Configuration

Service-level settings.

RecallGraph exports two settings - snapshot-intervals and sampling-probability. These are explained in the sections below.

snapshot-intervals

This is a JSON object that stores the snapshot interval for each collection. Its keys are collection names and values are non-negative integers. If the value is 0, then snapshots are disabled for that collection. For a number greater than 0, RecallGraph interprets the number as the minimum number of events that must occur on a document until a snapshot is generated for that document. A snapshot is created only if the latest event is not a DELETE.

There is also a global setting for snapshot intervals which applies to all collections which are not explicitly listed in this object. This global setting is stored in the key _default in the same object. The default value for this setting is:

{
"_default": 5
}

A sample object with some collection-specific values might look like:

{
"_default": 7,
"flights": 10,
"airports": 0 //snapshots disabled
}

If this setting is changed globally, or for a collection, after some snapshots have already been created, the existing snapshots are left untouched and the new value(s) only apply to snapshots created thereafter.

sampling-probability

This setting is used for determining whether to collect a tracing sample. The default is 0. Leave it at 0 if you're not going to use tracing in your deployment.

If set to a value between 0 and 1 (inclusive), it is interpreted as the probability with which a tracing sample may be collected for an incoming HTTP request. Regardless of the value set here, a trace may be force-collected or force-suppressed using designated HTTP headers. These headers and other tracing parameters are covered in more detail in the tracing section.