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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AlwaysOn Availability Group error after Windows Update in environment without a failover cluster [migrated]

Our SQL Server service was down this morning which brought down some of our websites. When I went to check the Windows Event Viewer I saw the following errors: Script level upgrade for database ...
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1answer
22 views

S3 dropouts in one region only - is this normal?

I'm using S3 to serve static image assets to a website. I'm a developer in Montréal, Quebec. My client's office is in LA. Once every month or three we're seeing S3 completely fail to serve images to ...
0
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1answer
32 views

vSphere High Availability, Fault Tolerance and Snapshots

I've heard claims from a vSphere server administrator that VMs configured for high availability continue to transparently function even in the event of an ESXi host failure. He also claims VMs ...
0
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0answers
17 views

Server 2012R2 DFS High Availability - with local storage?

Can I use clustering for high availability on two identical 2012R2 boxes that use LOCAL storage (not attached or SAN)? Local storage is super cheap and scalable, which is why the SAN has been ...
0
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2answers
33 views

the pacemaker can't start the drbd resource

here is crm the configure show [root@node1 /]# crm configure show node node1 node node1.mycluster.org node node2 node node2.mycluster.org primitive Apache apache \ params ...
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1answer
53 views

pacemaker config resource for nginx

i'm trying to build cluster by two vm using virtualbox i follow this tutorial http://www.tokiwinter.com/clustering-with-drbd-corosync-and-pacemaker/ and type the command as below [root@node1 data]# ...
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31 views

MariaDB Multimaster replication and AWS Auto Scaling Group

One of the things I hate most about RDBMS is that it can't sit on an ASG like the web servers and bounce it around and scale it up and down like a yoyo. Or can it? Recently looking at MariaDB galera ...
0
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0answers
18 views

Add security/authentication to mongodb (2.6) without downtime?

We have a 3 node replica set (running 2.6.1) that's running mostly defaults. We'd like to add authentication, but do it without downtime. I'm fine with restarting the nodes one-by-one and even ...
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1answer
21 views

Corosync 2.3.3: Unable to enable cipher

I'm trying to set up a new pacemaker/corosync stack of 2 machines. I was using it before with corosync1, but on Ubuntu 14.04 I've got corosync 2.3.3 OK - I said, and tried to use this version of ...
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2answers
67 views

Never miss a HTTP post [closed]

I have a webservice that have a couple of "machine" clients connected to it that does HTTP post with data once in a while. The nature of the service is that I cant allow the service to loose a single ...
1
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0answers
20 views

Running iSCSI LIO with high availability

I've build a two node storage setup with OCFS on top of DRBD to provide storage for a couple of ESXi servers. Will it be possible to setup iSCSI targets on both storage nodes and make one of the nodes ...
0
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2answers
134 views

Centos 6.5 configuring HA cluster

I need to configure HA cluster using 2 computers. But I've got a problem, when I'm trying to start a heartbeat service it starts but throws an error. Here's the error message: Starting ...
1
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1answer
71 views

High Availability/Failover hardware hookup

I'm learning about clustering and high availability techniques, and stumbled upon an article about configuring a network with a pair of servers, using DRBD for replication and heartbeat for monitoring ...
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2answers
169 views

corosync fails to install

I was trying to setup cluster using corosync and pacemaker on RHEL6 (CentOS release 6.5) I have added following repo data [haclustering] name=HA Clustering type=rpm-md ...
5
votes
2answers
390 views

Which STONITH hardware for power fencing?

I'd like to setup a two node high availability cluster using corosync/pacemaker/drbd. For that, of course, I need fencing. As far as I understand, all IPMI/iLO/... solutions do the job, but only as ...
2
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2answers
89 views

Static IP in AWS but with possible Load Balance feature

I am playing a bit with AWS. My goal is to setup infrastructure, which will have static IP on outgoing connections (requirement from payment provider which solution has been implemented in our app) ...
1
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1answer
164 views

Simple fencing/STONITH script in Centos 7

I am installing a simple Corosync/pacemaker/drbd high availability cluster using Centos 7 and would like to provide fencing/STONITH using custom hardware (power switches using USB connections). As ...
0
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0answers
26 views

HA router with keepalived showing unexpected traceroute

I have a couple of routers in HA using keepalived vrrp daemon under linux. Here are the addresses x.x.x.129 floating (keepalive) x.x.x.130 router1 (static) x.x.x.131 router2 (static) Something ...
0
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3answers
67 views

Load balancing for a running server process with sessions

I'm developing a server application that accepts incoming connections and works with client applications. The customer wants to have two machines working: in case one goes offline, the second will ...
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3answers
62 views

Web-based System High Availability [closed]

I'm a SysAdmin in one of the construction sites in a remote place. There is no reasonable internet speed can be reached there except a poor 3G/4G signal coverage which provide the users with ...
0
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0answers
31 views

Geo replication for a GlusterFS mirror

I'm assigned with a task to setup a HA setup and what I'm looking for is if it possible to have GlusterFS do the following: DC1: 2 glusterFS servers are set in replication DC2: 2 GlusterFS servers ...
1
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1answer
276 views

redhat cluster failover not working (corosync [TOTEM ] Retransmit List)

I'm using following: [root@kpdbm01 ~]# cat /etc/redhat-release Red Hat Enterprise Linux Server release 6.5 (Santiago) [root@kpdbm01 ~]# uname -a Linux kpdbm01 2.6.32-431.20.3.el6.x86_64 #1 SMP Fri ...
0
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1answer
50 views

Avoiding a Single Point of Failure with link aggregation

I have a requirement for a system with no Single Point of Failure. The client have offered two Ethernet cables per server. Each of the servers will connect into their network, however I want to ...
0
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2answers
127 views

Corosync :: Restarting some resources after Lan connectivity issue

I am currently looking into corosync to build a two-node cluster. So, I've got it working fine, and it does what I want to do, which is: Lost connectivity between the two nodes gives the first node ...
1
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0answers
71 views

RabbitMQ - How I do configure servers for zero-downtime upgrades?

