Patent Publication Number: US-2023146501-A1

Title: Techniques for graph data structure augmentation

Description:
BACKGROUND 
     Machine learning models can be trained to identify key-value pairs in a document using graph data structure. For example, relationships between molecules can be identified using such a model. However, training a machine learning model on a graph data structure can produce an overfitted model if the graph data structure contained an insufficient number of graphs. Thus, challenges exist in training a machine learning model on a graph data structure. 
     BRIEF SUMMARY 
     Techniques are provided for training a machine learning model on an augmented graph data structure. 
     In an embodiment, a set of user documents can be received at a computer device. data can be extracted from the set of user documents by the computer device. A first graph data structure can be generated by the computing device. The graph data structure can contain one or more initial graphs containing the data extracted from the user document. The data can include a set of key-value pairs. The model can be trained on the first graph data structure to classify the set of key-value pairs. The model can be trained by the computing device. Until a set of evaluation metrics for the model exceeds a set of deployment thresholds: generating the set of evaluation metrics for the model. The evaluation metrics can be generated by the computing device. The set of evaluation metrics for the model can be compared to the set of deployment thresholds. The evaluation metrics and deployment thresholds can be compared by the computing device. In response to a determination that the set of evaluation metrics are below the set of deployment thresholds: generating one or more new graphs to produce a second graph data structure. The one or more new graphs can be generated by a first augmentation module of the computing device. The one or more new graphs can be generated from the one or more initial graphs in the first graph data structure. The model can be trained on at least one of the first graph data structure and the second graph data structure by the computing device. 
     In one general aspect, generating the one or more new graphs to produce the second graph data structure further comprises: receiving the one or more initial graphs from the first graph data structure. The one or more initial graphs can be received by the first augmentation module of the computing device. One or more edges and nodes in the one or more graphs of the one or more initial graphs can be deleted to produce one or more new graphs. The one or more edges and nodes can be deleted by the first augmentation module of the computing device. The one or more new graphs can be stored in the first graph data structure to produce the second graph data structure. The one or more new graphs can be stored by the first augmentation module of the computing device. 
     In one general aspect, deleting one or more edges and nodes further comprises: determining an occurrence metric. The occurrence metric can comprise a frequency distribution of a set of node labels. The occurrence metric can be determined by the computing device. An importance metric can be determined by a computing device. The importance metric can comprise a weight for the set of node labels. A proximity metric can be determined by the computing device. One or more edge and nodes can be deleted by the computing device. The one or more edges and nodes can be deleted based at least in part on one or more of the occurrence metric, the importance metric, or the proximity metric. 
     In one general aspect, the method further comprises: until a set of robustness metrics for the model exceeds a set of robustness thresholds: generating the set of robustness metrics for the model. The set of robustness metrics can be generated by the computing device. The set of robustness metrics can be compared to the set of robustness thresholds by the computing device. In response to a determination that the set of robustness metrics are below a set of robustness thresholds: altering key-value pairs in the second graph data structure to produce a third graph data structure. The key-value pairs can be altered by the second augmentation module of the computing device. Training the model on at least one of the first graph data structure, the second graph data structure, or the third graph data structure to classify key-value pairs. The model can be trained by the computing device. 
     In one general aspect, altering the key-value pairs further comprises: changing a sequence of words in one or more key-value pairs in the second graph data structure. The sequence of words can be changed by the second augmentation module of the computing device. A spelling of one or more words in one or more key-value pairs can be changed in at least one of the first graph data structure or the second graph data structure. The spelling can be changed by the second augmentation module of the computing device. 
     In one general aspect, the user documents can include at least one of: drivers licenses, gun licenses, passports or checks. 
     In one general aspect, the data can be extracted from the user documents using optical character recognition (OCR). 
     One general aspect includes one or more non-transitory computer-readable storage media that may include computer-executable instructions that, when executed by one or more processors of a computing device, cause the computing device to perform instructions comprising: receiving a set of user documents. The instructions include extracting data from the set of user documents. The instructions include generating a first graph data structure with one or more initial graphs containing the data extracted from the user document. The data can include a set of key-value pairs. The instructions include training a model on the first graph data structure to classify the set of key-value pairs. The instructions include until a set of evaluation metrics for the model exceeds a set of deployment thresholds: generating the set of evaluation metrics for the model. The instructions include comparing the set of evaluation metrics to the set of deployment thresholds. The instructions include in response to a determination that the set of evaluation metrics are below the set of deployment thresholds: generating one or more new graphs from the one or more initial graphs in the first graph data structure to produce a second graph data structure. The one or more new graphs can be generated by a first augmentation module of the computing device. The instructions include training the model on at least one of the first graph data structure and the second graph data structure. 
     One general aspect includes, a system comprising: a memory storing computer-executable instructions and one or more processors configured to access the memory, and execute the computer-executable instructions to at least: receive a set of user documents. The system is also configured to extract data from the set of user documents. The system is also configured to generate a first graph data structure with one or more initial graphs containing the data extracted from the user document, the data including a set of key-value pairs. The system is also configured to train a model on the first graph data structure to classify the set of key-value pairs. The system is also configured to, until a set of evaluation metrics for the model exceeds a set of deployment thresholds: generate the set of evaluation metrics for the model. The system is also configured to compare the set of evaluation metrics to the set of deployment thresholds. The system is also configured to, in response to a determination that the set of evaluation metrics are below the set of deployment thresholds: generate one or more new graphs from the one or more initial graphs in the first graph data structure to produce a second graph data structure. The one or more new graphs can be generated by a first augmentation module of a computing device. The system is also configured to train the model on the second graph data structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a graph of an overfit polynomial model. 
         FIG.  2 A  is a visually rich document with a key-value pair according to an embodiment. 
         FIG.  2 B  shows a visually rich document with a key that is associated with two values according to an embodiment. 
         FIG.  2 C  shows a visually rich document with a single key associated with multiple values according to an embodiment. 
         FIG.  3    shows a visually rich document with labeled key-value pairs according to an embodiment. 
         FIG.  4 A  shows a simplified graph generated from the visually rich document from  FIG.  3    according to an embodiment. 
         FIG.  4 B  shows a perturbed view of a simplified graph according to an embodiment. 
         FIG.  4 C  shows a perturbed view of a simplified graph according to an embodiment. 
         FIG.  5    depicts a process for generating a graph from a visually rich document according to an embodiment. 
         FIG.  6    shows a process for generating a perturbed view from a graph according to an embodiment. 
         FIG.  7 A  shows an example of a spelling error according to an embodiment. 
         FIG.  7 B  shows an example of a keyboard error according to an embodiment. 
         FIG.  7 C  shows an example of an optical character recognition (OCR) error according to an embodiment. 
         FIG.  7 D  shows an example of a character jumbling error according to an embodiment. 
         FIG.  8    shows a process for data augmentation and training according to an embodiment. 
         FIG.  9    is a process for training a model to satisfy a set of robustness metrics. 
         FIG.  10    shows a method for training a graph neural network (GNN) on an augmented training data set. 
         FIG.  11    is a block diagram illustrating one pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  12    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  13    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  14    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  15    is a block diagram illustrating an example computer system, according to at least one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, various embodiments will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the embodiments may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described. 
     Embodiments of the present disclosure provide techniques for augmenting a graph data structure used to train a graph neural network (GNN) model. A graph data structure can comprise a series of edges, or connections, showing relationships between data points called nodes. Graph neural networks are useful for classifying nodes in complex systems with large amounts of data. For instance, graph neural networks are often used to describe social media networks or molecules. 
     Visually rich documents (e.g., user documents) can include documents where information is conveyed both by content and layout. For instance, understanding a birth date field in a license can require information conveyed by content (e.g., 01/01/1997) and layout (e.g., the content “01/01/1997” is proximate to a “DOB” field and not the “EXP” field of a document). Visually rich documents can include driver&#39;s licenses, passports, checks, gun licenses, etc. Data from visually rich documents can be described as key-value pairs (e.g., attribute-value pair or field-value pair). For instance a key from a driver&#39;s license can be “weight” and the value can be “142 lb.” 
     A graph neural network (GNN) model can be used to classify text in visually rich documents. A visually rich document can be represented as a graph where the nodes comprise individual words. The nodes in the graphs can contain the word&#39;s layout information, visual features, and textual features. The textual features can be words extricated from the visually rich document using optical character recognition (OCR). The visual features can be the license&#39;s background, color, texture, font design or other pixel level information from the license image. The layout information can be the text&#39;s location on the license. A graph neural network trained on visually rich documents can predict whether a node is a key or a value. A graph neural network trained on visually rich documents can also predict which nodes are related. 
     While GNN models can learn the relationships between words in visually rich documents, training a GNN model can require a large set of training data. Visually rich documents often contain sensitive personal data and obtaining large amounts of visually rich documents can be challenging. Additionally, many sample visually rich documents are not ideal for training because the documents are altered to prevent misuse. For example, a government&#39;s sample driver&#39;s licenses, in contrast to a legitimate license, often state in large letters that the document is a sample. 
     If a GNN is trained on a small set of training data, the GNN can become overfit to the data. An overfitted model has become aligned too closely with a minimal set of data. The overfitted model can accurately classify the training data but the model struggles to classify new information. Traditionally, overfitting is prevented by using a large training set or by limiting training time so that the model cannot align too closely to the training data. 
     As proposed herein, overfitting by a GNN model can be mitigated by augmenting a small set of training data. Using domain statistics, a small sample of graphs (e.g., visually rich documents) can be augmented without altering the graph&#39;s class labels. Edges and nodes within a graph can be deleted to produce a new view (e.g., perturbed view) of the graph. The perturbed view of the graph is structurally different from the original graph but the graph&#39;s altered layout does not changes the meaning of existing key-value pairs within the graph. The GNN model can learn the original graphs (e.g., original views) and new graphs (e.g., perturbed views) with equal weight. By creating perturbed views, the GNN model can be trained on a small dataset without overfitting. The perturbed views can be efficient at reducing overfitting for GNN models. For example, a GNN model trained on 90 graphs can be overfit to the data. The initial 90 graphs can be augmented with 90 perturbed views for a total of 180 graphs. While 180 graphs can be considered a small dataset, the GNN model can be trained without overfitting on the 180 graphs. 
