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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3
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3answers
667 views

Does it work to run mysql with the data directory on a CephFS mount?

We have a database cluster that uses MySQL on DRBD with Pacemaker+Corosync, which is great. My question is whether it is possible (and whether anyone has been successful) to mount a CephFS drive to ...
0
votes
1answer
261 views

HAProxy MySQL Failover is not starting

I am trying to setup HAProxy with MySQL failover with Ubuntu. I used a setup similar to this serverfault question, however I am getting the following error when starting haproxy: [ALERT] 341/220001 ...
0
votes
1answer
98 views

lvsd config correct?

I have used Piranha to setup fail-over for httpd. I set the servers the same, but one shows the VIPS and the other doesn't. Is this normal? Server A) [Primary] [root@titania ~]# ipvsadm -L IP ...
1
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1answer
283 views

How to improve availability on a starting up PHP+MySQL application?

Yesterday, Rackspace DFW data center went down for a few hours and made me think on taking the delayed action of improving my server structure there. So far, I've been using a single CentOS instance ...
-1
votes
2answers
67 views

Is a virtual IP assigned by a hosting provider?

I'm going to be setting up HA proxy with 2 physical servers, using heartbeatd. I'm going to have clients point domains to an IP address which can't change after doing so. My hosting provider has ...
0
votes
1answer
79 views

How to manage SOAP requests to a pool of VM each listening on a HTTP port with a priority value in these requests?

I have a front SOAP web-server under Linux. It will have to communicate with Windows Servers VM listening each on a HTTP port, for a HTTP POST request. The chosen VM should return a report of a task ...
-1
votes
1answer
103 views

Relying on shared disks for heartbeat

I read somewhere that using shared disks for heartbeats is reliable even if network totally fails. I read it in the context of remedy from split-brain. Is this correct? But I can not understand this. ...
1
vote
2answers
495 views

How to configure HA iSCSI for Solaris 10

BACKGROUND: We have a StarWind NAS that we are currently using for High Availability storage with our Windows network. Starwind has mirrored drives and multiple ip paths, that the Windows Server ...
2
votes
2answers
81 views

Suggestions on providing HA access to an external (fibre) RAID subsystem

We are looking at upgrading our storage capacity with an external RAID subsystem that has redundant (2) fibre controllers, each controller has 4 x 8 Gbps fibre ports. I would like to make access to ...
2
votes
0answers
393 views

Highly-available, Web-accessible and scalable deployment of statsd and graphite

I'd like to setup statsd/graphite so that I can log JS apps running on HTML devices (ie. not in a contained LAN environment, and possibly with a large volume of incoming data that I don't directly ...
0
votes
1answer
708 views

What's the difference between keepalived and corosync, others?

I'm building a failover firewall for a server cluster and started looking at the various options. I'm more familiar with carp on freebsd, but need to use linux for this project. Searching google has ...
2
votes
2answers
456 views

Clustered file systems as XenServer storage

I want to use shared storage for a XenServer environment with 4 host servers which are running various VMs under XenServer. Planning to use 2 extra servers as storage with high availability of some ...
1
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0answers
861 views

Nginx Active/Active Cluster Setup

I am currently attempting to configure a pair of load balancing servers in an Active/Active configuration using the following: Nginx Corosync Pacemaker Applicable instructions were followed ...
1
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1answer
3k views

How to setup a simple Ubuntu Server Tomcat cluster on VirtualBox for testing? [closed]

I am looking for the step by step instructions to setup at least two simple Ubuntu Virtual Core 12.10 Server VMs on Oracle VirtualBox under Windows 7 64bit. The test setup would be: Apache HTTP ...
0
votes
1answer
60 views

Oracle replication A->B and B<-A?

If you have two unrelated Oracle databases on separate servers, can you replicate A to B and B to A so both servers have a copy of both db's? Idea is for DR "on the cheap" without buying more Oracle ...
1
vote
1answer
38 views

Can I use Veritias Storage Manager to provide HA storage using server-local storage?

