Abstract: A method, apparatus and program product simulate a high performance computing (HPC) application environment by creating a cluster of virtual nodes in one or more operating system instances executing on one or more physical computing node, thereby enabling a plurality of parallel tasks from an HPC application to be executed on the cluster of virtual nodes.

Abstract: A method, apparatus and program product simulate a high performance computing (HPC) application environment by creating a cluster of virtual nodes in one or more operating system instances executing on one or more physical computing node, thereby enabling a plurality of parallel tasks from an HPC application to be executed on the cluster of virtual nodes.

Abstract: A method, apparatus and program product utilize an empirical approach to determine the locations of one or more IO adapters in an HPC environment. Performance tests may be run using a plurality of candidate mappings that map IO adapters to various locations in the HPC environment, and based upon the results of such testing, speculative adapter affinity information may be generated that assigns one or more IO adapters to one or more locations to optimize adapter affinity performance for subsequently-executed tasks.

Abstract: A message flow controller limits a process from passing a new message in a reliable message passing layer from a source node to at least one destination node while a total number of in-flight messages for the process meets a first level limit. The message flow controller limits the new message from passing from the source node to a particular destination node from among a plurality of destination nodes while a total number of in-flight messages to the particular destination node meets a second level limit. Responsive to the total number of in-flight messages to the particular destination node not meeting the second level limit, the message flow controller only sends a new packet from among at least one packet for the new message to the particular destination node while a total number of in-flight packets for the new message is less than a third level limit.

Abstract: A method, apparatus and program product utilize an empirical approach to determine the locations of one or more IO adapters in an HPC environment. Performance tests may be run using a plurality of candidate mappings that map IO adapters to various locations in the HPC environment, and based upon the results of such testing, speculative adapter affinity information may be generated that assigns one or more IO adapters to one or more locations to optimize adapter affinity performance for subsequently-executed tasks.

Abstract: Administering group identifiers of processes in a parallel computer includes each process in a set of processes, receiving from a compute node of the plurality of compute nodes, a request to establish the set of processes as an operational group including receiving a list of process identifiers for each process of the set of processes. Embodiments also include each process generating without communication amongst the processes, a unique group identifier in dependence upon the list of process identifiers.

Abstract: In a distributed computing environment that includes compute nodes, where the compute nodes execute a plurality of tasks, a lock for resources may be administered. Administering the lock may be carried out by requesting, in an atomic operation by a requesting task, the lock, including: determining, by the requesting task, whether the lock is available; if the lock is available, obtaining the lock; and if the lock is unavailable, joining, by the requesting task, a queue of tasks waiting for availability of the lock.

Abstract: In a distributed computing environment that includes compute nodes, where the compute nodes execute a plurality of tasks, a lock for resources may be administered. Administering the lock may be carried out by requesting, in an atomic operation by a requesting task, the lock, including: determining, by the requesting task, whether the lock is available; if the lock is available, obtaining the lock; and if the lock is unavailable, joining, by the requesting task, a queue of tasks waiting for availability of the lock.

Abstract: A method, apparatus and program product utilize an empirical approach to determine the locations of one or more IO adapters in an HPC environment. Performance tests may be run using a plurality of candidate mappings that map IO adapters to various locations in the HPC environment, and based upon the results of such testing, speculative adapter affinity information may be generated that assigns one or more IO adapters to one or more locations to optimize adapter affinity performance for subsequently-executed tasks.

Abstract: A method, apparatus and program product utilize an empirical approach to determine the locations of one or more IO adapters in an HPC environment. Performance tests may be run using a plurality of candidate mappings that map IO adapters to various locations in the HPC environment, and based upon the results of such testing, speculative adapter affinity information may be generated that assigns one or more IO adapters to one or more locations to optimize adapter affinity performance for subsequently-executed tasks.

Abstract: Methods, apparatuses, and computer program products for responding to a timeout of a message in a parallel computer are provided. The parallel computer includes a plurality of compute nodes operatively coupled for data communications over one or more data communications networks. Each compute node includes one or more tasks. Embodiments include a first task of a first node sending a message to a second task on a second node. Embodiments also include the first task sending to the second node a command via a parallel operating environment (POE) in response to a timeout of the message. The command instructs the second node to perform a timeout motivated operation.