     A GNN model trained on an augmented training set can have better generalization and robustness in the model performance when compared to a model trained on the original un-augmented data. Generalization can refer to the ability of a model to classify data that was not contained in the training set. Robustness can refer to the ability of a model to accurately classify corrupt or erroneous data. 
     Robustness can be difficult to evaluate for key information extraction (KIE) from visually rich documents. Current techniques for evaluating key information extraction from visually rich documents are based on error-free text extraction and recognition. However, errors are common for text extraction using optical character recognition (OCR) from visually rich documents. A new robustness metric, proposed herein, can help to quantify the effect of OCR errors on the downstream application of key information extraction from visually rich documents. The robustness metric can include comparing a model&#39;s performance on a test data set with the model&#39;s performance on a modified data set. Simulated OCR errors can be introduced to the test data set to produce the modified data set. A comparison between a model&#39;s performance on the test data set and the modified data set can quantify the mode&#39;s robustness to OCR errors. 
     A GNN model can be trained to classify key-pairs using a training pipeline. A computing device can be used to generate graphs from visually rich documents. Perturbed views of the graphs are created with a first data augmentation module (e.g., data augmenter 1). The training data, including the perturbed views and original graphs, can be provided to a graph model trainer that produces a trained GNN model. The trained GNN can be evaluated on one or more evaluation metrics to produce an evaluation score (e.g., F1 score). Evaluating the trained GNN model can include using the model to classify key-value pairs in a set of test data. If the trained GNN&#39;s evaluation score does not exceed a threshold (e.g., deployment criteria) the training data can be passed through data augmenter 1 to produce more perturbed views. After more perturbed views are added to the training data, the GNN model can be retrained. 
     If the trained GNN&#39;s evaluation score exceeds the threshold, the robustness of the trained GNN can be evaluated using a robustness metric. Determining a robustness score for the robustness metric can include using the trained GNN to classify key-value pairs in a set of test data after errors are introduced into test data. The robustness metric can be a difference in score between the trained graph neural network model&#39;s performance on the test data without errors and the test data with errors. If a decrease in the trained GNN model&#39;s performance exceeds a threshold, model can be retrained. Before retraining, errors can be introduced into the training data using a second data augmentation module (data augmenter 2). The trained GNN model can be ready for deployment as a service if the model satisfies the evaluation metric and robustness metric. 
     In an illustrative example, a graph neural network (GNN) model is trained on a training set comprising 90 driver&#39;s licenses from a variety of states. The trained GNN model is intended as part of a bank&#39;s software. An employee can verify a customer&#39;s driver&#39;s license and can fill out an account application by photographing the customer&#39;s license. Other use cases for a trained GNN model can include searching a database for customer records using a photograph of the customer&#39;s license or verifying a license&#39;s validity by photographing the license. The 90 driver&#39;s licenses are used to generate graphs that are augmented with perturbed views using a first data augmenter. After training, the GNN model can classify the key-value pairs from a test set with a high degree of precision. The trained GNN model&#39;s precision is reflected in a high F1 score. A F1 score is a measure of precision and recall for binary classification and multi-class classification systems. F1 scores range from 1.0 to 0 with 1.0 indicating perfect recall and precision. Based on the GNN model&#39;s F1 score, the GNN model satisfies the evaluation metric. 
     However, the GNN model performs poorly on the robustness metric. In this case, the F1 score drops significantly when simulated optical character recognition (OCR) errors are introduced to the test data set at random. The trained GNN model fails the robustness metric because the decrease in F1 score exceeds a threshold. Based on the GNN&#39;s performance on the test set, the model is not suitable for its intended purpose and the model should be retrained. 
     Before retraining the training data is augmented using a second data augmenter. The second data augmentation module introduces simulated errors into the training data. The augmented data set still includes the 90 original drivers licenses and the perturbed views generated from those original licenses. However after augmentation, some of the words in the augmented data set are misspelled. The GNN model is trained on the augmented data set and satisfies both the evaluation metric and robustness metric. Accordingly, the augmented training set of 90 drivers licenses was sufficient to produce a GNN model. 
       FIG.  1    shows a graph  100  of an overfit polynomial model. The graph includes a plot of data points  105 . The data points  105  are noisy but the data is roughly linear. The data points  105  have a slight positive correlation and the data points  105  can be described by line  110 . An overfit model is shown by the polynomial  115 . While polynomial  115  passes through every data point (e.g., data point  105 ), the polynomial  115  is too specific to the data points on the graph. Polynomial  115  perfectly describes the data points, but polynomial  115  also has captured the data&#39;s noise. Accordingly polynomial  115  is not likely useful for making future predictions on similar data. In contrast, line  110  does not perfectly describe the data points, but line  110  can likely be used to make predictions about related data. 
       FIG.  2 A  is a visually rich document  200  with a key-value pair according to an embodiment. The visually rich document in this case is a Texas license to carry a handgun. The visually rich document includes key-value pairs. A key-value pair can include a key and one or more values associated with the key. The key defines the data set and values are a variable that belongs to the set. 
     In this case, WGT represents a WGT key  205  that defines the data set as containing one or more variables describing the license holder&#39;s weight. WGT key  205  is associated with a single WGT value  210  listing the weight as “146 lb.” Key-value pairs convey a relationship between WGT key  205  and WGT value  210 . WGT key  205  without an associated value is not likely to provide useful information. Alone WGT key  205  states that the license holder has a weight without defining the weight. Similarly, the value  210  lists a weight, 146 lb, without providing a meaning for that weight. 
       FIG.  2 B  shows a visually rich document  201  with a key that is associated with two values according to an embodiment. The visually rich document  201  is a driver&#39;s license. The key is “FN” and FN key  215  defines the data set as containing the license holder&#39;s first name. However, in this case the first name is two separate names and the license holder&#39;s first name is Judy Jane. The first FN value  220   a  is Judy and the second FN value  220   b  is Jane. A key-value pair is not limited to two values and a key-value pair can include as many values as are required by the data. 
       FIG.  2 C  shows a visually rich document  202  with a single key associated with multiple values according to an embodiment. In this case, the visually rich document is a check. The key defines the data set as representing a dollars and the key is represented by dollar key  225 . In this example, there are 14 values spread over two lines on the check. The values comprise the amount of dollars that the check authorizes the bank to transfer. The first line dollars values  230   a  is the first half of the amount of dollars and the second line dollars values  230   b  is the second half of the amount of dollars. 
     Visually rich document  202  shows how the layout of a visually rich document conveys information. The amount of money that the bank authorizes the check holder to withdraw depends on the order of values in the set of dollar values  230   a - b . The check authorizes the transfer of “seven hundred twenty four thousand two hundred ninety three and forty cents” (e.g.,  724293.40). If the order is rearranged, the amount of money authorized by the check can vary significantly from the intended amount. 
       FIG.  3    shows a visually rich document  300  with labeled key-value pairs according to an embodiment. In this case, the visually rich document is a driver&#39;s license. DL  305  is a key that defines the associated value as containing a driver&#39;s license number. The DL value  310  contains the driver&#39;s license number “G1111111.” EXP  315  is a key that corresponds with values containing the driver&#39;s license&#39;s expiration date. EXP value  320  is a value that contains the drivers license&#39;s expiration date “01/01/2020.” CLASS  325  is a key representing the driver&#39;s license class and the CLASS value  330  for this license is “C.” END  335  is a key that documents whether the license holder has any endorsements or additional driving privileges. In this case the END value  340  is “none” but a license holder could have, for example, a “M” as an END value  340  indicating the license holder is allowed to ride a motorcycle. In some circumstances, a value can be present in a visually rich document without an explicitly stated key. California is an example of a value without an explicitly stated key. The key associated with California can be a region key. If a visually rich document has a value without an explicitly stated key, the key can be predicted by the model based at least in part on the value&#39;s neighbors. 
       FIG.  4 A  shows a simplified graph  400  generated from the visually rich document from  FIG.  3    according to an embodiment. While a subset of the possible keys and values from visually rich document  300  are shown in simplified graph  400 , a graph generated from visually rich document  300  could contain different configurations of the keys and values from visually rich document  300 . 
     Turning to  FIG.  4 A  in greater detail, both keys and values are depicted as nodes in simplified graph  400 . Keys are shown as dashed line circles while values are shown as solid line circles or ovals. Keys include DL  405 , EXP  415 , Class  425 , and END  435 . Values include DL value  410 , EXP value  420 , CLASS value  430 , END value  435 , and California  450 . The keys and values described in relation to  FIGS.  4 A- 4 C  are similar to related features described in relation to  FIG.  3   . Connections between the nodes, including both keys and values, are shown as lines between the nodes called edges  440   a - c . In some implementations, edges can connect more nodes than depicted in simplified graph  400 . 
       FIG.  4 B  shows a perturbed view  401  of simplified graph  400  according to an embodiment. Perturbed view  401  is generated by deleting nodes from simplified graph  400 . In this case two value nodes, EXP value  420  and CLASS value  425 , are deleted to create a perturbed view. However, in some implementations key nodes or a mix of key nodes and value nodes can be deleted to create a perturbed view. The deleted nodes can be selected using domain statistics. 
       FIG.  4 C  shows a perturbed view  402  of simplified graph  400  according to an embodiment. Perturbed view  402  is generated by deleting edges from simplified graph  400 . In this case three edges  445   a - c  have been deleted. Two of the edges,  445   a  and  445   c , are edges connecting two different value nodes. Edge  445   b  is an edge connecting a key node (e.g., END  435 ) and a value node (e.g., EXP value  420 ), but the key node and value node do not constitute a key-value pair. In some implementations, edges connecting a key-value pair can be deleted. Deleting edges connecting a key-value pair can allow the GNN model to learn the neighbors for a value. 
       FIG.  5    depicts a process  500  for generating a graph from a visually rich document according to an embodiment. This process, in addition to the processes from  FIGS.  6 ,  8  and  9    and the method from  FIG.  10   , are illustrated as a logical flow diagram, each operation of which can be implemented in hardware, computer instructions, or a combination thereof. In the context of computer instructions, the operations may represent computer-executable instructions stored on one or more computer-readable storage media that, when executed by one or more processors, perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures and the like that perform particular functions or implement particular data types. The orders in which the operations are described are not intended to be construed as a limitation, and any number of the described operations can be combined in any order and/or in parallel to implement the processes or the method. 
