Broadcast and decentralized communication operations

Abstract

According to one aspect, a computer-implemented method for performing a distributed communication operation includes receiving, by a first computing system, a request to perform the distributed communication operation, and obtaining, by the first computing system, a tree structure for performing the distributed communication operation, where the first computing system is a root node of the tree structure. The method further includes creating, by the first computing system, a message having header information and a payload for the distributed communication operation, and transmitting, by the first computing system, a portion of the message to each child node of the first computing system, where the portion transmitted to each child node is unique.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention generally relates to communication networks and, more particularly, to computer systems, computer-implemented methods, and computer program products for performing distributed operations such as broadcast and scatter communication operations.

[0002] Broadcasting a message to a group of participants (e.g., processes, machines) over a network is a frequently used pattern in distributed systems. In this pattern, a source participant (sometimes referred to as the "root") typically sends the same message to a group of remote participants in a tree pattern. Scattering a message can be considered a derivative of the broadcast operation. The source participant ("root") typically sends a different message to each remote participant using a tree pattern to improve performance over a centralized point-to-point communication pattern.

[0003] Many high-performance computing (HPC) and machine learning (ML) applications rely on the Message Passing Interface (MPI) standard and similar libraries for point-to-point and collective communication between distributed operations. The MPI standard defines two widely used collective MPI_Bcast and MPI_Scatter(v) operations. Additionally, other collective algorithms (such as MPI_Allgather and MPI_Allreduce) typically rely on broadcast and scatter operations to support higher-level algorithms.

[0004] Broadcast and scatter collective algorithms are also beneficial for information distribution in any distributed system of persistent daemons. HPC schedulers and job launchers frequently use these patterns to update the distributed state and send a "job start" message to all remote systems that starts an application. Specifically, the latter example of job start greatly benefits from an efficient broadcast and scatter algorithm that results in a faster start time for user applications and increased machine utilization. Generally, improvements to these two collective communication patterns (especially in a dynamic networking environment such as the cloud) can yield significant performance benefits for client applications and data center middleware. SUMMARY OF THE INVENTION

[0005] Embodiments of the present invention relate to a method for performing distributed communication operations. According to one aspect, a computer-implemented method includes receiving, by a first computing system, a request to perform a distributed communication operation and obtaining, by the first computing system, a tree structure for performing the distributed communication operation, wherein the first computing system is a root node of the tree structure. The method also includes creating, by the first computing system, a message having header information and a payload for the distributed communication operation and transmitting, by the first computing system, a portion of the message to each child node of the first computing system, wherein the portion transmitted to each child node is unique.

[0006] Other embodiments of the invention implement the features of the methods described above in computer systems and computer program products.

[0007] Additional technical features and benefits are realized through the techniques of the present invention. Embodiments and aspects of the invention are described in detail herein and are considered to be part of the claimed subject matter. For a better understanding, reference is made to the detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The details of the exclusive rights described herein are particularly pointed out and clearly claimed in the claims at the end of the specification. The foregoing and other features and advantages of the embodiments of the invention are apparent from the following detailed description in conjunction with the drawings, in which:

[0009] Figure 1 A block diagram of an example computer system for use in conjunction with one or more embodiments of the invention is depicted;

[0010] Figure 2 is a block diagram of a tree structure for use in conjunction with one or more embodiments of the invention;

[0011] Figure 3 is a block diagram showing a broadcast operation in accordance with one or more embodiments of the invention;

[0012] Figure 4 is a block diagram showing a scatter operation in accordance with one or more embodiments of the invention;

[0013] Figure 5 is a block diagram showing a combination of a broadcast operation and a scatter operation in accordance with one or more embodiments of the invention;

[0014] Figure 6 is a flowchart of a method for initiating a distributed communication operation in accordance with one or more embodiments of the invention; and

[0015] Figure 7 is a flowchart of a method for performing a distributed communication operation in accordance with one or more embodiments of the invention. DETAILED DESCRIPTION

[0016] As discussed above, broadcast and scatter algorithms have become increasingly used in HPC and ML processes. Existing broadcast and scatter algorithms require members to know the tree structure before they can understand their role in the communication protocol at the start of an operation. If the tree structure needs to adapt to membership, network conditions, and / or message size, updates to the tree structure must be distributed before the collective operation begins. This typically requires hard synchronization when switching the tree that interrupts network traffic. For scatter communication patterns, the organization of data in the buffer can affect the performance of the operation. For example, if each stage in the algorithm requires computing different memory offsets and accessing different regions of memory to compile subsets of the buffer for their subtrees.

[0017] In an exemplary embodiment, an improved broadcast and scatter algorithm is provided that does not require members other than the root to have prior knowledge of the tree structure. The improved broadcast and scatter algorithm dynamically adapts to the current network environment without synchronization. Additionally, the improved broadcast and scatter algorithm is configured to manage the data to be transmitted during the broadcast and scatter algorithm to improve performance.

