Update anomaly detection jobs API

Updates certain properties of an anomaly detection job.

Request

POST _ml/anomaly_detectors/<job_id>/_update

Prerequisites

Path parameters

<job_id>

(Required, string) Identifier for the anomaly detection job.

Request body

The following properties can be updated after the job is created:

allow_lazy_open

(boolean) Advanced configuration option. Specifies whether this job can open when there is insufficient machine learning node capacity for it to be immediately assigned to a node. The default value is false; if a machine learning node with capacity to run the job cannot immediately be found, the open anomaly detection jobs API returns an error. However, this is also subject to the cluster-wide xpack.ml.max_lazy_ml_nodes setting; see Advanced machine learning settings. If this option is set to true, the open anomaly detection jobs API does not return an error and the job waits in the opening state until sufficient machine learning node capacity is available.

If the job is open when you make the update, you must stop the datafeed, close the job, then reopen the job and restart the datafeed for the changes to take effect.

analysis_limits

(Optional, object) Limits can be applied for the resources required to hold the mathematical models in memory. These limits are approximate and can be set per job. They do not control the memory used by other processes, for example the Elasticsearch Java processes.

Properties of analysis_limits

  • model_memory_limit

    (long or string) The approximate maximum amount of memory resources that are required for analytical processing. Once this limit is approached, data pruning becomes more aggressive. Upon exceeding this limit, new entities are not modeled. The default value for jobs created in version 6.1 and later is 1024mb. This value will need to be increased for jobs that are expected to analyze high cardinality fields, but the default is set to a relatively small size to ensure that high resource usage is a conscious decision. The default value for jobs created in versions earlier than 6.1 is 4096mb.

    If you specify a number instead of a string, the units are assumed to be MiB. Specifying a string is recommended for clarity. If you specify a byte size unit of b or kb and the number does not equate to a discrete number of megabytes, it is rounded down to the closest MiB. The minimum valid value is 1 MiB. If you specify a value less than 1 MiB, an error occurs. For more information about supported byte size units, see Byte size units.

    If your elasticsearch.yml file contains an xpack.ml.max_model_memory_limit setting, an error occurs when you try to create jobs that have model_memory_limit values greater than that setting. For more information, see Machine learning settings.

    You can update the analysis_limits only while the job is closed. The model_memory_limit property value cannot be decreased below the current usage.

    If the memory_status property in the model_size_stats object has a value of hard_limit,mthis means that it was unable to process some data. You might want to re-run the job with an increased model_memory_limit.

background_persist_interval

(time units) Advanced configuration option. The time between each periodic persistence of the model. The default value is a randomized value between 3 to 4 hours, which avoids all jobs persisting at exactly the same time. The smallest allowed value is 1 hour.

For very large models (several GB), persistence could take 10-20 minutes, so do not set the background_persist_interval value too low.

If the job is open when you make the update, you must stop the datafeed, close the job, then reopen the job and restart the datafeed for the changes to take effect.

custom_settings

(object) Advanced configuration option. Contains custom meta data about the job. For example, it can contain custom URL information as shown in Adding custom URLs to machine learning results.

daily_model_snapshot_retention_after_days

(long) Advanced configuration option, which affects the automatic removal of old model snapshots for this job. It specifies a period of time (in days) after which only the first snapshot per day is retained. This period is relative to the timestamp of the most recent snapshot for this job. Valid values range from 0 to model_snapshot_retention_days. For new jobs, the default value is 1. For jobs created before version 7.8.0, the default value matches model_snapshot_retention_days. For more information, refer to Model snapshots.

description

(string) A description of the job.

detectors

(array) An array of detector update objects.

Properties of detectors

  • custom_rules

    (array) An array of custom rule objects, which enable you to customize the way detectors operate. For example, a rule may dictate to the detector conditions under which results should be skipped. For more examples, see Customizing detectors with custom rules.

    Properties of custom_rules

    • actions

      (array) The set of actions to be triggered when the rule applies. If more than one action is specified the effects of all actions are combined. The available actions include:

      • skip_result: The result will not be created. This is the default value. Unless you also specify skip_model_update, the model will be updated as usual with the corresponding series value.
      • skip_model_update: The value for that series will not be used to update the model. Unless you also specify skip_result, the results will be created as usual. This action is suitable when certain values are expected to be consistently anomalous and they affect the model in a way that negatively impacts the rest of the results.
  1. -   `conditions`
  3.     (array) An optional array of numeric conditions when the rule applies. A rule must either have a non-empty scope or at least one condition. Multiple conditions are combined together with a logical `AND`. A condition has the following properties:
  5.     Properties of `conditions`
  7.     `applies_to`
  9.     (string) Specifies the result property to which the condition applies. The available options are `actual`, `typical`, `diff_from_typical`, `time`. If your detector uses `lat_long`, `metric`, `rare`, or `freq_rare` functions, you can only specify conditions that apply to `time`.
  11.     `operator`
  13.     (string) Specifies the condition operator. The available options are `gt` (greater than), `gte` (greater than or equals), `lt` (less than) and `lte` (less than or equals).
  15.     `value`
  17.     (double) The value that is compared against the `applies_to` field using the `operator`.
  20. -   `scope`
  22.     (object) An optional scope of series where the rule applies. A rule must either have a non-empty scope or at least one condition. By default, the scope includes all series. Scoping is allowed for any of the fields that are also specified in `by_field_name`, `over_field_name`, or `partition_field_name`. To add a scope for a field, add the field name as a key in the scope object and set its value to an object with the following properties:
  24.     Properties of `scope`
  26.     `filter_id`
  28.     (string) The id of the filter to be used.
  30.     `filter_type`
  32.     (string) Either `include` (the rule applies for values in the filter) or `exclude` (the rule applies for values not in the filter). Defaults to `include`.
  35. `description`
  37. (string) A description of the detector. For example, `Low event rate`.
  39. `detector_index`
  41. (integer) A unique identifier for the detector. This identifier is based on the order of the detectors in the `analysis_config`, starting at zero.
  43. If you want to update a specific detector, you must use this identifier. You cannot, however, change the `detector_index` value for a detector.