     Turning to process  500  in greater detail, at block  505 , an input dataset can be generated. The input dataset can be generated from a visually rich document. The visually rich document can be an image-based document. The input dataset can include one or more of a set of identified words, a class label for the identified words, spatial location information, or a number of key-value pairs. The identified words can be detected using optical character recognition (OCR). The identified words can be typewritten text, handwritten block text, or handwritten cursive text. The identified words can be labeled with a class label of a key-value pair by a human annotator. The spatial location information can include a coordinate location (e.g., pixel coordinates) of the identified words. The spatial location information can include the spatial location for a bounding box surrounding the identified words. The number of key value pairs can be a minimum number of key-value pairs that a model should learn for classification. 
     At block  510 , a node is created for the identified words. The identified words can include words, numbers, dates, identification numbers, etc. The nodes can be connected with edges. The edges can be initialized with distance information. The distance information can be determined from the spatial location for the identified words in the nodes. For instance, the distance information can be a distance (e.g., a number of pixels or Euclidian distance) from a centroid of the bounding boxes for the node&#39;s identified words. The edges can also store a height to width ratio for the bounding boxes. 
     At block  515 , the edges connecting key-value pairs can be flagged. The key-value pairs can be assigned a relative importance. The relative importance can be a ranking of the key-value pairs or an importance weight that is assigned to the key-value pairs. For example, a driver&#39;s license number key-value pair can be more important than a weight key-value pair. The flagged edges can store the relative importance of the key-value pair connected by the edges. 
       FIG.  6    shows a process  600  for generating a perturbed view from a graph according to an embodiment. Process  600  can be used to generate structurally different graphs (e.g., perturbed views) for the same visually rich document. The perturbed views can be generated using domain statistics. The first data augmentation module (e.g., data augmenter 1; first augmentation module) can produce a second graph data structure from a first data structure using the process disclosed in  FIG.  6   . 
     Turning to process  600  in greater detail, at block  605 , an occurrence metric can be determined. The occurrence metric can be a frequency distribution of labels (e.g., semantic classes) for node classification. The occurrence metric can be based at least in part on statistics. In some circumstances, the occurrence metric can be based at least in part on domain statistics. The domain can be the type of visually rich document, and, for example, checks, passports, and drivers licenses can be domains. Accordingly, the occurrence metric can be scalable and adaptive to different domains. The occurrence metric can be the count of words for each label in the dataset for the key. 
     At block  610 , an importance metric can be determined. The importance metric can be a weight for each label or semantic class. The weight can be the importance of information in the domain associated with the label. For instance, the weight for the key “last name” can indicate a higher importance than the weight for the key “class.” The importance metric can be based at least in part on statistics, and, in particular, the importance metric can be based on domain statistics. 
     At block  615 , a proximity metric is determined. The proximity metric can be the “n” nearest neighbor for each label or semantic class in the dataset. The proximity metric can indicate the graphs density. The graph&#39;s density can be a ratio of how many connections exist in the graph to the amount of possible connections that can exist in the graph. The proximity metric can be the proximity and affinity between nodes. For example, if the WGT key and HEIGHT key can occur near each other in 90% of licenses. The proximity metric can be based at least in part on statistics, and, in particular, the proximity metric can be based on domain statistics. 
     At block  620 , an edge or node can be deleted to create a perturbed view of the graph. In some circumstances, more than one edge or node can be deleted. When a node is deleted, the associated edges can be deleted as well. The edges or nodes can be assigned a deletion probability using at least one of the occurrence metric, the importance metric, or the proximity metric. Nodes with a high occurrence metric can be assigned a higher probability for deletion than nodes with an average occurrence metric. Nodes with a low occurrence metric can be assigned a higher deletion probability than nodes with an average occurrence metric. The deletion probability for nodes can be based at least in part on the importance metric. A node with a weight indicating a higher importance can be less likely to be deleted when compared to a node with a weight indicating a lower importance. The proximity metric can be used to assign a deletion probability to edges. The deletion probability for edges can increase as the frequency of edges between labels increases. Edges can be deleted to reduce proximity dependence between nodes. Edges can also be deleted to reduce the graph&#39;s density. 
     Current evaluation techniques for key-value extraction models often assume error-free text extraction. However, optical character recognition (OCR) errors can occur during text extraction. It can be difficult to distinguish whether the key-value extraction model received a poor evaluation score because the OCR model is error prone or if the poor score is due to the key-value extraction model&#39;s performance. A robustness metric, described herein, can address the OCR model&#39;s influence on the key-value extraction model&#39;s performance by quantifying the effect of input errors on the key-value extraction model&#39;s evaluation score. 
     The robustness metric can include word-order metrics. Models can learn the sequence of words in a document. To evaluate a model&#39;s robustness, the order of words in a test visually rich document can be rearranged when the document is fed to the key-value extraction model. The words can retain the words&#39; spatial location in the visually rich document. The model can then classify the words into key-value pairs. The classified key-value pairs can be used to calculate an evaluation score (e.g., F1 score). 
     The robustness metric can also include character-reorder metrics. Models can become overfit to the character order in words. To evaluate the model&#39;s robustness to character order errors, the characters in a test visually rich document can be reordered to replicate common input errors. The characters can be reordered to replicate spelling errors, keyboard errors, OCR errors, or character jumbling. The key-value extraction model can classify the words from the test document into key-value pairs. The classified key-value pairs can be used to calculate an evaluation score (e.g., F1 score). 
       FIG.  7 A  shows an example of a spelling error  700  according to an embodiment. The intended sentence  705   a  is “this is very COOL.” The input sentence  710   a  contains a misspelled word  715   a . Instead of “this” the misspelled word  715  was input as “thes.” 
       FIG.  7 B  shows an example of a keyboard error  701  according to an embodiment. A keyboard error can be a specific type of spelling error. Keyboard errors can be caused because a key on an keyboard was mistakenly entered. For example, the intended sentence  705   b  again is “this is very COOL.” The input sentence  710   b  contains the misspelled word  715   b . Instead of “very,” misspelled word  715   b  was input as “bery.” The typing mistake can be attributed to the proximity of the V key  720  and the B key  725 . During input the user likely intended to hit the V key  720  and instead the user accidentally hit the B key  725 . 
       FIG.  7 C  shows an example of an optical character recognition (OCR) error  702  according to an embodiment. OCR errors can occur when an OCR model mistakenly identifies a character as a different incorrect character. Common OCR errors can include recognizing a 2 as a z, recognizing a Z or E as a B, or recognizing the numeral 1 as the lower case letter 1. In this case, the input sentence  705   c  is again “this is very COOL.” The OCR model mistakenly identified a letter in the input sentence  710   c . Instead of the word “COOL,” the OCR model detected the misspelled word  715   c  as “COOL.” The can result from the OCR model detecting the upper case letter 0 as the numeral 0. 
       FIG.  7 D  shows an example of a character jumbling error  703  according to an embodiment. In a character jumbling error, the misspelled word  715   d  from the input sentence  710   d  can contain the proper characters for the word from the intended sentence  705   d . in this case the intended word can be “COOL” and the misspelled word  715   d  can be “LOCO.” Misspelled word  715   d  can contain the proper characters however the error can result from an incorrect character order. 
       FIG.  8    is a process  800  for training a model to satisfy a set of robustness metrics. The model can be trained on a training data set that is augmented with introduced errors. The training data set can be augmented using a data augmenter (e.g., data augmenter 2). 
     Turning to process  800  in further detail, at block  805 , a robustness metric can be generated for a graph neural network (GNN) model. The robustness metric can include a comparison between one or more evaluation scores. The evaluation scores can include a F1 score. A first evaluation score can be generated from the GNN model&#39;s performance on a first test data set that does not contain errors. A second evaluation score can be generated from the GNN model&#39;s performance on a second test data set. The second test data set can be produced by introducing errors into the first test data set. In some circumstances, generating the robustness metric can include comparisons between the first evaluation score and more than one additional evaluation score. 
     Errors can include word order errors. Models can learn the order of words in a document. A word order error can be introduced by shuffling the sequence of words in a visually rich document. The words can retain the information of their spatial location in the visually rich document. Errors can also include the errors discussed above in relation to  FIG.  7    including spelling errors, keyboard errors, OCR errors, and character jumbling errors. 
     At block  810 , the robustness metric can be compared to a robustness threshold. The robustness threshold can be an acceptable second evaluation score relative to the first evaluation score. For example, a second evaluation score can exceed the robustness threshold if the second evaluation score is 80% or more of the first evaluation score. The robustness metric can depend on the intended use case for the trained GNN model. 
     At block  815 , an updated training data set can be generated. The updated training set (e.g., third graph data structure) can be generated if the GNN model&#39;s robustness metric is below the robustness threshold. The updated training set can be generated from the training set used to train the GNN model. The updated training data set can be generated using a data augmenter (e.g., data augmenter 2). The data augmenter can introduce errors into the training data set. The errors can be introduced by assigning a probability that an error will be added to a node. The errors can be the errors discussed above with relation to block  805 . 
     At block  820 , the GNN model can be trained on the updated training data set. The GNN model can trained by to generate a model that can classify nodes in the training data set. The nodes can be classified as being a key or value in a key-value pair. 
       FIG.  9    shows a process  900  for data augmentation and training according to an embodiment. 
     Turning to process  900  in greater detail, at block  905 , a set of visually rich documents can be received. The visually rich documents can be received at a computing device. The set of visually rich documents can be any document where information is conveyed by both the content and layout. Visually rich documents can include identification cards, passports, visas, credit cards, bank cards, checks, diplomas, professional credentials, receipts, etc. The visually rich documents can be provided as input to the computing device training the graph neural network (GNN) model as an image file (e.g., Joint Photographic Experts Group (JPEG) file, a Windows bitmap (BMP) file, a Portable Network Graphics (PNG) file, etc.). 
     At block  910 , graphs can be constructed. Constructing the graphs can include identifying words in the visually rich documents. A graph can be constructed for a visually rich document. The words can be identified using optical character recognition (OCR). Nodes in the graph can contain the identified words. Edges can connect the graph&#39;s nodes. One edge can connect two nodes. The edges can indicate a distance between the words in the connected node. The words in the visually rich document can be bordered by boxes. The distance between the words in the connected nodes can be measured from a centroid of the boxes surrounding each of the words. The edges can also indicate that the two connected nodes are a key-value pair. 
     At block  915 , the training data set&#39;s graphs can be augmented by the first data augmentation module (e.g., data augmenter 1). The graphs can be augmented to create perturbed views by deleting nodes. The graphs can also be augmented by deleting edges between nodes. In some circumstances edges and nodes can both be deleted to create a perturbed view. Generating perturbed views is discussed above with relation to  FIG.  6   . 
     At block  920 , the GNN model can be trained using a graph neural network trainer. The GNN can be trained to classify nodes in the training data set&#39;s graphs as key-value pairs. 
     At block  925 , the GNN is evaluated to determine the model&#39;s performance on an evaluation metric. The evaluation metric can be satisfied if an evaluation score exceeds a threshold. The evaluation score can be a F1 score. A F1 score can be generated using the following formula: 
     