[0018] In an exemplary embodiment, when a broadcast and / or scatter operation begins, only the source participant (“root”) knows the tree structure. This allows the source (“root”) to dynamically adjust the tree structure for each message without synchronizing with other communication participants. The root encodes the tree structure of the communication operation in the header(s) of the message(s) sent to its children. Non-source participants (child nodes) receive messages from their parent nodes in the tree that contain instructions for the next hop relative to themselves in the tree. The message includes a header that describes the subtree structure at and below that point in the tree, as well as instructions for pruning irrelevant data for the next step in the communication operation. Non-source participants only need to unpack their instructions for sending to their children (if any) in the tree, without regard for the tree structure above them or below their children. Additionally, the data in each message is organized to optimize memory references as it travels down the tree in a scatter operation. In an exemplary embodiment, the method can be used for broadcast operations, scatter operations with regular-sized and irregular-sized participant messages, and combinations of both in combined operations.

[0019] Aspects of the present disclosure are described by narrative text, flowcharts, block diagrams of computer systems, and / or block diagrams of machine logic included in computer program product (CPP) embodiments. With respect to any flowchart, operations may be performed in an order different from that shown in a given flowchart, depending on the technology involved. For example, again depending on the technology involved, two operations shown in consecutive flowchart blocks may be performed in reverse order, as a single integrated step, simultaneously, or in a manner that at least partially overlaps in time.

[0020] A computer program product embodiment (“CPP embodiment” or “CPP”) is a term used in this disclosure to describe any collection of one or more storage media (also referred to as “media”) that are collectively included in a set of one or more storage devices, the set of one or more storage devices collectively including machine-readable code corresponding to instructions and / or data for performing computer operations specified in a given CPP claim. A “storage device” is any tangible device that can hold and store instructions used by a computer processor. By way of non-limitation, a computer-readable storage medium can be an electronic storage medium, a magnetic storage medium, an optical storage medium, an electromagnetic storage medium, a semiconductor storage medium, a mechanical storage medium, or any suitable combination of the foregoing. Some known types of storage devices that include these media include: magnetic disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), compact disk read-only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanically encoded devices (such as punched cards or pits / lands formed in the main surface of a disk), or any suitable combination of the foregoing. A computer-readable storage medium (as the term is used in this disclosure) should not be construed to store in the form of a transient signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide, optical pulses transmitted through an optical fiber cable, electrical signals transmitted through a wire, and / or other transmission media. As those skilled in the art will understand, data is typically moved at certain incidental points in time during the normal operation of a storage device (such as during access, defragmentation, or garbage collection), but this does not make the storage device transient because the data is not transient when it is stored.

[0021] Computing environment 100 includes an example of an environment for the execution of at least some of the computer code involved in performing the methods of the present invention, such as broadcast and scatter operations 150. In addition to block 150, computing environment 100 includes, for example, computer 101, wide area network (WAN) 102, end-user device (EUD) 103, remote server 104, public cloud 105, and private cloud 106. In this embodiment, computer 101 includes a set of processors 110 (including processing circuitry 120 and cache 121), communication fabric 111, volatile memory 112, persistent storage 113 (including operating system 122 and block 150 as identified above), a set of peripherals 114 (including user interface (UI), set of devices 123, storage 124, and Internet of Things (IoT) sensor set 125), and network module 115. Remote server 104 includes remote database 130. Public cloud 105 includes gateway 140, cloud orchestration module 141, set of host physical machines 142, set of virtual machines 143, and set of containers 144.

[0022] Computer 101 can take the form of a desktop computer, laptop computer, tablet computer, smart phone, smart watch or other wearable computer, mainframe computer, quantum computer, or any other form of computer or mobile device now known or to be developed in the future that is capable of running programs, accessing networks, or querying databases (such as remote database 130). As is well known in the computer art and depending on the technology, the execution of computer-implemented methods can be distributed among multiple computers and / or multiple locations. On the other hand, in this presentation of computing environment 100, the detailed discussion focuses on a single computer (especially computer 101) to keep the presentation as simple as possible. Computer 101 can be located in the cloud, even if it is not shown in the cloud in Figure 1 the figure. On the other hand, computer 101 does not need to be in the cloud, unless to any degree that can be affirmatively indicated.

[0023] The processor set 110 includes one or more computer processors of any type now known or later to be developed. The processing circuitry 120 may be distributed across multiple packages, such as multiple cooperating integrated circuit chips. The processing circuitry 120 may implement multiple processor threads and / or multiple processor cores. The cache 121 is a memory located within the (multiple) processor chip packages and is generally used for data or code that should be made available for rapid access by the threads or cores running on the processor set 110. Cache memory is typically organized into multiple levels based on its relative proximity to the processing circuitry. Alternatively, some or all of the cache of the processor set may be located "off-chip". In some computing environments, the processor set 110 may be designed to work with qubits and perform quantum computing.

