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.
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Make a Docker application write to stdout
I'm deploying a 3rd-party application in compliance with the 12 factor advisory, and one of the points tell that application logs should be printed to stdout/stderr: then clustering software can ...
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Redis Cluster: (error) MOVED
I have a Redis cluster with the following nodes:
192.168.0.14:6379 master (slots from 0 to 16383)
192.168.0.15:6379 slave (slots from 0 to 16383)
192.168.0.16:6379 master (without slots)
...
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nginx automatic failover load balancing
I'm using nginx and NginxHttpUpstreamModule for loadbalancing. My config is very simple:
upstream lb {
server 127.0.0.1:8081;
server 127.0.0.1:8082;
}
server {
listen 89;
...
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How can I pre-sign puppet certificates?
Puppet requires certificates between the client (puppet) being managed and the server (puppetmaster). You can run manually on the client and then go onto the server to sign the certificate, but how do ...
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Cheapest iSCSI SAN for Windows 2008/SQL Server clustering?
Are there any production-quality iSCSI SANs suitable for use with Windows Server 2008/SQL Server for failover clustering?
So far, I've only seen Dell's MD3000i, and HP's MSA 2000 (2012i), which both ...
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Is it a good idea to store Docker volumes in glusterfs?
I am currently thinking about migrating some of our servers and apps to a coreOS environment. One of the problems I see here is the management of persistent data as coreOS does not handle Docker ...
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Bidirectional real-time sync of large file tree between two distant linux servers
By large file tree I mean about 200k files, and growing all the time. A relatively small number of files are being changed in any given hour though.
By bidirectional I mean that changes may occur on ...
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4
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Are ZFS clustered filesystems possible?
Is it possible to create a ZFS cluster? Or would you need to go the seemingly ugly (to me at least) route of ZFS with UFS formatted pools governed by GlusterFS?
The idea is to see if it is possible ...
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1
answer
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Which messaging layer to use, Heartbeat or Corosync?
Just about finished my research into setting up a web server cluster and I'm still undecided as to which messaging layer to use with Pacemaker. The servers I'm using are all Fedora so both layers are ...
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When is the right time to introduce high availability for web site?
When is the right time to introduce high availability for web site?
There are many articles on High Availability options.
It’s not that obvious however WHEN is the right time to switch from single ...
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Redis cluster: 3 master nodes minimum?
I'm evaluating the cluster capabilities of Redis 3 (I'm using Redis 2 standalone at the moment), so I am reading the info at http://redis.io/topics/cluster-tutorial.
In this document I read a very ...
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Managing an application across multiple servers, or PXE vs cfEngine/Chef/Puppet
We have an application that is running on a few (5 or so and will grow) boxes. The hardware is identical in all the machines, and ideally the software would be as well.
I have been managing them by ...
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mirrored filesystem across a few servers
I'm looking for a solution to mirror or replicate one directory (or one filesystem) across a few Linux servers. Ideal solution would be one, which permits all servers read-write access. I also want it ...
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How to setup STONITH in a 2-node active/passive linux HA pacemaker cluster?
I am trying to setup an active/passive (2 nodes) Linux-HA cluster with corosync and pacemaker to hold a PostgreSQL-Database up and running. It works via DRBD and a service-ip. If node1 fails, node2 ...
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How does one cluster multiple machines to act as one to run multiple virtual machines on this single-seeming machine? [duplicate]
How does one take multiple computers and make them act as one, such that all their processors and memory are combined now and you are running any application such that yo are running them on a single ...
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Multiple servers acting like a single one with all the hardware? [closed]
by now I have 10 servers for hpc, power computing oriented.
My users need to launch several processes using qmake.
The users are used to work with ubuntu 9.10, and the software from the repositories ...
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Clusterssh alternative for managing multiple SSH server [closed]
Is there any alternative to Clusterssh, pssh etc, to manage multiple ssh based servers through one interface?
One weakness in Clusterssh is that my servers use key based authentication, with ...
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answer
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What is the minimum amount of servers for a production mongoDB cluster?
On the mongoDB documentation for a production cluster architecture I read that the minimum amount of servers for a running production mongoDB cluster is 7:
Is it possible to share the routers, config ...
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downgrade cluster functional level
I would like to try to add a Server 2012 Hyper-V server to my current cluster,
Currently 2 server 2016 Hyper-V servers clustered.
I need to be able to add the third because I have to do some ...
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Best way to load balance across multiple static file servers for even an bandwidth distribution?
First off, I'll explain my situation to you. I'm running a fairly popular website as a side project, so I can't really invest a ton of money into it. I currently have just one server with HAProxy in ...
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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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what cluster management software to use for linux?
I have found the following cluster management software tools:
pacemaker (clusterlabs.org), - original a Heartbeat project, focus for high-availability, will be in the next debian version
openqrm (...
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What distributed shell utilities do people feel are good, flexible, and easy to use? [closed]
I've been searching and collecting links for a lot of them, but many of these tools don't have enough use case or demonstration documentation to be able to evaluate their potential worth without ...
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Why does requesting GPUs as a generic resource on a cluster running SLURM with the built-in plugin fail?
Disclaimer: This post is quite long as I tried to provide all relevant configuration information.
Status and Problem:
I adminster a gpu cluster and I want to use slurm for job management.
...
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votes
4
answers
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DIY Hadoop Cluster - Heat & Dust issues?
Following are links of my DIY 6-Node Hadoop Cluster using i3 Machines,
What is the best possible way to protect my design from dust & provide better heat transfer? What should I use to cover four ...
