TheHistoryParameters Properties

Availability of this record The higher this number the higher the availability of this record The Storage Service might store the data in multiple location to ensure maximum availability

Timestamp of this class. Will be set to DateTimeOffset.Now on creation of the Class

Expiration in Seconds of the class If a derived class is stored in a StorageMirror and cdeEXP is set to>0, the StorageMirror will automatically delete this record after the time has passed

Unique Key for the class derived from TheDataBase. this will be used in the StorageService as the Unique Index in the SQL Tables

Guid of Hosting Node - new in 4.108: Moved from MetaDataBase to here

Priority of this record. A lower number means a higher priority. Data with higher priority will be retrieved faster than those with lower prio

For each property, add a property [name].Avg that contains the average of the values in the SamplingWindow. The computed property must be requested in the list of properties.

For each property, add a property [name].Max that contains the maximum of the values in the SamplingWindow. The computed property must be requested in the list of properties.

For each property, add a property [name].Min that contains the minimum of the values in the SamplingWindow. The computed property must be requested in the list of properties.

For each property, add a property [name].N that contains the count of the values in the SamplingWindow. The computed property must be requested in the list of properties.

Timespan to wait before declaring a sampling windows as closed. This let's callers trade off latency for correct sampling in case of delays from external sources. The cooldown period is started when the first value for a sampling window is received, even if the the timestamp of that value is far in the past or in the future; this allows for clock drift between systems or processing of historical data.

If false, a storage mirror containing TheThingStore instances will be created with default storage mirror configurations, or HistoryStoreParameters if specified. The store can be retrieved using the GetHistoryStore method. If true, a custom storage mirror needs to be created by the caller and passed to RegisterForUpdateHistory/RestartUpdateHistory. The custom storage mirror can contain instances of any class (derived from TheMetaBase) and property values will be set using reflection (class property names must match the thing property names, missing properties are ignored).

If MaintainHistoryStore is true and ExternalHistoryStore is false, these parameters are used to create the storage mirror to receive history entries.

By default any available history will be returned. IgnoreExistingHistory = true returns only updates that arrive after the registration

If false, history entries will be recorded internally and can only be retrieved via calls to GetThingHistory: this option is used primarily in conjunction with ClearHistory/RestartUpdateHistory for processing or transmitting streams of property changes with at least once delivery guarantees. If true, history entries will be recorded into a storage mirror that can be consumed directly by plug-ins. Calls to GetThingHistory will return null.

Timespan for which to keep items in the history store. Items with timestamps older the the current time minus the MaxAge will be deleted (lazily). TimeSpan.Zero mean no expiration.

Maximum number if history items to keep. 0 means no limit on item count.

Friendly Name of the consumer, for diagnostics purposes. This name will also be used as part of the file name of any buffers/stores

The Thing that owns this history registration: used for diagnostics/management purposes and cleaning up registration when things are deleted

The cdeMID of a TheThing that owns this history registration: used for diagnostics/management purposes and cleaning up registration when things are deleted

Keep history items across restarts of the C-DEngine host. All changes to the thing during shutdown and startup will be recorded.

List of properties for which changes are to be recorded. If null, changes for all properties of the thing will be recorded. If empty, no changes will be recorded.

List of properties for which changes are not to be recorded. Typically used in conjunction with Properties == null.

If true, the current values for the properties at the time of registration will be returned before any property updates

If true, each history entry will contain all property values (as per the Properties/PropertiesToExclude parameters) as current at the end of the sample window, regardless if they were updated or not. If false, only changed properties will be included in history entries.

Timespan over which property changes are to be sampled or aggregated. At most one history entry per sampling window is generated.

If the token is not accessed for this time, it will be deleted and become invalid