Abstract: Methods, systems, and products are disclosed for configuring an application for execution on a parallel computer that include: booting up a first subset of a plurality of nodes in a serial processing mode; booting up a second subset of the plurality of nodes in a parallel processing mode; profiling, prior to application deployment on the parallel computer, the application to identify the serial segments and the parallel segments of the application; and deploying the application for execution on the parallel computer in dependence upon the profile of the application and proximity within the data communications network of the nodes in the first subset relative to the nodes in the second subset.

Abstract: A method, apparatus, and program product optimize power consumption in a parallel computing system that includes a plurality of computing nodes by selectively throttling performance of selected nodes to effectively slow down the completion of quicker executing parts of a workload of the computing system when those parts are dependent upon or otherwise associated with the completion of other, slower executing parts of the same workload. Parts of the workload are executed on the computing nodes, including concurrently executing a first part on a first computing node and a second part on a second computing node. The first node is selectively throttled during execution of the first part to decrease power consumption of the first node and conform a completion time of for the first node in completing the first part of the workload with a completion time for the second node in completing the second part.

Abstract: Methods, apparatus, and products are disclosed for node selection for executing a Java application among a plurality of nodes connected together for data communications using a data communication network, the plurality of nodes also connected to a service node, that include: tracking, by the service node, loaded Java classes currently loaded on each of the plurality of nodes; receiving, in the service node, an instruction to execute a Java application using the plurality of nodes; identifying, by the service node, Java classes utilized in executing the Java application; selecting, by the service node, one of the plurality of nodes for executing the Java application in dependence upon the loaded Java classes and the Java classes utilized in executing the Java application; and configuring, by the service node, the Java application for execution on the selected node.

Abstract: Embodiments of the invention enable application programs running across multiple compute nodes of a highly-parallel system to compile source code into native instructions, and subsequently share the optimizations used to compile the source code with other nodes. For example, determining what optimizations to use may consume significant processing power and memory on a node. In cases where multiple nodes exhibit similar characteristics, it is possible that these nodes may use the same set of optimizations when compiling similar pieces of code. Therefore, when one node compiles source code into native instructions, it may share the optimizations used with other similar nodes, thereby removing the burden for the other nodes to figure out which optimizations to use. Thus, while one node may suffer a performance hit for determining the necessary optimizations, other nodes may be saved from this burden by simply using the optimizations provided to them.

Abstract: Methods, apparatus, and products are disclosed for reducing power consumption while synchronizing a plurality of compute nodes during execution of a parallel application that include: beginning, by each compute node, performance of a blocking operation specified by the parallel application, each compute node beginning the blocking operation asynchronously with respect to the other compute nodes; reducing, for each compute node, power to one or more hardware components of that compute node in response to that compute node beginning the performance of the blocking operation; and restoring, for each compute node, the power to the hardware components having power reduced in response to all of the compute nodes beginning the performance of the blocking operation.

Abstract: Embodiments of the invention may be used to increase query processing parallelism of an in-memory database stored on a parallel computing system. A group of compute nodes each store a portion of data as part of the in-memory database. Further, a pool of compute nodes may be reserved to create copies of data from the compute nodes of the in-memory database as part of query processing. When a query is received for execution, the query may be evaluated to determine whether portions of in-memory should be duplicated to allow multiple elements of the query (e.g., multiple query predicates) to be evaluated in parallel.

Abstract: An apparatus and method retrieves a database record from an in-memory database of a parallel computer system using a non-unique key. The parallel computer system performs a simultaneous search on each node of the computer system using the non-unique key and then utilizes a global combining network to combine the local results from the searches of each node to efficiently and quickly search the entire database.

Abstract: Embodiments of the invention enable a database spread over multiple nodes to allow each node to have different indexes over the data in tables, depending on how each node would benefit (or not benefit) from having the index(es). When a database table is spread across the nodes of a multi-node or distributed system, each node may maintain only the portion of the index relevant to that node, if doing so would improve the performance of query processing operations on that node. Further, the database may periodically redistributed across the compute nodes based on index performance. Doing so allows the database system to intelligently trade off between consuming space for the index on a node and the usefulness of having an index on that node.

Abstract: Methods, apparatus, and product for tracking network contention on links among compute nodes of an operational group in a point-to-point data communications network of a parallel computer are disclosed. In embodiments of the present invention, each compute node is connected to an adjacent compute node in the point-to-point data communications network through a link. Tracking network contention according to embodiments of the present invention includes maintaining, by a network contention module on each compute node in the operational group, a local contention counter for each compute node, each local contention counter representing network contention on links among the compute nodes originating from the compute node; and maintaining a global contention counter, the global contention counter representing network contention currently on all links among the compute nodes in the operational group.