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Ganeti vs Proxmox [closed]
I'm system administrator in small software house. I'm going to virtualise our servers. The main reason for doing this is providing highest possible uptime, but probably it will also increase resources ...
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SSH Host key verification issues using VIP
We have 2 production servers on a VIP, only one is in use at a time, for example:
myservice.mycompany.uk normally points to server1, in the event that server1 fails it is changes to point at server2.
...
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Best options for storing and sharing data over mutiple servers, to be accessed by multiple users
In the environment I currently work in there are several servers dedicated to various departments. However we recently got our hands on several identical servers potentially, around 10+. I'm hoping ...
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Linux Filesystem options for iSCSI shared storage
I am trying to determine my 'best choice' for a filesystem to use for a shared storage device that will be mounted via iSCSI across an indeterminate number of servers.
Setup:
27TB Synology RS2212+ ...
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How to build a single virtual machine on top of multiple computers? [duplicate]
Is there a way to run Linux operating system on a virtual machine which aggregates the resources of physical machines on the local network and acts as a single super-computer? If possible, how?
...
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Advantages of Using Nginx or HA Proxy as Load Balancer
In our environment we us both Nginx and HA Proxy on different clusters. Are there advantages of using one over the other?
Or, what is the best way to go about load balancing a basic LAMP server ...
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A roundrobin for incoming files
A bunch of new files with unique filenames regularly "appears"1 on one server. (Like hundreds GBs of new data daily, solution should be scalable to terabytes. Each file is several megabytes large, up ...
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Redis high availability and load balancing
I'm using Redis for some time and now we want to move to a redundant cluster which would be fault tolerant, highly available and load balanced.
I principally use Redis for some PHP web application ...
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Test-Cluster Powershell cmdlet List vs Validate
The Powershell cmdlet Test-Cluster queries a myriad of data and performs validation tests which it wraps into a pretty report. If you run Test-Cluster -List you get a list of item's you can ...
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High availability virtual machines
I've been reading a lot about high availability virtualization, either via Hyper-V or VMWare. In that context, essentially high availability means that the VM is hosted by a cluster of physical ...
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Load balanced Drupal servers: a good way to share data among the servers?
I'm trying to get an overview of how i would go about creating a load balanced web server setup. Setting up the actual load balancer and adding two or more web servers seems fair enough. However, I ...
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Which database servers are not interrupted by server reboots? (Clusters?)
We have been asked to deliver a system where the central database server continues its operations, even when applying security updates to the server's operating system or to the database server ...
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5
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KVM+DRBD replicated between two active-passive servers with manual switching
I need to build 2-node cluster(-like?) solution in active-passive mode, that is, one server is active while the other is passive (standby) that continuously gets the data replicated from active. KVM-...
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Is it possible to create a faster computer from many computers?
My post below was (I think rather unfairly) closed on StackOverflow hence my reposting here.
Original Question: How can I use several computers to create a faster environment? I have about 12 ...
Ranja
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5
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Skip over intermediate server via SSH
I just got hired to work in a lab with a big 'ol linux cluster. I'm a mac/windows guy, so I'm still trying to figure out how to navigate around using a 'nix command line. So far I haven't run into any ...
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Error when create a MicroK8s cluster : Connection failed. The hostname (xx) of the joining node does not resolve to the IP "xx". Refusing join (400)
I have installed microk8s(1.24/stable) on two machines.
The ip of the two machines are：172.29.99.187, 172.29.99.188.
I operate the command at 172.29.99.187：microk8s add-node
Output:
From the node you ...
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Two-Node Server 2012 R2 Hyper-V Cluster: Is it possible use local physical disks in the cluster?
Looking at the following Clustered Shared Spaces TechNet article, and it looks like this only applies to hosts sharing a JBOD enclosure by way of external SAS backplane.
However, each host in the two-...
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How can I shut down (power off) cluster nodes during low load?
I'm developing software for the energy consulting business and in monitoring energy use in datacenters, I've noticed that the typical electric load "pattern" of a datacenter is just a flat line, ...
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Load balancing and HTTPS strategies
I am faced with the following problem: Servers get saturated since current load balancing strategy is based on client IP. Some corporate clients access our servers from behind large proxies so all ...
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Cluster failover and strange gratuitous arp behavior
I am experiencing a strange Windows 2008R2 cluster related issue that is bothering me. I feel that I have come close as to what the issue is, but still don't fully understand what is happening.
I ...
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Miserable performance of Hyper-V storage on CSV
I recently setup a new environment consisting of:
- QSAN Storage with 10Gib network
- Mellanox switches 10Gib
- 4 x Physical nodes connect to LAN and SAN 10Gib
The physical hosts are connected ...
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Does CoreOS have a cluster aware job scheduler?
Ive been checking out CoreOS and I'm impressed. Before I found CoreOS I was looking at the Mesos/Marathon/Chronos stack as a "cluster kernel".
Given the following comparison:
init.d == Mesos+...
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Hyper-V Cluster with failover - NETWORKING
We are looking to setup a 3 node Hyper-V cluster with live migration and failover using:
3 x Dell R710's with dual quad core Xeon & 128 GB RAM & 6 NICs in each
1 x Dell MD 3220i SAN
We will ...
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What "pieces" are needed in order to set up a cluster of physical servers?
Background:
Currently, we use Rackspace cloud servers. We have no intention to stop using them, but would like to look into setting up a cluster of physical servers (probably desktop computers in the $...
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Pacemaker/corosync timeout before resource transfers
This seems like a simple question, but one I can't seem to find the answer for despite going over the pacemaker documentation multiple times.
I've got corosync set up with pacemaker to share a ...
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