Distributed Data Scalable Adaptive Map-Reduce Framework

FIELD OF THE INVENTION

0001Embodiments of the invention generally relate to information technology, and, more particularly, to a map reduce framework.

BACKGROUND OF THE INVENTION

0002Petascale analytics require an efficient map reduce framework that can leverage advances in processor technologies to improve the performance/cost ratio. Communication bottlenecks are a major roadblock for high throughput map-reduce over large quantities of data (for example, terabytes to petabytes). Currently, map-reduce frameworks suffer from such communication bottlenecks. Further, existing map-reduce frameworks are not able to leverage hybrid systems that provide accelerators. Additionally, the scheduling of the map reduce system is primarily centralized. Accordingly, there exists a need for distributed map reduce over large clusters.

SUMMARY OF THE INVENTION

0003In one aspect of the present invention, a distributed data scalable adaptive map-reduce framework is provided. An exemplary computer-implemented method for generating a distributed data scalable adaptive map-reduce framework for at least one multi-core cluster can include steps of partitioning a cluster into at least one computational group, determining at least one key-group leader within each computational group, performing a local combine operation at each computational group, performing a global combine operation at each of the at least one key-group leader within each computational group based on a result from the local combine operation, and performing a global map-reduce operation across the at least one key-group leader within each computational group.

0004Another aspect of the invention or elements thereof can be implemented in the form of an article of manufacture tangibly embodying computer readable instructions which, when implemented, cause a computer to carry out a plurality of method steps, as described herein.

0005Furthermore, another aspect of the invention or elements thereof can be implemented in the form of an apparatus including a memory and at least one processor that is coupled to the memory and operative to perform noted method steps.

0006Yet further, another aspect of the invention or elements thereof can be implemented in the form of means for carrying out the method steps described herein, or elements thereof; the means can include (i) hardware module(s), (ii) software module(s), or (iii) a combination of hardware and software modules; any of (i)-(iii) implement the specific techniques set forth herein, and the software modules are stored in a tangible computer-readable storage medium (or multiple such media).

0007These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

0008<figref idref="DRAWINGS">FIG. 1</figref> is an example cluster diagram illustrating an example embodiment, according to an aspect of the invention;

0009<figref idref="DRAWINGS">FIG. 2</figref> is a diagram illustrating an example embodiment, according to an aspect of the invention;

0010<figref idref="DRAWINGS">FIG. 3</figref> is a flow diagram illustrating techniques for generating a distributed data scalable adaptive map-reduce framework for at least one multi-core cluster, according to an embodiment of the invention; and

0011<figref idref="DRAWINGS">FIG. 4</figref> is a system diagram of an exemplary computer system on which at least one embodiment of the invention can be implemented.

DETAILED DESCRIPTION OF EMBODIMENTS

0012As described herein, an aspect of the present invention includes an optimized distributed map reduce framework for large scale multi-core hybrid clusters. An embodiment of the invention includes a global combine phase and splitting batch mode map-reduce into multiple map-reduce iterations. A user can specify this combine function along with the final reduce function. Additionally, the framework detailed herein uses a two-level approach that enables a divide-conquer strategy for very large scale clusters and efficient communication within each computation group at a level.

0013Accordingly, a data scalable designed framework as detailed herein provides significant performance and cost advantage over conventional map reduce approaches. For example, an aspect of the invention includes leveraging advances in process technologies to improve performance/cost ratio, as well as reducing communication bottlenecks due to high throughput map-reduce over large quantities of data (terabytes to petabytes).

0014As described herein, an asynchronous map reduce algorithm includes mapping, combining locally, combining globally, and reducing globally. A cluster is partitioned into computational groups. Each computational group represents a locally dense group, which can include, for example, multiprocessor machines and tightly coupled clusters. Also, each map reduce computation is converted into an iterative map-combine then reduce operation. This can include a large number of smaller maps, combine-local, and/or combine-global operations, as well as one reduce operation per key.

