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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6
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4answers
3k views

Multiple servers acting like a single one with all the hardware?

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 ...
14
votes
4answers
5k views

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 ...
4
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1answer
3k views

what is gen_clust_index used for in mysql?

It seems I have a deadlock in mysql (running innodb) that's due in part to a lock on gen_clust_index, however, this isn't a table that I've created. So... what's the short and sweet description of ...
14
votes
2answers
27k views

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; ...
11
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6answers
4k views

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 ...
2
votes
2answers
813 views

SQL Cluster install on Hyper V options

I've been reading up on running a SQL Cluster in a Hyper V environment and there seems to be a couple of options: Install guest cluster on 2 VMs that are themselves part of a fail over cluster. ...
4
votes
2answers
646 views

puppetrun not reporting client errors

puppetrun doesn't report errors my puppetclients encounter. for instance, if I put jibberish into site.pp and run puppetd --test on the clients I get an error. if I run puppetrun on the puppetmaster ...
2
votes
2answers
893 views

why would adding a crossover private nic cause IP address resource fail?

2 node Win 2008 R2 quorum cluster Configured 192.168.0.0/24 "public network" Configured cluster MSDTC Installed SQL 2008 R2 cluster instance Manually failover groups - OK Reboot server w/o failing ...
1
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2answers
5k views

Sql server active/passive vs active/active clustering

What is the difference between SQL Server clustering methods: - Active/Active - Active/Passive in simple worlds and an example usage scenario per method...
0
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2answers
600 views

Just a few questions about Hyper-V virtual machines and clustering

I have been using Microsoft’s Hyper-V technology for a little while now, but I am just now dipping my toe into clustering. In particular, I am trying to implement a fault-tolerant SQL DB. This ...
24
votes
4answers
7k views

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 ...
25
votes
15answers
19k views

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 ...
5
votes
6answers
1k views

(*nix) Cloud/cluster solutions for scalable web-services

I'm going to build a high-performance web service. It should use a database (or any other storage system), some processing language (either scripting or not), and a web-server daemon. The system ...
6
votes
9answers
3k views

Managing a Linux cluster

I'm interested in learning about tools and techniques used to manage many Linux machines. (That is, deploying and maintaining updates.) One way that I thought of to do this is write a Bash script ...
6
votes
7answers
1k views

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, ...
4
votes
5answers
1k views

Decent 1gb switch (16-24 port) for rack

For a rack containing a smaller nubmer of servers (5 at the moment, going to stay in this area), I am looking to replace the currently aging 100Mbit switch with a 1Gb switch. This is for the backend ...
4
votes
3answers
5k views

How to mount glusterfs inside a OpenVZ container?

glusterfs uses fuse to mount a glusterfsd volume, wich works fine on any hardwarenode without virtualization. But, I now try to mount the device inside a container glusterfs --debug -f /etc/...
7
votes
2answers
20k views

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 ...
6
votes
2answers
3k views

VMware Virtual Machine Clustered Filesystem Setup

The situation is: I am running VMware ESX 3.5 (3 ESX Hosts w/ vCenter Server in a Cluster); I need five Virtual Machines to read from the same disk running a clustered file system; I cannot ...
1
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2answers
4k views

How to configure failover for JBoss AS 5?

I am currently an intern in my company. My boss basically wants me to perform a failover from a JBoss AS to another just for a proof of concept. Load balancing is not required as i am only required to ...
0
votes
2answers
1k views

HA web cluster setup

I'm setting up a highly available web cluster, I'm planning to start out with 2 web servers connected to shared storage (perhaps via NFS). What's the best way of implementing this? Should the web ...
2
votes
1answer
245 views

What database is easy to maintain and manage in a cluster?

I'm looking for a database (DBMS) that is easy to scale out. I would like to have high availability so I need a multi-master cluster, where the data is replicated to two or more physical computers. I ...
2
votes
1answer
8k views

Tomcat Cluster Farm Deployer issue

I have setup apache-tomcat cluster with mod_jk on ubuntu server. I have some issues with FarmDeployer which deploys war files to other web servers in the cluster and I got some hope that it works as I ...
1
vote
1answer
472 views

Advantage of Microsoft Cluster over Microsoft Network Load Balancer

Till recently, I assumed that Microsoft NLB worked at an OS/Machine level rather than an Application Level. i.e. the NLB just monitors heartbeats on the machine to check if machine is alive and then ...
1
vote
1answer
606 views

