72 lines
2.2 KiB
Markdown
72 lines
2.2 KiB
Markdown
---
|
|
layout: default
|
|
title: Scripted metric
|
|
parent: Metric aggregations
|
|
grand_parent: Aggregations
|
|
nav_order: 100
|
|
---
|
|
|
|
# Scripted metric aggregations
|
|
|
|
The `scripted_metric` metric is a multi-value metric aggregation that returns metrics calculated from a specified script.
|
|
|
|
A script has four stages: the initial stage, the map stage, the combine stage, and the reduce stage.
|
|
|
|
* `init_script`: (OPTIONAL) Sets the initial state and executes before any collection of documents.
|
|
* `map_script`: Checks the value of the `type` field and executes the aggregation on the collected documents.
|
|
* `combine_script`: Aggregates the state returned from every shard. The aggregated value is returned to the coordinating node.
|
|
* `reduce_script`: Provides access to the variable states; this variable combines the results from the `combine_script` on each shard into an array.
|
|
|
|
The following example aggregates the different HTTP response types in web log data:
|
|
|
|
```json
|
|
GET opensearch_dashboards_sample_data_logs/_search
|
|
{
|
|
"size": 0,
|
|
"aggregations": {
|
|
"responses.counts": {
|
|
"scripted_metric": {
|
|
"init_script": "state.responses = ['error':0L,'success':0L,'other':0L]",
|
|
"map_script": """
|
|
def code = doc['response.keyword'].value;
|
|
if (code.startsWith('5') || code.startsWith('4')) {
|
|
state.responses.error += 1 ;
|
|
} else if(code.startsWith('2')) {
|
|
state.responses.success += 1;
|
|
} else {
|
|
state.responses.other += 1;
|
|
}
|
|
""",
|
|
"combine_script": "state.responses",
|
|
"reduce_script": """
|
|
def counts = ['error': 0L, 'success': 0L, 'other': 0L];
|
|
for (responses in states) {
|
|
counts.error += responses['error'];
|
|
counts.success += responses['success'];
|
|
counts.other += responses['other'];
|
|
}
|
|
return counts;
|
|
"""
|
|
}
|
|
}
|
|
}
|
|
}
|
|
```
|
|
{% include copy-curl.html %}
|
|
|
|
#### Example response
|
|
|
|
```json
|
|
...
|
|
"aggregations" : {
|
|
"responses.counts" : {
|
|
"value" : {
|
|
"other" : 0,
|
|
"success" : 12832,
|
|
"error" : 1242
|
|
}
|
|
}
|
|
}
|
|
}
|
|
```
|