       
         
           
             
               F 
               1 
             
             = 
             
               
                 2 
                 * 
                 
                   
                     precision 
                     * 
                     recall 
                   
                   
                     precision 
                     + 
                     recall 
                   
                 
               
               = 
               
                 true_positives 
                 
                   true_positives 
                   + 
                   
                     
                       1 
                       2 
                     
                     ⁢ 
                     
                       ( 
                       
                         false_positives 
                         + 
                         false_negatives 
                       
                       ) 
                     
                   
                 
               
             
           
         
       
     
     At decision block  930 , if the evaluation metric is not satisfied, the training data set is augmented by the first augmenter. The GNN model is retrained on the augmented data and an evaluation score is generated for the retrained model. If the GNN model satisfies the evaluation metric, the model&#39;s performance on the robustness metric can be determined. 
     At block  935 , the GNN model can be evaluated to determine if the model satisfies a robustness metric. The robustness metric can be a comparison between the GNN model&#39;s performance on a test data set without errors and the GNN model&#39;s performance on a test data set with errors. In some circumstances, the robustness metric can include a comparison to the GNN model&#39;s performance on more than one data set with errors. The model&#39;s performance can be evaluated using an evaluation score. The evaluation score can be a F1 score. The errors can include word order errors, spelling errors, keyboard errors, OCR errors, or character jumbling errors. In some circumstances the test data set with errors can include a single type of error (e.g., only spelling errors). The test data set with errors can include multiple types of errors. 
     At decision block  940 , if the robustness metric is not satisfied, the training data set can be augmented with a second data augmentation module (e.g., data augmenter 2). The second data augmentation module can introduce errors into the training data set. The errors can be the same type of errors discussed with regard to block  935  above. The GNN model can be retrained on the augmented training data set using the graph model trainer. If the GNN model satisfies the robustness criteria the model can be provided as output. The GNN model can satisfy the robustness metric if the decrease in the GNN model&#39;s evaluation score for a test data set with errors is less than a threshold. The decrease is determined by comparing the evaluation score for a test set without errors to an evaluation score for a test set with errors. 
     At block  950 , a trained GNN model can be received. If the GNN model has satisfied the evaluation metric and the robustness metric, the GNN can be ready for deployment as a service. 
       FIG.  10    shows a method  1000  for training a graph neural network (GNN) using an augmented training data set. 
     Turning to method  1000  in greater detail, at block  1005 , a set of user documents can be received. The user documents can be visually rich documents. The visually rich documents can include drivers licenses, gun licenses, bank cards, checks, diplomas, professional credentials, passports, identification cards, etc. A visually rich document can be any document where information is conveyed by the document&#39;s content and layout. 
     At block  1010 , data can be extracted from the user documents. The data can be extracted using optical character recognition (OCR). The data can include words that are identified in the document. The data can also include spatial information. The spatial information can include a coordinate location for the identified words. The data can also include an indication that a word is a key or a value in a key-value pair. 
     At block  1015 , a first graph data structure can be generated using the extracted data. The first graph data structure can be a training data set. The graph data structure can include nodes connected by edges. The nodes can contain the words identified in the user documents. The nodes can indicate whether the word in the node is a key or a value in a key-value pair. The edges can connect two nodes. An edge can indicate whether the edge is connecting a key value pair. The edge can also indicate a distance between the words represented by the connected nodes. The distance can be the distance between the words in the user documents. The words in the user document can be bordered by a box. The distance indicated in the edge can be a distance between the coordinate location of the centroids of the boxes bordering the connected words. Generating a graph data structure is described in greater detail above in relation to  FIG.  5   . 
     At block  1020 , the model can be trained on the first graph data structure. The model can be a GNN model. The model can be trained to identify nodes as a key or value belonging to a key-value pair. A key-value pair can contain more than one key. A key-value pair can contain more than one value. 
     At block  1025 , while evaluation metrics are below a threshold, evaluation metrics can be generated. The evaluation metrics can be an evaluation score (e.g. F1 score). In some circumstances, the evaluation metrics can include more than one evaluation scores. The evaluation metrics can be generated based at least in part on the GNN model&#39;s performance categorizing nodes in a test data set. The GNN model can categorize the nodes as being a key or value in a key value pair. 
     At block  1030 , while the evaluation metrics are below a threshold, the evaluation metrics can be compared to deployment thresholds. The deployment thresholds can include a minimum acceptable evaluation score. 
     At block  1035 , in response to a determination that the set of evaluation metrics are below a set of deployment thresholds, a second graph structure can be generated. The second graph structure can be generated by augmenting the first graph structure. The first graph structure can be augmented using a first data augmentation module (e.g., data augmenter 1). The data can be augmented by creating new graphs (e.g., perturbed views) from the graphs in the first graph structure. The new graphs can be created by deleting nodes or edges from the graphs in the first data structure. The process for generating new graphs from the graphs in the first data set is described in greater detail above in relation to  FIG.  6   . 
     At block  1040 , in response to a determination that the set of evaluation metrics are below a set of deployment thresholds, the model can be trained on at least one of the first or second graph structure. The model can be a GNN model. The model can be trained to identify nodes as a key or value belonging to a key-value pair. A key-value pair can contain more than one key. A key-value pair can contain more than one value. 
     Infrastructure as a service (IaaS) is one particular type of cloud computing. IaaS can be configured to provide virtualized computing resources over a public network (e.g., the Internet). In an IaaS model, a cloud computing provider can host the infrastructure components (e.g., servers, storage devices, network nodes (e.g., hardware), deployment software, platform virtualization (e.g., a hypervisor layer), or the like). In some cases, an IaaS provider may also supply a variety of services to accompany those infrastructure components (e.g., billing, monitoring, logging, security, load balancing and clustering, etc.). Thus, as these services may be policy-driven, IaaS users may be able to implement policies to drive load balancing to maintain application availability and performance. 
     In some instances, IaaS customers may access resources and services through a wide area network (WAN), such as the Internet, and can use the cloud provider&#39;s services to install the remaining elements of an application stack. For example, the user can log in to the IaaS platform to create virtual machines (VMs), install operating systems (OSs) on each VM, deploy middleware such as databases, create storage buckets for workloads and backups, and even install enterprise software into that VM. Customers can then use the provider&#39;s services to perform various functions, including balancing network traffic, troubleshooting application issues, monitoring performance, managing disaster recovery, etc. 
     In most cases, a cloud computing model will require the participation of a cloud provider. The cloud provider may, but need not be, a third-party service that specializes in providing (e.g., offering, renting, selling) IaaS. An entity might also opt to deploy a private cloud, becoming its own provider of infrastructure services. 
     In some examples, IaaS deployment is the process of putting a new application, or a new version of an application, onto a prepared application server or the like. It may also include the process of preparing the server (e.g., installing libraries, daemons, etc.). This is often managed by the cloud provider, below the hypervisor layer (e.g., the servers, storage, network hardware, and virtualization). Thus, the customer may be responsible for handling (OS), middleware, and/or application deployment (e.g., on self-service virtual machines (e.g., that can be spun up on demand) or the like. 
     In some examples, IaaS provisioning may refer to acquiring computers or virtual hosts for use, and even installing needed libraries or services on them. In most cases, deployment does not include provisioning, and the provisioning may need to be performed first. 
     In some cases, there are two different challenges for IaaS provisioning. First, there is the initial challenge of provisioning the initial set of infrastructure before anything is running. Second, there is the challenge of evolving the existing infrastructure (e.g., adding new services, changing services, removing services, etc.) once everything has been provisioned. In some cases, these two challenges may be addressed by enabling the configuration of the infrastructure to be defined declaratively. In other words, the infrastructure (e.g., what components are needed and how they interact) can be defined by one or more configuration files. Thus, the overall topology of the infrastructure (e.g., what resources depend on which, and how they each work together) can be described declaratively. In some instances, once the topology is defined, a workflow can be generated that creates and/or manages the different components described in the configuration files. 
     In some examples, an infrastructure may have many interconnected elements. For example, there may be one or more virtual private clouds (VPCs) (e.g., a potentially on-demand pool of configurable and/or shared computing resources), also known as a core network. In some examples, there may also be one or more security group rules provisioned to define how the security of the network will be set up and one or more virtual machines (VMs). Other infrastructure elements may also be provisioned, such as a load balancer, a database, or the like. As more and more infrastructure elements are desired and/or added, the infrastructure may incrementally evolve. 
     In some instances, continuous deployment techniques may be employed to enable deployment of infrastructure code across various virtual computing environments. Additionally, the described techniques can enable infrastructure management within these environments. In some examples, service teams can write code that is desired to be deployed to one or more, but often many, different production environments (e.g., across various different geographic locations, sometimes spanning the entire world). However, in some examples, the infrastructure on which the code will be deployed must first be set up. In some instances, the provisioning can be done manually, a provisioning tool may be utilized to provision the resources, and/or deployment tools may be utilized to deploy the code once the infrastructure is provisioned. 
