? E.g., if 1 server goes down(due to connection or power, etc), the other kicks in either ...
1
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0answers
514 views

How to configure cluster.conf for failover routing two networks?

I'm routing between an "external" subnet with Internet connectivity and two "internal" subnets, using iptables forwarding on a Linux box running CentOS 6.4: I'd like to now duplicate this router ...
4
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2answers
692 views

How to change the master in a MongoDB cluster without restarting the process?

Reading the documentation of MongoDB about how to configure a master-slave configuration of a cluster (our cluster will have more than 12 nodes, so unfortunately we can't have a replica-set ...
0
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1answer
533 views

How to achieve high availability PostgreSQL on windows server 2008?

I am looking for a way to get a postgresql database running with high availability on some windows 2008 server boxes. I am not an expert in windows server administration nor postgresql, so I am a bit ...
0
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1answer
143 views

Setting up apache + mysql + exim on new servers. Redundancy/HA/Failover?

We are currently moving our single Linux server to a few other physical Linux servers, and would like to take the opportunity to have some more failover options. Backups are fine, and we don't ...
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2answers
3k views

Getting started with KVM coming from Vmware

In order to test new ideas and reduce cost I would like to test KVM. I think Vmware has these 3 things which are valuable: - HA which restart VMs (Virtual Machines) in other hosts when a Hardware ...
0
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1answer
135 views

multi-site web farm for IIS [duplicate]

I am having a terrible time finding information on this and I am hoping someone here can help or point me in the right direction. I am working on a project of setting up an IIS webfarm that is ...
2
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2answers
4k views

Alternative to GlusterFS [closed]

I need to create a redunant 2-linux machines configuration so that the files on server1:/dir are in sync with the files on server2:/dir I managed to configure GlusterFs to do this but while it works ...
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0answers
221 views

High-availability for ZMQ traffic

We have a lot of incoming third-party ZMQ traffic (zmq.PULL on our side). We need to implement a high-availability solution for that traffic. At the very least, we need to be able to manually switch ...
3
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1answer
420 views

corosync binding to 127.0.0.1 instead of correct interface

I have the following problem when trying to implement a two-node failover cluster, using Hetzner as the hosting provider. my corosync.conf is as follows: # Please read the corosync.conf.5 manual ...
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1answer
289 views

corosync and multiple load balancers

I am trying to provide HA capabilities for our load balancers (nginx, pgpool and haproxy optionally) using pacemaker/corosync. I have defined three primitives: 1 for the failover IP, 1 for ...
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1answer
1k views

job interview - technical questions (hardware / network) [closed]

i recently had a phone interview, and did not get the job. i'm curious if i didn't get the technical questions correct, or whether there was something else about my interview that caused me to not get ...
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1answer
45 views

domain redirecting/forwarding during server shutdown temporary [closed]

I rack my brain how could I solve the following issue: my website/server needs to be available all the time, so just few minutes downtime could be critical I would run a separate server (server ...
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2answers
72 views

How to create a redundent webserver using virtual machines

I would like to create a fail-over web server using one physical box and 2 virtual instances. What I am aiming for is the host OS monitors performance of a web server running in a virtual machine (ie ...
1
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1answer
233 views

Is possible to use Pacemaker failover without hardware?

Is possible to use Pacemaker failover without hardware? On quickstart http://clusterlabs.org/quickstart-redhat.html you can find the followowing commands: ccs -f /etc/cluster/cluster.conf ...
6
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2answers
14k views

How to setup STONITH in a 2-node active/passive linux HA pacemaker cluster?

I am trying to setup an active/passive (2 nodes) Linux-HA cluster with corosync and pacemaker to hold a PostgreSQL-Database up and running. It works via DRBD and a service-ip. If node1 fails, node2 ...
1
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1answer
432 views

Log into a specific server in a Windows 2012 Remote Desktop Collection

I have 4 Windows 2012 Remote Desktop servers in 1 collection. All 4 of the servers have the RD Session Host role. I've also put the collection into High Availability Mode, so all 4 servers also have ...
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0answers
42 views

Prevent NGINX from rerouting to a backend that was previously down

I'm using NGINX's ip_hash directive to ensure that client requests always end up at the same backend server. In the case of a backend server outage, NGINX will reroute to the available server, and ...
3
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3answers
3k views

What happens if an OpenStack cloud controller dies?