Having read through the docs and RabbitMQ in Action, creating a RabbitMQ cluster seems straightforward enough, but upgrading or patching an existing RabbitMQ cluster seems to require the whole cluster ...
0
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1answer
138 views

iptable CLUSTERIP doesn't work

We have some requirements which explained here. We tried to satisfy them without any success as described. Here is the brief information: Here are requirements: High Availability Load Balancing ...
0
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1answer
210 views

Multimaster Keepalived Configuration (Virtual IP with Load Balancing)

Here are requirements: 1. High Availability 2. Load Balancing First configuration 1. Two linux servers have been configured with one static IP for each: 10.17.243.11, 10.17.243.12 2. Keepalived has ...
0
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1answer
108 views

HA - Heartbeat / Pacemaker - CentOS - Manual Symlinks

I have a MySQL Master <> Master pair setup for HA. I would like to setup automatic failover not just if the node hosting the current write mysql instance goes down, but also if the mysql instance ...
0
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2answers
74 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
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1answer
152 views

uwsgi + Django with nginx: High Availability Setup

Moved from : http://stackoverflow.com/questions/25304968/uwsgi-django-with-nginx-high-availability-setup to here. I was setting up High Availability on RHEL 6.5 . My Stack is 1. uwsgi 2. nginx ...
0
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2answers
174 views

Microsoft SQL Server Standard High Availability without Shared Storage

I'm a software dev with little experience managing SQL so please bear with me! We are developing a piece of software that needs to be highly available, with a significant degree of resilience. This ...
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1answer
135 views

How to lower Gluster FS down peer timeout / reduce down peer impact?

The setting: Two fresh CentOS 6.5 server with latest updates. Both have a fresh install of Gluster 3.5.2. What I did ( from the perspective of server 2, shared1 and shared2 are logical volumes ) : ...
2
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1answer
134 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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1answer
47 views

What FLOSS linux software should I use for high-availability on an FTP server on vmware? [closed]

I don't mean this as an opinion-based question. I want to know if my assumption is correct to use a network-oriented tool (keepalived) as opposed to a cluster-oriented tool (heartbeat) in a scenario ...
1
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0answers
33 views

Deploying High Availability Remote Desktops on Server 2008 R2 Ent - Do they have to be virtual desktops

I am looking at upgrading an existing 2008 R2 RDS Server to be part of a high availabilty environment. (It cannot be 2012 or 2012 R2 due to management not liking Windows 8 UI and associated training) ...
4
votes
1answer
485 views

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 ...
2
votes
1answer
26 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
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1answer
44 views

Setup Galera Cluster with two servers

Can I Create Gallera Cluster with two servers ?? Actually I have 6 servers: 2 Server for Load Balancer 2 Server for Apache Or anyone here can suggest me how to create High Availability Web Server ...
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104 views

Haproxy load balancing TPS lower than single node

I have 2 apache2 servers running in the back end and have a haproxy between them and the clients. If I bench tested anyone of these apache2 severs with ab i get north of a 1500TPS however when I bench ...
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1answer
227 views

Corosync dynamically add node

I have been experimenting with Pacemaker & Corosync for a HA setup. I installed it on two Ubuntu 14.04 Linode's and after a lot of back and forth on outdated config examples and tutorials, managed ...
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0answers
126 views

LVS + HA Proxy for L4 to L7 load balancing

Currently we are using HA proxy for our load balancing needs. We are planning to integrate LVS with HA proxy to create a load balancing solution that can take care of L4 to L7 load balancing and HA. ...
4
votes
3answers
135 views

Website high availability without load-balancer?

I'm considering options for changing a 'high availability' website that provides a service via an https api. The current setup is: Two self-contained VMs, from different cloud providers (AWS and ...
1
vote
1answer
150 views

IBM V7000 firmware upgrade effect on mounted LUN

We've IBM storwize V7000 Storage where the firmware is going to be upgraded to latest version.. This will require a reboot to the storage. I've got arround 10 LUN's (almost 10TB) coming from this ...
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votes
1answer
86 views

What's the best way to sync folders across 03 or more webservers? [closed]

I have 03 servers and I want to sync some folders across them. I'm using DRBD + OCFS2 for a year or so, but it doesn't support more than 02 servers right now. I read about GlusterFS and CEPH, but ...
1
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0answers
79 views

Redundant Debian Gateway

I have to configure a redundant gateway with Debian boxes and I would like to get some recommendation what's the best solution in my case. There are certain limitations in my setup and I have to go ...
0
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1answer
524 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 ...
3
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0answers
133 views

Using ZFS head node as database server?

I'm using a dual-head ZFS-backed NAS for high availability cluster shared storage, based on Nexenta's recommended architecture as seen here: The disks in 1 JBOD will store the database files for a ...
2
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1answer
52 views

Should each machine in a high availability cluster have same time zone?

I'm curious if people with experience think it makes sense to give all machines in a replication cluster the same time zone and time regardless of physical location to help ensure that dates are ...
0
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1answer
246 views

HDFS' ZKFC service unable to start

Introduction CDH4's ZooKeeper Failover Controller (ZKFC) has been installed. Starting the ZKFC service: [vagrant@localhost ~]$ sudo service hadoop-hdfs-zkfc start Starting ...
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1answer
228 views

Unable to convert HDFS from non-HA to HA

Introduction Aim: Convert HDFS from non-HA to HA. Method: According to this documentation it should be possible to convert HFDS from non- to HA by implementing following configuration: ...