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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27 views

What is the proper way to shutdown an iSCSI target with connected clients?

iSCSI with two DRBD primary nodes is a bad idea to use if the two paths get concurrent write requests. But I am thinking about using this idea as backend storage for an ESXi 5.5U2 host. I already did ...
1
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1answer
22 views

why configure cluster nodes to reboot when out of memory

I have access to a research HPC cluster which is configured so that if your job tries to use more memory than the node has available the node crashes and automatically reboots. This appears to be ...
1
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1answer
41 views

Does hardware RAID1 offer significant advantages to S/W RAID in a computer cluster that's highly redundant?

I'm about to set up a Linux cluster of 5 physical server nodes (more nodes to be added later, probably). the cluster will be managed by Proxmox (and yes, it works in software RAID) shared storage ...
1
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0answers
26 views

Windows cluster has lost or discarded the CLUSDB

Both nodes of a two node windows failover cluster on 2008R2 have lost the CLUSDB file. I think this happened because an inexperienced admin came to a cluster with a reserved disk issue and ...
0
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2answers
44 views

What is optimal sql server cluster storage solution?

I have been assigned a project where sql server is running on a single server with single raid 1 volume. This setup has worked fine until hardware failure resulted in about a day worth of downtime ...
0
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0answers
14 views

JBOSS cluster cannot access master or Slave individually

I have setup a JBOSS cluster using two VM nodes as Master and Slave. The Mod-Cluster-manager console shows that all the traffic has been redirected to only the master Both the JBOSS nodes are running ...
0
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1answer
56 views

Apache Tomcat 7.0.57 Cluster & mod_proxy / mod_proxy_ajp

I have set up an Apache Tomcat Cluster with an Apache HTTP server and load balancing on CentOS 6.6 the following way: + 1 VM running HTTP server & 1 Tomcat instance (used for deployment, not ...
0
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0answers
15 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 ...
0
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0answers
28 views

Direct server return loadbalancer for mariadb galera cluster with 2 networks

Is it possible to configure LVS (keepalived) loadbalancer with direct server return (DSR) for 2 leg network setup? The desired architecture is as follows: mariadb galera cluster, where each node has ...
1
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0answers
45 views

Windows 2012 R2 Hyper-V cluster without shared hardware

I have several servers with local SATA/SAS RAID arrays. I would like to run there virtual machines with some level of automated failover - sync VM to secondary node in 1 minute interval and automated ...
0
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0answers
10 views

Python libraries slow to load from NFS mount point

Several of our computers are diskless, and they load their Python libraries from an NFS mount point across the network. This means it can take up to three minutes to start up a Python process that ...
1
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1answer
61 views

CoreOS Cluster DNS setup

I'm unsure of how to setup DNS for a coreos cluster. Currently I have all of my api instances behind a haproxy load balancer and a DNS A record which points to the (elastic) ip of the load balancer. ...
1
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1answer
59 views

Redis/Sentinel cluster failover results in “failover-abort-not-elected master”

I have a 2 node Redis cluster set-up. [master] 192.168.56.102: Redis Master (:6379), Redis Slave (:6380), Sentinel(:26379), Sentinel#2(:26380) [rescue] 192.168.56.103: Redis Master (:6379), Redis ...
0
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1answer
23 views

Adding hosts to existing 2012r2 Hyper-V cluster

Situation: Two separate clusters, server 2012 and server 2012r2 In process of disassembling the 2012 cluster and upgrading those hosts to 2012r2 Prior to this I must move all of the guests to the ...
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0answers
11 views

Does Stop-CauRun Stop the Current Server or the Whole CAU action?

When using a PreUpdateScript or PostUpdateScript with "Windows Cluster Aware Updating" and "Updating Run Profiles" would calling the cmdlet Stop-CauRun do any of the following: Would it actually ...
1
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1answer
38 views

“Applications and Services” is missing from Failover Cluster Manager

Microsoft instructions advise to use "Services and Applications" but it's missing from the Failover Cluster Manager. For example, the documentation for Test the Failover of a Clustered Service or ...
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0answers
120 views

Windows Failover Cluster - Create Cluster Wizard: error occurred while creating the cluster

I have 2 identical Windows Server 2008 R2 servers which I am trying to setup a failover cluster on. The "Validate a Configuration" passes, but the actual creation process produces an error: An error ...
0
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0answers
31 views

