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.

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MAAS for diskless computational hpc cluster

I'm considering to use MAAS to deploy OS for a computational cluster. All nodes are diskless. Only head node and (probably) MAAS rack controller will have hard drives. It seems MAAS have to finish a node commissioning before using it, but how…
rth
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Transform Galera cluster into single node mariadb server

We want to get rid of all cluster features on our galera cluster (currently consisting of three virtual machines). The connection between the nodes is not stable enough so the cluster is much slower than our previous single node setup was. Is it…
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Should io and cpu intensive servers be separated in kubernetes cluster?

We are designing a new cluster architecture for our web service and are planing to use Ceph object storage and kubernetes for our services. for optimizing our servers We have different options: Use identical servers and run Ceph and our services…
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Why Redis slaves don't take over the master after master fail in Redis Cluster?

I have a Redis Cluster with 2 masters and 4 slaves (2 slaves for each master). After I manually crash a master (i.e. redis-cli -p 6379 debug segfault) slaves doesn't do anything. They detects that something wrong with the master but they are doing…
Oleksandr
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Galera cluster - cannot start MariaDB (CentOS7)

I'm trying to install a Galera cluster with 3 mariadb VM's (all of them CentOS 7). I've never done this before, so I was following this guide: http://tunnelix.com/mariadb-galera-cluster-installation/ The problem is that after I enter my settings on…
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In a container cluster like Kubernetes or Docker 1.12 Swarm, how do you resolve with external DNS to the good container on the good host?

Maybe I am dumb, maybe am I just not using the good words, but I can't find even one answer anywhere on Stackexchange or the whole Web. I have created lots of website, mostly with Wordpress, Drupal, ... (And recently, I have begun experiencing with…
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Replacing failed hardware in a hyper-converged cluster node

Is it possible to replace failed physical components (such as disk, RAM, or power supply) in a hyper-converged node (such as VXrail or Nutanix) without taking the node offline?
SamErde
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Postgresql replication with pgpool or pgbouncer

I'm looking for a good configuration for a postgresql replication with a robust failover strategy (self hosted). Actually, I configured two postgresql instances in master / slave with repmgr. Now, I don't know what to put before these two instances…
Luca Leen
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Is there a difference between LVM and HA-LVM or is it just how you use it.

I am studying up on HA Clusters using pacemaker and corosync. The Red Hat documentation treats LVM, HA-LVM and CLVM as separate topics. I understand the added features and benefits of CLVM over HA-LVM. What I am not sure of is what HA-LVM is…
digitaladdictions
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ceph - can't start osd on rebooted cluster host

I've rebooted the server (one of ceph's hosts). Started the cluster, but the osd, that's on the host, which was rebooted is down. The osd's # is 2, so when I try: sudo /etc/init.d/ceph start osd.2 it shows: Starting ceph (via systemctl):…
igoryonya
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Hyper-v failover or replication in 2 node cluster

I'm trying to setup some form of a failover cluster between 2 hosts. I want to be able to have high availability on 2 of my VMs. It seems that some form of shared storage is required for this to work properly in a windows cluster but the goal at the…
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In a Pacemaker cluster, is there any way to set start-failure-is-fatal on a per resource basis?

I've got it set cluster-wide currently, but I'd really like it to be set to 'true' by default and false for only my Slave DRBD resource. Using Pacemaker 1.1.12 and Corosync 1.4.8.
javanix
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Must all nodes of an Elasticsearch cluster be identical?

In an Elasticsearch cluster, must all nodes be identical i.e. having the same: Operating System Amount of RAM CPU speed and number of cores etc. or is it allowed for the nodes to be different? (Apart from the obvious fact that an homogeneous…
dr_
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Pacemaker and DRBD on Hyper-V

I need to setup two-node Web cluster for Apache web site. I have Hyper-V infrastructure and only two nodes. The points are load-balancing and high availability. I installed and configured two VMs with CentOS 7, Pacemaker cluster, MariaDB 10. I…
Evgeniy
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etcd cluster setup with chef - determining initial-cluster-state

I am writing chef scripts to setup an etcd cluster. The list of nodes (including their IPs) will be hardcoded in the chef script (as an attribute) and it will pass them to etcd using static bootstrapping with --initial-cluster and…
Heinzi
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