[0024] Computer-readable program instructions are typically loaded onto the computer 101 so that the processor set 110 of the computer 101 executes a series of operational steps to implement a computer-implemented method such that the instructions so executed will instantiate the method specified in the flowchart and / or the narrative description of the computer-implemented method included in this document (collectively referred to as "the method of the present invention"). These computer-readable program instructions are stored in various types of computer-readable storage media, such as the cache 121 and other storage media discussed below. The program instructions and associated data are accessed by the processor set 110 to control and direct the execution of the method of the present invention. In the computing environment 100, at least some of the instructions for executing the method of the present invention may be stored in block 150 of the persistent storage device 113.

[0025] The communication structure 111 is a signal conduction path that allows the various components of the computer 101 to communicate with each other. Typically, this structure consists of switches and conductive paths, such as those that make up a bus, a bridge, a physical input / output port, etc. Other types of signal communication paths may be used, such as fiber optic communication paths and / or wireless communication paths.

[0026] The volatile memory 112 is any type of volatile memory now known or later to be developed. Examples include dynamic random access memory (RAM) or static RAM. Typically, volatile memory is characterized by random access, but this is not required unless affirmatively indicated. In the computer 101, the volatile memory 112 is located within a single package and inside the computer 101, but, alternatively or additionally, the volatile memory may be distributed across multiple packages and / or located external to the computer 101.

[0027] The persistent storage device 113 is any form of non-volatile storage device of a computer that is now known or to be developed in the future. The non-volatility of the storage device means that the stored data is maintained regardless of whether power is supplied to the computer 101 and / or directly to the persistent storage device 113. The persistent storage device 113 can be a read-only memory (ROM), but typically at least a portion of the persistent storage device allows for the writing of data, the deletion of data, and the re-writing of data. Some common forms of persistent storage devices include magnetic disks and solid-state storage devices. The operating system 122 can take several forms, such as various known proprietary operating systems or operating systems of the open-source portable operating system interface type that employ a kernel. The code included in block 150 typically includes at least some of the computer code involved in performing the method of the present invention.

[0028] The set of peripheral devices 114 includes a collection of the peripheral devices of the computer 101. The data communication connection between the peripheral devices and other components of the computer 101 can be implemented in various ways, such as a Bluetooth connection, a near-field communication (NFC) connection, a connection constituted by a cable (such as a universal serial bus (USB)-type cable), a plug-in connection (e.g., a Secure Digital (SD) card), a connection constituted by a local communication network, and even a connection constituted by a wide-area network such as the Internet. In various embodiments, the set of UI devices 123 can include components such as a display screen, a speaker, a microphone, wearable devices (such as goggles and smartwatches), a keyboard, a mouse, a printer, a touchpad, a game controller, and a haptic device. The storage device 124 is an external storage device (such as an external hard drive) or a plug-in storage device (such as an SD card). The storage device 124 can be persistent and / or volatile. In some embodiments, the storage device 124 can take the form of a quantum computing storage device for storing data in the form of qubits. In embodiments where the computer 101 needs to have a large amount of storage (e.g., in the case where the computer 101 locally stores and manages a large database), the storage device can be provided by a peripheral storage device designed to store a very large amount of data, such as a storage area network (SAN) shared by multiple geographically distributed computers. The set of IoT sensors 125 consists of sensors that can be used in Internet of Things applications. For example, one sensor can be a thermometer, and another sensor can be a motion detector.

[0029] The network module 115 is a collection of computer software, hardware, and firmware that allows the computer 101 to communicate with other computers via the WAN 102. The network module 115 can include hardware such as a modem or a Wi-Fi signal transceiver, software for encapsulating and / or de-encapsulating data transmitted over a communication network, and / or web browser software for transmitting data over the Internet. In some embodiments, the network control function and the network forwarding function of the network module 115 are executed on the same physical hardware device. In other embodiments (e.g., embodiments utilizing software-defined networking (SDN)), the control function and the forwarding function of the network module 115 are executed on physically separate devices such that the control function manages several different network hardware devices. The computer-readable program instructions for performing the methods of the present invention can generally be downloaded to the computer 101 from an external computer or an external storage device via a network adapter or a network interface included in the network module 115.

[0030] The WAN 102 is any wide area network (e.g., the Internet) capable of transmitting computer data over non-local distances via any technology for transmitting computer data known now or to be developed in the future. In some embodiments, the WAN can be replaced and / or supplemented by a local area network (LAN) designed to transmit data between devices located in a local area, such as a Wi-Fi network. The WAN and / or the LAN generally include computer hardware such as copper transmission cables, fiber optic transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and edge servers.

[0031] The end-user device (EUD) 103 is any computer system used and controlled by an end user (e.g., a customer of an enterprise operating the computer 101) and can take any of the forms discussed above in connection with the computer 101. The EUD 103 typically receives helpful and useful data from the operation of the computer 101. For example, in the hypothetical case where the computer 101 is designed to provide recommendations to an end user, the recommendations will typically be transmitted from the network module 115 of the computer 101 to the EUD 103 via the WAN 102. In this way, the EUD 103 can display or otherwise present the recommendations to the end user. In some embodiments, the EUD 103 can be a client device such as a thin client, a thick client, a mainframe computer, a desktop computer, etc.

