views (instance statistics)

The views resource contains information about the views in the AMPS instance. Clicking a view will display the detailed statistics for views.

AMPS also collects SOW statistics for views. These are available from the sow resource, with the name of the view as the topic name.

Element	Description	Type
conflation	The inline conflation mode of the view.	fixed
conflation_ratio	The ratio of incoming to conflated updates. (If there are no updates, this is not calculated and shows as 0.0.)	snapshot
grouping	List of one or more fields, which are used to determine message aggregation.	fixed
message_type	The message type of messages produced by this view.	fixed
projection	The formula defined in the AMPS config for the computed transformation of one or more fields onto a new field.	fixed
queue_depth	The number of updates to the view that are pending, but have not yet been applied.	snapshot
topic	The name of the new AMPS topic created by this view.	fixed
underlying_topic	The source topic used to compute the projected view.	fixed

Admin Path: /amps/instance/views/<id>/<metric>

Statistics Database Tables: IVIEWS_STATIC, IVIEWS_DYNAMIC

Additional topic information: ISOW_STATIC, ISOW_DYNAMIC

Sample amps-sqlite3 query:

SELECT iso8601_local(v.timestamp), v.topic, v.queue_depth, v.conflation_ratio,
       s.updates_per_sec, s.inserts_per_sec, s.deletes_per_sec
FROM IVIEWS AS v
JOIN ISOW AS s ON v.oid = s.oid AND v.timestamp=s.timestamp
WHERE (v.queue_depth + s.updates_per_sec + s.inserts_per_sec + s.deletes_per_sec) > 0
ORDER BY v.oid, v.timestamp asc

This query shows information about changes to the views in the instance. The query joins information from the ISOW record for the topics using matching oid and timestamp fields to show the inserts, updates, and deletes to the View (per second) for each sample. The query includes the pending updates (queue depth) at each sample. The WHERE clause only includes samples where there is activity to the view, to avoid showing samples where the contents of the queue are not changing.