0015An aspect of the invention additionally includes facilitating stronger combine operations which allow for lesser communication overhead. This can be useful, for example, in scenarios where data reduction is substantial. The splitting of map-combine-reduce into multiple map-network combine stages then a global reduce allows the network utilization to be smoothed over time, rather than providing small time windows with substantial data movement.

0016A map algorithm, as detailed herein, includes work stealing within a group (computation-group), as well as load balancing within a computation-group. A combiner algorithm includes key clustering. With an objective of low communication in combine-global and reduce steps, a combiner algorithm generates key-groups. Such an algorithm also includes a two-level hierarchy. Within computation groups, key-group leaders are determined. A local combine operation is performed at each node, and a global combine operation is performed at the leaders for each key group. Also, across the key-group leaders, a Steiner tree-based reduce operation is performed.

0017Accordingly, distributed Steiner trees are used one each per key-group, changing topology with changing computation-spread per key-group. That is, the Steiner tree is dependent on the spread of each key-group with a different tree for each key group. An aspect of the invention also includes locality-driven Steiner trees. Further, adaptive Steiner tree construction and key grouping can be used specifically in the case of a compute or communication dominated kernel on map-reduce. Additionally, an embodiment of the invention includes bloom filters used in connection with key availability queries.

0018As also described herein, a reduce algorithm includes merging all combiner outputs into a single output. A disk-based map reduce enables pipelined reduce functionality with reduce-compute overlap with a disk-based read. An embodiment of the invention includes virtual fat nodes, which include using a group of base nodes in a small cluster to leverage a distributed shared memory infrastructure. Message passing interface/deep computing messaging framework (MPI/DCMF) based communication can be used within a fat node, which may be useful, for example, for in-memory map reduce.

0019For disk-based communication for large data, the number of files generated can include map tasks*reduce/combine tasks. Disk-based communication also includes merging of <key, value> pairs for each reduce tasks, in-memory merge-sort of key-value pairs, a reduce/combine compute and communication overlap, as well as the use of accelerators. Disk-based communication across the fat nodes can include Hadoop distributed file system/general parallel file system (HDFS/GPFS) based communication (across the fat nodes).

0020Additionally, an aspect of the invention includes the use of accelerators from hybrid systems (such as, for example, Power EN). This can also include HEA communication across the nodes (for example, direct packet injection into the cache), and a compression/de-compression accelerator (for example, compress <key, value> data in communication across the nodes). Accelerators also include a cryptographic accelerator (for example, a bloom filter for processing key-availability queries), and a RegEx accelerator, which can include a lower depth B+ tree and search time acceleration for keys.

0021Accordingly, an aspect of the invention includes communication optimizations via mapping of map and reduce tasks (for example, topology dependent mapping and two-dimensional map and reduce mapping over a three-dimensional (3D) torus network), dynamic data movement, multi-level map reduce, a structure of combine-reduce trees, and generic/dynamic producer/consumer communication and optimization framework (including, for example, iterative map reduce). Further, as detailed herein, an embodiment of the invention includes locality in combine/reduce tasks, load balancing in compute and communication across the map tasks and reduce tasks, and adaptivity to the nature of the kernel.

0022Additionally, distributed combiner optimization includes a map/combiner output that is highly distributed. For a given network, for each set of keys, a unique temporary node is selected using a hash/mapping function. A topology tree is created for each key set at a temporary node, and for each key, a temporary node selects a sink node and a combiner tree. The topology of the network is preprocessed to mark bottleneck edges, and nodes are grouped into tightly coupled groups.

0023Accordingly, an aspect of the invention minimizes the number of bottleneck edges in each topology tree. Each node sorts keys hash mapped to it based on the number of critical links and the number of nodes (#N) having the key. Each communication link offers a predetermined fixed bandwidth for each time window. Key sets with high #N values and a high number of critical links choke bandwidth. High and low valued key groups are interleaved to reduce collisions and congestion, and their approximate data flow tree is built. Additionally, keys that can be accommodated in an earlier time frame are shifted. For each set in the sorted list, the process is repeated until all keys are parsed. As such, each node is given data sources, keys, a time frame and a destination node.

