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20

You probably want to use the ServerAlive settings for this. They do not require any configuration on the server, and can be set on the command line if you wish. ssh -o ServerAliveInterval=5 -o ServerAliveCountMax=1 $HOST This will send a ssh keepalive message every 5 seconds, and if it comes time to send another keepalive, but a response to the last one ...


7

Creating an ha environment has a lot of caveats and is complicated, and often times depends on the actual software (e.g. creating a master-slave environment for mysql is different than for postfix0 If you want to get started and only want to have two systems and don't have time to configure all your daemons accordingly you should have a look at drbd, raid-1 ...


5

There's the rocks linux distro which is made for clustering, and is based on CentOS/RHEL. The strong point of rocks is that it'll for the most part manage and do a lot of the minutia for you. It'll do automatic installation and reinstallation, and if your computers can boot via PXE, the initial install will consist of PXE booting your nodes. If you have a ...


4

It isn't normal for mandb to run continuously. It is typical to run mandb once a day in a cron job, to perform maintenance task such as updating an index of installed man pages and building or trimming a cache of formatted man pages. The daily job should run in a few seconds, perhaps a few minutes if you have a lot of man pages and a slow disk. If the job ...


4

Using a compute cluster? Since you're asking about qsub I'm going to assume you're using GridEngine or some computer clustering product. qsub When you run the command qsub script_name.sh you're telling the cluster's head node that you want to submit a script to run on that server. So that server would need to have access to the same filesystem's that ...


3

As already mentioned in the comments, since memory and CPU usage are negligible as you said, idle users won't hurt anyone. If you still want to get rid of them, you could automatically hunt down idle users and kick them off, either by e.g. a shell script you call in regular intervals via cron, or by setting ClientAliveInterval 1800 ClientAliveCountMax 0 ...


3

You can use Redhat Cluster Suit for the same. Let's understand little bit of clustering There is a different cluster for every problem. Generally speaking though, there are two main problems that clusters try to resolve. Performance and High Availability. and As per your requirement ( will continue to work even if a node in the cluster becomes inoperable ...


3

I'm a little confused what exactly you want your cluster to do. It sounds a bit like all you want is starting programs and running them on different boxes. If that's the case, SSH/X-forwarding/NFS should do you ok. IMHO this doesn't really have anything to do with clustering, its simply remote controlling different machines. I really have to ask one thing ...


2

We have a small cluster that has openSUSE as its base distro, but I do not think it is too important. Ubuntu looks like a viable alternative and has quite a bit of documentation and community support. On top of linux, we run Sun Grid Engine (and our cluster even includes Mac OS machines pretty seamlessly), but slurm would probably work for a simple setup. ...


2

It really depends on what you are trying to accomplish, and what you mean by "Distributed Computing Cluster." I did a similar thing once in Uni using old machines and PVM that's the "Cluster" in the sense of a bunch of machines acting as one single computer to do parallel processing - think Beowulf clusters. Of course, you will need code that is written to ...


2

What you're talking about is called a Single System Image cluster, or sometimes a distributed shared memory system (in a more limiting context). There are some projects listed on the linked Wikipedia pages you should look into. I've used the SGI Altix cluster (the NUMAlink ones), and it can be quite powerful if you have a process that requires a huge ...


2

The rup command from the rstatclient package will poll all the machines on your subnet for information, including their load averages. The machines must be running rstatd to serve up that information, and I would tcpwrapper it to only respond to your admin desktops. You can also specify individual machines to collect data from. With rstatd running on the ...


2

While @wnoise's answer is a the nicer solution, it might not be possible for you to implement it (i.e. do you administer the cluster?)... so, why not have a look at one of the 'cluster SSH' solutions @Chaleb mentioned here (pssh, pdsh, clusterssh, clusterit) or Fabric (also mentioned in this thread, by @Crankyadmin) to gather usage statistics. Add a ...


2

There are many "batch systems" that are designed to handle this sort of problem. One specifically tailored to handle "cycle stealing" from otherwise unoccupied systems is condor, a long running research project at the University of Wisconsin.


2

It doesn't make any changes on the EMC storage. It only scans the fibre channel bus to see what world-wide names are visible through each local port. If it sees the same WWN through multiple ports, then it sets that storage device up for multipath I/O. Changes are made to emcp.conf in /kernel/drv, and those changes in turn effect how device paths are ...


