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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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 ...
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2answers
810 views

Xen Remus setup

Currently, I'm running the IT for a small organization, and we just purchased a new server to replace our aging Dell poweredge. As the Dell isn't so bad as to be junk, I was hoping to set up Xen on ...
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2answers
55 views
+50

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 ...
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3answers
28 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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0answers
58 views

POP/IMAP HA solution for 5k users [on hold]

I want to build simple, cheap HA solution for 5000 users with postfix/dovecot. Each user will have 1.3 GB mailbox (maildir) storage quota. All of the users will use POP and also plus half of them will ...
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1answer
44 views

MSTDC in SQL Server 2012 - Windows Server 2012 R2 with high availability

We had implemented SQL Server High Availability on two physical servers over the VPN network. SQL Server 2012, Windows Server 2012 R2. It was noted that, Distributed Transaction was working perfectly ...
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2answers
37 views

Web-based System High Availability

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 ...
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2answers
42 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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0answers
11 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 ...
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1answer
30 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 ...
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1answer
25 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 ...
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1answer
35 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 ...
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1answer
42 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 ...
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1answer
29 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 ...
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0answers
18 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 ...
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1answer
706 views

unable to destroy windows 2008 r2 failover cluster after SAN rebuild

I created a windows 2008 r2 failover cluster for a sql 2008 active/passive cluster. This two node cluster was using a SAN device for a quorum disk resource as well as MSDTC resource. Well....I ...
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1answer
142 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 ...
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2answers
33 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 ...
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1answer
48 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 ...
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1answer
43 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
120 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
35 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 ...
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0answers
17 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) ...
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1answer
128 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 ...
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1answer
22 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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1answer
20 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 ...
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1answer
33 views

Parallel filesystem which schedules simultaneous file requests to mutually exclusive sets of OSSs

My environment is RHEL based, interconnect is infiniband. I have some experience with Lustre. What i want to know is: Is there a parallel file-system, where if simultaneous write request arrive, ...
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1answer
101 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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3answers
4k views

What is the difference between Anycast and GeoDNS / GeoIP wrt HA?

Based on the Wikipedia description of Anycast, it includes both the distribution of a domain-name-to-many-IP-mapping across many DNS servers as well as replying to clients with the most geographically ...
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0answers
57 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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11answers
14k views

Multiple data centers and HTTP traffic: DNS Round Robin is the ONLY way to assure instant fail-over?

Multiple A records pointing to the same domain seem to be used almost exclusively to implement DNS Round Robin as a cheap load balancing technique. The usual warning against DNS RR is that it is not ...
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1answer
77 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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50 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. ...
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1answer
1k views

Where are Nagios Availability-Report files stored?

How to access Nagios Availability-Report files to retrieve "UP Time Percent" and so other information about Hosts and Services? I know It can be accessed through Nagios CGI but I want to use it on a ...
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1answer
528 views

is it possible to synchronize the states of TCP proxies in real time (for real-high-availability of SLB)?

Consider that there are two server load balancers working in the tcp proxy mode (e.g., for L7 load balancing). Is it possible to synchronize their states in real time so that they can be a backup for ...
2
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1answer
587 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 ...
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1answer
405 views

SonicWALL HA w/ Dual WAN HSRP from two redundant switches

We're adding two SonicWALL NSA 2600 firewalls to our current setup. We currently get two WAN connections from two separate Cisco routers running on the same external subnet with what I believe is ...
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7answers
8k views

Avoiding DNS timeouts when a dns server fails

We have a small datacenter with about a hundred hosts pointing to 3 internal dns servers (bind 9). Our problem comes when one of the internal dns servers becomes unavailable. At that point all the ...
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1answer
67 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 ...
4
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3answers
115 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 ...
3
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0answers
74 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 ...
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1answer
63 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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0answers
55 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 ...
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2answers
138 views

SQL Server Failover Cluster on Azure (HA Strategy)

In the context of SQL Server 2012 Standard Edition, is it possible to make Azure Blob storage available to a SQL Failover cluster directly as a shared SCSI resource on a Windows Cluster? An Azure blob ...
2
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1answer
45 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 ...
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1answer
102 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: ...
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1answer
55 views

Multi domain server with dedicated SSL's HA

I am hosting a server with 150 domain names (websites), each of the ssl's requere dedicated IP address. So server windows 2008, with 150 IP addressees and 150 websites. I need to have high ...
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1answer
723 views

Does HP IRF work the way I think it does?

I finally have approval to better centralize our Ethernet. When last I left off I was looking to the future to figure out how best to handle expansion. Now, I have answers. I now have a pair of A5820 ...
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1answer
96 views

Shared storage solution for Debian Wheezy [closed]

I need to setup a new infrastructure which provides high available shared storage between debian servers. Our current solution is a "clustered DRBD NFS solution". We have setup 2 virtual file ...
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1answer
205 views

How to make active/passive jboss resource in pacemaker

I want to configure my pacemaker for jboss server. I have 2 nodes with mysql master/slave configured. The problem is I want to start jboss on node which is located master database. The one possible ...