[0032] The remote server 104 is any computer system that provides at least some data and / or functionality to the computer 101. The remote server 104 can be controlled and used by the same entity that operates the computer 101. The remote server 104 represents a (multiple) machine that collects and stores helpful and useful data used by other computers such as the computer 101. For example, in the hypothetical case where the computer 101 is designed and programmed to provide recommendations based on historical data, the historical data can be provided to the computer 101 from the remote database 130 of the remote server 104.

[0033] The public cloud 105 is any computer system that can be used by multiple entities, which provides on-demand availability of computer system resources and / or other computer capabilities (especially data storage (cloud storage) and computing power) without direct active management by the user. Cloud computing typically utilizes the sharing of resources to achieve consistency and economy of scale. The direct and active management of the computing resources of the public cloud 105 is performed by the computer hardware and / or software of the cloud orchestration module 141. The computing resources provided by the public cloud 105 are typically implemented by virtual computing environments running on various computers that make up the set of host physical machines 142, which is the universe of physical computers in the public cloud 105 and / or the universe of physical computers available for the public cloud. The virtual computing environment (VCE) typically takes the form of virtual machines from the set of virtual machines 143 and / or containers from the set of containers 144. It should be understood that these VCEs can be stored as images and can be transferred between various physical machine hosts as images or after the instantiation of the VCE. The cloud orchestration module 141 manages the transfer and storage of images, deploys new instantiations of the VCE, and manages the active instantiations of the VCE deployment. The gateway 140 is a collection of computer software, hardware, and firmware that allows the public cloud 105 to communicate via the WAN 102.

[0034] Some further explanations of the virtualized computing environment (VCE) will now be provided. The VCE can be stored as an "image". New active instances of the VCE can be instantiated from this image. Two common types of VCEs are virtual machines and containers. A container is a VCE that uses operating system-level virtualization. This refers to an operating system feature where the kernel allows the existence of multiple isolated user space instances (referred to as containers). From the perspective of the programs running within them, these isolated user space instances typically behave as actual computers. A computer program running on a normal operating system can utilize all the resources of that computer, such as connected devices, files and folders, network shares, CPU capabilities, and quantifiable hardware capabilities. However, a program running within a container can only use the contents of the container and the devices allocated to the container, which is a feature known as containerization.

[0035] The private cloud 106 is similar to the public cloud 105, except that the computing resources are only available for use by a single enterprise. Although the private cloud 106 is depicted as communicating with the WAN 102, in other embodiments, the private cloud can be completely disconnected from the Internet and only accessible through a local / private network. A hybrid cloud is generally a combination of multiple clouds of different types (e.g., private, community, or public cloud types) typically implemented by different vendors. Each of the multiple clouds remains a separate and discrete entity, but the larger hybrid cloud architecture is tied together by standardized or proprietary technologies that enable orchestration, management, and / or data / application portability between the multiple constituent clouds. In this embodiment, the public cloud 105 and the private cloud 106 are both part of the larger hybrid cloud.

[0036] Now referring to Figure 2 , a block diagram of a tree structure 200 for use in conjunction with one or more embodiments of the present invention is shown. In an exemplary embodiment, the tree structure 200 includes a root node 202 (also referred to as a source node or source participant), and a plurality of child nodes 204 (also referred to as participant nodes). As shown, one or more of the plurality of child nodes 204 may have child nodes 206 subordinate to the child nodes 204, and the child nodes 206 may have child nodes 208 subordinate to the child nodes 206. In an exemplary embodiment, as Figure 1 shown, each of the nodes (root node 202 and child nodes 204, 206, and 208) may be embodied in a computer 101.

[0037] In an exemplary embodiment, before initiating a distributed communication operation such as a broadcast or scatter operation, the source participant 200 obtains the tree structure 200 to be used for the distributed communication operation. In one embodiment, the tree structure 200 is only known to the source participant 202 and not to the other participant nodes. In an exemplary embodiment, the tree structure 200 can even be different for the same set of participants depending on the communication operation. The tree structure does not have to be a regular pattern, but can be irregular based on external inputs such as network conditions. The method for creating the tree structure 200 is outside the scope of the present invention, and any of a variety of known techniques can be used to create the tree structure 200.

[0038] Now referring to Figure 3, which shows a block diagram illustrating a broadcast operation according to one or more embodiments of the present invention. In the broadcast operation, the source participant 300 adds a header 302 to the message payload at a known location before or after the message payload 306. The header 302 describes the base address of the data payload 306, the length of the data payload 306, and the subtree structure 308 of the receiving participant ("child"). As shown, the headers 312, 322, 342 transmitted to the child nodes 310, 320, 340, respectively, are different from each other because each header includes a different subtree structure 308. In one embodiment, a cache subtree structure is used, and a tag identifying the cache subtree is sent instead of the subtree structure of the receiving participant.