0024Distribution reduce optimizations include a reduce operation assigned to nodes dynamically. Also, such optimizations include a reduce operation for a given key set given to a centrally located node, which can decrease in amount of data moved over the network. Additionally, a distributed combiner reduces data movement over the network.

0025An aspect of the invention can also include hybrid systems/prism multi-core cluster (for example, a systems and technology group (STG) differentiator). DCMF based optimizations include the use of an IO accelerator to help in one-sided and asynchronous communication primitives of DCMF. Also, an in-memory map reduce can be used for communication amongst nodes using high speed interconnect.

0026Accordingly, as detailed herein, a high throughput disk-based map-reduce can include fat nodes as a single Hadoop task. Additionally, an embodiment of the invention includes a local disk per node within the fat node, high speed interconnect-based communication, and use of in-memory performance optimizations (for example, bloom filter, compression/decompression, HEA, and RegEx).

0027Map-reduce compute efficiency optimizations can include, for example, a map-reduce locality optimization. Such an optimization can include automatic inference of map-reduce locality in workloads with multiple map-reduce iterations, as well as weighted bi-partite graph based analysis for repeating pattern analysis on intermediate pairs coming from map threads and going to reduce threads. A map-reduce locality optimization also includes online sequence motif discovery over map-reduce intermediate pairs access patterns.

0028Also, map-reduce compute efficiency optimizations can include, for example, a tree-based pipelined reduce for 100s-1000 cores and/or large scale symmetric multiprocessing (SMP) architectures. This includes a reduction in the number of <key, value> pairs observed at the final reduce step per key (as well as a local reduction in total number of <key, value> pairs). Additionally, this can also include cache-aware and load-balance aware reduce tree construction. Each node of the tree can be annotated with a subset of keys for which to reduce, and tree topology is dynamically determined based on the location of key-value hash at map threads. A tree-based pipelined reduce can also include multiple trees for separate subsets of keys, a reduce specified as associative operator+final operator, and optimizations based on target many-core architecture.

0029<figref idref="DRAWINGS">FIG. 1</figref> is an example cluster diagram illustrating an example embodiment, according to an aspect of the invention. By way of illustration, <figref idref="DRAWINGS">FIG. 1</figref> depicts an interconnect network <b>102</b> and a parallel file system <b>104</b>, with compute nodes <b>106</b>, nodes to a file system interface <b>108</b> and nodes to an interconnect interface <b>110</b> therebetween. Put together, they form a generalized model of a cluster. Communication and transfer of computer readable data across the compute nodes is performed over the interconnect network <b>102</b>. For any interaction between two compute nodes, each compute node <b>106</b> utilizes the interconnect interface <b>110</b> to form a connection to the interconnect network <b>102</b>. The interconnection network then allows the two compute nodes to interact with each other using the interconnect interface. The parallel filesystem <b>104</b> allows each compute node to write information to a common resource. The parallel filesystem is accessible to all the compute nodes through the file system interface.

0030<figref idref="DRAWINGS">FIG. 2</figref> is a diagram illustrating an example embodiment, according to an aspect of the invention. Step <b>202</b> includes initializing a map reduce via an initialization module. Step <b>204</b> includes mapping a task via a mapping module. Step <b>206</b> includes performing a local combine operation through each computational group via a local combine module. Step <b>208</b> includes determining disjoint paths for each key group via a path determination module. Step <b>210</b> includes performing a network based combine operation on each such disjoint path via a network combine module. If the complete data has not yet been processed by the map in step <b>212</b>, then the process returns to step <b>204</b>. Otherwise, the process continues to step <b>214</b>, which includes performing a global reduce operation via a global reduce module. Further, step <b>216</b> includes redistributing the result of the global reduce via a redistribution module.

0031<figref idref="DRAWINGS">FIG. 3</figref> is a flow diagram illustrating techniques for generating a distributed data scalable adaptive map-reduce framework for at least one multi-core cluster, according to an embodiment of the present invention. Step <b>302</b> includes partitioning a cluster into at least one computational group. This step can be carried out, for example, using at least one module as detailed herein.

