# Special Events

## Metadata

The metadata consists of the columns
• Id, is the id of the MQTT message in which the event was transmitted
• Inserted, the time it was inserted into the database
• Size, data size of the event
• Thing, id or name of the machine which generated the data
• Timestamp, timestamp describing the event
• Type, name/type of the event
These columns are contained in every event schema and are used to connect the different event schemas. The metadata events contain the collective of all metadata regardless of the event schema they actually belong to.

## Senseforce client state

The SF client state events contain information about the state of the edge component.
• Reason, this attribute isn't used at the moment.
• State, shows the status changes (connected/disconnected) of the according to SF edge.
• Status code, shows some information as State but in binary format (1/0).

## Senseforce messages

The SF message events contain information about the data included in the messages which were sent by the edge component.
• Inserted events, is the number of events that where included in the message with the given Id and inserted into the database. Each event is stored in a single row in the database.
• Rejected events, is the number of events that where included in the message with the given Id and rejected because of a violation against the event schema definition.
• Compressed size, is the size of the compressed message given in bytes.
• Uncompressed size, is the size of the uncompressed message given in bytes.
• Compression ratio, is the ratio between uncompressed and compressed size given by
$compression\_ratio = compressed\_size/uncompressed\_size$
• Space savings, is the data amount saved due to the compression.
$space\_savings = 1-uncompressed\_size/compressed\_size$
Last modified 1yr ago