[0039] In an exemplary embodiment, once the source participant 300 has assembled the data payload 306 and the header, the source participant 300 begins the broadcast operation. The source participant 300 sends the header 312 and the data payload 306 to the child node 310, sends the header 322 and the data payload 306 to the child node 320, and sends the header 342 and the data payload 306 to the child node 340.

[0040] In an exemplary embodiment, the child participant will receive the data payload from its parent participant, which is unknown to them before the start of the message transmission protocol. The child participant will examine the data payload to discover the structure of the data payload and the form of the subtree below them (if any). In an exemplary embodiment, when the child participant receives the header and the data payload 306, the child participant prunes the header for subtree information that does not belong to the subtree it is sending to, and transmits the new header and data payload to its child nodes. For example, after the node 310 receives the header 312 and the data payload 306, the node 310 will prune the header 312 to create headers 332 and 352, which are transmitted to the nodes 330 and 350 together with the data payload 306, respectively.

[0041] If the child node is a terminal node such as node 370, the propagation of the payload data 306 is terminated. If confirmation is requested, each node sends a confirmation message to its direct parent node (i.e., the one it received the message from). If the child node is a non-terminal node and confirmation is requested, the node will wait until it receives a confirmation message from its subtree, and then forward the confirmation to its direct parent node for that message. In an exemplary embodiment, the propagation mode continues until all participants have received the data payload destined for them and sent any required confirmations.

[0042] Now refer to Figure 4, which shows a block diagram illustrating a decentralization operation 400 according to one or more embodiments of the present invention. In an exemplary embodiment, when the source participant 402 initiates the decentralization operation 400, the source participant 402 obtains a tree structure that will be used for the decentralization operation 400. The tree structure includes a plurality of nodes 403, 404, 405, 406, 407, 408, and 409.

[0043] After obtaining the tree structure, the source participant 402 creates a message 410 that includes a plurality of headers 412, 416, 424, and a plurality of data payloads 414, 418, 420, 422, 426, 428, 430. In an exemplary embodiment, the source participant 402 creates data payloads 414, 418, 420, 422, 426, 428, 430 for each of the nodes 403, 404, 405, 406, 407, 408, and 409 in the tree structure. Similarly, the source participant 402 creates headers 412, 416, 424 for each of the nodes 403, 406, 404 of the tree structure that have at least one child node. In an exemplary embodiment, the headers 412, 416, 424 of each of the nodes 403, 406, 404 include a description of the subtree of the tree structure that is subordinate to the nodes 403, 406, 404. The headers 412, 416, 424 may also describe the base address of the data payloads 414, 418, 420, 422, 426, 428, 430 and the length of the data payloads 414, 418, 420, 422, 426, 428, 430.

[0044] In an exemplary embodiment, the message 410 is created by the source participant 402 such that the portions of the message 410 that will be transmitted to each child node are contiguous. For example, as shown, the headers 412, 416 and the data payloads 414, 418, 420, 422 that are transmitted to the child node 403 are contiguous. Similarly, the header 424 and the data payloads 426, 428 that will be transmitted to the child node 404 are contiguous. In one embodiment, a cache subtree structure is used, and a tag identifying the cache subtree is sent instead of the subtree structure of the receiving participant.

[0045] Once a child node receives a portion of message 410, the child node is configured to extract the data required by the child node and use the information from the header of the child node to split the remaining header and data payload. For example, once child node 403 receives a portion of a message from source participant 402, child node 403 extracts data payload 414 required by child node 403 and uses the information in header 412 to separate the remaining portion of message 410 into individual parts. The child node then propagates a portion of the message, i.e., it sends only a subset of the header and data payloads that are designated for a particular subtree to that subtree. For example, child node 403 transmits header 416 and data payloads 418, 420 to child node 406 and data payload 422 to child node 407.

[0046] Now referring to Figure 5 , a block diagram illustrating a combination of broadcast operations and scatter operations 500 in accordance with one or more embodiments of the present invention is shown. In an exemplary embodiment, when source participant 502 initiates combined broadcast scatter operation 500, source participant 502 obtains a tree structure that will be used for combined broadcast scatter operation 500. The tree structure includes a plurality of nodes 503, 504, 505, 506, 507, 508, and 509.

