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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store high amount of photos (150 million) and make available for web [closed]

For a actual project I must setup a high-available storage server who can store and publish (http) 150 million photos in 7 sizes means total 1050 million files. For every photo we need total 200 KB ...
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1answer
777 views

What are the advantages of async. database mirroring over transaction replication?

I've primarily a developer, but our organization is small, so I have been tasked with developing a HA strategy for our SQL servers. Currently, I manage our transactional replication to two additional ...
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3answers
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High Availability and Load Balancing with Debian 5.0 (Lenny)

Suppose I have two Debian 5.0 servers and a generic session-based DB-driven website is running on them. Assume that the two DB instances are already clustered. Each server has its own internal IP ...
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3answers
393 views

Firewall that supports HighAvailability and Spanning Tree

I'm looking for a firewall appliance that supports high availability and spanning tree. I have two ha-cluster nodes and I'd like to protect them with a firewall. To avoid a single point of failure, ...
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1answer
67 views

Installing two versions of MSSQL on a production server?

We've just provisioned a second dedicated server so we can use database mirroring for high availability. The existing server uses MSSQL Express 2005. We have MSSQL Web 2008 and want to minimise the ...
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1answer
818 views

vSphere HA - Dealing with storage hba/link failure?

I'm looking at putting in a small cluster spanning two locations on the same campus. The vSphere hosts in each location would have a vSwitch connected to the production LAN, and I'd also be using a ...
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1answer
550 views

Does order of servers in nginx config matter?

I have a custom tool which generates a part of nginx config in the following form, for example: upstream backend { ip_hash; server server1:8080; server server2:8080; server localhost:8080 ...
2
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1answer
234 views

What database is easy to maintain and manage in a cluster?

I'm looking for a database (DBMS) that is easy to scale out. I would like to have high availability so I need a multi-master cluster, where the data is replicated to two or more physical computers. I ...
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1answer
71 views

connect to my website from multiple external remote sites

I remember seeing a website where I could type in my home page url, and then get a list of a bunch of servers that connected to my url in real time, from all over the world. the report would show ...
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2answers
442 views

tools for geographical redundancy

I'm writing a spec for a high availability application. I need a low budget solution to be able to failover between two data centers. Replicating databases and content I'll be able to manage solutions ...
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2answers
315 views

MySQL Proxies

In a similar line to... http://serverfault.com/questions/35899/mysql-5-1-replication-topologies-multi-master What I'd like to know is whether there are any really good proxies for MySQL out there? ...
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1answer
86 views

How does systemd decide if a service is ok or not

This question is related to: reliable systemd service for autossh I have a service which uses type=simple. Here the systemd docs: Type=simple (default): systemd considers the service to be ...
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48 views

Get IP of node running a specific resource when demoting master nodes to slaves

Setup I am setting up a HA cluster for a web application with 2 nodes (2 physical servers): node1 (current master node) node2 (current slave node) Using Corosync & Pacemaker I was able to ...
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2answers
442 views

Configure HA Proxy between Apache and Tomcat servers

Want to configure HA Proxy with my existing structure. Currently I have Apache->Tomcat server. This I want to change to Apache->HA Proxy->Tomcat Server. HA I have configured for Http request. But my ...
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4answers
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new hyper V High Avaliability setup and SMB 3.0 storage

I am looking at building an new 2012 R2 with Hyper V setup, everything has to be HP hardware. 2x HyperV 2012 R2 servers running 20-30 VMs. These will be dual 6 core xeons with 128gb of ram. 2x 2012 ...
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1answer
586 views

Simple redundancy setup using two servers in two different datacenters? [closed]

Scope of the question This question is solely about getting a client requesting a domain: example.com to one of the two available servers. How it is handled from there on, is another problem to solve ...
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1answer
602 views

Linux HA Heartbeat Virtual IP Switching with domain name linked to it

I have heartbeat set up on two servers like so: Master: 10.15.1.50 Backup: 10.15.1.51 (Virtual IP: 10.15.1.52) So, the master always has 10.15.1.52 as well, but if it goes down, the backup will ...
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2answers
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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 ...
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1answer
137 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 ...
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2answers
146 views

Swap DNS entry on failure

I'm building an application that requires high-availability. We currently run: 4 webservers, 2 varnish servers (both with Pound for SSL proxy), 3 Cassandra nodes. The varnish servers are used as ...
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1answer
79 views

Availability & Scaling : Three Tier or Two Tier

I began working on a three -Physical- tier website (UI:MVC / Application:REST / DB), I've always considered that three tier is more scalable than two (taboo for high traffic websites), but lately i ...
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1answer
2k 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
328 views

Change hostname on linux ha failover case

I have configured two machines to do a warm standby so that machine 2 can take the ip of machine 1 if that should fail and become its replacement. sadly, thats not enough, i need to change the ...
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2answers
121 views

Veritas Cluster Server for HA for regular user processes

In the past I have used Veritas Cluster Server for HA clusters of Sybase and other databases at large financial institutions. Now I am going to have locally written processes that could benefit from ...
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2answers
90 views

