DATALOSS STORE_DISCARD_DATALOSS

The advisory reports potential data loss at a subscriber to a last-value durable. The reason is that the subscriber has either missed one or more messages, or disconnected from the persistence store.

Details

A subscriber to a last-value durable receives every message that updates that durable. However, if the subscriber cannot keep up with the stream of updates from publishers, the subscriber might miss messages, as the durable stores only the most recent message.

If the subscriber disconnects from the persistence store, it could miss messages during the interval in which it remains disconnected.

This advisory reports only inbound data loss, not outbound.

This advisory does not indicate the volume of lost data, but rather the number of data loss incidents. Each data loss incident represents the potential for lost messages. (The volume of lost data could be zero.)

Actions

Report this advisory to an administrator.

Fields

Field	Description
`name`	`DATALOSS`
`reason`	`STORE_DISCARD_DATALOSS`
`endpoints`	The string array value of this field lists the endpoints that could have lost data. Although data loss occurs primarily in a transport, its symptoms could affect all endpoints that use the transport, and by extension, any subscriber on those endpoints. Furthermore, transport names are meaningful to administrators, but usually not available to programmers. This advisory field reports the set of all endpoints through which the program could access the problematic transport, according to the configuration in the local realm object.
`aggregation_count`	The long value of this field reports the cumulative number of discard or disconnect incidents during the time interval (see `aggregation_time`). The base library aggregates this count separately for each transport.
`aggregation_time`	The double floating point value, in seconds, of this field indicates the length of the time interval for aggregating the incidents that `aggregation_count` reports. The time interval ends shortly before the `timestamp`.
`timestamp`	The `DateTime` value of this field indicates the time that the library generated the advisory. Although DateTime values can represent time with nanosecond precision, the actual resolution of the timestamp is only as fine-grained as the host computer's operating system supports.