Update readme with details about archive

And clean up option description for archive values in example
config.

README.md

@@ -33,6 +33,15 @@ layer. These include **`setup_adapter`**, **`load_defaults`**, and
 **`get_usage_data`**. Details about these hookspecs are found in
 [hookspecs.py](https://github.com/SUSE-Enceladus/csp-billing-adapter/blob/main/csp_billing_adapter/hookspecs.py).
 
+### Archive layer
+
+There are three hookspecs for retrieving and persisting the metering
+archive to stateful storage. A plugin implementing the hooks for
+the archive layer is required for the archive functionality to work.
+The hooks include **`get_archive_location`**, **`get_metering_archive`**,
+**`save_metering_archive`**. Details can be found in
+[archive_hookspecs.py](https://github.com/SUSE-Enceladus/csp-billing-adapter/blob/data-archive/csp_billing_adapter/archive_hookspecs.py).
+
 ## Configuration
 
 The adapter is configured via a YAML file that is accesible to the
@@ -47,6 +56,8 @@ api: THE_PATH_WHERE_WE_GET_THE_UNIT_INFORMATION
 billing_interval: monthly|hourly
 query_interval: Time in seconds
 product_code: TBD
+archive_retention_period: 6
+archive_bytes_limit: 1048576
 usage_metrics:
   metric_1:
     usage_aggregation: maximum
@@ -185,6 +196,41 @@ timestamp that denotes when the usage record was reported and
 **dimensions:** A dictionary containing the dimension names and units
 billed in the last metering.
 
+### Archive
+
+This is the metering and usage records archive. It contains a list of
+metering records with the relevent usage data, billing status, and
+timestamps. The format is as follows:
+
+```
+[
+  {
+        'billing_time': 'string(date timestamp)',
+        'billing_status': {
+            '{usage_key}': {
+                'record_id': string,
+                'status': 'succeeded'
+            }
+        },
+        'billed_usage': {
+            '{usage_key}': int
+        },
+        'usage_records': [
+            {
+                '{usage_metric}': int,
+                'reporting_time': 'string(date timestamp)',
+                'base_product': 'cpe:/o:suse:product:v1.2.3'
+            }
+        ]
+    }
+]
+```
+
+**billing_time:** A timestamp denoting when the metering record was submitted.
+**billing_status:** A dictionary of the dimensions billed and billing status.
+**billed_usage:** A dicitonary of the usage incurred during the billing cycle per dimension.
+**usage_records:** A list of all the usage records logged during the billing period.
+
 ## Service
 
 The adapter service runs continuously based on the query interval which is

examples/README.md

@@ -31,10 +31,10 @@ reporting_interval:
     Sets the time in seconds when the csp-billing-adapter reports to the CSP API. The values the csp-billing-adapter reports are determined by a combination of the settings for `reporting_api_is_cumulative` and `billing_interval`.
 
 archive_retention_period:
-    Sets the time in months that meterings and usage records are retained in the data archive.
+    Sets the time in billing cycles that meterings and usage records are retained in the data archive. For example when the billing period is is in months a value of 6 will retain 6 months of records. If the value is set to 0 the archive functionality will be disabled.
 
 archive_bytes_limit:
-    Sets the max size in bytes for the metering archive. The archive will be trimmed to stay below this limit.
+    Sets the max size in bytes for the metering archive. The archive will be trimmed to stay below this limit. To disable the bytes limit set the value to -1. To disable the archive functionality set the value to 0.
 
 usage_metrics: