Acrolynx

Author: spelluru

articles/event-grid/availability-zones-disaster-recovery.md

@@ -22,41 +22,41 @@ Event Grid resource definitions for topics, system topics, domains, and event su
 
 When an Azure region experiences a prolonged outage, you might be interested in failover options to an alternate region for business continuity. Many Azure regions have geo-pairs, and some don't. For a list of regions that have paired regions, see [Azure cross-region replication pairings for all geographies](../availability-zones/cross-region-replication-azure.md#azure-paired-regions). 
 
-For regions with a geo-pair, Event Grid offers a capability to fail over the publishing traffic to the paired region for custom topics, system topics, and domains. Behind the scenes, Event Grid automatically synchronizes resource definitions of topics, system topics, domains, and event subscriptions to the paired region. However, event data isn't replicated to the paired region. In the normal state, events are stored in the region you selected for that resource. When there's a region outage and Microsoft initiates the failover, new events will begin to flow to the geo-paired region and are dispatched from there with no intervention from you. Events published and accepted in the original region are dispatched from there after the outage is mitigated. 
+For regions with a geo-pair, Event Grid offers a capability to fail over the publishing traffic to the paired region for custom topics, system topics, and domains. Behind the scenes, Event Grid automatically synchronizes resource definitions of topics, system topics, domains, and event subscriptions to the paired region. However, event data isn't replicated to the paired region. In the normal state, events are stored in the region you selected for that resource. When there's a region outage and Microsoft initiates the failover, new events begin to flow to the geo-paired region and are dispatched from there with no intervention from you. Events published and accepted in the original region are dispatched from there after the outage is mitigated. 
 
 Microsoft-initiated failover is exercised by Microsoft in rare situations to fail over Event Grid resources from an affected region to the corresponding geo-paired region. Microsoft reserves the right to determine when this option will be exercised. This mechanism doesn't involve a user consent before the user's traffic is failed over.
 
-You can enable or disable this functionality by updating the configuration for your topic or domain. Select **Cross-Geo** option (default) to enable Microsoft-initiated failover and **Regional** to disable it. For detailed steps to configure this setting, see [Configure data residency](configure-custom-topic.md#configure-data-residency). If you opt for "regional", no data of any kind is replicated to another region by Microsoft, and you may define your own disaster recovery plan. For more information, see Build your own disaster recovery plan for Azure Event Grid topics and domains. 
+You can enable or disable this functionality by updating the configuration for your topic or domain. Select **Cross-Geo** option (default) to enable Microsoft-initiated failover and **Regional** to disable it. For detailed steps to configure this setting, see [Configure data residency](configure-custom-topic.md#configure-data-residency). If you opt for regional, no data of any kind is replicated to another region by Microsoft, and you can define your own disaster recovery plan. For more information, see Build your own disaster recovery plan for Azure Event Grid topics and domains. 
 
 :::image type="content" source="./media/availability-zones-disaster-recovery/configuration-page.png" alt-text="Screenshot showing the Configuration page for an Event Grid custom topic.":::
 
-Here are a few reasons why you may want to disable the Microsoft-initiated failover feature: 
+Here are a few reasons why you want to disable the Microsoft-initiated failover feature: 
 
 - Microsoft-initiated failover is done on a best-effort basis. 
-- Some geo pairs may not meet your organization's data residency requirements. 
+- Some geo pairs don't meet your organization's data residency requirements. 
 
 In such cases, the recommended option is to build your own disaster recovery plan for Azure Event Grid topics and domains. While this option requires a bit more effort, it enables faster failover, and you are in control of choosing secondary regions. If you want to implement client-side disaster recovery for Azure Event Grid topics, see [Build your own client-side disaster recovery for Azure Event Grid topics](custom-disaster-recovery-client-side.md). 
 
 ## RTO and RPO
 
 Disaster recovery is measured with two metrics:
 
-- Recovery Point Objective (RPO): the minutes or hours of data that may be lost.
-- Recovery Time Objective (RTO): the minutes or hours the service may be down.
+- Recovery Point Objective (RPO): the minutes or hours of data that might be lost.
+- Recovery Time Objective (RTO): the minutes or hours the service might be down.
 
-Event Grid’s automatic failover has different RPOs and RTOs for your metadata (topics, domains, event subscriptions.) and data (events). If you need different specification from the following ones, you can still implement your own client-side failover using the topic health apis.
+Event Grid’s automatic failover has different RPOs and RTOs for your metadata (topics, domains, event subscriptions) and data (events). If you need different specification from the following ones, you can still implement your own client-side failover using the topic health APIs.
 
 ### Recovery point objective (RPO)
 
 - **Metadata RPO**: zero minutes. For applicable resources, when a resource is created/updated/deleted, the resource definition is synchronously replicated to the geo-pair. When a failover occurs, no metadata is lost.
 
-- **Data RPO**: When a failover occurs, new data is processed from the paired region. As soon as the outage is mitigated for the affected region, the unprocessed events will be dispatched from there. If the region recovery required longer time than the [time-to-live](delivery-and-retry.md#dead-letter-events) value set on events, the data could get dropped. To mitigate this data loss, we recommend that you [set up a dead-letter destination](manage-event-delivery.md) for an event subscription. If the affected region is completely lost and non-recoverable, there will be some data loss. In the best-case scenario, the subscriber is keeping up with the publish rate and only a few seconds of data is lost. The worst-case scenario would be when the subscriber isn't actively processing events and with a max time to live of 24 hours, the data loss can be up to 24 hours.
+- **Data RPO**: When a failover occurs, new data is processed from the paired region. As soon as the outage is mitigated for the affected region, the unprocessed events are dispatched from there. If the region recovery required longer time than the [time-to-live](delivery-and-retry.md#dead-letter-events) value set on events, the data could get dropped. To mitigate this data loss, we recommend that you [set up a dead-letter destination](manage-event-delivery.md) for an event subscription. If the affected region is lost and nonrecoverable, there will be some data loss. In the best-case scenario, the subscriber is keeping up with the publishing rate and only a few seconds of data is lost. The worst-case scenario would be when the subscriber isn't actively processing events and with a max time to live of 24 hours, the data loss can be up to 24 hours.
 
 ### Recovery time objective (RTO)
 
-- **Metadata RTO**: Failover decision making is based on factors like available capacity in paired region and can last in the range of 60 minutes or more. Once failover is initiated, within 5 minutes, Event Grid will begin to accept create/update/delete calls for topics and subscriptions.
+- **Metadata RTO**: Failover decision making is based on factors like available capacity in paired region and can last in the range of 60 minutes or more. Once failover is initiated, within 5 minutes, Event Grid begins to accept create/update/delete calls for topics and subscriptions.
 
-- **Data RTO**: Same as above.
+- **Data RTO**: Same as above information.
 
 > [!IMPORTANT]
 > - In case of server-side disaster recovery, if the paired region has no extra capacity to take on the additional traffic, Event Grid cannot initiate failover. The recovery is done on a best-effort basis.