groups

(array of strings) A list of job groups. A job can belong to no groups or many.

model_plot_config

(object) This advanced configuration option stores model information along with the results. It provides a more detailed view into anomaly detection.

If you enable model plot it can add considerable overhead to the performance of the system; it is not feasible for jobs with many entities.

Model plot provides a simplified and indicative view of the model and its bounds. It does not display complex features such as multivariate correlations or multimodal data. As such, anomalies may occasionally be reported which cannot be seen in the model plot.

Model plot config can be configured when the job is created or updated later. It must be disabled if performance issues are experienced.

Properties of model_plot_config

  • annotations_enabled

    (boolean) If true, enables calculation and storage of the model change annotations for each entity that is being analyzed. Defaults to enabled.

    enabled

    (boolean) If true, enables calculation and storage of the model bounds for each entity that is being analyzed. By default, this is not enabled.

    terms

    [experimental] This functionality is experimental and may be changed or removed completely in a future release. Elastic will take a best effort approach to fix any issues, but experimental features are not subject to the support SLA of official GA features. (string) Limits data collection to this comma separated list of partition or by field values. If terms are not specified or it is an empty string, no filtering is applied. For example, “CPU,NetworkIn,DiskWrites”. Wildcards are not supported. Only the specified terms can be viewed when using the Single Metric Viewer.

model_snapshot_retention_days

(long) Advanced configuration option, which affects the automatic removal of old model snapshots for this job. It specifies the maximum period of time (in days) that snapshots are retained. This period is relative to the timestamp of the most recent snapshot for this job. The default value is 10, which means snapshots ten days older than the newest snapshot are deleted. For more information, refer to Model snapshots.

per_partition_categorization

(object) Settings related to how categorization interacts with partition fields.

Properties of per_partition_categorization

  • enabled

    (boolean) To enable this setting, you must also set the partition_field_name property to the same value in every detector that uses the keyword mlcategory. Otherwise, job creation fails.

    stop_on_warn

    (boolean) This setting can be set to true only if per-partition categorization is enabled. If true, both categorization and subsequent anomaly detection stops for partitions where the categorization status changes to warn. This setting makes it viable to have a job where it is expected that categorization works well for some partitions but not others; you do not pay the cost of bad categorization forever in the partitions where it works badly.

  • renormalization_window_days

    (long) Advanced configuration option. The period over which adjustments to the score are applied, as new data is seen. The default value is the longer of 30 days or 100 bucket_spans.

If the job is open when you make the update, you must stop the datafeed, close the job, then reopen the job and restart the datafeed for the changes to take effect.

  • results_retention_days

    (long) Advanced configuration option. The period of time (in days) that results are retained. Age is calculated relative to the timestamp of the latest bucket result. If this property has a non-null value, once per day at 00:30 (server time), results that are the specified number of days older than the latest bucket result are deleted from Elasticsearch. The default value is null, which means all results are retained.

Examples

  1. POST _ml/anomaly_detectors/low_request_rate/_update
  2. {
  3.   "description":"An updated job",
  4.   "detectors": {
  5.     "detector_index": 0,
  6.     "description": "An updated detector description"
  7.   },
  8.   "groups": ["kibana_sample_data","kibana_sample_web_logs"],
  9.   "model_plot_config": {
  10.     "enabled": true
  11.   },
  12.   "renormalization_window_days": 30,
  13.   "background_persist_interval": "2h",
  14.   "model_snapshot_retention_days": 7,
  15.   "results_retention_days": 60
  16. }

When the anomaly detection job is updated, you receive a summary of the job configuration information, including the updated property values. For example:

  1. {
  2.   "job_id" : "low_request_rate",
  3.   "job_type" : "anomaly_detector",
  4.   "job_version" : "7.5.1",
  5.   "groups" : [
  6.     "kibana_sample_data",
  7.     "kibana_sample_web_logs"
  8.   ],
  9.   "description" : "An updated job",
  10.   "create_time" : 1578101716125,
  11.   "finished_time" : 1578101721816,
  12.   "analysis_config" : {
  13.     "bucket_span" : "1h",
  14.     "summary_count_field_name" : "doc_count",
  15.     "detectors" : [
  16.       {
  17.         "detector_description" : "An updated detector description",
  18.         "function" : "low_count",
  19.         "detector_index" : 0
  20.       }
  21.     ],
  22.     "influencers" : [ ]
  23.   },
  24.   ...
  25. }