[0047] After obtaining the tree structure, source participant 502 creates message 510, which includes a broadcast header 512, a broadcast data payload 514, a plurality of scatter headers 516, 520, 528, and a plurality of scatter data payloads 518, 522, 524, 526, 530, 532, 534. In an exemplary embodiment, source participant 502 creates scatter data payloads 518, 522, 524, 526, 530, 532, 534 for each of the nodes 503, 504, 505, 506, 507, 508, and 509 in the tree structure. Similarly, source participant 502 creates scatter headers 516, 520, 528 for each of the nodes 503, 506, 504 of the tree structure that have at least one child node. In an exemplary embodiment, the scatter headers 516, 520, 528 of each of the nodes 503, 506, 504 include a description of the subtree of the tree structure that is subordinate to nodes 503, 506, 504. The scatter headers 516, 520, 528 may also describe the base address of the scatter data payloads 518, 522, 524, 526, 530, 532, 534 and the length of the scatter data payloads 518, 522, 524, 526, 530, 532, 534.

[0048] In an exemplary embodiment, the message 510 is created by the source participant 502 such that the portions of the message 510 that are to be transmitted to each child node are contiguous. For example, as shown, the headers 516, 520 and the data payloads 518, 522, 524, 526 that are to be transmitted to the child node 503 are contiguous. Similarly, the header 528 and the data payloads 530, 532 that are to be transmitted to the child node 504 are contiguous.

[0049] Once a child node receives a portion of the message 510, the child node is configured to examine the header corresponding to the child node to discover the structure of the data payload and the form of the subtree (if any) below that child node. The child node is also configured to extract a copy of the broadcast payload 514 for its consumption and remove the fragmented payload corresponding to the child node. For example, the child node 503 will examine the broadcast header 512 and extract a copy of the broadcast payload 514, and examine the fragmented header 516 and extract the fragmented payload 518. Based on the information in the broadcast header 512 and the fragmented header 516, the child node 503 will create a message and transmit the message to the child nodes 506 and 507.

[0050] In an exemplary embodiment, a child node only propagates a portion of the message to each child node subordinate to it, i.e., the child node only sends a subset of the headers and data payloads that are designated for a particular subtree to that subtree. For example, the child node 503 transmits the broadcast header 512, the broadcast data payload 514, the fragmented headers 520 and the fragmented data payloads 522, 524 to the child node 506, and transmits the broadcast header 512, the broadcast data payload 514, and the fragmented data payload 526 to the child node 507.

[0051] In an exemplary embodiment, each child node may be configured to add additional data to the headers and / or data payloads that are propagated to its subtree. Additionally, each child node may be configured to change the tree structure of its subtree. For example, a child node may know that a node in its subtree is offline or has an unexpected performance issue, in which case the child node may replace the node in its subtree with a different node.

[0052] Now referring Figure 6 , a flowchart of a method 600 for initiating a distributed communication operation according to one or more embodiments of the present invention is shown. In an exemplary embodiment, the distributed communication operation is one of a broadcast operation, a fragmentation operation, or a combination of a broadcast and a fragmentation operation. As shown, the method 600 includes receiving a request to perform a distributed communication operation, as shown in block 602. Next, as shown in block 604, the method 600 includes obtaining a tree structure for performing the distributed communication operation. In an exemplary embodiment, the computing system that initiates the distributed communication operation is the root node of the tree structure.

[0053] As shown in block 606, method 600 also includes creating a message having header information and a payload for distributed communication operations. In an exemplary embodiment, the message is created by organizing the header information and the payload based on a tree structure. In one embodiment, the header information and the payload are organized such that a portion of the header information and a portion of the payload data to be transmitted to a child node are contiguous. Method 600 also includes transmitting a portion of the message to each child node of a first computing system, where the portion transmitted to each child node is unique, as shown in block 608. In an exemplary embodiment, the portion of the message transmitted to each child node includes a sub-header defining a subtree structure of the child node.

[0054] In one embodiment, the distributed communication operation is a broadcast operation, and the payload of the message transmitted to each child node includes a broadcast payload, which is the same for each child node. In another embodiment, the distributed communication operation is a scatter operation, and the portion of the message transmitted to each child node includes a scatter payload obtained based on the payload. The scatter payloads transmitted to each child node are different from the scatter payloads transmitted to other child nodes.

[0055] Now referring Figure 7 to, a flowchart of a method 700 for performing distributed communication operations in accordance with one or more embodiments of the present invention is shown. As shown in block 702, method 700 begins with a child node receiving a distributed communication operation message from a parent node. In an exemplary embodiment, the distributed communication operation is one of a broadcast operation, a scatter operation, or a combination of a broadcast and a scatter operation. Once the child node receives the distributed communication operation message, it obtains information about its subtree from the header of the distributed communication operation message. Next, as shown at decision block 704, based on the subtree information, method 700 determines whether the child node is a terminal node.

[0056] Based on the determination that the child node is a terminal node, method 700 proceeds to block 710, and the child node extracts the data payload required by the child node. Based on the determination that the child node is not a terminal node, method 700 proceeds to block 706, and the child node obtains subtree data from the header of the message and creates a message for each node subordinate to the child node. In an exemplary embodiment, the message created for each node includes only the header information and the payload data required for the subtree corresponding to the destination child node. The message transmitted to each child node may include one or more of a broadcast header, a scatter header, a broadcast payload, and a scatter payload. Next, as shown in block 708, method 700 includes transmitting the message to each node subordinate to the child node. As shown in block 712, method 700 also includes transmitting an acknowledgment message to the parent node.

