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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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
1k views

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
112 views

Pacemaker ocf:heartbeat:IPaddr on different subnets

I'm trying to add a Pacemaker virtual IP address; with it, the gateway, and the two VMs it serves on different subnets. I've only done this before with all IPs on the same subnet, and I need some ...
2
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0answers
55 views

JBoss EAP 6.2 high availability without HTTP server

i'm looking for some solution to make a Jboss Cluster ( 2 nodes ) in H.A. ( 1 live, 1 backup) but i don't want to use a third element ( machine, service or whatever ). Most configuration I found uses ...
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0answers
55 views

Solving an asymetric HA Firewall/router

I have an old Linux HA firewall/router setup that never quite worked. As it was never quite put into true production (just testing and demo's), I always had to have one firewall shutdown to make it ...
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0answers
84 views

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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0answers
58 views

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
40 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
749 views

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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0answers
95 views

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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446 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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2k views

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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115 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
509 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
120 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 ...
2
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1answer
906 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
387 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
187 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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197 views

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
968 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 ...
2
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0answers
659 views

Windows 2008R2 RemoteAPP Failover

I'm trying to setup 2 remoteapp servers with a bit of fail-over in the design. I keep running into a few dead ends where there is no load balancing... or connections take a ridiculous amount of time ...
2
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1answer
458 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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1answer
73 views

Performance issue when configuring non-HA VM in cluster

A quote from the Technet Planning for Highly Available Virtual Machines Important It is recommended that you not deploy virtual machines that are not highly available on your host clusters. ...
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6answers
262 views

Use two website hostings for better availability

I have two VPS servers from two different hosting companies. I want to make some fallback to second VPS if first is not available (preferably automatic). I understand that if I have a single ...
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7answers
5k views

How to deploy web application for 2 million users?

I've been tasked with figuring out how to do a large scale deployment for a high availability, high traffic, dynamic, flash based web application. There is a good possibility that this application can ...
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3answers
74 views

If my DNS is a VM with HA do I need a secondary?

Same question would apply to mail server - if I have these running as VMs with failover / HA do I need to run a secondary / backup for either? This is a relatively small site (< 50 machines) so ...
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5answers
2k views

Free DNS software with failover support? [closed]

I'm looking for DNS software that can accomplish the following: Check health of all A records at set intervals If server is unresponsive after multiple successive checks, replace A record with a ...
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4answers
227 views

Configuring DNS to serve pages from multiple servers for a single domain

I have some really high-availability web page content that needs to be online 24x7. So instead of relying on a single server I was wondering if I could handle one domain name with multiple servers? ...
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2answers
337 views

Linux High Availability

I have two Linux Active/Passive nodes on which i have the same simple processing application(not webapp). I just need to have a HA cluster when one machine is down the application on the second takes ...
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3answers
151 views

How to set up an event website?

For my work, I need to set up an event website. The site will be up to 2 or 3 months during the campaign. The site needs to be stable and have high availability, especially during the rush hours. ...
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2answers
3k views

Getting started with KVM coming from Vmware

In order to test new ideas and reduce cost I would like to test KVM. I think Vmware has these 3 things which are valuable: - HA which restart VMs (Virtual Machines) in other hosts when a Hardware ...
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4answers
1k views

Server CPU spikes suddenly and becomes unusuable - Tips to monitor/analyze this?

my server has been going down over the last 24-48 hours, CPU spikes from 15% to 100% and server becomes unusable and all my sites go down as a consequence of it. Any tips on how I could track what is ...
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4answers
873 views

Low cost solution to http loadbalancer single point of failure?

I have many low end atom servers for a startup project, each server have a few public ip addresses (no private network). I'm currently in the process of making it failsafe. There now is a load ...
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3answers
2k views

SAN/NAS with high availability?

I have two servers that I plan to use for storage. Each of them has a few SATA disks directly attached. I want the storage to be available even if one of the storage servers is down (preferably the ...
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6answers
687 views

Windows Server 2003 Availability / Uptime

I'm looking at putting together a support SLA. As a base line I'd like to know roughly what sort of percentage availability I should expect from a non-clustered Windows 2003 Server. Assumptions are ...
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3answers
804 views

MySQL / InnoDB replication: how to perform crash recovery?

How do I perform crash recovery in a MySQL/InnoDB Master-Slave asynchronous replication setup? Specifically: If a slave crashes, how do I make it syncs up with the master after I bring it back up? ...
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6answers
1k views

Will the OS crash if the system partition can't be access for a short period?

An operating system is installed in a virtual machine environment, such as VMWare or KVM. A network shared disk volume (e.g., iSCSI disk) is used as the OS system partition. Heavy traffic is running ...
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2answers
274 views

Options for sessions handling in IIS

What options are there for session handling with a modern .NET IIS Web architecture? I understand that IIS' native session support loses sessions upon restart. Furthermore, Microsoft recommends ...
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3answers
668 views

How should I perform database maintenance on a 24x7 system

I'm a software developer who inherited a part-time DBA role. I'm responsible for an application backend by a small, high-volume 24x7 database on SQL Server 2008. While there's other stuff in the DB, ...
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5answers
922 views

High Availability iSCSI Target Options

I have two servers (Intel Xeon) with running ESXi on them. There are about 70 clients in the network (16 thin clients among them). We've got pretty large data storage (it's about 100TB). We're using ...
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2answers
494 views

hosting a website on multiple hosts

Is there a way to host a website on multiple hosts. exactly the same site, for example on hosting companies HostingABC and HostingDEF? In case there is ever a problem with HostingABC (either a ...
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4answers
5k views

NFS v4, HA Migration, and stale handles on clients

I'm managing a server running NFS v4 with Pacemaker/OpenAIS. NFS is configured to use TCP. When I migrate the NFS server to another node in the Pacemaker cluster, even though the metadata is ...
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2answers
72 views

How to create a redundent webserver using virtual machines

I would like to create a fail-over web server using one physical box and 2 virtual instances. What I am aiming for is the host OS monitors performance of a web server running in a virtual machine (ie ...
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1answer
332 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 ...
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1answer
518 views

Is there an ideal filesystem type for the MySQL database directory (/var/lib/mysql)?

I've used ext3 and ext4 in the past with no issues, but I've seen a lot of installations on XFS as well. What are the advantages of XFS vs ext4 vs ?? with respect to the /var/lib/mysql directory? ...
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1answer
1k views

Best RAID setup for DRBD

I would like to setup a two nodes PROXMOX cluster with DRBD storage. The nodes will be connected by gigabit ethernet. What would be the best storage setup in terms of reliability, performance and ...
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2answers
521 views

Convert HyperV Servers in to HyperV Cluster

We have 2 Hyperv Servers and a SAN. When they were configured, High Availability wasn't on the horizon. But it is now. Can I convert the current servers in place to use Failover Clustering? Or ...
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2answers
4k views

heartbeat: find out machine's status within a cluster?

I'm trying to do some heartbeat debugging. Is there a simple way to ask a machine whether it thinks it's part of a cluster, and whether it's the master or the slave? I've tried $ heartbeat -s ...
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2answers
464 views

High Availability without IP Failover?

Are there strategies or techniques to create HA environment when IP failover isn't available? I'm reading a guide at Linode's library which describes exactly what I want to do, but I'm not sure my ...
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2answers
550 views

Exchange 2010 mailbox server role on a secondary dc - what is your opinion

I'm looking at the database availability groups in regards to creating a constant replication of the mailbox database. Here are three options I'm thinking of (and sorry if I'm wrong with my ...