High Performance Computing
What’s HPC(High Performance Computing)? HPC is based on concurrency that computing in which multiple tasks are active at the same time, and will be used in solving bigger problems or fixed-size problem in less time. For example, scientific computing in physical, biologic or chamical subjects which both have may data need to be access and computed, we could not waiting very long for the computers completed this work. It seems that HPC would solve this problem perfectly.Althought adding more cpus would speed up, but the whole cost become very expensive. The nodes of HPC was common so that all the hardware of the nodes could be brought in the market.In this way, we get better performance with less money.What’s cluster? Collection of connectors, independent computers which work together to solve a problem. When we talk about clusters, the stack including environment (such as location, power,cooling ,sercurity )and assistance (Trainning) must be considered.There are many cluster solution stacks for Linux. OSCAR, NPACI-ROCKS and Score are open-source software, and Scyld and Callident must be purchased for license.
Cluster hardware desire:Interconnect, 100Mps Ethernet, 1Gbit/s Ethernet, SCI, Myricon Myrinet,InfiniBand,Quadrics QsNet(Pay attention to InfiniBand who has another name “IB”). Processors(CPU), all Inter serie processor including P4, Xeon ,Itanium would be used in the Cluster, however, Intel recommends Xeon and Itanium(Tiger 2 Platform). Pentium processor only support 1-way platform, they will cause net constructure more complex.
For example, painting a picket fence, more people can finish painting soon, but all the processing time also including prepairing(loading data) and cleaning up(consume the data) time, we should buy the painter, and clear workspace when the work completed. All of this need time which could not be ignored!So the speedup has a limit pointe when the load and consume time are zero.It is not realizable.
indicate that we could not improve speed only be adding painers. The right way we should found is deciding good price/performaning value.
Load Balancing, when the opera was going to end, some fat woman came out to sing. The load balancing are determined by the slowest nodes because only after this nodes finished working the whole cluster is considered having completed working.Load Balanceing Granularity, when Application granularity matches hardware granularity the cluster gets the best price/performance situation.
Some useful Linux commands:
#server network restart (when edit the network configuration) #vi /etc/sysconfig/network-script/ifeth0 (configure the eth0) #halt -p (shutdown the system with power off) (mount DVD ROM, Linux recognise the DVD as SCSI device) #mknod /dev/sr0 b 11 0 #mount /dev/sr0 /mnt/cdrom
How to install Rocks?
First, insert Rock based CD, and press “f” when displays Rock’s installation logo. In the command line, input “frontend”, then, the Rock will be in setup statues. It will ask for ROLLS which is package of packages in the fact. We input the following three CDs in this sequence “”BASE,HPC,Kernel,SGE”. the installation program runs automaticlly after loading the ROLLS needed. This is called master node.In the second machine named node1, we insert the BASE cd in the DVD ROM, and it will install automaticlly without any user’s action. When installing, the statue list in the master node will display node1.If we have no BASE CD, how could we do to install another node named node2? OK, power on the node2, and press F12 when bios posts. It will come in the PXE starup instance. As same as node2, the installation program runs automaticlly. We need to do nothing so we should drink a cup of water or have a short rest.It is convenience for building the nodes in fast way.