[0057] Technical advantages and benefits include methods, systems, and computer program products for performing distributed communication operations using an execution tree configured to dynamically adapt based on network and computing conditions. The method for performing distributed communication operations only requires the source participant or root node to know the tree structure used to perform the distributed communication operations. Thus, different tree structures can be used to perform different distributed communication operations, and the tree structure can be updated without synchronizing knowledge of the tree structure to each node of the tree.

[0058] Various embodiments of the present invention are described herein with reference to the related drawings. Alternative embodiments of the present invention can be designed without departing from the scope of the present invention. In the following description and drawings, various connection and positional relationships (e.g., above, below, adjacent, etc.) are set forth between elements. Unless otherwise stated, these connections and / or positional relationships can be direct or indirect, and the present invention is not intended to be limited in this regard. Thus, the coupling of entities can refer to direct or indirect coupling, and the positional relationship between entities can be a direct or indirect positional relationship. In addition, the various tasks and process steps described herein can be incorporated into a more comprehensive program or process having additional steps or functions not described in detail herein.

[0059] One or more of the methods described herein can be implemented using any one or combination of the following techniques known in the art: (multiple) discrete logic circuits having logic gates for implementing logical functions according to data signals, application specific integrated circuits (ASICs) having appropriate combinational logic gates, (multiple) programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0060] For the sake of brevity, conventional techniques related to the manufacture and use of aspects of the present invention may or may not be described in detail herein. Specifically, aspects of the computing systems and specific computer programs for implementing the various technical features described herein are known. Thus, for the sake of brevity, many conventional implementation details are only briefly mentioned or completely omitted herein without providing details of the known systems and / or processes.

[0061] In some embodiments, the various functions or actions can occur at a given location and / or in conjunction with the operation of one or more devices or systems. In some embodiments, a portion of a given function or action can be performed at a first device or location, and the remainder of the function or action can be performed at one or more additional devices or locations.

[0062] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements components, and / or groups thereof.

[0063] All structural, material, acts, and equivalents of the means or step plus function elements in the following claims are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The present disclosure has been presented for purposes of illustration and description but is not intended to be exhaustive or limited to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the disclosure. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical application and to enable others of ordinary skill in the art to understand the disclosure with various modifications suited to the particular use contemplated.

[0064] The figures depicted herein are illustrative. There may be many variations to the figures or steps (or operations) described therein without departing from the scope of the disclosure. For example, acts may be performed in a different order, or acts may be added, deleted, or modified. Additionally, the term "coupled" describes having a signal path between two elements and does not imply a direct connection without intermediate elements / connections between the elements. All such variations are considered to be a part of the present disclosure.

[0065] The following definitions and abbreviations are used to interpret the claims and the specification. As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", "contains", or "containing", or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or apparatus that includes a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.

[0066] Additionally, the term "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or design described herein as "exemplary" is not necessarily to be construed as more preferred or advantageous than other embodiments or designs. The terms "at least one" and "one or more" are understood to include any integer greater than or equal to one, i.e., one, two, three, four, etc. The term "plurality" shall be understood to include any integer greater than or equal to two, i.e., two, three, four, five, etc. The term "connected" may include both indirect "connection" and direct "connection".

[0067] The terms "about", "substantially", "approximately", and their variants are intended to include the degree of error associated with a particular quantity measurement based on the equipment available at the time of filing this application. For example, "about" can include a range of ±8%, or 5%, or 2% of a given value.

[0068] The present invention can be a system, method, and / or computer program product at any possible level of integration of technical details. The computer program product can include a computer-readable storage medium (or medium) having thereon computer-readable program instructions for causing a processor to execute aspects of the present invention.

[0069] The computer-readable storage medium can be a tangible device capable of retaining and storing instructions for use by an instruction execution device. The computer-readable storage medium can be, by way of example and not limitation, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer-readable storage medium includes the following: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanical encoding device such as a punched card or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium shall not be construed as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., an optical pulse transmitted through an optical fiber cable), or an electrical signal transmitted through a wire.

[0070] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device or can be downloaded to an external computer or an external storage device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network). The network can include copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium within the corresponding computing / processing device.

[0071] The computer-readable program instructions for carrying out operations of the present invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuit devices, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages (such as Smalltalk, C++, etc.) and procedural programming languages (such as the "C" programming language or similar programming languages). The computer-readable program instructions may be executed entirely on a user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network (including a local area network (LAN) or a wide area network (WAN)), or may be connected to an external computer (e.g., through the Internet using an Internet service provider). In some embodiments, in order to carry out aspects of the present invention, an electronic circuit device (including, for example, a programmable logic circuit device, a field-programmable gate array (FPGA), or a programmable logic array (PLA)) may execute the computer-readable program instructions by utilizing state information of the computer-readable program instructions to personalize the electronic circuit device.