I have a need to provide an high-availability ftp/http file repository. Upload will happne to one server, but the uploaded file must be immediately visisble on all other servers I can handle the ...
2
votes
1answer
119 views

Monit server went down

One of our developers needs some sort of notification in order to know whether the application is running smoothly or not.And We already decided that we will implement monit in order to get this ...
1
vote
1answer
262 views

ssh host key management between ha hosts

We have a setup with 2 Redhat-based servers which are both ha hosts behind a virtual ip. 192.168.0.3 dataserver (virtual ip) 192.168.0.1 dataserver_ha1 (physical server) 192.168.0.2 dataserver_ha2 ...
1
vote
1answer
139 views

Why state is needed for keepalived

From the doc ! MASTER and BACKUP state are determined by the priority ! even if you specify MASTER as the state, the state will ! be voted on by priority (so if your state is MASTER but your ! ...
2
votes
2answers
1k views

Windows Server 2012: Possible to have High Availability and reliability without needing a SAN, but connecting servers together?

I have some questions below -- tried to word them the best I could. If you downvote my post, please make a comment explaining why you downvoted so that I can try to do better when I post in the ...
0
votes
1answer
284 views

Is it not possible to use keepalived in EC2

The problem is two of my EC2 instances (ha proxy) need to bind a single virtual IP if I want to use keepalived, but they are not possible in EC2 as only a single instance can use a elastic IP at a ...
4
votes
1answer
184 views

How does a SQL Server Availability Group decide on which secondary will become the new primary when an automatic failover is triggered?

How does a SQL Server Availability Group with multiple synchronous-commit secondary replicas decide on which secondary replica will become the new primary when an automatic failover is triggered? ...
-2
votes
1answer
212 views

Cheapest High Available Web Server [closed]

I would like to create a high-available setup (e.g. a small cluster) for a webserver, i.e. it will run Apache, PHP and MySQL. There will be between 2-8 small websites running with only very little ...
11
votes
2answers
3k views

Options for Multisite High Availability with Puppet

I maintain two datacenters, and as more of our important infrastructure starts to get controlled via puppet, it is important the the puppet master work at the second site should our primary site fail. ...
2
votes
4answers
98 views

Looking for a solid redirection infrastructre [closed]

We have critical servers (webservers and databases) that are fully replicated, except for the reverse proxy that we use to hide the internal stuff. This proxy is acting like a router that filters and ...
6
votes
1answer
3k views

Should an HA failover occur in this scenario?

I'm running vSphere 5 in an HA cluster across two hosts (vsphereA and vsphereB). I have the HA cluster configured for host monitoring and datastore heartbeat monitoring with admission control disabled ...
1
vote
0answers
194 views

High availability setup with 2 tomcat servers in Windows

I am trying to set up a high availability setup(not load balancing, only HA) with 2 tomcat servers. When I google for information, I get tons of links with apache+HAProxy+keepalived setup for linux ...
0
votes
2answers
778 views

HAProxy — pause/queue all traffic without losing requests

I basically have the same problem as mentioned in this thread -- I would like to temporarily suspend all requests to all servers of a certain backend, so that I can upgrade the backend and the ...
2
votes
2answers
3k 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 ...
4
votes
3answers
241 views

How to handle server failure in an n-tier architecture?

Imagine I have an n-tier architecture in an auto-scaled cloud environment with say: a load balancer in a failover pair reverse proxy tier web app tier db tier Each tier needs to connect to the ...
1
vote
1answer
469 views

2 servers, high availability and faster response

I recently bought a second webserver because I worry about hardware failure of my old server. Now that I have that second server I wish to do a little more then just have one server standby and ...
0
votes
1answer
863 views

Keepalived not honoring nopreempt

I'm using Keepalived to manage two Redis instances in a master/slave configuration. I'm experiencing a situation where, if Keepalived is terminated on the Master box (the one with the higher ...
1
vote
2answers
419 views

Drbd Primary/Primary + iSCSI: accessing to different files avoids split brain?

