The structure of JSON training data configuration files - Amazon Neptune
Configuration objectEdges objectNode objectNFeature objectNode label objectCustom splits
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The structure of JSON training data configuration files

The training configuration file refers to CSV files saved by the export process in the nodes/ and edges/ folders.

Each file under nodes/ stores information about nodes that have the same property-graph node label. Each column in a node file stores either the node ID or the node property. The first line of the file contains a header that specifies the ~id or property name for each column.

Each file under edges/ stores information about nodes that have the same property-graph edge label. Each column in a node file stores either the source node ID, the destination node ID, or the edge property. The first line of the file contains a header specifying the ~from, ~to, or property name for each column.

The training data configuration file has three top-level elements:

{
  "version" : "v2.0",
  "query_engine" : "gremlin",
  "graph" : [ ... ]
}

  • version   –   (String) The version of configuration file being used.

  • query_engine   –   (String) The query language used for exporting the graph data. Currently, only "gremlin" is valid.

  • graph   –   (JSON array) lists one or more configuration objects that contain model parameters for each of the nodes and edges that will be used.

    The configuration objects in the graph array have the structure described in the next section.

Contents of a configuration object listed in the graph array

A configuration object in the graph array can contain three top-level nodes:

    {
      "edges"    : [ ... ],
      "nodes"    : [ ... ],
      "warnings" : [ ... ],
    }

  • edges   –   (array of JSON objects) Each JSON object specifies a set of parameters to define how an edge in the graph will be treated during the model processing and training. This is only used with the Gremlin engine.

  • nodes   –   (array of JSON objects) Each JSON object specifies a set of parameters to define how a node in the graph will be treated during the model processing and training. This is only used with the Gremlin engine.

  • warnings   –   (array of JSON objects) Each object contains a warning generated during the data export process.

Contents of an edge configuration object listed in an edges array

An edge configuration object listed in an edges array can contain the following top-level fields:

      {
        "file_name" : "(path to a CSV file)",
        "separator" : "(separator character)",
        "source"    : ["(column label for starting node ID)", "(starting node type)"],
        "relation"  : ["(column label for the relationship name)", "(the prefix name for the relationship name)"],
        "dest"      : ["(column label for ending node ID)", "(ending node type)"],
        "features"  : [(array of feature objects)],
        "labels"    : [(array of label objects)]
      }

  • file_name   –   A string specifying the path to a CSV file that stores information about edges having the same property-graph label.

    The first line of that file contains a header line of column labels.

    The first two column labels are ~from and ~to. The first column (the ~from column) stores the ID of the edge's starting node, and the second (the ~to column) stores the ID of the edge's ending node.

    The remaining column labels in the header line specify, for each remaining column, the name of the edge property whose values have been exported into that column.

  • separator   –   A string containing the delimiter that separates columns in that CSV file.

  • source   –   A JSON array containing two strings that specify the starting node of the edge. The first string contains the header name of the column that the starting node ID is stored in. The second string specifies the node type.

  • relation   –   A JSON array containing two strings that specify the edge's relation type. The first string contains the header name of the column that the relation name (relname) is stored in. The second string contains the prefix for the relation name (prefixname).

    The full relation type consists of the two strings combined, with a hyphen character between them, like this: prefixname-relname.

    If the first string is empty, all edges have the same relation type, namely the prefixname string.

  • dest   –   A JSON array containing two strings that specify the ending node of the edge. The first string contains the header name of the column that the node ID is stored in. The second string specifies the node type.

  • features   –   A JSON array of property-value feature objects. Each property-value feature object contains the following fields:

    • feature   –   A JSON array of three strings. The first string contains the header name of the column that contains the property value. The second string contains the feature name. The third string contains the feature type.

    • norm   –   (Optional) Specifies a normalization method to apply to the property values.

  • labels   –   A JSON array of objects. Each of the objects defines a target feature of the edges, and specifies the proportions of the edges that the training and validation stages should take. Each object contains the following fields:

    • label   –   A JSON array of two strings. The first string contains the header name of the column that contains the target feature property value. The second string specifies one of the following target task types:

      • "classification"   –   An edge classification task. The property values provided in the column identified by the first string in the label array are treated as categorical values. For an edge classification task, the first string in the label array can't be empty.

      • "regression"   –   An edge regression task. The property values provided in the column identified by the first string in the label array are treated as numerical values. For an edge regression task, the first string in the label array can't be empty.

      • "link_prediction"   –   A link prediction task. No property values are required. For a link prediction task, the first string in the label array is ignored.

    • split_rate   –   A JSON array containing three numbers between zero and one that add up to one and that represent an estimate of the proportions of nodes that the training, validation, and test stages will use, respectively. Either this field or the custom_split_filenames can be defined, but not both. See split_rate.

    • custom_split_filenames   –   A JSON object that specifies the file names for the files that define the training, validation and test populations. Either this field or split_rate can be defined, but not both. See Custom train-validation-test proportions for more information.

Contents of a node configuration object listed in a nodes array

A node configuration object listed in a nodes array can contain the following fields:

      {
        "file_name" : "(path to a CSV file)",
        "separator" : "(separator character)",
        "node"      : ["(column label for the node ID)", "(node type)"],
        "features"  : [(feature array)],
        "labels"    : [(label array)],
      }

  • file_name   –   A string specifying the path to a CSV file that stores information about nodes having the same property-graph label.

    The first line of that file contains a header line of column labels.

    The first column label is ~id, and the first column (the ~id column) stores the node ID.

    The remaining column labels in the header line specify, for each remaining column, the name of the node property whose values have been exported into that column.