       FIG.  11    is a block diagram  1100  illustrating an example pattern of an IaaS architecture, according to at least one embodiment. Service operators  1102  can be communicatively coupled to a secure host tenancy  1104  that can include a virtual cloud network (VCN)  1106  and a secure host subnet  1108 . In some examples, the service operators  1102  may be using one or more client computing devices, which may be portable handheld devices (e.g., an iPhone®, cellular telephone, an iPad®, computing tablet, a personal digital assistant (PDA)) or wearable devices (e.g., a Google Glass® head mounted display), running software such as Microsoft Windows Mobile®, and/or a variety of mobile operating systems such as iOS, Windows Phone, Android, BlackBerry 8, Palm OS, and the like, and being Internet, e-mail, short message service (SMS), Blackberry®, or other communication protocol enabled. Alternatively, the client computing devices can be general purpose personal computers including, by way of example, personal computers and/or laptop computers running various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems. The client computing devices can be workstation computers running any of a variety of commercially-available UNIX® or UNIX-like operating systems, including without limitation the variety of GNU/Linux operating systems, such as for example, Google Chrome OS. Alternatively, or in addition, client computing devices may be any other electronic device, such as a thin-client computer, an Internet-enabled gaming system (e.g., a Microsoft Xbox gaming console with or without a Kinect® gesture input device), and/or a personal messaging device, capable of communicating over a network that can access the VCN  1106  and/or the Internet. 
     The VCN  1106  can include a local peering gateway (LPG)  1110  that can be communicatively coupled to a secure shell (SSH) VCN  1112  via an LPG  1110  contained in the SSH VCN  1112 . The SSH VCN  1112  can include an SSH subnet  1114 , and the SSH VCN  1112  can be communicatively coupled to a control plane VCN  1116  via the LPG  1110  contained in the control plane VCN  1116 . Also, the SSH VCN  1112  can be communicatively coupled to a data plane VCN  1118  via an LPG  1110 . The control plane VCN  1116  and the data plane VCN  1118  can be contained in a service tenancy  1119  that can be owned and/or operated by the IaaS provider. 
     The control plane VCN  1116  can include a control plane demilitarized zone (DMZ) tier  1120  that acts as a perimeter network (e.g., portions of a corporate network between the corporate intranet and external networks). The DMZ-based servers may have restricted responsibilities and help keep security breaches contained. Additionally, the DMZ tier  1120  can include one or more load balancer (LB) subnet(s)  1122 , a control plane app tier  1124  that can include app subnet(s)  1126 , a control plane data tier  1128  that can include database (DB) subnet(s)  1130  (e.g., frontend DB subnet(s) and/or backend DB subnet(s)). The LB subnet(s)  1122  contained in the control plane DMZ tier  1120  can be communicatively coupled to the app subnet(s)  1126  contained in the control plane app tier  1124  and an Internet gateway  1134  that can be contained in the control plane VCN  1116 , and the app subnet(s)  1126  can be communicatively coupled to the DB subnet(s)  1130  contained in the control plane data tier  1128  and a service gateway  1136  and a network address translation (NAT) gateway  1138 . The control plane VCN  1116  can include the service gateway  1136  and the NAT gateway  1138 . 
     The control plane VCN  1116  can include a data plane mirror app tier  1140  that can include app subnet(s)  1126 . The app subnet(s)  1126  contained in the data plane mirror app tier  1140  can include a virtual network interface controller (VNIC)  1142  that can execute a compute instance  1144 . The compute instance  1144  can communicatively couple the app subnet(s)  1126  of the data plane mirror app tier  1140  to app subnet(s)  1126  that can be contained in a data plane app tier  1146 . 
     The data plane VCN  1118  can include the data plane app tier  1146 , a data plane DMZ tier  1148 , and a data plane data tier  1150 . The data plane DMZ tier  1148  can include LB subnet(s)  1122  that can be communicatively coupled to the app subnet(s)  1126  of the data plane app tier  1146  and the Internet gateway  1134  of the data plane VCN  1118 . The app subnet(s)  1126  can be communicatively coupled to the service gateway  1136  of the data plane VCN  1118  and the NAT gateway  1138  of the data plane VCN  1118 . The data plane data tier  1150  can also include the DB subnet(s)  1130  that can be communicatively coupled to the app subnet(s)  1126  of the data plane app tier  1146 . 
     The Internet gateway  1134  of the control plane VCN  1116  and of the data plane VCN  1118  can be communicatively coupled to a metadata management service  1152  that can be communicatively coupled to public Internet  1154 . Public Internet  1154  can be communicatively coupled to the NAT gateway  1138  of the control plane VCN  1116  and of the data plane VCN  1118 . The service gateway  1136  of the control plane VCN  1116  and of the data plane VCN  1118  can be communicatively couple to cloud services  1156 . 
     In some examples, the service gateway  1136  of the control plane VCN  1116  or of the data plane VCN  1118  can make application programming interface (API) calls to cloud services  1156  without going through public Internet  1154 . The API calls to cloud services  1156  from the service gateway  1136  can be one-way: the service gateway  1136  can make API calls to cloud services  1156 , and cloud services  1156  can send requested data to the service gateway  1136 . But, cloud services  1156  may not initiate API calls to the service gateway  1136 . 
     In some examples, the secure host tenancy  1104  can be directly connected to the service tenancy  1119 , which may be otherwise isolated. The secure host subnet  1108  can communicate with the SSH subnet  1114  through an LPG  1110  that may enable two-way communication over an otherwise isolated system. Connecting the secure host subnet  1108  to the SSH subnet  1114  may give the secure host subnet  1108  access to other entities within the service tenancy  1119 . 
     The control plane VCN  1116  may allow users of the service tenancy  1119  to set up or otherwise provision desired resources. Desired resources provisioned in the control plane VCN  1116  may be deployed or otherwise used in the data plane VCN  1118 . In some examples, the control plane VCN  1116  can be isolated from the data plane VCN  1118 , and the data plane mirror app tier  1140  of the control plane VCN  1116  can communicate with the data plane app tier  1146  of the data plane VCN  1118  via VNICs  1142  that can be contained in the data plane mirror app tier  1140  and the data plane app tier  1146 . 
     In some examples, users of the system, or customers, can make requests, for example create, read, update, or delete (CRUD) operations, through public Internet  1154  that can communicate the requests to the metadata management service  1152 . The metadata management service  1152  can communicate the request to the control plane VCN  1116  through the Internet gateway  1134 . The request can be received by the LB subnet(s)  1122  contained in the control plane DMZ tier  1120 . The LB subnet(s)  1122  may determine that the request is valid, and in response to this determination, the LB subnet(s)  1122  can transmit the request to app subnet(s)  1126  contained in the control plane app tier  1124 . If the request is validated and requires a call to public Internet  1154 , the call to public Internet  1154  may be transmitted to the NAT gateway  1138  that can make the call to public Internet  1154 . Memory that may be desired to be stored by the request can be stored in the DB subnet(s)  1130 . 
     In some examples, the data plane mirror app tier  1140  can facilitate direct communication between the control plane VCN  1116  and the data plane VCN  1118 . For example, changes, updates, or other suitable modifications to configuration may be desired to be applied to the resources contained in the data plane VCN  1118 . Via a VNIC  1142 , the control plane VCN  1116  can directly communicate with, and can thereby execute the changes, updates, or other suitable modifications to configuration to, resources contained in the data plane VCN  1118 . 
     In some embodiments, the control plane VCN  1116  and the data plane VCN  1118  can be contained in the service tenancy  1119 . In this case, the user, or the customer, of the system may not own or operate either the control plane VCN  1116  or the data plane VCN  1118 . Instead, the IaaS provider may own or operate the control plane VCN  1116  and the data plane VCN  1118 , both of which may be contained in the service tenancy  1119 . This embodiment can enable isolation of networks that may prevent users or customers from interacting with other users&#39;, or other customers&#39;, resources. Also, this embodiment may allow users or customers of the system to store databases privately without needing to rely on public Internet  1154 , which may not have a desired level of security, for storage. 
     In other embodiments, the LB subnet(s)  1122  contained in the control plane VCN  1116  can be configured to receive a signal from the service gateway  1136 . In this embodiment, the control plane VCN  1116  and the data plane VCN  1118  may be configured to be called by a customer of the IaaS provider without calling public Internet  1154 . Customers of the IaaS provider may desire this embodiment since database(s) that the customers use may be controlled by the IaaS provider and may be stored on the service tenancy  1119 , which may be isolated from public Internet  1154 . 
       FIG.  12    is a block diagram  1200  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  1202  (e.g. service operators  1102  of  FIG.  11   ) can be communicatively coupled to a secure host tenancy  1204  (e.g. the secure host tenancy  1104  of  FIG.  11   ) that can include a virtual cloud network (VCN)  1206  (e.g. the VCN  1106  of  FIG.  11   ) and a secure host subnet  1208  (e.g. the secure host subnet  1108  of  FIG.  11   ). The VCN  1206  can include a local peering gateway (LPG)  1210  (e.g. the LPG  1110  of  FIG.  11   ) that can be communicatively coupled to a secure shell (SSH) VCN  1212  (e.g. the SSH VCN  1112  of  FIG.  11   ) via an LPG  1110  contained in the SSH VCN  1212 . The SSH VCN  1212  can include an SSH subnet  1214  (e.g. the SSH subnet  1114  of  FIG.  11   ), and the SSH VCN  1212  can be communicatively coupled to a control plane VCN  1216  (e.g. the control plane VCN  1116  of  FIG.  11   ) via an LPG  1210  contained in the control plane VCN  1216 . The control plane VCN  1216  can be contained in a service tenancy  1219  (e.g. the service tenancy  1119  of  FIG.  11   ), and the data plane VCN  1218  (e.g. the data plane VCN  1118  of  FIG.  11   ) can be contained in a customer tenancy  1221  that may be owned or operated by users, or customers, of the system. 
     The control plane VCN  1216  can include a control plane DMZ tier  1220  (e.g. the control plane DMZ tier  1120  of  FIG.  11   ) that can include LB subnet(s)  1222  (e.g. LB subnet(s)  1122  of  FIG.  11   ), a control plane app tier  1224  (e.g. the control plane app tier  1124  of  FIG.  11   ) that can include app subnet(s)  1226  (e.g. app subnet(s)  1126  of  FIG.  11   ), a control plane data tier  1228  (e.g. the control plane data tier  1128  of  FIG.  11   ) that can include database (DB) subnet(s)  1230  (e.g. similar to DB subnet(s)  1130  of  FIG.  11   ). The LB subnet(s)  1222  contained in the control plane DMZ tier  1220  can be communicatively coupled to the app subnet(s)  1226  contained in the control plane app tier  1224  and an Internet gateway  1234  (e.g. the Internet gateway  1134  of  FIG.  11   ) that can be contained in the control plane VCN  1216 , and the app subnet(s)  1226  can be communicatively coupled to the DB subnet(s)  1230  contained in the control plane data tier  1228  and a service gateway  1236  (e.g. the service gateway of  FIG.  11   ) and a network address translation (NAT) gateway  1238  (e.g. the NAT gateway  1138  of  FIG.  11   ). The control plane VCN  1216  can include the service gateway  1236  and the NAT gateway  1238 . 
     The control plane VCN  1216  can include a data plane mirror app tier  1240  (e.g. the data plane mirror app tier  1140  of  FIG.  11   ) that can include app subnet(s)  1226 . The app subnet(s)  1226  contained in the data plane mirror app tier  1240  can include a virtual network interface controller (VNIC)  1242  (e.g. the VNIC of  1142 ) that can execute a compute instance  1244  (e.g. similar to the compute instance  1144  of  FIG.  11   ). The compute instance  1244  can facilitate communication between the app subnet(s)  1226  of the data plane mirror app tier  1240  and the app subnet(s)  1226  that can be contained in a data plane app tier  1246  (e.g. the data plane app tier  1146  of  FIG.  11   ) via the VNIC  1242  contained in the data plane mirror app tier  1240  and the VNIC  1242  contained in the data plane app tier  1246 . 
