Request Syntax Request Parameters Response Syntax Response Elements Errors Examples See Also

GetLogGroupFields

Returns a list of the fields that are included in log events in the specified log group. Includes the percentage of log events that contain each field. The search is limited to a time period that you specify.

You can specify the log group to search by using either logGroupIdentifier or logGroupName. You must specify one of these parameters, but you can't specify both.

In the results, fields that start with @ are fields generated by CloudWatch Logs. For example, @timestamp is the timestamp of each log event. For more information about the fields that are generated by CloudWatch logs, see Supported Logs and Discovered Fields.

The response results are sorted by the frequency percentage, starting with the highest percentage.

If you are using CloudWatch cross-account observability, you can use this operation in a monitoring account and view data from the linked source accounts. For more information, see CloudWatch cross-account observability.

Request Syntax


{
   "logGroupIdentifier": "string",
   "logGroupName": "string",
   "time": number
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

logGroupIdentifier

Specify either the name or ARN of the log group to view. If the log group is in a source account and you are using a monitoring account, you must specify the ARN.

Note

You must include either logGroupIdentifier or logGroupName, but not both.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 2048.

Pattern: [\w#+=/:,.@-]*

Required: No

logGroupName

The name of the log group to search.

Note

You must include either logGroupIdentifier or logGroupName, but not both.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 512.

Pattern: [\.\-_/#A-Za-z0-9]+

Required: No

time

The time to set as the center of the query. If you specify time, the 8 minutes before and 8 minutes after this time are searched. If you omit time, the most recent 15 minutes up to the current time are searched.

The time value is specified as epoch time, which is the number of seconds since January 1, 1970, 00:00:00 UTC.

Type: Long

Valid Range: Minimum value of 0.

Required: No

Response Syntax


{
   "logGroupFields": [ 
      { 
         "name": "string",
         "percent": number
      }
   ]
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

logGroupFields

The array of fields found in the query. Each object in the array contains the name of the field, along with the percentage of time it appeared in the log events that were queried.

Type: Array of LogGroupField objects

Errors

For information about the errors that are common to all actions, see Common Errors.

InvalidParameterException

A parameter is specified incorrectly.

HTTP Status Code: 400

LimitExceededException

You have reached the maximum number of resources that can be created.

HTTP Status Code: 400

ResourceNotFoundException

The specified resource does not exist.

HTTP Status Code: 400

ServiceUnavailableException

The service cannot complete the request.

HTTP Status Code: 500

Examples

Retrieve fields found in log events in a log group

The following example lists the log events and how often they occur in MyLogGroup for the 15 minutes before November 1, 2018, 00:00:00UTC.

Sample Request


POST / HTTP/1.1
Host: logs.<region>.<domain>
X-Amz-Date: <DATE>
Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=content-type;date;host;user-agent;x-amz-date;x-amz-target;x-amzn-requestid, Signature=<Signature>
User-Agent: <UserAgentString>
Accept: application/json
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Connection: Keep-Alive
X-Amz-Target: Logs_20140328.GetLogGroupFields
{
   "logGroupName": "MyLogGroup",
   "time": 1541030400
}

Sample Response


HTTP/1.1 200 OK
x-amzn-RequestId: <RequestId>
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Date: <Date>
{
    "logGroupFields": [
        {
            "name": "@timestamp",
            "percent": 100
        },
        {
            "name": "@message",
            "percent": 100
        },
        {
            "name": "@logStream",
            "percent": 100
        },
        {
            "name": "type",
            "percent": 57
        },
        {
            "name": "duration",
            "percent": 13
        }
    ]
}

Example

The following example lists the log events and how often they occur in MyLogGroup for the 15 minutes before November 1, 2018, 00:00:00UTC.

Sample Request


{
  "logGroupIdentifier": "arn:aws:logs:us-east-1:123456789012:log-group:monitoring-logGroup-1234:*",
  "time": 1541030400
}

Sample Response


{
    "logGroupFields": [
    {
        "name": "@timestamp",
        "percent": 100
    },
    {
      "name": "@message",
      "percent": 100
    },
    {
       "name": "@logStream",
       "percent": 100
    },
    {
       "name": "type",
       "percent": 57
    },
    {
       "name": "duration",
       "percent": 13
   }
] }