0032Step <b>304</b> includes determining at least one key-group leader within each computational group. This step can be carried out, for example, using at least one module as detailed herein. Step <b>306</b> includes performing a local combine operation at each computational group. This step can be carried out, for example, using at least one module as detailed herein. Step <b>308</b> includes performing a global combine operation at each of the at least one key-group leader within each computational group based on a result from the local combine operation. This step can also be carried out, for example, using at least one module as detailed herein.

0033Step <b>310</b> includes performing a global map-reduce operation across the at least one key-group leader within each computational group. This step can be carried out, for example, using at least one module as detailed herein. Performing a global map-reduce operation can include performing a Steiner tree-based reduce operation across the key-group leader(s) within each computational group. Also, performing a Steiner tree-based reduce operation includes using one distributed Steiner tree used per key-group.

0034As detailed herein, the distributed data scalable adaptive map-reduce framework is adaptive to a nature of kernel (for example, compute intensive (load balance issue) to communication intensive (huge key-value pairs)). Additionally, the techniques depicted in <figref idref="DRAWINGS">FIG. 3</figref> also include using at least one accelerator to accelerate an execution of a map-reduce operation. The at least one accelerator can include, for example, a bloom filter (for example, used in connection with key availability queries), a compression/de-compression accelerator, a cryptographic accelerator and a hybrid system accelerator (for example, HEA and RegEx).

0035An aspect of the invention further includes merging all combine operation outputs into a single output. Also, the techniques depicted in <figref idref="DRAWINGS">FIG. 3</figref> can include using at least one virtual fat node for a disk based map-reduce operation, wherein using at least one virtual fat node comprises using a group of at least one base node in a cluster to leverage a distributed shared memory infrastructure. Using a virtual fat node can include, for to example, using a virtual fat node for an in-memory map-reduce operation.

0036Additionally, an embodiment of the invention can also include using the distributed data scalable adaptive map-reduce framework to carry out analytics over multiple clusters using peta-bytes of data.

0037The techniques depicted in <figref idref="DRAWINGS">FIG. 3</figref> can also, as described herein, include providing a system, wherein the system includes distinct software modules, each of the distinct software modules being embodied on a tangible computer-readable recordable storage medium. All the modules (or any subset thereof) can be on the same medium, or each can be on a different medium, for example. The modules can include any or all of the components shown in the figures. In an aspect of the invention, the modules include an initialization module, a mapping module, a local combine module, a path determination module, a network combine module, a global reduce module and a redistribution module that can run, for example on a hardware processor. The method steps can then be carried out using the distinct software modules of the system, as described above, executing on a hardware processor. Further, a computer program product can include a tangible computer-readable recordable storage medium with code adapted to be executed to carry out at least one method step described herein, including the provision of the system with the distinct software modules.

0038Additionally, the techniques depicted in <figref idref="DRAWINGS">FIG. 3</figref> can be implemented via a computer program product that can include computer useable program code that is stored in a computer readable storage medium in a data processing system, and wherein the computer useable program code was downloaded over a network from a remote data processing system. Also, in an aspect of the invention, the computer program product can include computer useable program code that is stored in a computer readable storage medium in a server data processing system, and wherein the computer useable program code are downloaded over a network to a remote data processing system for use in a computer readable storage medium with the remote system.

0039As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in a computer readable medium having computer readable program code embodied thereon.

0040An aspect of the invention or elements thereof can be implemented in the form of an apparatus including a memory and at least one processor that is coupled to the memory and operative to perform exemplary method steps.