     The Internet gateway  1234  contained in the control plane VCN  1216  can be communicatively coupled to a metadata management service  1252  (e.g. the metadata management service  1152  of  FIG.  11   ) that can be communicatively coupled to public Internet  1254  (e.g. public Internet  1154  of  FIG.  11   ). Public Internet  1254  can be communicatively coupled to the NAT gateway  1238  contained in the control plane VCN  1216 . The service gateway  1236  contained in the control plane VCN  1216  can be communicatively couple to cloud services  1256  (e.g. cloud services  1156  of  FIG.  11   ). 
     In some examples, the data plane VCN  1218  can be contained in the customer tenancy  1221 . In this case, the IaaS provider may provide the control plane VCN  1216  for each customer, and the IaaS provider may, for each customer, set up a unique compute instance  1244  that is contained in the service tenancy  1219 . Each compute instance  1244  may allow communication between the control plane VCN  1216 , contained in the service tenancy  1219 , and the data plane VCN  1218  that is contained in the customer tenancy  1221 . The compute instance  1244  may allow resources, that are provisioned in the control plane VCN  1216  that is contained in the service tenancy  1219 , to be deployed or otherwise used in the data plane VCN  1218  that is contained in the customer tenancy  1221 . 
     In other examples, the customer of the IaaS provider may have databases that live in the customer tenancy  1221 . In this example, the control plane VCN  1216  can include the data plane mirror app tier  1240  that can include app subnet(s)  1226 . The data plane mirror app tier  1240  can reside in the data plane VCN  1218 , but the data plane mirror app tier  1240  may not live in the data plane VCN  1218 . That is, the data plane mirror app tier  1240  may have access to the customer tenancy  1221 , but the data plane mirror app tier  1240  may not exist in the data plane VCN  1218  or be owned or operated by the customer of the IaaS provider. The data plane mirror app tier  1240  may be configured to make calls to the data plane VCN  1218  but may not be configured to make calls to any entity contained in the control plane VCN  1216 . The customer may desire to deploy or otherwise use resources in the data plane VCN  1218  that are provisioned in the control plane VCN  1216 , and the data plane mirror app tier  1240  can facilitate the desired deployment, or other usage of resources, of the customer. 
     In some embodiments, the customer of the IaaS provider can apply filters to the data plane VCN  1218 . In this embodiment, the customer can determine what the data plane VCN  1218  can access, and the customer may restrict access to public Internet  1254  from the data plane VCN  1218 . The IaaS provider may not be able to apply filters or otherwise control access of the data plane VCN  1218  to any outside networks or databases. Applying filters and controls by the customer onto the data plane VCN  1218 , contained in the customer tenancy  1221 , can help isolate the data plane VCN  1218  from other customers and from public Internet  1254 . 
     In some embodiments, cloud services  1256  can be called by the service gateway  1236  to access services that may not exist on public Internet  1254 , on the control plane VCN  1216 , or on the data plane VCN  1218 . The connection between cloud services  1256  and the control plane VCN  1216  or the data plane VCN  1218  may not be live or continuous. Cloud services  1256  may exist on a different network owned or operated by the IaaS provider. Cloud services  1256  may be configured to receive calls from the service gateway  1236  and may be configured to not receive calls from public Internet  1254 . Some cloud services  1256  may be isolated from other cloud services  1256 , and the control plane VCN  1216  may be isolated from cloud services  1256  that may not be in the same region as the control plane VCN  1216 . For example, the control plane VCN  1216  may be located in “Region 1,” and cloud service “Deployment 11,” may be located in Region 1 and in “Region 2.” If a call to Deployment 11 is made by the service gateway  1236  contained in the control plane VCN  1216  located in Region 1, the call may be transmitted to Deployment 11 in Region 1. In this example, the control plane VCN  1216 , or Deployment 11 in Region 1, may not be communicatively coupled to, or otherwise in communication with, Deployment 11 in Region 2. 
       FIG.  13    is a block diagram  1300  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  1302  (e.g. service operators  1102  of  FIG.  11   ) can be communicatively coupled to a secure host tenancy  1304  (e.g. the secure host tenancy  1104  of  FIG.  11   ) that can include a virtual cloud network (VCN)  1306  (e.g. the VCN  1106  of  FIG.  11   ) and a secure host subnet  1308  (e.g. the secure host subnet  1108  of  FIG.  11   ). The VCN  1306  can include an LPG  1310  (e.g. the LPG  1110  of  FIG.  11   ) that can be communicatively coupled to an SSH VCN  1312  (e.g. the SSH VCN  1112  of  FIG.  11   ) via an LPG  1310  contained in the SSH VCN  1312 . The SSH VCN  1312  can include an SSH subnet  1314  (e.g. the SSH subnet  1114  of  FIG.  11   ), and the SSH VCN  1312  can be communicatively coupled to a control plane VCN  1316  (e.g. the control plane VCN  1116  of  FIG.  11   ) via an LPG  1310  contained in the control plane VCN  1316  and to a data plane VCN  1318  (e.g. the data plane  1118  of  FIG.  11   ) via an LPG  1310  contained in the data plane VCN  1318 . The control plane VCN  1316  and the data plane VCN  1318  can be contained in a service tenancy  1319  (e.g. the service tenancy  1119  of  FIG.  11   ). 
     The control plane VCN  1316  can include a control plane DMZ tier  1320  (e.g. the control plane DMZ tier  1120  of  FIG.  11   ) that can include load balancer (LB) subnet(s)  1322  (e.g. LB subnet(s)  1122  of  FIG.  11   ), a control plane app tier  1324  (e.g. the control plane app tier  1124  of  FIG.  11   ) that can include app subnet(s)  1326  (e.g. similar to app subnet(s)  1126  of  FIG.  11   ), a control plane data tier  1328  (e.g. the control plane data tier  1128  of  FIG.  11   ) that can include DB subnet(s)  1330 . The LB subnet(s)  1322  contained in the control plane DMZ tier  1320  can be communicatively coupled to the app subnet(s)  1326  contained in the control plane app tier  1324  and to an Internet gateway  1334  (e.g. the Internet gateway  1134  of  FIG.  11   ) that can be contained in the control plane VCN  1316 , and the app subnet(s)  1326  can be communicatively coupled to the DB subnet(s)  1330  contained in the control plane data tier  1328  and to a service gateway  1336  (e.g. the service gateway of  FIG.  11   ) and a network address translation (NAT) gateway  1338  (e.g. the NAT gateway  1138  of  FIG.  11   ). The control plane VCN  1316  can include the service gateway  1336  and the NAT gateway  1338 . 
     The data plane VCN  1318  can include a data plane app tier  1346  (e.g. the data plane app tier  1146  of  FIG.  11   ), a data plane DMZ tier  1348  (e.g. the data plane DMZ tier  1148  of  FIG.  11   ), and a data plane data tier  1350  (e.g. the data plane data tier  1150  of  FIG.  11   ). The data plane DMZ tier  1348  can include LB subnet(s)  1322  that can be communicatively coupled to trusted app subnet(s)  1360  and untrusted app subnet(s)  1362  of the data plane app tier  1346  and the Internet gateway  1334  contained in the data plane VCN  1318 . The trusted app subnet(s)  1360  can be communicatively coupled to the service gateway  1336  contained in the data plane VCN  1318 , the NAT gateway  1338  contained in the data plane VCN  1318 , and DB subnet(s)  1330  contained in the data plane data tier  1350 . The untrusted app subnet(s)  1362  can be communicatively coupled to the service gateway  1336  contained in the data plane VCN  1318  and DB subnet(s)  1330  contained in the data plane data tier  1350 . The data plane data tier  1350  can include DB subnet(s)  1330  that can be communicatively coupled to the service gateway  1336  contained in the data plane VCN  1318 . 
     The untrusted app subnet(s)  1362  can include one or more primary VNICs  1364 ( 1 )-(N) that can be communicatively coupled to tenant virtual machines (VMs)  1366 ( 1 )-(N). Each tenant VM  1366 ( 1 )-(N) can be communicatively coupled to a respective app subnet  1367 ( 1 )-(N) that can be contained in respective container egress VCNs  1368 ( 1 )-(N) that can be contained in respective customer tenancies  1370 ( 1 )-(N). Respective secondary VNICs  1372 ( 1 )-(N) can facilitate communication between the untrusted app subnet(s)  1362  contained in the data plane VCN  1318  and the app subnet contained in the container egress VCNs  1368 ( 1 )-(N). Each container egress VCNs  1368 ( 1 )-(N) can include a NAT gateway  1338  that can be communicatively coupled to public Internet  1354  (e.g. public Internet  1154  of  FIG.  11   ). 
     The Internet gateway  1334  contained in the control plane VCN  1316  and contained in the data plane VCN  1318  can be communicatively coupled to a metadata management service  1352  (e.g. the metadata management system  1152  of  FIG.  11   ) that can be communicatively coupled to public Internet  1354 . Public Internet  1354  can be communicatively coupled to the NAT gateway  1338  contained in the control plane VCN  1316  and contained in the data plane VCN  1318 . The service gateway  1336  contained in the control plane VCN  1316  and contained in the data plane VCN  1318  can be communicatively couple to cloud services  1356 . 
     In some embodiments, the data plane VCN  1318  can be integrated with customer tenancies  1370 . This integration can be useful or desirable for customers of the IaaS provider in some cases such as a case that may desire support when executing code. The customer may provide code to run that may be destructive, may communicate with other customer resources, or may otherwise cause undesirable effects. In response to this, the IaaS provider may determine whether to run code given to the IaaS provider by the customer. 
     In some examples, the customer of the IaaS provider may grant temporary network access to the IaaS provider and request a function to be attached to the data plane tier app  1346 . Code to run the function may be executed in the VMs  1366 ( 1 )-(N), and the code may not be configured to run anywhere else on the data plane VCN  1318 . Each VM  1366 ( 1 )-(N) may be connected to one customer tenancy  1370 . Respective containers  1371 ( 1 )-(N) contained in the VMs  1366 ( 1 )-(N) may be configured to run the code. In this case, there can be a dual isolation (e.g., the containers  1371 ( 1 )-(N) running code, where the containers  1371 ( 1 )-(N) may be contained in at least the VM  1366 ( 1 )-(N) that are contained in the untrusted app subnet(s)  1362 ), which may help prevent incorrect or otherwise undesirable code from damaging the network of the IaaS provider or from damaging a network of a different customer. The containers  1371 ( 1 )-(N) may be communicatively coupled to the customer tenancy  1370  and may be configured to transmit or receive data from the customer tenancy  1370 . The containers  1371 ( 1 )-(N) may not be configured to transmit or receive data from any other entity in the data plane VCN  1318 . Upon completion of running the code, the IaaS provider may kill or otherwise dispose of the containers  1371 ( 1 )-(N). 
     In some embodiments, the trusted app subnet(s)  1360  may run code that may be owned or operated by the IaaS provider. In this embodiment, the trusted app subnet(s)  1360  may be communicatively coupled to the DB subnet(s)  1330  and be configured to execute CRUD operations in the DB subnet(s)  1330 . The untrusted app subnet(s)  1362  may be communicatively coupled to the DB subnet(s)  1330 , but in this embodiment, the untrusted app subnet(s) may be configured to execute read operations in the DB subnet(s)  1330 . The containers  1371 ( 1 )-(N) that can be contained in the VM  1366 ( 1 )-(N) of each customer and that may run code from the customer may not be communicatively coupled with the DB subnet(s)  1330 . 