Exchange & MS SQL high availability

Could anyone suggest how high availability can be achieved for MS exchange and for MS SQL server between two Data centres when one server each is located in a data centre? Users from a siteA connected ...
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2answers
870 views

load balancing, high availability for webapp setup

We have build a special interest social network and need to setup now the proper server setup for the webapp servers. We have for the webapp 5 physical server available (2xE5645 CPU, 24 GB Ram, RAID, ...
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3answers
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Implementation of a fully-redundant, high-available iscsi SAN (consisting of n machines) in conjunction with clustered filesystem

a short example of how the infrastructure may look like: 4 servers act as iscsi targets and expose 1x2TB each (every of those servers has a raid10 for the storage, thus 2TB of usable capacity) n ...
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2answers
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Unexpected start of already-primary server processes when heartbeat on secondary is stopped

I've got an active-passive Heartbeat cluster with Apache, MySQL, ActiveMQ and DRBD. Today, I wanted to perform hardware-maintenance on the secondary node (node04), so I stopped the heartbeat service ...
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0answers
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crm_mon -E does not run the external-agent on Debian Jessie

Setup I'm currently having a working 2-nodes HA cluster using Pacemaker+Corosync. My nodes are running on Debian 8 (Jessie). Now I would be able to get notified when changes occur in the cluster ...
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0answers
104 views

HAProxy failing at random times (backend has no server available!)

I have a CentOS 7.1 (x64) droplet configured to load balance between 2 apache/php servers. I have it working perfectly, but randomly throughout the day it reports the following: haproxy[12947]: ...
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0answers
136 views

Loadbalancing and HA with SolrCloud?

I have a LAMP Application running with solr 3.x on one server for several years now. Now I am migrating due to heavy load to a setup with two dedicated machines where all services are loadbalanced via ...
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391 views

SLES 12 High Availability Cluster - scsi persistant reservation fencing

I'm trialling SLES 12 w/ HAE to run a Fileserver cluster consisting of two nodes. Idea was to use SCSI persistant reservation as a fencing method using the fence_scsi script from stonith fence agents. ...
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How to let Corosync / pcs control nginx?

Folks, I'm trying to replace a single aging load balancer with multiple virtual machines running nginx. However after I got centos 7 and nginx installed I realized that heartbeat has been ...
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Is it possible to prevent pcs/dlm/crm from fencing the node when it fails?

Is it possible to prevent pcs/dlm/crm from fencing the node when it fails? I use cluster only to be able to build GFS2 storage, and there's my own way of avoiding split-brain. So I do not need things ...
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0answers
530 views

DRBD + corosync + pacemaker - Servers won't connect after failover

I got 2 servers configured with drbd, corosync with pacemaker. It is all working fine, primary server gets secondary if it fails, and secondary gets primary. But if the 1st server comes up again ...
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269 views

Clustering with Jboss EAP and Load balancing with Haproxy

I'm doing load balancing with HAProxy and use JBoss EAP as application servers. The Haproxy server is configured to route incoming requests to the application servers. How can I integrate Jboss EAP ...
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Is it at all commonplace to make service available via the same host as its redundancy, just different ports? [closed]

I am writing software that allows for the configuration of parameters for authentication with a Primary and Secondary RADIUS server. Server administrators, in your experience, is it common or not for ...
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1answer
49 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
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NFS failover fails with stale file handles while migrating resources

Running into a bit of a problem here , I set up two servers ( Centos 6 ) with Glusterfs and a shared directory between them, I have moved the nfs directory to the shared Gluster folder and have ...
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Multiple httpd with JBoss cluster: provide httpd HA

I have a working configuration like this: +-----+ +-----+ +-----+ +-----+ | i1 | | i2 | | i3 | ... | in | JBoss Cluster +--+--+ +--+--+ +--+--+ +--+--+ | ...
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673 views

TeamCity (or Jenkins) with Cluster/Replicated servers

We use Team City 7 for Continuous Intergration. Sometimes I need to bring down the server for maintenance which stirs up complaints. Is anyone using a cluster for these types of servers where there ...
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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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140 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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2answers
648 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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0answers
123 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 ...
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1answer
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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
414 views

which high availability model to choose for website (nginx/mysql)

We have 5 physical servers. All are identical. 16 gb ram, 4x146 10k sas in raid 10. So, we need high availability. Current plan is following: 2 boxes with Heartbeat for load balancing. At this ...
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1answer
190 views

VPS hosting with IP failover across datacenters

Is there any VPS hosting that would allow IP failover (or remapping) across different datacenters ? The only one I aware of is EC2 with their Elastic IP. What I'm trying to achieve is to have servers ...
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network mount across WAN [closed]

I have 2 networks separated by a WAN (25/25 fiber optic VPN). I would like to provide some files to both servers on networks via NFS (and Samba for the desktops, but that's on a per-site basis). some ...
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2answers
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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 ...