Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revisionBoth sides next revision | ||
public:lofar_cluster [2010-03-09 14:58] – Arno Schoenmakers | public:lofar_cluster [2017-05-01 14:18] – Arno Schoenmakers | ||
---|---|---|---|
Line 1: | Line 1: | ||
- | ====== The LOFAR Cluster | + | ====== The LOFAR Clusters |
- | This page describes the LOFAR cluster | + | This page describes the LOFAR clusters |
- | We welcome authorized users on the cluster. For the time being the users are bound to only a part of the cluster. | + | We welcome authorized users on the LOFAR clusters. |
+ | |||
+ | ===== CEP3 ====== | ||
+ | |||
+ | CEP3 is the processing cluster that is available | ||
+ | |||
+ | ===== CEP4 ====== | ||
+ | |||
+ | CEP4 is the main storage and processing | ||
===== User Access ===== | ===== User Access ===== | ||
Line 13: | Line 21: | ||
> ssh -X portal.lofar.eu | > ssh -X portal.lofar.eu | ||
</ | </ | ||
- | Please send an email to //grit at astron.nl// or //h.paas | + | Please send an email to //grit at astron.nl// or //rbokhorst |
When you are logged in for the first time, you'll have an empty home directory. | When you are logged in for the first time, you'll have an empty home directory. | ||
- | To get onto the cluster, you first have to login at one of the two frontend nodes '' | + | To get onto the CEP3 cluster, you first have to login at one of the two frontend nodes '' |
For more sophisticated useage of '' | For more sophisticated useage of '' | ||
Line 34: | Line 43: | ||
+ | ===== Contributed Software ===== | ||
- | ===== Short LOFAR Cluster layout ===== | + | Some groups or people would like their favourite tools or pipelines added to the cluster |
- | + | ||
- | The Lofar cluster is devided into 8 subclusters. Each subcluster is a processing cluster for a specific commsissioning group. There are 72 compute nodes (named '' | + | |
- | + | ||
- | + | ||
- | + | ||
- | ==== Frontend ==== | + | |
- | + | ||
- | A frontend has 2 Intel Xeon L5420 quad core processors, 16GB internal meomory, 2 GbE interfaces and 2TB disks in RAID5 configuration. | + | |
- | There are actually two identical frontends: '' | + | |
- | + | ||
- | ==== Processing units ==== | + | |
- | + | ||
- | The compute elements have 2 Intel Xeon L5420 quad core processors, 16GB internal meomory, 2 GbE interfaces and 1TB disks in RAID0 configuration. They can be accessed by secure shell and they are grouped. | + | |
- | + | ||
- | + | ||
- | ==== Storage Units ==== | + | |
- | + | ||
- | The storage nodes are HP DL180G5 boxes, having 2 Intel Xeon L5420 quad core processors, 16GB internal memory, 6 GbE network interfaces and a total of 24TB disk space. | + | |
- | The nodes have been named '' | + | |
- | + | ||
- | The disk space is divided into 4 partitions of 6 disks each, set up in RAID5 configuration. The partitions | + | |
- | + | ||
- | ===== Available Subclusters ===== | + | |
- | + | ||
- | The current subcluster assignment is: | + | |
- | + | ||
- | lfe001: | + | |
- | + | ||
- | This script shows the subcluster definitions | + | |
- | + | ||
- | sub lce-nodes | + | |
- | ==== ========= | + | |
- | sub1 lce001-lce009 | + | |
- | sub2 lce010-lce018 | + | |
- | sub3 lce019-lce027 | + | |
- | sub4 lce028-lce036 | + | |
- | sub5 lce037-lce045 | + | |
- | sub6 lce046-lce054 | + | |
- | sub7 lce055-lce063 | + | |
- | sub8 lce064-lce072 | + | |
- | + | ||
- | The lce-nodes ar ethe compute/ | + | |
- | + | ||
- | ====== Bootleg mechanism ====== | + | |
- | + | ||
- | The new cluster is subject | + | |
- | + | ||
- | ==== Central administration ==== | + | |
- | + | ||
- | The way the CEP cluster has been set up is as follows: | + | |
- | We are using Ubuntu Linux LTS-8.04 as Operating System within the whole cluster. Bootleg takes care of all of the server management in the cluster by creating new images, administering servers, keeping track of updates and correct start up of servers by sending them new images when it finds outdated versions at boot time. | + | |
- | + | ||
- | ==== Profiles ==== | + | |
- | + | ||
- | Bootleg also administers machine profiles: Depending on the function of the server in the cluster it needs other settings and profiles. | + | |
- | This management strategy implies that we have to keep track of all programs installed in the Linux system itself, so we will be able to add them to the image. We plan to build fresh images every month (at the maintenance days). | + | |
- | + | ||
- | ==== Instantanious changes ==== | + | |
- | + | ||
- | We are also able to respond quickly on extra-program demands for system programs. Within bootleg there is a mechanism to roll-out extra programs through the cluster from a central administration point (CAP). From the CAP we order to deploy a program or a settings-change and after 1 minute the whole cluster will be updated with the change. So if you need extra system programs, simply ask, and you get it almost instantly on every server in the cluster! | + | |
- | + | ||
- | ==== Application programs ==== | + | |
- | + | ||
- | For an application program change or addition there is another method. | + | |
- | Of course you develop your programs in your own user space and/or svn repositories. So you have completely control over all of this. | + | |
- | Program releases for the cluster itself reside on a central disk. | + | |
- | Normally we (as system administrators) are not involved in the application program deployment. | + | |
- | Only if a completely new package is added under a new directory name we | + | |
- | need to make this available in the cluster by connecting it in the O.S. | + | |
- | via a link to the newly created package name. | + | |
- | So there is a clear interface between system programs and applications: | + | |
- | The connection between them is at a well defined point, the /opt directory is intended for this. | + | |
- | The same goes for database content (mysql, postgresql, ...). | + | |
- | Although it might involve OS program installation and services, the database content itself will never be on the Linux system image but stored on a separate data server. | + | |
- | + | ||
- | Again: Simply ask, we can connect your program and make it available cluster-wide. | + | |