“A virtual machine fails to power on with the error: Thin/TBZ disks cannot be opened in multiwriter mode” - after disk size change in client

I tried to increase the size of my clustered virtual disk (2 vms) though the vSphere client. Big mistake apparently. Now when I attempt to start the vms, I get "A virtual machine fails to power on ...
1
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1answer
85 views

Intel MPI Gives 'channel initialization failed' error (mpirun)

I'm trying to setup a small cluster consisting of 3 servers. Their hardware is identical, and they are running CentOS 7. I'm using Intel's cluster compiler and MPI implementation. Everything is setup: ...
0
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1answer
70 views

Clustered Apache 2.4 LoadBalancer displays no content on /balancer-manager

I have a Clustered Loadbalancer (pacemaker, corosync, apache 2.4) on CentOS 7. There are two configuration files, one for the actual balanced site and one for the balancer-manager. When I access the ...
0
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0answers
59 views

Monitor network statistics with vnstat on CoreOS?

I notice that vnstat isn't installed on CoreOS. Is there a comparable way to monitor network usage on a CoreOS cluster? Certainly one could run vnstat through a Docker container but I assume that ...
2
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1answer
50 views

Using a JBOD for redundant NFS

I have a Xyratex sp-2224 JBOD enclosure (dual controller) and a pair of Dell servers with SAS HBAs installed that I'm looking to utilize in a redundant NFS cluster. The hardware isn't what I'm ...
8
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4answers
181 views

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 ...
0
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0answers
35 views

Can Windows Cluster Aware Updating be configured to allow for downtime?

I thought I'd ask here before giving up completely on this. We have a Windows 2012 Cluster with two nodes and quorum type as "Node and File Share Majority". Failover is not allowed to happen ...
0
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1answer
75 views

apache proxypassreverse ServerName not working

I have a secondary development wordpress site. (Centos 6.6 x86 ,LAMP) Since the size of the site is growing. (300GB+). Now I divide it into 3 server. domain: www.example.com server1 46.192.22.01 ...
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1answer
51 views

centos single domain multiple server

I have a secondary development wordpress site. (Centos 6.6 x86 ,LAMP) Since the size of the site is growing. (300GB+). Now I have 3 server totally. domain: www.example.com server1 172.192.22.01 ...
1
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1answer
155 views

Migrating windows server 2008 r2 hyper-v cluster to Server 2012 r2

I did some browsing of the existing articles regarding this question but I couldn't find it so I apologize if I simply missed it. My current setup: 1 x 2008 R2 Hyper-V Cluster 3 x Windows Server ...
0
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0answers
27 views

PBS, adding job - job added, seems that it didnt run at all

First of all, Im very new to clusters and PBS systems. I was told to prepare a simple script (which I did): #PBS -S /bin/bash #PBS -o host_out #PBS -e host_err #PBS -q batch hostname date exit 0 ...
0
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1answer
56 views

High Load Website. how to load balancing? [closed]

i have the following problem: i have two servers (intel xeon 3,4 GHZ with 32GB RAM and RAID 10 (4x1TB Enterprise Harddiscs). all servers are installed with vmware esxi 5.5 (free). webserver, ...
-1
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1answer
48 views

How to setup a group profile based for terminal server via LDAP?

I have 4 terminal server "they are clustered together." All of them have the same specs and same configuration. and have Windows Server 2008 R2 installed on them. All users are using LDAP to log in. ...
0
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2answers
22 views

Rsync through secure head-node on storage cluster

I wish to use a specific head-node as contact address for my rsync backups, I do no wish to have the backend accessed directly, as it is not as hardened, nor as compatible with the rest of my ...
0
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0answers
60 views

mkfs.gfs2 failing silently on centos7 cluster?

I'm building a test cluster using centos7 and pacemaker, with shared storage on GFS2 over clustered LVM. I've set up a 2-node cluster, dlm and clvmd, both nodes can see the clustered logical volumes. ...
2
votes
1answer
80 views

How do I set the pacemaker cluster name with pcs?

I'm running two pacemaker clusters on the corosync stack on CentOS 7 with all packages up to date with the distro release/updates packages. Both clusters shows no cluster name with the command pcs ...
0
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0answers
20 views

clustat : How to get a list of logical services included in a cluster service?