0041Additionally, an aspect of the present invention can make use of software running on a general purpose computer or workstation. With reference to <figref idref="DRAWINGS">FIG. 4</figref>, such an implementation might employ, for example, a processor <b>402</b>, a memory <b>404</b>, and an input/output interface formed, for example, by a display <b>406</b> and a keyboard <b>408</b>. The term “processor” as used herein is intended to include any processing device, such as, for example, one that includes a CPU (central processing unit) and/or other forms of processing circuitry. Further, the term “processor” may refer to more than one individual processor. The term “memory” is intended to include memory associated with a processor or CPU, such as, for example, RAM (random access memory), ROM (read only memory), a fixed memory device (for example, hard drive), a removable memory device (for example, diskette), a flash memory and the like. In addition, the phrase “input/output interface” as used herein, is intended to include, for example, a mechanism for inputting data to the processing unit (for example, mouse), and a mechanism for providing results associated with the processing unit (for example, printer). The processor <b>402</b>, memory <b>404</b>, and input/output interface such as display <b>406</b> and keyboard <b>408</b> can be interconnected, for example, via bus <b>410</b> as part of a data processing unit <b>412</b>. Suitable interconnections, for example via bus <b>410</b>, can also be provided to a network interface <b>414</b>, such as a network card, which can be provided to interface with a computer network, and to a media interface <b>416</b>, such as a diskette or CD-ROM drive, which can be provided to interface with media <b>418</b>.

0042Accordingly, computer software including instructions or code for performing the methodologies of the invention, as described herein, may be stored in an associated memory devices (for example, ROM, fixed or removable memory) and, when ready to be utilized, loaded in part or in whole (for example, into RAM) and implemented by a CPU. Such software could include, but is not limited to, firmware, resident software, microcode, and the like.

0043A data processing system suitable for storing and/or executing program code will include at least one processor <b>402</b> coupled directly or indirectly to memory elements <b>404</b> through a system bus <b>410</b>. The memory elements can include local memory employed during actual implementation of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during implementation.

0044Input/output or I/O devices (including but not limited to keyboards <b>408</b>, displays <b>406</b>, pointing devices, and the like) can be coupled to the system either directly (such as via bus <b>410</b>) or through intervening I/O controllers (omitted for clarity).

0045Network adapters such as network interface <b>414</b> may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.

0046As used herein, including the claims, a “server” includes a physical data processing system (for example, system <b>412</b> as shown in <figref idref="DRAWINGS">FIG. 4</figref>) running a server program. It will be understood that such a physical server may or may not include a display and keyboard.

0047As noted, aspects of the present invention may take the form of a computer program product embodied in a computer readable medium having computer readable program code embodied thereon. Also, any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

0048A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

0049Program code embodied on a computer readable medium may be transmitted using an appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

0050Computer program code for carrying out operations for aspects of the present invention may be written in any combination of at least one programming language, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the 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 the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

0051Aspects 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 program instructions. These computer program instructions may 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, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

0052These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. Accordingly, an aspect of the invention includes an article of manufacture tangibly embodying computer readable instructions which, when implemented, cause a computer to carry out a plurality of method steps as described herein.

0053The computer 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 which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

0054The flowchart 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 block in the flowchart or block diagrams may represent a module, component, segment, or portion of code, which comprises at least one executable instruction for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, 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.

0055It should be noted that any of the methods described herein can include an additional step of providing a system comprising distinct software modules embodied on a computer readable storage medium; the modules can include, for example, any or all of the components detailed herein. The method steps can then be carried out using the distinct software modules and/or sub-modules of the system, as described above, executing on a hardware processor <b>402</b>. Further, a computer program product can include a computer-readable storage medium with code adapted to be implemented to carry out at least one method step described herein, including the provision of the system with the distinct software modules.

0056In any case, it should be understood that the components illustrated herein may be implemented in various forms of hardware, software, or combinations thereof; for example, application specific integrated circuit(s) (ASICS), functional circuitry, an appropriately programmed general purpose digital computer with associated memory, and the like. Given the teachings of the invention provided herein, one of ordinary skill in the related art will be able to contemplate other implementations of the components of the invention.

0057The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. 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 be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of another feature, integer, step, operation, element, component, and/or group thereof.

0058The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

0059At least one aspect of the present invention may provide a beneficial effect such as, for example, leveraging advances in process technologies to improve performance/cost ratio.

0060The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.