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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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
1k 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
189 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 ...
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3answers
446 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 ...
8
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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
55 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 ...
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1answer
210 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 ...
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0answers
184 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 ...
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1answer
202 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
819 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
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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
303 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 ...
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1answer
119 views

IP-based load balancing on external and internal interface

I have a certain distributed (as in, multiple components on multiple machines) service, that should be made available from the outside world. So, in LVS terminology, the clients are "on the internet", ...
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1answer
300 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 ...
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2answers
653 views

Cisco Switch connected to 2 routers

I have following setup: The router on the left is a router on a stick to route traffic within the LAN that has different VLANS. The left switch is the root switch for our LAN and works as the VTP ...
2
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0answers
107 views

Solr on a two node Jboss cluster

Are there any issues with deploying Solr on two node jboss cluster with the index shared on a NFS mount point? We would like to do this for high-availability across data centers.
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4answers
4k views

Ganeti vs Proxmox [closed]

I'm system administrator in small software house. I'm going to virtualise our servers. The main reason for doing this is providing highest possible uptime, but probably it will also increase resources ...
2
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1answer
450 views

Clustering on cloud/VPS providers

I'm wondering if anyone can give some clustering recommendations to me. I'm currently on Linode, which I'm impressed and happy with, but they (along with just about every other VPS provider I know of) ...
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8answers
5k views

High Availability DNS Hosting Strategy?

I'm trying to find a few options of ways to do high availability DNS hosting for a few existing websites. This morning, the company I work for was brought to its knees because the DNS hosting we have ...
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1answer
230 views

SSL Session Persistence - HA Heartbeat

I have two servers, let's call them Milo and Otis. Now Milo and Otis are setup to be an active-passive pair of highly available servers where Milo is usually the master and Otis stands-by waiting for ...
0
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1answer
696 views

Howto setup 3-node heartbeat cluster?

I want to set up a virtual IP on three nodes using heartbeat. Currently, I have this: ha.cf: # Facility to use for syslog()/logger (alternative to log/debugfile) logfacility local0 # ...
2
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1answer
1k views

heartbeat: Bad nodename in /etc/ha.d//haresources [node1]

I'm trying to start heartbeat on Ubuntu 10.04 with service heartbeat start, but getting the following errors: heartbeat[24829]: 2011/11/22_19:31:07 ERROR: Bad nodename in /etc/ha.d//haresources ...
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1answer
517 views

could heartbeat v3 monitor service/resource status without pacemaker?

I am trying to setup a HA system based on CentOS, I want to use heartbeat v3 for the "heartbeat" mechanism, resource start/stop, looks heartbeat can get it done. But about the resource status, ...
0
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1answer
88 views

How to connect to mysql-master-ha from my application server

I am trying to use mysql-master-ha. I managed to get it connected with the master and slave mysql servers. Now I would like to know how to connect to mysql-master-ha from my web application server ...
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13answers
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Move SQL-Server Database with zero downtime

Is it possible to move a sql server 2005 db to a different server running sql server 2008 without any downtime? The system is 24/7 and has to be moved to a different server with different storage. We ...
0
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1answer
623 views

Tomcat Failover High Availability (active / passive)

we have a jee web application running on apache tomcat , we need to deploy this application on production environment and we decided to use failover structure so we have one server active and another ...
0
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1answer
761 views

after split brain recovery filesystem not mounted

I have an active/passive high availability cluster with pacemaker+split brain. After split brain condition I use automatic split-brain recovery to recover my systems. The problem is that since file ...
0
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1answer
533 views

Setup HA postgres database, failover concept

I want to setup a HA postgres database. I setup master and slave database with synchronous streaming replication on different physical servers. When there is an error in the replication, the slave db ...
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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 ...
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5answers
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When my A web server gets unplugged, how do I automatically redirect all the users to my B web server in another city, and vice versa?