Can't create clusters in PostgreSQL 9.0

I'm trying to setup and run multiple clusters of PostgreSQL 9.0 in the same Ubuntu/Debian machine. Debian has a package called 'postgresql-common' to facilitate managing database clusters. However, ...
4
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2answers
2k views

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 ...
4
votes
1answer
556 views

SQL Server 2008 R2 100% availability

Is there any way to provide 100% uptime on SQL Server 2008 R2? From my experience, the downtimes for the different replication methods are: Log Shipping: Lots (for DR only) Mirroring w. NLB: ~ 45 ...
3
votes
3answers
2k views

Sharing SSL Certificates in a Cluster

Hopefully a very simple question, if I wanted several servers providing the same service to hold a certificate (e.g interface.internal.org) would the procedure be; Generate Public/Private Pair on ...
3
votes
1answer
247 views

Active directory (AD) best-practice for clustering

We want to use AD as a regular LDAP for storing and accessing our application data in fast and reliable way. We have two physical server and want to organize some sort of clustering for AD and its ...
2
votes
2answers
6k views

Farm Deployer not working in Tomcat Cluster

I have setup apache-tomcat clustering(Ubuntu Server) and I used tomcat supported clustering technique with mod_jk following the link. I've setup with One Load Balancer and Two web servers. The major ...
2
votes
3answers
2k views

DRBD / Heartbeat on Virtual Machines

Does anyone have experience configuring drbd with heartbeat between 2 virtual linux machines (VMWare Infrastructure)? The problem I am running into is that heartbeat likes multiple data paths to see ...
2
votes
2answers
2k views

MSDTC failed in windows cluster any idea?

I have created a windows2003 cluster and then try to configure MSDTC by following the link http://support.microsoft.com/kb/301600/#appliesto after follow this i have enable network DTC access in ...
1
vote
2answers
606 views

Sun Grid Engine: Automatically Terminating Idle Interactive Jobs

We're considering using Sun Grid Engine on a small compute cluster. Right now, the current set up is pretty crude and just involves having people ssh to an open machine to run their jobs. We'd like ...
1
vote
3answers
773 views

password for ssh and scp

(1) I want to upload some files to a server for (( i=0 ; i < 23 ; i+=1 )); do echo mypassword | scp tim@xxx.xxx.xxx.xxx:project/$i/train10000/finer_search_c_g ~/project/$i/train10000/ done ...
1
vote
1answer
2k views

setting up a high speed load balancing server cluster - web/db/NFS

I'm looking for advice on the best way (mainly in terms of hardware) to set up a high speed load balancing server cluster on a budget (say £2,000 - £ 3,000) to host web services behind a single ip ...
1
vote
3answers
193 views

Appropriate network file system for huge (5+ Gb) files

I've got a number of servers used for HPC / cluster computing and I noticed that, given the fact that part of the computations they run use huge files over NFS, this causes significant bottlenecks. I'...
0
votes
2answers
2k views

Failover pacemaker cluster with two network interfaces?

So, i have two test servers in one vlan. srv1 eth1 10.10.10.11 eth2 10.20.10.11 srv2 eth1 10.10.10.12 eth2 10.20.10.12 Cluster VIP - 10.10.10.100 Corosync config with two interfaces: ...
0
votes
1answer
1k views

iptable CLUSTERIP doesn't work

We have some requirements which explained here. We tried to satisfy them without any success as described. Here is the brief information: Here are requirements: High Availability Load Balancing ...
0
votes
1answer
396 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 /...
0
votes
3answers
2k views

Failover clustering: tempdb on SAN?

We are considering clustering our SQL Server 2008 EE instances. The storage is on SAN. Can we put tempdb data/log files on SAN? What are the pros and cons on this solution? For optimal performance, ...
0
votes
1answer
977 views

Active Directory Lightweight Directory Services (AD LDS) best practice for clustering

We decide to use Active Directory Lightweight Directory Services (AD LDS) for our application. But we cannot find the guide for clustering this service. Can anybody suggest or give a link to the best-...
0
votes
2answers
1k views

SAN + MySQL replication- is that what I want for my load-balanced Drupal cluster?

I need to put together a Drupal instance using Drupal's built-in multisite features, which will allow me to use a single code base for all the sites- a big time-saver and headache-preventer. We're ...