     In other embodiments, the control plane VCN  1316  and the data plane VCN  1318  may not be directly communicatively coupled. In this embodiment, there may be no direct communication between the control plane VCN  1316  and the data plane VCN  1318 . However, communication can occur indirectly through at least one method. An LPG  1310  may be established by the IaaS provider that can facilitate communication between the control plane VCN  1316  and the data plane VCN  1318 . In another example, the control plane VCN  1316  or the data plane VCN  1318  can make a call to cloud services  1356  via the service gateway  1336 . For example, a call to cloud services  1356  from the control plane VCN  1316  can include a request for a service that can communicate with the data plane VCN  1318 . 
       FIG.  14    is a block diagram  1400  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  1402  (e.g. service operators  1102  of  FIG.  11   ) can be communicatively coupled to a secure host tenancy  1404  (e.g. the secure host tenancy  1104  of  FIG.  11   ) that can include a virtual cloud network (VCN)  1406  (e.g. the VCN  1106  of  FIG.  11   ) and a secure host subnet  1408  (e.g. the secure host subnet  1108  of  FIG.  11   ). The VCN  1406  can include an LPG  1410  (e.g. the LPG  1110  of  FIG.  11   ) that can be communicatively coupled to an SSH VCN  1412  (e.g. the SSH VCN  1112  of  FIG.  11   ) via an LPG  1410  contained in the SSH VCN  1412 . The SSH VCN  1412  can include an SSH subnet  1414  (e.g. the SSH subnet  1114  of  FIG.  11   ), and the SSH VCN  1412  can be communicatively coupled to a control plane VCN  1416  (e.g. the control plane VCN  1116  of  FIG.  11   ) via an LPG  1410  contained in the control plane VCN  1416  and to a data plane VCN  1418  (e.g. the data plane  1118  of  FIG.  11   ) via an LPG  1410  contained in the data plane VCN  1418 . The control plane VCN  1416  and the data plane VCN  1418  can be contained in a service tenancy  1419  (e.g. the service tenancy  1119  of  FIG.  11   ). 
     The control plane VCN  1416  can include a control plane DMZ tier  1420  (e.g. the control plane DMZ tier  1120  of  FIG.  11   ) that can include LB subnet(s)  1422  (e.g. LB subnet(s)  1122  of  FIG.  11   ), a control plane app tier  1424  (e.g. the control plane app tier  1124  of  FIG.  11   ) that can include app subnet(s)  1426  (e.g. app subnet(s)  1126  of  FIG.  11   ), a control plane data tier  1428  (e.g. the control plane data tier  1128  of  FIG.  11   ) that can include DB subnet(s)  1430  (e.g. DB subnet(s)  1330  of  FIG.  13   ). The LB subnet(s)  1422  contained in the control plane DMZ tier  1420  can be communicatively coupled to the app subnet(s)  1426  contained in the control plane app tier  1424  and to an Internet gateway  1434  (e.g. the Internet gateway  1134  of  FIG.  11   ) that can be contained in the control plane VCN  1416 , and the app subnet(s)  1426  can be communicatively coupled to the DB subnet(s)  1430  contained in the control plane data tier  1428  and to a service gateway  1436  (e.g. the service gateway of  FIG.  11   ) and a network address translation (NAT) gateway  1438  (e.g. the NAT gateway  1138  of  FIG.  11   ). The control plane VCN  1416  can include the service gateway  1436  and the NAT gateway  1438 . 
     The data plane VCN  1418  can include a data plane app tier  1446  (e.g. the data plane app tier  1146  of  FIG.  11   ), a data plane DMZ tier  1448  (e.g. the data plane DMZ tier  1148  of  FIG.  11   ), and a data plane data tier  1450  (e.g. the data plane data tier  1150  of  FIG.  11   ). The data plane DMZ tier  1448  can include LB subnet(s)  1422  that can be communicatively coupled to trusted app subnet(s)  1460  (e.g. trusted app subnet(s)  1360  of  FIG.  13   ) and untrusted app subnet(s)  1462  (e.g. untrusted app subnet(s)  1362  of  FIG.  13   ) of the data plane app tier  1446  and the Internet gateway  1434  contained in the data plane VCN  1418 . The trusted app subnet(s)  1460  can be communicatively coupled to the service gateway  1436  contained in the data plane VCN  1418 , the NAT gateway  1438  contained in the data plane VCN  1418 , and DB subnet(s)  1430  contained in the data plane data tier  1450 . The untrusted app subnet(s)  1462  can be communicatively coupled to the service gateway  1436  contained in the data plane VCN  1418  and DB subnet(s)  1430  contained in the data plane data tier  1450 . The data plane data tier  1450  can include DB subnet(s)  1430  that can be communicatively coupled to the service gateway  1436  contained in the data plane VCN  1418 . 
     The untrusted app subnet(s)  1462  can include primary VNICs  1464 ( 1 )-(N) that can be communicatively coupled to tenant virtual machines (VMs)  1466 ( 1 )-(N) residing within the untrusted app subnet(s)  1462 . Each tenant VM  1466 ( 1 )-(N) can run code in a respective container  1467 ( 1 )-(N), and be communicatively coupled to an app subnet  1426  that can be contained in a data plane app tier  1446  that can be contained in a container egress VCN  1468 . Respective secondary VNICs  1472 ( 1 )-(N) can facilitate communication between the untrusted app subnet(s)  1462  contained in the data plane VCN  1418  and the app subnet contained in the container egress VCN  1468 . The container egress VCN can include a NAT gateway  1438  that can be communicatively coupled to public Internet  1454  (e.g. public Internet  1154  of  FIG.  11   ). 
     The Internet gateway  1434  contained in the control plane VCN  1416  and contained in the data plane VCN  1418  can be communicatively coupled to a metadata management service  1452  (e.g. the metadata management system  1152  of  FIG.  11   ) that can be communicatively coupled to public Internet  1454 . Public Internet  1454  can be communicatively coupled to the NAT gateway  1438  contained in the control plane VCN  1416  and contained in the data plane VCN  1418 . The service gateway  1436  contained in the control plane VCN  1416  and contained in the data plane VCN  1418  can be communicatively couple to cloud services  1456 . 
     In some examples, the pattern illustrated by the architecture of block diagram  1400  of  FIG.  14    may be considered an exception to the pattern illustrated by the architecture of block diagram  1300  of  FIG.  13    and may be desirable for a customer of the IaaS provider if the IaaS provider cannot directly communicate with the customer (e.g., a disconnected region). The respective containers  1467 ( 1 )-(N) that are contained in the VMs  1466 ( 1 )-(N) for each customer can be accessed in real-time by the customer. The containers  1467 ( 1 )-(N) may be configured to make calls to respective secondary VNICs  1472 ( 1 )-(N) contained in app subnet(s)  1426  of the data plane app tier  1446  that can be contained in the container egress VCN  1468 . The secondary VNICs  1472 ( 1 )-(N) can transmit the calls to the NAT gateway  1438  that may transmit the calls to public Internet  1454 . In this example, the containers  1467 ( 1 )-(N) that can be accessed in real-time by the customer can be isolated from the control plane VCN  1416  and can be isolated from other entities contained in the data plane VCN  1418 . The containers  1467 ( 1 )-(N) may also be isolated from resources from other customers. 
     In other examples, the customer can use the containers  1467 ( 1 )-(N) to call cloud services  1456 . In this example, the customer may run code in the containers  1467 ( 1 )-(N) that requests a service from cloud services  1456 . The containers  1467 ( 1 )-(N) can transmit this request to the secondary VNICs  1472 ( 1 )-(N) that can transmit the request to the NAT gateway that can transmit the request to public Internet  1454 . Public Internet  1454  can transmit the request to LB subnet(s)  1422  contained in the control plane VCN  1416  via the Internet gateway  1434 . In response to determining the request is valid, the LB subnet(s) can transmit the request to app subnet(s)  1426  that can transmit the request to cloud services  1456  via the service gateway  1436 . 
     It should be appreciated that IaaS architectures  1100 ,  1200 ,  1300 ,  1400  depicted in the figures may have other components than those depicted. Further, the embodiments shown in the figures are only some examples of a cloud infrastructure system that may incorporate an embodiment of the disclosure. In some other embodiments, the IaaS systems may have more or fewer components than shown in the figures, may combine two or more components, or may have a different configuration or arrangement of components. 
     In certain embodiments, the IaaS systems described herein may include a suite of applications, middleware, and database service offerings that are delivered to a customer in a self-service, subscription-based, elastically scalable, reliable, highly available, and secure manner. An example of such an IaaS system is the Oracle Cloud Infrastructure (OCI) provided by the present assignee. 
       FIG.  15    illustrates an example computer system  1500 , in which various embodiments may be implemented. The system  1500  may be used to implement any of the computer systems described above. As shown in the figure, computer system  1500  includes a processing unit  1504  that communicates with a number of peripheral subsystems via a bus subsystem  1502 . These peripheral subsystems may include a processing acceleration unit  1506 , an I/O subsystem  1508 , a storage subsystem  1518  and a communications subsystem  1524 . Storage subsystem  1518  includes tangible computer-readable storage media  1522  and a system memory  1510 . 
     Bus subsystem  1502  provides a mechanism for letting the various components and subsystems of computer system  1500  communicate with each other as intended. Although bus subsystem  1502  is shown schematically as a single bus, alternative embodiments of the bus subsystem may utilize multiple buses. Bus subsystem  1502  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. For example, such architectures may include an Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus, which can be implemented as a Mezzanine bus manufactured to the IEEE P1386.1 standard. 
     Processing unit  1504 , which can be implemented as one or more integrated circuits (e.g., a conventional microprocessor or microcontroller), controls the operation of computer system  1500 . One or more processors may be included in processing unit  1504 . These processors may include single core or multicore processors. In certain embodiments, processing unit  1504  may be implemented as one or more independent processing units  1532  and/or  1534  with single or multicore processors included in each processing unit. In other embodiments, processing unit  1504  may also be implemented as a quad-core processing unit formed by integrating two dual-core processors into a single chip. 
     In various embodiments, processing unit  1504  can execute a variety of programs in response to program code and can maintain multiple concurrently executing programs or processes. At any given time, some or all of the program code to be executed can be resident in processor(s)  1504  and/or in storage subsystem  1518 . Through suitable programming, processor(s)  1504  can provide various functionalities described above. Computer system  1500  may additionally include a processing acceleration unit  1506 , which can include a digital signal processor (DSP), a special-purpose processor, and/or the like. 
     I/O subsystem  1508  may include user interface input devices and user interface output devices. User interface input devices may include a keyboard, pointing devices such as a mouse or trackball, a touchpad or touch screen incorporated into a display, a scroll wheel, a click wheel, a dial, a button, a switch, a keypad, audio input devices with voice command recognition systems, microphones, and other types of input devices. User interface input devices may include, for example, motion sensing and/or gesture recognition devices such as the Microsoft Kinect® motion sensor that enables users to control and interact with an input device, such as the Microsoft Xbox® 360 game controller, through a natural user interface using gestures and spoken commands. User interface input devices may also include eye gesture recognition devices such as the Google Glass® blink detector that detects eye activity (e.g., ‘blinking’ while taking pictures and/or making a menu selection) from users and transforms the eye gestures as input into an input device (e.g., Google Glass®). Additionally, user interface input devices may include voice recognition sensing devices that enable users to interact with voice recognition systems (e.g., Siri® navigator), through voice commands. 
