tencent cloud

Request address

The address is the instance IP and port, such as 10.13.20.15:9200, which can be obtained in the console.

Request path and method

• Path: /_metric/${metric_name}, where ${metric_name} is the name of the metric to be created.
• Method: PUT

Note：

For the naming limits of metrics, see System limits.

Request parameters

None

Request content

• The name of the time field is of the timestamp type by default. The time formats (format) are fully compatible with those in Elasticsearch, such as epoch_millis (Unix timestamp in milliseconds), epoch_second (Unix timestamp in seconds), basic_date (in yyyyMMdd format), and basic_date_time (in yyyyMMdd'T'HHmmss.SSSZ format).

• options values and their descriptions:

  • expire_day: Data expiration time in days, which is a non-zero integer. Once expired, the data will be automatically cleared. By default, it is the minimum value -1, which indicates that the data will never expire.

  • refresh_interval: Data refresh interval, which is 10 seconds by default. The written data can be queried after being refreshed from the memory to disk.

  • number_of_shards: Number of metric shards, which is a positive integer and 3 by default. This parameter can be ignored for small metrics. A large metric can be divided into shards, and each shard can be up to 25 GB in size.

  • number_of_replicas: Number of replicas, which is a positive integer; for example, 1 indicates one master and one replica. The default value is 1.

  • rolling_period: Child metric period (in days), which is a non-zero integer. When CTSDB stores data, to facilitate data expiration and improve query efficiency, it stores data in child metrics by the specified time interval, which is subject to the data expiration time by default. The relationships between the default child metric period and data expiration time are as detailed below:

  • max_string_length: Maximum length of a custom string, which is a positive integer. Its maximum value is 32765, and its default value is 256.

  • default_date_format: Format of the date data type of custom tags and fields, which is strict_date_optional_time or epoch_millis by default.

  • indexed_fields: Fields whose indexes need to be retained in the fields. You can use an array to specify multiple fields.

  • default_type: Default type of new fields. Its valid values are tag and field, and its default value is tag.

    Expiration Time	Child Metric Period
    ≤ 7 days	1 day
    > 7 days but ≤ 20 days	3 days
    > 20 days but ≤ 49 days	7 days
    > 49 days but ≤ 3 months	15 days
    > 3 months	30 days
    Never expires	30 days

Response content

You need to judge whether a request is successful based on the error field. If the response content contains the error field, the request failed. For the error details, see the error field description.

Sample code for curl

Request:

curl -u root:le201909 -H 'Content-Type:application/json' -X PUT 172.xx.xx.4:9201/_metric/ctsdb_test -d'
{
  "tags":
  {
      "region":"string"
  },
  "time":
  {
      "name":"timestamp",
      "format":"epoch_second"
  },
  "fields":
  {
      "cpuUsage":"float"
  },
  "options":
  {
      "expire_day":7,
      "refresh_interval":"10s",
      "number_of_shards":5
  }
 }
'

Response upon success:

{
  "acknowledged": true,
  "message": "create ctsdb metric ctsdb_test success!"
 }

Response upon failure:

{
  "error": {
  "reason": "table ctsdb_test already exist",
  "type": "metric_exception"
  },
  "status": 201
 }