updated cloud durability doc with PR feedback

content/influxdb/cloud/reference/internals/durability.md

@@ -1,8 +1,8 @@
 ---
 title: InfluxDB Cloud data durability
 description: >
-  InfluxDB Cloud ensures the durability of all stored data by automatically creating
-  backups, replicating data across geographic locations, and verifying replicated
+  InfluxDB Cloud ensures the durability of all stored data by replicating data across
+  geographic locations, automatically creating backups, and verifying that replicated
   data is consistent and backups are readable.
 weight: 101
 menu:
@@ -12,32 +12,42 @@ menu:
 influxdb/cloud/tags: [backups, internals]
 ---
 
-InfluxDB Cloud ensures the durability of all stored data by automatically creating
-backups, replicating data across geographic locations, and verifying replicated
+InfluxDB Cloud ensures the durability of all stored data by replicating data across
+geographic locations, automatically creating backups, and verifying that replicated
 data is consistent and backups are readable.
 
 ##### On this page
 
+- [Data replication](#data-replication)
 - [Backup processes](#backup-processes)
 - [Recovery](#recovery)
 - [Data verification](#data-verification)
 
+## Data replication
+InfluxDB Cloud replicates data in both the write tier and in the storage tier.
+
+- **Write tier:** all data written to InfluxDB is processed by a durable message queue.
+  The message queue partitions each batch of points and then replicates each partition
+  across other physical nodes in the message queue cluster.
+- **Storage tier:** All data in the storage tier is replicated across two geographic locations.
+
 ## Backup processes
-InfluxDB Cloud stores **two out-of-band backup copies** of all data.
-The following processes each generate backups:
+InfluxDB Cloud backs up all data in the following way:
 
 - [Backup on write](#backup-on-write)
 - [Backup after compaction](#backup-after-compaction)
 
 ### Backup on write
-All inbound write requests to InfluxDB Cloud queue in a durable message queue.
-The message queue stores the raw [line protocol](/influxdb/cloud/reference/glossary/#line-protocol)
-of each write request in an object storage location as an out-of-band backup.
-The message queue also writes data to the live storage service, replicates it twice
-across two geographic locations, and makes it available to the InfluxDB Cloud service.
+All inbound write requests to InfluxDB Cloud are added to a durable message queue.
+The message queue caches the raw [line protocol](/influxdb/cloud/reference/glossary/#line-protocol)
+of each write request before writing the data to the storage tier.
+The queue then routinely persists the cache to an object storage location as an out-of-band backup.
+Message queue backups provide raw line protocol that can be used to recover from
+catastrophic failure in the storage tier or an accidental deletion.
 
-The durability of the message queue is 72 hours, meaning InfluxDB Cloud can sustain
-a failure of its underlying storage tier or object storage services for up to 72 hours.
+The durability of the message queue is 96 hours, meaning InfluxDB Cloud can sustain
+a failure of its underlying storage tier or object storage services for up to 96 hours
+without any data loss.
 
 To minimize potential data loss due to defects introduced within the broader InfluxDB Cloud service,
 InfluxData minimizes code between the data ingest and backup processes.
@@ -58,12 +68,12 @@ InfluxDB Cloud uses out-of-band backups stored in object storage to recover data
 The Recovery Point Objective (RPO) is any accepted write.
 The Recovery Time Objective (RTO) is harder to definitively predict as potential failure modes can vary.
 While most common failure modes can be resolved within minutes or hours,
-catastrophic or extreme failure modes may take longer.
+critical failure modes may take longer.
 For example, if we need to rebuild all data from the message queue backup,
 it could take 24 hours or longer.
 
 ## Data verification
-InfluxDB Cloud has two data verification services running 24x7:
+InfluxDB Cloud has two data verification services running at all times:
 
 - **Entropy detection:** ensures that replicated data is consistent
 - **Backup verification:** validates and ensures backups in object storage are readable