When my A web server gets unplugged, how do I automatically redirect all the users to my B web server in another city, and vice versa? A load-balancing switch does what I want, except I can't figure ...
0
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1answer
280 views

MySQL High Availability with VMWare/DRBD/Heartbeat still common practice?

Is it still common practice to use a DRBD/Heartbeat solution for a high available MySQL Instance when the whole environment is virtualized (in our Case VMWare) Are there other/better solutions out ...
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2answers
471 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 ...
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1answer
862 views

Load balancing with High Availability - SQL Server + IIS using AWS

This is my first time load-balancing with high-availability using Windows and SQL Server. Looking for some validation and input on my planned setup. Now, typically when I want to create a HA ...
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0answers
73 views

Solaris and Hot-Standby

i have a short question. is it possible to create a hot-standby-cluster with 2 nodes and solaris 10? in Linux i would use DRBD and Hearbeat/corosync, but in Solaris? maybe do you have an tutorial? ...
3
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1answer
289 views

Virtual IP Failover when machine is overloaded

We have been using keepalived in combination with a virtual IP address for two years now. In the rare case that a machine crashes this works very well. But when there are issues on the box itself we ...
2
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1answer
810 views

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 ...
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1answer
50 views

Backing up a mirrored SQL environment

I have 2 SQL servers in Mirror configuration. I want to backup these servers but backing up the SQL databases in Mirror state causes an error. These two mirrors also have a witness set. I would ...
0
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1answer
99 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 ...
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0answers
789 views

Exchange 2010 DAG Failover Cluster DNS Issues

I am having an issues with my Exchange 2010 servers. I have two servers that have HUB/CAS/MAILBOX installed on them. They are configured to use DAG failover cluster. I expereienced an issue recently ...
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6answers
310 views

Should HA hardware be in separate cabinets?

I want to host (co-located) a service at a Pier1, Q9 or some similar hosting facility. Is it best practice to put my failover hardware in separate cabinets, and in your experience, will the hosting ...
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0answers
220 views

Unable to remote desktop using failover cluster name

I am using Microsoft Failover Cluster and I have 2 nodes - say node1 & node2. The nodes are successfully accessed by remote desktop. but the cluster name is not accessible. The cluster name is ...
9
votes
2answers
3k views

Avoiding SPOFS with GlusterFS and Windows

We have a GlusterFS cluster we use for our processing function. We want to get Windows integrated into it, but are having some trouble figuring out how to avoid the single-point-of-failure that is a ...
5
votes
1answer
831 views

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 ...
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1answer
346 views

Advantage of Microsoft Cluster over Microsoft Network Load Balancer

Till recently, I assumed that Microsoft NLB worked at an OS/Machine level rather than an Application Level. i.e. the NLB just monitors heartbeats on the machine to check if machine is alive and then ...
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6answers
1k views

Real HA/FT SAN for VMware?

I'm planning a redundant set-up for VMware. Two locations (about 8-12km distance) are to be connected with dark fibre for SAN connectivity. I am looking for a FC-SAN product that allows transparent ...
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1answer
203 views

Addressing SQL 2008 mirror cluster

Hallo SQL jedis, I want my database to be always available. So I've set up database mirroring, which is working peachy. My question though, is how can I consistently address the database? I want ...
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1answer
73 views

Highavailability/Global Loadbalancing of clusters [closed]

I know this website 1channel.ch which has like 4 servers in 4 different datacenters across the globe (czech republic, estonia, sweden, germany). What happens is as i am browsing this website the ...
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1answer
171 views

Using Amazon route53 for high availability

Using Amazon Route53 DNS, is it possible to build a highly available setup pointing to multiple web servers not on Amazon? I don't need to worry about session stickyness. Let's assume I have two web ...
0
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1answer
200 views

HA Options for Windows Servers

We are looking at different options to allow us to stay up and running when our primary datacenter (DC1) goes down for any reason. What is the main difference in having a offsite server updated all ...