I've been reading up on OpenStack and how we can re-create an EC2/S3-style cloud for our internal development and I'm having a hard time finding information on how the OpenStack cloud controller ...
3
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2answers
68 views

Is it possible to have automatic failover of a windows service without windows clustering?

Due to a partial failure of our SAN we have switched our message queuing (Active MQ) from using network storage to using local storage. Because the secondary server is no longer sharing the same ...
1
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2answers
827 views

Best way to load balancing between AWS and Rackspace?

I have a SaaS product hosted on AWS and I would like to have the same infrastructure hosted on Rackspace (or any other host) to offer a high availability (eventually load balancing) for my users in ...
0
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1answer
76 views

Windows Server 2012 Virtualization for Limited Downtime? [closed]

We're planning on purchasing a new server and consolidating most of our websites onto it. The initial thought was to use Windows Server 2012 with 4 VMs on it (1 e-commerce web, 1 e-commerce database, ...
2
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1answer
1k views

ESXi Beacon Probing Limitation - Three Switches Required?

We are currently using Link Status Only for our NIC Teams on our VM hosts, but recently ran into an issue where one of our two switches had a memory error and stopped passing traffic. All of our VM ...
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2answers
2k views

Per-packet round-robin load balancing for UDP

I need to load-balance UDP traffic between a number of "realservers" and do it in a truly round-robin fashion. I've started with keepalived, but unexpectedly discovered, that LVS treats UDP traffic as ...
8
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2answers
5k views

Can not switch drbd to secondary

I'm running drbd83 with ocfs2 in centos 5 and planning to use packemaker with them. Afer some time, I'm facing drbd split brain problem. version: 8.3.13 (api:88/proto:86-96) GIT-hash: ...
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1answer
211 views

Azure extra small vm availability set [closed]

My current extra small vm reaches the limits, so I decided to create a second extra small instance and add the two into a availability set so my service is everytime available and through the load ...
3
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3answers
462 views

How can I create a “fail whale” for my website?

I have a website that we load-balance across a few machines. The load-balancer (a Brocade ServerIron ADX) is on the local network. I know it has the capability to configure a "backup" ip address to ...
9
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4answers
6k views

What exactly does Gluster do?

I've been playing with gluster for the last 2 days and been asking questions here and on their questions system. I really don't understand some of the stuff. I see people saying stuff like Set up ...
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0answers
61 views

DRBD mount randomly unmounts itself

We have setup setup an NFS HA "cluster" using drbd/heartbeat. Everything works as expected when tested... If the instance nfs1 goes down, nfs2 picks up and everything seems to be fine. On both ...
1
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1answer
218 views

Bond0 Failover when link light stays up: High Availability Network

Configuration: Two switches, each with a separate internet route Centos servers with eth0 and eth1 bonded as an active-backup on bond0, eth0 in on switch and eth1 in the other /etc/modprobe.conf ...
0
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0answers
208 views

configure heartbeat HA on Amazon VPC instance

I'm trying to implement HA with Heartbeat (and monit) on two Amazon VPC instances. I read many articles about it and I tried all possible options I can think of. few articles I read (don't work for ...
0
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1answer
223 views

Memcached distribution

I have a question about memcached distribution across nodes. We have 20 memcached nodes with 200GB memcached on each. Our apps are PHP apps. $memcache->setOption(Memcached::OPT_DISTRIBUTION, ...
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3answers
840 views

Resilient Linux Mail Server Setup

How would people design a resilient mail server setup with Linux? On an application level what the system needs to provide is both an incoming and outgoing mail service (i.e. SMTP & IMAP), along ...
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0answers
2k views

LVM DRBD Shared between nodes proxmox

Context : I have proxmox cluster with the volume group shared with drbd for the VM - KVM. I have a problem with drbd. Indeed, when a node disconnect, the associate link between the differents nodes ...
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0answers
334 views

Strange Keepalived VRRP email notification

I have a 3 nodes keepalived (K1 to K3) installed and receiving email notification. The setup of keepalived is K1 VI_50, priority 100 VI_51, priority 98 VI_52, priority 99 K2 VI_50, priority 99 ...