Abstract: Methods, apparatuses, and computer program products for responding to a timeout of a message in a parallel computer are provided. The parallel computer includes a plurality of compute nodes operatively coupled for data communications over one or more data communications networks. Each compute node includes one or more tasks. Embodiments include a first task of a first node sending a message to a second task on a second node. Embodiments also include the first task sending to the second node a command via a parallel operating environment (POE) in response to a timeout of the message. The command instructs the second node to perform a timeout motivated operation.

Abstract: A job may be divided into multiple tasks that may execute in parallel on one or more compute nodes. The tasks executing on the same compute node may be coordinated using barrier synchronization. However, to perform barrier synchronization, the tasks use (or attach) to a barrier synchronization register which establishes a common checkpoint for each of the tasks. A leader task may use a shared memory region to publish to follower tasks the location of the barrier synchronization register—i.e., a barrier synchronization register ID. The follower tasks may then monitor the shared memory to determine the barrier synchronization register ID. The leader task may also use a count to ensure all the tasks attach to the BSR. This advantageously avoids any task-to-task communication which may reduce overhead and improve performance.

Abstract: A message flow controller limits a process from passing a new message in a reliable message passing layer from a source node to at least one destination node while a total number of in-flight messages for the process meets a first level limit. The message flow controller limits the new message from passing from the source node to a particular destination node from among a plurality of destination nodes while a total number of in-flight messages to the particular destination node meets a second level limit. Responsive to the total number of in-flight messages to the particular destination node not meeting the second level limit, the message flow controller only sends a new packet from among at least one packet for the new message to the particular destination node while a total number of in-flight packets for the new message is less than a third level limit.

Abstract: A job may be divided into multiple tasks that may execute in parallel on one or more compute nodes. The tasks executing on the same compute node may be coordinated using barrier synchronization. However, to perform barrier synchronization, the tasks use (or attach) to a barrier synchronization register which establishes a common checkpoint for each of the tasks. A leader task may use a shared memory region to publish to follower tasks the location of the barrier synchronization register—i.e., a barrier synchronization register ID. The follower tasks may then monitor the shared memory to determine the barrier synchronization register ID. The leader task may also use a count to ensure all the tasks attach to the BSR. This advantageously avoids any task-to-task communication which may reduce overhead and improve performance.

Abstract: A method, apparatus and program product simulate a high performance computing (HPC) application environment by creating a cluster of virtual nodes in one or more operating system instances executing on one or more physical computing node, thereby enabling a plurality of parallel tasks from an HPC application to be executed on the cluster of virtual nodes.

Abstract: A method, apparatus and program product simulate a high performance computing (HPC) application environment by creating a cluster of virtual nodes in one or more operating system instances executing on one or more physical computing node, thereby enabling a plurality of parallel tasks from an HPC application to be executed on the cluster of virtual nodes.

Abstract: In a distributed computing environment that includes compute nodes, where the compute nodes execute a plurality of tasks, a lock for resources may be administered. Administering the lock may be carried out by requesting, in an atomic operation by a requesting task, the lock, including: determining, by the requesting task, whether the lock is available; if the lock is available, obtaining the lock; and if the lock is unavailable, joining, by the requesting task, a queue of tasks waiting for availability of the lock.

Abstract: In a distributed computing environment that includes compute nodes, where the compute nodes execute a plurality of tasks, a lock for resources may be administered. Administering the lock may be carried out by requesting, in an atomic operation by a requesting task, the lock, including: determining, by the requesting task, whether the lock is available; if the lock is available, obtaining the lock; and if the lock is unavailable, joining, by the requesting task, a queue of tasks waiting for availability of the lock.

Abstract: A message flow controller limits a process from passing a new message in a reliable message passing layer from a source node to at least one destination node while a total number of in-flight messages for the process meets a first level limit. The message flow controller limits the new message from passing from the source node to a particular destination node from among a plurality of destination nodes while a total number of in-flight messages to the particular destination node meets a second level limit. Responsive to the total number of in-flight messages to the particular destination node not meeting the second level limit, the message flow controller only sends a new packet from among at least one packet for the new message to the particular destination node while a total number of in-flight packets for the new message is less than a third level limit.