Metrics

Metrics are collected for all requests to the service (unless client specifies skipMetric). Metrics may be stored in MongoDB itself, or a service that supports the ILP.

MongoDB

Metrics are collected in the specified database and collection combination (or their defaults). No TTL index is set on this (as it is left to the user's requirements). A date property is stored to create a TTL index as required.

The schema for a metric is as follows:

{
  "_id": {"$oid": "5fd4b7e55f1ba96a695d1446"},
  "action": "retrieve",
  "database": "wpreading2",
  "collection": "databaseVersion",
  "size": 88,
  "time": 414306,
  "timestamp": 437909021088978,
  "date": {"$date": 437909021},
  "application": "bootstrap"
}

action - The database action performed by the client.
database - The database against which the action was performed.
collection - The collection against which the action was performed.
size - The total size of the response document.
time - The time in nanoseconds for the action (includes any interaction with version history).
timestamp - The time since UNIX epoch in nanoseconds for use when exporting to other timeseries databases.
date - The BSON date at which the metric was created. Use to define a TTL index as appropriate.
application - The application that invoked the service if specified in the request payload.

ILP

Metrics may be stored in a time series database of choice that supports the ILP. We have only tested storing metrics in QuestDB. The id, duration, and size values are stored as field sets and the other values stored as tag sets. The name for the series (measurement) can be specified via the command line argument, or will default to the name of the metrics collection.

Last modified: 18 February 2025