  • separator   –   A string containing the delimiter that separates columns in that CSV file.

  • node   –   A JSON array containing two strings. The first string contains the header name of the column that stores node IDs. The second string specifies the node type in the graph, which corresponds to a property-graph label of the node.

  • features   –   A JSON array of node feature objects. See Contents of a feature object listed in a features array for a node or edge.

  • labels   –   A JSON array of node label objects. See Contents of a node label object listed in a node labels array.

Contents of a feature object listed in a features array for a node or edge

A node feature object listed in a node features array can contain the following top-level fields:

  • feature   –   A JSON array of three strings. The first string contains the header name of the column that contains the property value for the feature. The second string contains the feature name.

    The third string contains the feature type. Valid feature types are listed in Possible values of the type field for features.

  • norm   –   This field is required for numerical features. It specifies a normalization method to use on numeric values. Valid values are "none", "min-max", and "standard". See The norm field for details.

  • language   –   The language field specifies the language being used in text property values. Its usage depends on the text encoding method:

    • For text_fasttext encoding, this field is required, and must specify one of the following languages:

      • en   (English)

      • zh   (Chinese)

      • hi   (Hindi)

      • es   (Spanish)

      • fr   (French)

      However, text_fasttext cannot handle more than one language at a time.

    • For text_sbert encoding, this field is not used, since SBERT encoding is multilingual.

    • For text_word2vec encoding, this field is optional, since text_word2vec only supports English. If present, it must specify the name of the English language model:

      "language" : "en_core_web_lg"

    • For tfidf encoding, this field is not used.

  • max_length   –   This field is optional for text_fasttext features, where it specifies the maximum number of tokens in an input text feature that will be encoded. Input text after max_length is reached is ignored. For example, setting max_length to 128 indicates that any tokens after the 128th in a text sequence are ignored.

  • separator  –   This field is used optionally with category, numerical and auto features. It specifies a character that can be used to split a property value into multiple categorical values or numerical values.

    See The separator field.

  • range  –   This field is required for bucket_numerical features. It specifies the range of numerical values that are to be divided into buckets.

    See The range field.

  • bucket_cnt  –   This field is required for bucket_numerical features. It specifies the number of buckets that the numerical range defined by the range parameter should be divided into.

    See Bucket-numerical features in Neptune ML.

  • slide_window_size  –   This field is used optionally with bucket_numerical features to assign values to more than one bucket.

    See The slide_window_size field.

  • imputer  –   This field is used optionally with numerical, bucket_numerical, and datetime features to provide an imputation technique for filling in missing values. The supported imputation techniques are "mean", "median", and "most_frequent".

    See The imputer field.

  • max_features  –   This field is used optionally by text_tfidf features to specify the maximum number of terms to encode.

    See The max_features field.

  • min_df  –   This field is used optionally by text_tfidf features to specify the minimum document frequency of terms to encode

    See The min_df field.

  • ngram_range  –   This field is used optionally by text_tfidf features to specify a range of numbers of words or tokens to considered as potential individual terms to encode

    See The ngram_range field.

  • datetime_parts  –   This field is used optionally by datetime features to specify which parts of the datetime value to encode categorically.

    See The datetime_parts field.

Contents of a node label object listed in a node labels array

A label object listed in a node labels array defines a node target feature and specifies the proportions of nodes that the training, validation, and test stages will use. Each object can contain the following fields:

      {
        "label"      : ["(column label for the target feature property value)", "(task type)"],
        "split_rate" : [(training proportion), (validation proportion), (test proportion)],
        "custom_split_filenames" : {"train": "(training file name)", "valid": "(validation file name)", "test": "(test file name)"},
        "separator"  : "(separator character for node-classification category values)",
      }

  • label   –   A JSON array containing two strings. The first string contains the header name of the column that stores the property values for the feature. The second string specifies the target task type, which can be:

    • "classification"   –   A node classification task. The property values in the specified column are used to create a categorical feature.

    • "regression"   –   A node regression task. The property values in the specified column are used to create a numerical feature.

  • split_rate   –   A JSON array containing three numbers between zero and one that add up to one and represent an estimate of the proportions of nodes that the training, validation, and test stages will use, respectively. See split_rate.

  • custom_split_filenames   –   A JSON object that specifies the file names for the files that define the training, validation and test populations. Either this field or split_rate can be defined, but not both. See Custom train-validation-test proportions for more information.

  • separator   –   A string containing the delimiter that separates categorical feature values for a classification task.

Note

If no label object is provided for both edges and nodes, the task is automatically assumed to be link prediction, and edges are randomly split into 90% for training and 10% for validation.

Custom train-validation-test proportions

By default, the split_rate parameter is used by Neptune ML to split the graph randomly into training, validation and test populations using the proportions defined in this parameter. To have more precise control over which entities are used in these different populations, files can be created that explicitly define them, and then the training data configuration file can be edited to map these indexing files to the populations. This mapping is specified by a JSON object for the custom_split_filesnames key in the training configuration file. If this option is used, filenames must be provided for the train and validation keys, and is optional for the test key.

The formatting of these files should match the Gremlin data format. Specifically, for node-level tasks, each file should contain a column with the ~id header that lists the node IDs, and for edge-level tasks, the files should specify ~from and ~to to indicate the source and destination nodes of the edges, respectively. These files need to be placed in the same Amazon S3 location as the exported data that is used for data processing (see: outputS3Path).

For property classification or regression tasks, these files can optionally define the labels for the machine-learning task. In that case the files need to have a property column with the same header name as is defined in the training data configuration file. If property labels are defined in both the exported node and edge files and the custom-split files, priority is given to the custom-split files.