[0072] Aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0073] These computer-readable program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executed via the processor of the computer or other programmable data processing apparatus create means for implementing the functions / acts specified in one or more boxes of the flowchart and / or block diagram. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer-readable storage medium in which the instructions are stored comprises an article of manufacture including instructions that implement various aspects of the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0074] The computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other devices to produce a computer-implemented process, such that the instructions executed on the computer, other programmable apparatus, or other devices implement the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0075] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the box may not occur in the order noted in the figures. For example, two boxes shown in succession may, in fact, be executed substantially concurrently, or the boxes may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each box of the block diagrams and / or flowchart, and combinations of boxes in the block diagrams and / or flowchart, can be implemented by special-purpose hardware-based systems that perform the specified functions or acts, or combinations of special-purpose hardware and computer instructions.

[0076] The description of the various embodiments of the present invention has been presented for purposes of illustration, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the described embodiments. The terms used herein were chosen to best explain the principles of the embodiments, the practical application, or technical improvement of technologies found in the marketplace, or to enable other practitioners in the art of ordinary skill to understand the embodiments described herein.

Claims

1. A computer-implemented method, comprising: receiving, by a first computing system, a request to perform a distributed communication operation; obtaining, by the first computing system, a tree structure for performing the distributed communication operation, wherein the first computing system is the root node of the tree structure; creating, by the first computing system, a message having header information and a payload for the distributed communication operation; and transmitting, by the first computing system, a portion of the message to each child node of the first computing system, wherein the portion transmitted to each child node is unique.

2. The method according to claim 1, wherein the portion of the message transmitted to each child node comprises a sub-header defining a sub-tree structure of the child node.

3. The method according to claim 1, wherein the distributed communication operation is a broadcast operation, and wherein the payload of the message transmitted to each child comprises a broadcast payload.

4. The method according to claim 1, wherein the distributed communication operation is a scatter operation, and wherein the portion of the message transmitted to each child comprises a scatter payload obtained based on the payload.

5. The method according to claim 1, wherein the distributed communication operation is a broadcast and scatter operation.

6. The method according to claim 1, wherein the message is created by organizing the header information and the payload based on the tree structure.

7. The method according to claim 6, wherein the header information and the payload are organized such that a portion of the header information and a portion of the payload data to be transmitted to a child node are contiguous.

8. A system, comprising: a memory having computer-readable instructions; and one or more processors for executing the computer-readable instructions, the computer-readable instructions controlling the one or more processors to perform operations, the operations comprising: receiving, by a first computing system, a request to perform a distributed communication operation; obtaining, by the first computing system, a tree structure for performing the distributed communication operation, wherein the first computing system is the root node of the tree structure; creating, by the first computing system, a message having header information and a payload for the distributed communication operation; and transmitting, by the first computing system, a portion of the message to each child node of the first computing system, wherein the portion transmitted to each child node is unique.

9. The system according to claim 8, wherein the portion of the message transmitted to each child node comprises a sub-header defining a sub-tree structure of the child node.

10. The system according to claim 8, wherein the distributed communication operation is a broadcast operation, and wherein the payload of the message transmitted to each child comprises a broadcast payload.

11. The system according to claim 8, wherein the distributed communication operation is a scatter operation, and wherein the portion of the message transmitted to each child comprises a scatter payload obtained based on the payload.

12. The system according to claim 8, wherein the distributed communication operation is a broadcast and scatter operation.

13. The system according to claim 8, wherein the message is created by organizing the header information and the payload based on the tree structure.

14. The system according to claim 13, wherein the header information and the payload are organized such that a part of the header information and a part of the payload data to be transmitted to a child node are contiguous.

15. A computer program product comprising a computer-readable storage medium having program instructions embodied therewith, the program instructions being executable by a processor to cause the processor to perform operations, the operations comprising: receiving, by a first computing system, a request to perform a distributed communication operation; obtaining, by the first computing system, a tree structure for performing the distributed communication operation, wherein the first computing system is a root node of the tree structure; creating, by the first computing system, a message having header information and a payload for the distributed communication operation; and transmitting, by the first computing system, a part of the message to each child node of the first computing system, wherein the part transmitted to each child node is unique.

16. The computer program product according to claim 15, wherein the part of the message transmitted to each child node includes a sub-header defining a sub-tree structure of the child node.

17. The computer program product according to claim 15, wherein the distributed communication operation is a broadcast operation, and wherein the payload of the message transmitted to each child includes a broadcast payload.

18. The computer program product according to claim 15, wherein the distributed communication operation is a scatter operation, and wherein the part of the message transmitted to each child includes a scatter payload obtained based on the payload.

19. The computer program product according to claim 15, wherein the distributed communication operation is a broadcast and scatter operation.

20. The computer program product according to claim 15, wherein the message is created by organizing the header information and the payload based on the tree structure.

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