2

The kernel recognizes certain file formats that it can execute natively. This includes at least one binary format. Additionally, files that begin with #! (shebang) are considered scripts; for example, if a file is located at /path/to/script and begins with #!/bin/bash then the kernel executes /bin/bash /path/to/script arg1 arg2 when you invoke ...


2

ZFS is not a clustered file system, so what you talk about wouldn't actually work as described. In order to increase the capacity of a server's storage, you'd need to add more disks to the host, either in the chassis, or, if that's full, in a storage array. A host running ZFS can have up to 2^64 zpools, and each zpool can contain up to 2^64 vdevs, so you are ...


1

This is just one of the many ways in which NFS sucks. There is no way to do this just with NFS up to version 3. You are going to have to add on the functionality manually. This probably means: data replication or some shared storage IP takeover Some sort of heartbeat monitoring Cluster management There are packages out there to do all of this but you ...


1

This tutorial, titled: Smooth Active-Active NFS failover with Heartbeat and Pacemaker shows how to setup a NFS active/active using NFS, Heartbeat, & Pacemaker. You'll also probably want to take a look at these other links to familiarize yourself with the various technologies and terminologies. Global File System (GFS) Configuration Example - NFS Over ...


1

You cannot have NFS as active-active cluster as far as I know. Now, for Active-Passive there are certain tools that help you achieve this. I'm more familiar with Solaris OS and Solaris Cluster that provide you the possibility to create a high-availability NFS share/shares depending on your objective. One thing that you will need is a shared storage that ...


1

You don't specifically say which clustering software you're using, but based on the fact you're asking about qsub, I know that both GridEngine (and derivatives) along with PBS use that particular command, so let's start with those. I'm most familiar with GridEngine (and derivatives) so to submit a command using that package you'd do something like this. ...


1

You seem to be confusing what Solaris Cluster does vs. Oracle RAC. In Solaris Cluster (SunCluster) any application running is actually running on a single node in the cluster rather then on multiple ones. Which means that Veritas Volume Manager imports the associated Volume Group only on one of the nodes in the cluster. So there is no issue with it. If ...


1

I believe this tutorial is exactly what you're looking for. The tutorial is titled: Setting Up A High-Availability Load Balancer (With Failover and Session Support) With HAProxy/Heartbeat On Debian Lenny. In general you're /etc/haproxy.cfg file will look similar to this: global log 127.0.0.1 local0 log 127.0.0.1 local1 notice ...


1

An approach that works fairly well for me... Connect one of those obsolete monitors you have lying around "just in case" to each of the small computers (RaspberryPi, etc.). Run a tiny, fast, RAM-based O/S like Puppy Linux (see how it works) on every computer. Setup passwordless (pre-shared password distribution) SSH between all computers. Install KVM ...


1

This is a Heisenbug, and possibly one that has been fixed in recent versions of mandb. It has to do with broken manpages, filesystem traversal order, and incremental rebuilds of the mandb turning into very slow full rebuilds (15 million page faults or so, which takes minutes on spinning rust). If you want to troubleshoot it, run: sudo mandb --no-purge ...


1

There are several kinds of computer clusters, with different purposes. A "beowulf cluster" is generally referring to a set of machines configured with services for parallel processing. The purpose is to spread computationally intensive tasks over several computing nodes (computers). Other types of clusters are meant to ensure redundancy and reliability, ...


1

You know as weird as it might sound but using rtorrent with DHT enabled on the private ec2 range could work This would give you Automatic Peer discovery Verified file states (yay for hashes) Minimal configuration requirements (add the magnet(or virtual ip for the latest torrent) for the torrent in the start up script) scalability


1

Rsync upstream provides support for SLP (Service location protocol). It is not enabled in vanilla rsync sources, but you can find the SLP support in rsync-patches tarball at rsync homepage (slp.diff). E.g. SUSE rsync package is built with this patch, dunno about other distributions. I'm not sure this is what you are looking for nor do I have any experience ...


1

There is no way to "just" combine the resources of the individual machines. The software you run on top of your cluster has to be written with parallel in mind. You can't expect a single computation intensive process to magically split up between multiple cores, or even machines. And even if the software is written for parallel execution, once you go from ...



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