Questions tagged [cluster]

A computer cluster consists of a set of loosely connected computers that work together so that in many respects they can be viewed as a single system.

A computer cluster consists of a set of loosely connected computers that work together so that in many respects they can be viewed as a single system.

The components of a cluster are usually connected to each other through fast local area networks, each node running its own instance on an operating system. Computer clusters emerged as a result of convergence of a number of computing trends including the availability of low cost microprocessors, high speed networks, and software for high performance distributed computing.

Clusters are usually deployed to improve performance and availability over that of a single computer, while typically being much more cost-effective than single computers of comparable speed or availability.

Computer clusters have a wide range of applicability and deployment, ranging from small business clusters with a handful of nodes to some of the fastest supercomputers in the world such as the K computer.

Source: Wikipedia.

1360 questions
4
votes
2 answers

DRBD - no resources defined

I have some problems getting a drbd cluster running. When I want to start creating my storage, i get the following error: root@raspberrypi-ha1~# drbdadm create-md drbd1 no resources defined But my resource is definitely defined in /etc/drbd.conf…
Matzes
  • 41
  • 1
  • 2
4
votes
1 answer

Do you Suspend-ClusterNode before or after Move-ClusterGroup?

Which do you do first to avoid service interruption? Or does it not matter? Is it: Suspend-ClusterNode -Drain Get-ClusterNode $env:COMPUTERNAME | Get-ClusterGroup | Move-ClusterGroup or: Get-ClusterNode $env:COMPUTERNAME | Get-ClusterGroup |…
4
votes
1 answer

Can you list a Datastore Cluster's sDRS Schedule via PowerCLI?

We have a lot of datastore clusters, most if not all are supposed to have sDRS schedules applied to stop them moving VMs at busy periods. Obviously we could trawl through them manually to check if they're how they should be but I like to do things…
Chopper3
  • 101,299
  • 9
  • 108
  • 239
4
votes
0 answers

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 help. I have two VMs on 200.xx.xxx.9 and…
jetboy
  • 912
  • 2
  • 11
  • 25
4
votes
1 answer

SAS balancing vs Network balancing

I want to configure file server in MS Windows Server 2012 R2 environment, which would load balance traffic. I have got a SAS disk array with 2 SAS controllers which is connected to 2 Hyper-V cluster nodes by 4 redundant SAS multipaths: controller1…
4
votes
1 answer

Why Failover instead of Load Balancing for HA

From my understanding with failover clustering, only one machine is actually working, which means the other one(s) are sitting idle. So why would one use failover clustering instead of using a load balancing style with Windows Server 2012 to gain…
Jason
  • 3,931
  • 19
  • 66
  • 107
4
votes
1 answer

Scaling a web application horizontally in Tomcat (load balancing / clustering)

I develop a simple REST-style web application consisting of 2 basic modules. Module#1: server exposing REST web services, stateless, deployed in Tomcat Module#2: REST client There is one Tomcat instance with the Module#1 deployed. I would like to…
BartoszMiller
  • 143
  • 1
  • 5
4
votes
1 answer

Creating a stable, auto-scaling app server cluster

I have two servers, each running anywhere from 50-100 different legacy webapps, written in languages ranging from PHP to Python to Ruby-on-rails to NodeJS. We're wanting to kill off these machines as they're old, insecure and badly organised, have…
aendra
  • 177
  • 9
4
votes
5 answers

send files to dozens of servers quickly

We have a cluster of machines (around 50 and growing). Each machine has a search index that needs to be updated multiple times per day. We currently update the index on each machine individually, but ideally, we could update it on one machine, then…
Brian Lovett
  • 197
  • 2
  • 11
4
votes
1 answer

MariaDB how to handle 2/3 node failure in multi master cluster.

I run 3 node multi master MariaDB galera cluster. It basically works for me how it is. When one node fails, two other work and it's fine. But I'm wondering is there a way for it to keep working on one node? (that is really unlikely but I just…
piotrektt
  • 184
  • 2
  • 14
4
votes
2 answers

SQL Clustering or Hyper V Clustering

We will soon be implementing our Dynamics AX installation. Our aim is to have high availability and we are working closely with our implementers. We raised the question to them about SQL and Hyper-V Clustering. They recommended that when running in…
dqnet
  • 305
  • 2
  • 9
4
votes
1 answer

clvmd problems during the RHEV cluster deployment

We are deploying Red Hat Enterprise Virtualization cluster and we faced a problem attempting to start clvmd service after the lvm partition creating. The following has been completed successfully: vgchange -cy RHEVMVolGroup lvmconf…
Vitaly Isaev
  • 159
  • 2
  • 5
4
votes
2 answers

How can I move the data files for a VM to another location?

We have a cluster of 3 x 2008 R2 physical hosts running Hyper-V. How do I safely move the VHD(s) and accompanying XML files, etc, for a specific VM to a new location? I want to keep the VM with the same name in the same cluster - just relocate the…
Kez
  • 448
  • 4
  • 11
  • 22
4
votes
1 answer

Nginx - multiple servers configuration

I have a cluster of 8 independent web servers, each of them running nginx. They are all hosting the same websites and are being synced with rsync. Also, each server has 8 different IP addresses attached to it. My hosted websites are being directed…
shaharmor
  • 337
  • 4
  • 16
4
votes
0 answers

Windows Server 2012 - Hyper-V - iSCSI SAN - All Hyper-V Guests stops responding and extensive disk read/write

We have a problem with one of our deployments of Windows Server 2012 Hyper-V with a 2 node cluster connected to a iSCSI SAN. Our Problem Our problem is that for some reason all of the VMs stops responding or responds very slowly and you can for…