Abstract: A method and apparatus distributes database query joins on a multi-node computing system. In the illustrated examples, a join execution unit utilizes various factors to determine where to best perform the query join. The factors include user controls in a hints record set up by a system user and properties of the system such as database configuration and system resources. The user controls in the hints record include a location flag and a determinicity flag. The properties of the system include the free space on the node and the size join, the data traffic on the networks and the data traffic generated by the join, the time to execute the join and nodes that already have code optimization. The join execution unit also determines whether to use collector nodes to optimize the query join.

Abstract: An apparatus and method for a query governor to govern query execution in a parallel computer system with one or more networks. The query governor uses a network monitor to gather network status information to determine how to govern query execution. The query governor may also use historical information of previous query execution stored in a query file to determine if the query should be allowed to execute. The query governor may also use node and network restrictions to determine what networks the query can use.

Abstract: A massively parallel nodal computer system periodically collects and broadcasts usage data for an internal communications network. A node sending data over the network makes a global routing determination using the network usage data. Preferably, network usage data comprises an N-bit usage value for each output buffer associated with a network link. An optimum routing is determined by summing the N-bit values associated with each link through which a data packet must pass, and comparing the sums associated with different possible routes.

Abstract: Embodiments of the invention may be used to normalize data stored in an in-memory database on a parallel computer system. The data normalization may be used to achieve memory savings, thereby reducing the number of compute nodes required to store an in-memory database. Thus, as a result, faster response times may be achieved when querying the data. In one embodiment, normalization may be performed in a manner to avoid datasets that cross physical or logical boundaries of the compute nodes of a parallel system.

Abstract: In a networked computer system that includes multiple interconnected nodes, a commitment control mechanism allows designating certain portions of a record in an in-memory database as mandatory and other portions of the record as secondary, and performs mandatory commitment control once all the mandatory portions are available even if one or more secondary portions are not yet available. The secondary portions may be under separate commitment control that is asynchronous to the commitment control for the mandatory portions, or may be under no commitment control at all. The result is a commitment control mechanism that performs commitment control for portions of a record that are marked mandatory even when one or more of the portions marked secondary are not available.

Abstract: A database spread over multiple nodes allows each node to store a journal recording changes made to the database and also allows a journaling component to manage the memory space available for journaling. Two threshold size values may be specified for the journal. The first threshold value specifies a journal size at which to being pruning the journal on a given node. A journal pruning algorithm may be used to identify journal entries that may be removed. For example, once a given transaction completes (i.e., commits) the journal entries related to that transaction may be pruned from the journal. The second threshold value specifies the maximum size of the journal. After reaching this size, journal entries may be written to disk instead of the in-memory journal.

Abstract: Executing MIMD programs on a SIMD machine, the SIMD machine including a plurality of compute nodes, each compute node capable of executing only a single thread of execution, the compute nodes initially configured exclusively for SIMD operations, the SIMD machine further comprising a data communications network, the network comprising synchronous data communications links among the compute nodes, including establishing one or more SIMD partitions, booting one or more SIMD partitions in MIMD mode; establishing a MIMD partition; executing by launcher programs a plurality of MIMD programs on two or more of the compute nodes of the MIMD partition; and re-executing a launcher program by an operating system on a compute node in the MIMD partition upon termination of the MIMD program executed by the launcher program.

Abstract: A database spread over multiple nodes allows each node to store a journal recording changes made to the database and also allows a journaling component to manage the memory space available for journaling. Two threshold size values may be specified for the journal. The first threshold value specifies a journal size at which to being pruning the journal on a given node. A journal pruning algorithm may be used to identify journal entries that may be removed. For example, once a given transaction completes (i.e., commits) the journal entries related to that transaction may be pruned from the journal. The second threshold value specifies the maximum size of the journal. After reaching this size, journal entries may be written to disk instead of the in-memory journal.

Abstract: Embodiments of the present invention generally provide for network virtualization in a multi-network system. The virtual network may abstract multiple, underlying physical networks connecting compute nodes on a multi-node system. A network driver and control system may route traffic on the underlying physical networks according to system and/or application requirements, and a virtual-to-physical network mapping may be controlled by the driver and control system.

Abstract: An apparatus, program product and method optimize the operation of a parallel computer system by, in part, collecting performance data for a set of implementations of a function capable of being executed on the parallel computer system based upon the execution of the set of implementations under varying input parameters in a plurality of input dimensions. The collected performance data may be used to generate selection program code that is configured to call selected implementations of the function in response to a call to the function under varying input parameters. The collected performance data may be used to perform more detailed analysis to ascertain the comparative performance of the set of implementations of the function under the varying input parameters.

Abstract: Techniques are disclosed for reducing the number of two-phase commits required to perform atomic transactions in a multi-node system. By monitoring atomic operations that require two-phase commit protocols, a system may identify when it would be beneficial to consolidate data onto single (or at least fewer) compute node(s). In doing so, a less compute intensive commit protocol, such as a one-phase commit protocol may be used. Moreover, in situations where data consolidation is not available, the data may be migrated to compute nodes having a closer proximity. Thus, in such cases, network response times for two-phase commits required for an atomic operation may be reduced, thereby increasing the performance of a multi-node system.