This is an earlier version of the OpenSearch documentation. For the latest version, see the current documentation. For information about OpenSearch version maintenance, see Release Schedule and Maintenance Policy.
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 thetypefield 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 thecombine_scripton each shard into an array.
The following example aggregates the different HTTP response types in web log data:
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;
"""
}
}
}
}
Example response
...
"aggregations" : {
"responses.counts" : {
"value" : {
"other" : 0,
"success" : 12832,
"error" : 1242
}
}
}
}