I have a question / curiosity about split-brain on a Drbd Primary/Primary configuration. Supposing two nodes (hosts), host1 and host2 configured with Drbd Primary/Primary and two different shares ...
1
vote
2answers
245 views

Server Clustering on differen OS : CentOs and Debian [closed]

I have two dedicated servers in two different locations. One at USA (Based on CentOS), another at Asia (Based on Debian). Need to implement High Availability HTTP Clustering. The main complexity is ...
0
votes
2answers
110 views

Stratus Servers vs Virtualised Machines as a High Availability Solution [closed]

I've been asked to do this as a presentation, but to be honest, either I've totally missed the point or am I being asked to compare an actual company i.e. Stratus against the concept of virtualising ...
5
votes
3answers
3k views

If DNS Failover is not recommended, what is?

As a followup question to his very popular question: Why is DNS failover not recommended?, I think it was agreed that DNS failover is not 100% reliable due to caching. However the highest voted ...
1
vote
1answer
191 views

Service haproxy error

I want to configure Haproxy for outgoing mail load balancing. my configuration file /etc/haproxy.cfg is. global maxconn 4096 # Total Max Connections. This is dependent on ulimit ...
4
votes
3answers
196 views

Risks of Network Partitioning When a Split Brain Creates a Security Flaw

I'm looking to create a high-availability, scalable networking solution by using a distributed system of data. A node here, describes a network that has control over one copy of the data. These nodes ...
1
vote
1answer
749 views

MySQL HA and Magento DB

Is it possible to use MySQL cluster for Magento DB? I have Web app developed in Magento E-commerce platform and I want to make DB highly available using the MySQL cluster. Magento supports only InnoDB ...
1
vote
3answers
384 views

MySQL HA Solutions

I am evaluating the options to build MySQL HA and found the below solutions Percona XtraDB Cluster, Tungsten Replicator, and MySQL Cluster. Could you please help me to choose the best one with ...
0
votes
1answer
2k views

keepalived doesn't listen on virtual IP

I'm learning to use keepalived; for now within a single machine - just to make sure the forwarding works. I've started a mock webserver listening on 192.168.56.200:8080. It just replies with the ...
2
votes
1answer
45 views

Setup a constant web application availability on Windows Server

I am a part of a team that is building an ASP.NET web system. We need to guarantee, that when the main hosting server with IIS is being updated, web site visitors get the special message that the ...
3
votes
1answer
300 views

Highly available and scalable SQL Servers with read-only databases?

I've been thinking about building a website which could potentially get a lot of traffic. It would be a research site of sorts with wiki capabilities. So users would be able to edit information on ...
2
votes
1answer
785 views

SQL Server 2012 Mirroring / AlwaysOn - need for SAN?

There appears to be a great deal of conflicting information about whether or not SAN is required for a Sql Server 2012 Mirroring setup. I currently have an Active-Passive-Witness SQL 2008R2 setup ...
2
votes
0answers
113 views

Fence node in apache traffic server

I'm currently looking into Apache Traffic Server as a tool for providing better availability of web services. But looking at the manual I can't see any reference to how I can pro-actively fence a ...
0
votes
1answer
111 views

Failover solution for web servers

I'm looking for some failover solution between two web servers. The web servers (CentOS+Nginx) are running on KVM virtualization platform. I was testing RedHat high availability cluster but I've ...
0
votes
1answer
40 views

Heartbeat external plugin configuration format

I have developed an external Heartbeat v1 plugin, which expects its configuration by means of environment variables. AFAIK, this is what Heartbeat provides when configuring the plugin using the ...
5
votes
2answers
681 views

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 ...
8
votes
2answers
4k 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: ...
1
vote
1answer
551 views

How to setup heartbeat for IP fail over on SSH failure

I wonder if anyone can help me, I am trying to setup heartbeat on a redhat 5 to failover an IP address when ssh stops responding on a server. So basically you ssh to a VIP and then get put through ...