pem.getResourceUsageForPeriod

This method is supported by Operations starting from version 2.3.

This method returns usage statistics for Resource Types within the specified Subscription for a given period of time. It is complimentary to the pem.getResourceUsage method.

The method has the following input parameters:

Name	Type	Short Description
`subscription_id`	int	ID of Subscription. It indicates the Subscription the resource usage is returned for.
`resource_type_ids`	array of int	IDs of Resource Types in request.
`from_time`	int	It indicates the start time of the period the resource usage is returned for. Must be specified in the number of seconds since 1970-01-01 00:00:00 UTC (Unix time format).
`to_time`	int	It indicates the end time of the period the resource usage is returned for. Must be specified in the number of seconds since 1970-01-01 00:00:00 UTC (Unix time format).

The method has the following output parameters:

Name	Type	Short Description
`resource_type_usages`	array of struct	It contains resource usages for each requested Resource Type.
`usage_statistics`	struct	The usage statistics for Resource Type identified by the `resource_type_id` parameter.
`n/a`	array of struct	It contains the information on changes of resource's usage.
`delta`	int	It contains the actual change of the resource’s usage. The value of the change may be negative depending on the Resource Type.
`delta64`	bigint	64bit analog of the `delta` parameter.
`time`	int	It indicates the point in time when the usage of the resource was changed. It is specified in the number of seconds since 1970-01-01 00:00:00 UTC (Unix time format).
`parent_resource_type_id`	int	It indicates the parent Resource Type of the Resource Type the usage statistics is returned for. This value can be used to group usage statistics for related Resource Types.
`initial_usage`	int	It represents the absolute value of resource’s usage at the start of the requested period. The usage is specified in units the Resource Type is measured in.
`resource_type_id`	int	It indicates the Resource Type the usage statistics is returned for.
`initial_usage64`	bigint	64bit analog of the `initial_usage` parameter.
`actual_period`	struct	It indicates the actual period the resource usages are returned for. For the description of what the actual period is, see the note below.
`from_time`	int	It indicates the actual start time of the period the resource usages are returned for. It is specified in the number of seconds since 1970-01-01 00:00:00 UTC (Unix time format).
`to_time`	int	It indicates the actual end time of the period the resource usages are returned for. It is specified in the number of seconds since 1970-01-01 00:00:00 UTC (Unix time format).

Note: The caller may request usage statistics for a period of time for which there are no statistics in the system at all or there exist statistics for a part of the requested period only. The actual_period returned parameter serves the purposes to address such situations. Depending on the values of input from_time and to_time parameters and the period of time for which the statistics exist in the system, the actual_period returned parameter can take values described in the table below.

	from_time in history & to_time in history	from_time in history & to_time > history_end	from_time > history_end & to_time > history_end
`actual_period`
`from_time`	from_time	from_time	history_end
`to_time`	to_time	history_end	history_end

from_time in history

to_time in history

from_time in history

to_time > history_end

from_time > history_end

to_time > history_end

actual_period

from_time

from_time

history_end

to_time

to_time

history_end

Here "history_end" represents the point time when the given request for statistics is served (current time at callee side). "in history" means point in time that is earlier than "history_end".