When I use the command clustat, I get a list of cluster services like sOPS sQRY sBCK How can I get a list of services like dns, filesharing, ... running inside a cluster service?
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43 views

Windows Server 2012 Cluser on VMware esxi 5.5: Rebooting passive node causes san reset on active node

I'm running a SQL Cluster on windows server 2012 on VMWare 5.5 and find that when I restart the passive node to install a patch, the active node is affected. This appears to be covered by the kb ...
1
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1answer
129 views

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 ...
2
votes
1answer
117 views

Get-Cluster cmdlet fails when using -Name param

Summary When I call Get-Cluster powershell returns the name of my cluster. For simplicity sake, lets call it Cluster1. If I call Get-Cluster -Name Cluster1 it fails with an error. Error: ...
0
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0answers
50 views

Configuring Maui/Torque to map different queues to same nodes based on availability

I want to setup Maui/Torque to have queues mapping to specific nodes. I currently have 2 queues (main, priv) and 2 nodes (node1, node2). What I would like to achieve is the following: *queues* -> ...
1
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2answers
194 views

Best ways to discover servers in a public cloud? [closed]

I want to make a ubuntu server image to run in a public cloud that discovers when other servers from the same image come online. I came up with this list of solutions, but I'm not sure what is best? ...
0
votes
2answers
212 views

Centos 6.5 configuring HA cluster

I need to configure HA cluster using 2 computers. But I've got a problem, when I'm trying to start a heartbeat service it starts but throws an error. Here's the error message: Starting ...
1
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1answer
82 views

High Availability/Failover hardware hookup

I'm learning about clustering and high availability techniques, and stumbled upon an article about configuring a network with a pair of servers, using DRBD for replication and heartbeat for monitoring ...
0
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0answers
208 views

Virtualization-(Cluster) with KVM/libvirt on top of a FC SAN

I'd like to set up a 2-node HA-Cluster based on Ubuntu and KVM running about 30 VM's. Both nodes are connected to a HP MSA(5TB) via Fibre Channel. Multipathing's already working and the nodes are able ...
0
votes
1answer
301 views

Cassandra 2.x - cluster does not rebalance after adding new nodes

I had 3 nodes, all with ~550GB, and added 4 more. I hoped that data would migrate on its own from old servers to new ones. Unfortunately after one day, data seems to stay in old places. In parallel, ...
1
vote
1answer
116 views

Setup MongoDB on MS Azure virtual machine to access it from an azure website

I have setup a MongoDB replica cluster on 3 virtual machines (Ubuntu 14), on MS azure cloud. The mongodb cluster has been setup with MMS (https://mms.mongodb.com amazing tool btw) and it works fine. ...
1
vote
1answer
157 views

Persistent Disk Name in RedHAt Cluster on VMWare Workstation-10.01

I am trying to implement a 2 Node REDHAT HA cluster. The following is my environment. VMWare WorkStation 10.01 Node-1 >> CentOS-6.3 x86_64 Node-2 >> CentOS-6.3 x86_64 Node-3 >> CentOS-6.3 x86_64 [ ...
0
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0answers
27 views

MSSQL High Availability Advice Required

I'm looking to implement a high availability SQL installation using MSSQL2012 or 2014 and there is 1 part of this I'm not sure about. I plan to have a SQL cluster at site a, and a secondary SQL ...
0
votes
1answer
44 views

pg_createcluster ssl cert behaviour different for 9.1 and 9.3 on Debian Squeeze

I think i found a bug in pg_createcluster when creating a 9.3 cluster. At first, my configuration: Debian Squeeze with PostgreSQL 9.1 from squeeze-backports and PostgreSQL 9.3 from apt.postgresql.org ...
1
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0answers
23 views

Glassfish 2.0 - per node JVM config

I have a Glassfish (2.0) cluster with two nodes. I want to pass some extra JVM settings to a single node only. Is this configurable? At least from the console I see, this selective configuration is ...
2
votes
1answer
439 views

Unresponsive ESXi 5.5 server

I have a host that is part of a 4 host cluster in HA. Sometime yesterday I noticed the host stopped responding, in the vsphere console it shows up greyed out as (not responding) and all VMs on it ...
1
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1answer
80 views

redhat, multipath on cluster node display different result

I've a cluster with two nodes installed with "RedHat Entreprise Linux Server 5.6" If I execute "multipath -ll" on them, I do not get the same result. I've checked within "multipathd -k" with "show ...