     User interface input devices may also include, without limitation, three dimensional (3D) mice, joysticks or pointing sticks, gamepads and graphic tablets, and audio/visual devices such as speakers, digital cameras, digital camcorders, portable media players, webcams, image scanners, fingerprint scanners, barcode reader 3D scanners, 3D printers, laser rangefinders, and eye gaze tracking devices. Additionally, user interface input devices may include, for example, medical imaging input devices such as computed tomography, magnetic resonance imaging, position emission tomography, medical ultrasonography devices. User interface input devices may also include, for example, audio input devices such as MIDI keyboards, digital musical instruments and the like. 
     User interface output devices may include a display subsystem, indicator lights, or non-visual displays such as audio output devices, etc. The display subsystem may be a cathode ray tube (CRT), a flat-panel device, such as that using a liquid crystal display (LCD) or plasma display, a projection device, a touch screen, and the like. In general, use of the term “output device” is intended to include all possible types of devices and mechanisms for outputting information from computer system  1500  to a user or other computer. For example, user interface output devices may include, without limitation, a variety of display devices that visually convey text, graphics and audio/video information such as monitors, printers, speakers, headphones, automotive navigation systems, plotters, voice output devices, and modems. 
     Computer system  1500  may comprise a storage subsystem  1518  that comprises software elements, shown as being currently located within a system memory  1510 . System memory  1510  may store program instructions that are loadable and executable on processing unit  1504 , as well as data generated during the execution of these programs. 
     Depending on the configuration and type of computer system  1500 , system memory  1510  may be volatile (such as random access memory (RAM)) and/or non-volatile (such as read-only memory (ROM), flash memory, etc.) The RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated and executed by processing unit  1504 . In some implementations, system memory  1510  may include multiple different types of memory, such as static random access memory (SRAM) or dynamic random access memory (DRAM). In some implementations, a basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within computer system  1500 , such as during start-up, may typically be stored in the ROM. By way of example, and not limitation, system memory  1510  also illustrates application programs  1512 , which may include client applications, Web browsers, mid-tier applications, relational database management systems (RDBMS), etc., program data  1514 , and an operating system  1516 . By way of example, operating system  1516  may include various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems, a variety of commercially-available UNIX® or UNIX-like operating systems (including without limitation the variety of GNU/Linux operating systems, the Google Chrome® OS, and the like) and/or mobile operating systems such as iOS, Windows® Phone, Android® OS, BlackBerry® 15 OS, and Palm® OS operating systems. 
     Storage subsystem  1518  may also provide a tangible computer-readable storage medium for storing the basic programming and data constructs that provide the functionality of some embodiments. Software (programs, code modules, instructions) that when executed by a processor provide the functionality described above may be stored in storage subsystem  1518 . These software modules or instructions may be executed by processing unit  1504 . Storage subsystem  1518  may also provide a repository for storing data used in accordance with the present disclosure. 
     Storage subsystem  1500  may also include a computer-readable storage media reader  1520  that can further be connected to computer-readable storage media  1522 . Together and, optionally, in combination with system memory  1510 , computer-readable storage media  1522  may comprehensively represent remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing, storing, transmitting, and retrieving computer-readable information. 
     Computer-readable storage media  1522  containing code, or portions of code, can also include any appropriate media known or used in the art, including storage media and communication media, such as but not limited to, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage and/or transmission of information. This can include tangible computer-readable storage media such as RAM, ROM, electronically erasable programmable ROM (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other tangible computer readable media. This can also include nontangible computer-readable media, such as data signals, data transmissions, or any other medium which can be used to transmit the desired information and which can be accessed by computing system  1500 . 
     By way of example, computer-readable storage media  1522  may include a hard disk drive that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive that reads from or writes to a removable, nonvolatile magnetic disk, and an optical disk drive that reads from or writes to a removable, nonvolatile optical disk such as a CD ROM, DVD, and Blu-Ray® disk, or other optical media. Computer-readable storage media  1522  may include, but is not limited to, Zip® drives, flash memory cards, universal serial bus (USB) flash drives, secure digital (SD) cards, DVD disks, digital video tape, and the like. Computer-readable storage media  1522  may also include, solid-state drives (SSD) based on non-volatile memory such as flash-memory based SSDs, enterprise flash drives, solid state ROM, and the like, SSDs based on volatile memory such as solid state RAM, dynamic RAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, and hybrid SSDs that use a combination of DRAM and flash memory based SSDs. The disk drives and their associated computer-readable media may provide non-volatile storage of computer-readable instructions, data structures, program modules, and other data for computer system  1500 . 
     Communications subsystem  1524  provides an interface to other computer systems and networks. Communications subsystem  1524  serves as an interface for receiving data from and transmitting data to other systems from computer system  1500 . For example, communications subsystem  1524  may enable computer system  1500  to connect to one or more devices via the Internet. In some embodiments communications subsystem  1524  can include radio frequency (RF) transceiver components for accessing wireless voice and/or data networks (e.g., using cellular telephone technology, advanced data network technology, such as 3G, 4G or EDGE (enhanced data rates for global evolution), WiFi (IEEE 802.11 family standards, or other mobile communication technologies, or any combination thereof), global positioning system (GPS) receiver components, and/or other components. In some embodiments communications subsystem  1524  can provide wired network connectivity (e.g., Ethernet) in addition to or instead of a wireless interface. 
     In some embodiments, communications subsystem  1524  may also receive input communication in the form of structured and/or unstructured data feeds  1526 , event streams  1528 , event updates  1530 , and the like on behalf of one or more users who may use computer system  1500 . 
     By way of example, communications subsystem  1524  may be configured to receive data feeds  1526  in real-time from users of social networks and/or other communication services such as Twitter® feeds, Facebook® updates, web feeds such as Rich Site Summary (RSS) feeds, and/or real-time updates from one or more third party information sources. 
     Additionally, communications subsystem  1524  may also be configured to receive data in the form of continuous data streams, which may include event streams  1528  of real-time events and/or event updates  1530 , that may be continuous or unbounded in nature with no explicit end. Examples of applications that generate continuous data may include, for example, sensor data applications, financial tickers, network performance measuring tools (e.g. network monitoring and traffic management applications), clickstream analysis tools, automobile traffic monitoring, and the like. 
     Communications subsystem  1524  may also be configured to output the structured and/or unstructured data feeds  1526 , event streams  1528 , event updates  1530 , and the like to one or more databases that may be in communication with one or more streaming data source computers coupled to computer system  1500 . 
     Computer system  1500  can be one of various types, including a handheld portable device (e.g., an iPhone® cellular phone, an iPad® computing tablet, a PDA), a wearable device (e.g., a Google Glass® head mounted display), a PC, a workstation, a mainframe, a kiosk, a server rack, or any other data processing system. 
     Due to the ever-changing nature of computers and networks, the description of computer system  1500  depicted in the figure is intended only as a specific example. Many other configurations having more or fewer components than the system depicted in the figure are possible. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, firmware, software (including applets), or a combination. Further, connection to other computing devices, such as network input/output devices, may be employed. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate other ways and/or methods to implement the various embodiments. 
     Although specific embodiments have been described, various modifications, alterations, alternative constructions, and equivalents are also encompassed within the scope of the disclosure. Embodiments are not restricted to operation within certain specific data processing environments, but are free to operate within a plurality of data processing environments. Additionally, although embodiments have been described using a particular series of transactions and steps, it should be apparent to those skilled in the art that the scope of the present disclosure is not limited to the described series of transactions and steps. Various features and aspects of the above-described embodiments may be used individually or jointly. 
     Further, while embodiments have been described using a particular combination of hardware and software, it should be recognized that other combinations of hardware and software are also within the scope of the present disclosure. Embodiments may be implemented only in hardware, or only in software, or using combinations thereof. The various processes described herein can be implemented on the same processor or different processors in any combination. Accordingly, where components or modules are described as being configured to perform certain operations, such configuration can be accomplished, e.g., by designing electronic circuits to perform the operation, by programming programmable electronic circuits (such as microprocessors) to perform the operation, or any combination thereof. Processes can communicate using a variety of techniques including but not limited to conventional techniques for inter process communication, and different pairs of processes may use different techniques, or the same pair of processes may use different techniques at different times. 
     The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that additions, subtractions, deletions, and other modifications and changes may be made thereunto without departing from the broader spirit and scope as set forth in the claims. Thus, although specific disclosure embodiments have been described, these are not intended to be limiting. Various modifications and equivalents are within the scope of the following claims. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure. 
     Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is intended to be understood within the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present. 
     Preferred embodiments of this disclosure are described herein, including the best mode known for carrying out the disclosure. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. Those of ordinary skill should be able to employ such variations as appropriate and the disclosure may be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     In the foregoing specification, aspects of the disclosure are described with reference to specific embodiments thereof, but those skilled in the art will recognize that the disclosure is not limited thereto. Various features and aspects of the above-described disclosure may be used individually or jointly. Further, embodiments can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive.