Understanding HPC and HPC Cluster Management

What is the Scope of HPC

HPC has become interwoven into many organizations’ workflows and is only expected to grow over time. With such a wide range of industries using HPC today, designing and implementing an efficient infrastructure requires knowledge of the applications that will be used as well as planning for future growth as well as finding partners that can work with you to determine the ideal solution for your organization. Many organizations may be using HPC in more than one application, which requires the HPC solution to be flexible for different computing, storage, and networking requirements. According to the industry experts at MarketWatch and other sources, the market for HPC servers, storage, middleware, applications, and service is only expected to grow exponentially year over year.

HPC System Components

HPC systems infrastructures contain several subsystems that all must work together efficiently and scale together. The main subsystems of an HPC system are:

• Compute – This part runs the application, takes the data passed to it, and outputs an answer. Over the past two decades, most algorithms have been parallelized, where parts of a problem are run on separate computers or multiple cores. Each time the results are generated or partial results are generated, they need to be communicated with the other calculations or stored on a storage device. Modern servers contain two to four sockets (chips), each with up to 64 cores. Since each of these cores may need to store recently computed information, the demands on the storage device may increase as core counts increase. Many modern applications now take advantage of accelerators that are tightly connected with the main CPU that can accelerate certain portions of the application. Usually referred to as GPGPUs, these accelerators can speed up specific applications and can place their demands on the storage or networking infrastructure.
• Storage – During or at the beginning of a long-running simulation, a great deal of data is required to get the simulation going. As the application runs, more data may also be required based on the algorithm. The complexity of storage solutions can quickly grow with the complexity of your application so the PSSC Labs team works with you to make sure the storage is customized to meet your unique needs. The key point is that HPC storage is a key component for the smooth and efficient running of any HPC cluster.
• Networking – The communication between servers and storage devices should not slow down the performance of the entire system. Each core that is performing the computations may need to communicate with numerous other cores, and request information from other nodes in the process. The network needs to be designed to handle server-to-server communication as well as multiple servers concurrently communicating to the storage system.
• Application Software – Typically, sophisticated software simulates physical processes and runs across many cores. HPC application simulators are not just complex because of the mathematics behind them, but also because highly tuned libraries are used to manage networking, work distribution, and storage processes. The HPC application software needs to be architected to keep the overall system busy to maximize the investment for an HPC infrastructure.  To learn more about HPC application software click here.
• Orchestration – Organizing a large cluster can be challenging for network administrators.  Rarely will the entire system of a large supercomputer be dedicated to a single application. Therefore, application software is needed to allow a network engineer to allocate a certain number of servers, GPUs, network bandwidth, and storage capacities. All of these sub-systems, as well as the installation of an Operating System and the associated software on the allocated system need to be handled seamlessly and effortlessly. For applications that require rapid access to data, it is absolutely crucial to correctly set up the software for HPC storage.

What is HPC Cluster Management?

HPC Clusters are composed of components that enable applications to be executed. Therefore, the HPC cluster software will typically run across many nodes and access storage both for reading and writing data. All of this, including the communication between nodes and the storage system, needs seamless communication. According to the European Grid Infrastructure, “High Performance Computing” (HPC) requires distributed computing between many nodes to deliver efficient computational performance, which is typically described as HPC Clusters. Typically, several different types of nodes comprise an HPC Cluster. HPC cluster components will include:

• Head Node (i.e. the login node) – Often, a head node is nothing more than a simple setup designed to act as a bridge between the cluster and an external network.
• Compute Nodes – These nodes perform the numerical computations and will probably contain the highest clock rates available with the maximum number of cores at the given clock rate. According to Alex Lesser, a VP at PSSC Labs, “the persistent storage on these nodes may be minimal, while the DRAM memory will be high.”
• Accelerator Nodes – Some nodes may include one or more accelerators since not all applications can take advantage of these accelerators. In addition, smaller HPC clusters, designed for a specific application may be set up where all the nodes contain an accelerator
• Storage Nodes (i.e. storage system) – An efficient HPC cluster will need to contain a high performance, parallel file system or PFS. Parallel file systems allow all nodes to communicate with storage drives in parallel. HPC storage enables the compute nodes to operate with minimal wait times.
• Network Fabric – In HPC clusters, typically, an Infiniband or another high performing Ethernet network switch will be used, due to the requirement of low latency and high bandwidth features.
• Software – Cluster management software is required to control the underlying infrastructure, as well as the applications to run on the cluster. Managing the multiple I/O streams that are inherent to HPC applications requires the appropriate cluster management software for an optimal HPC cluster.  Parallel transfer of data from the large number of CPUs to the storage system (on the HPC servers or externally) is critical and must not be overlooked.

To learn more about HPC cluster management and HPC servers built for the highest possible performance and reliability including support for Intel Xeon, AMD Epyc, NVIDIA GPU, and Mellanox Infiniband click here https://pssclabs.com/products/ai-hpc-servers/