Merge pull request #219199 from KennedyDMSFT/T2010338

November freshness review (5/8)

Author: v-regandowner

articles/iot-hub/iot-hub-scaling.md

@@ -6,19 +6,19 @@ manager: timlt
 ms.service: iot-hub
 services: iot-hub
 ms.topic: conceptual
-ms.date: 06/28/2019
+ms.date: 11/21/2022
 ms.author: kgremban
 ms.custom: [amqp, mqtt, 'Role: Cloud Development', 'Role: Operations']
 ---
 # Choose the right IoT Hub tier for your solution
 
-Every IoT solution is different, so Azure IoT Hub offers several options based on pricing and scale. This article is meant to help you evaluate your IoT Hub needs. For pricing information about IoT Hub tiers, see [IoT Hub pricing](https://azure.microsoft.com/pricing/details/iot-hub).
+Every IoT solution is different, so Azure IoT Hub offers several options based on pricing and scale. This article is meant to help you evaluate your IoT Hub needs. For pricing information about IoT Hub tiers, see [Azure IoT Hub pricing](https://azure.microsoft.com/pricing/details/iot-hub).
 
 To decide which IoT Hub tier is right for your solution, ask yourself two questions:
 
 **What features do I plan to use?**
 
-Azure IoT Hub offers two tiers, basic and standard, that differ in the number of features they support. If your IoT solution is based around collecting data from devices and analyzing it centrally, then the basic tier is probably right for you. If you want to use more advanced configurations to control IoT devices remotely or distribute some of your workloads onto the devices themselves, then you should consider the standard tier. For a detailed breakdown of which features are included in each tier continue to [Basic and standard tiers](#basic-and-standard-tiers).
+Azure IoT Hub offers two tiers, basic and standard, that differ in the number of features they support. If your IoT solution is based around collecting data from devices and analyzing it centrally, then the basic tier is probably right for you. If you want to use more advanced configurations to control IoT devices remotely or distribute some of your workloads onto the devices themselves, then you should consider the standard tier. For a detailed breakdown of which features are included in each tier, continue to [Basic and standard tiers](#basic-and-standard-tiers).
 
 **How much data do I plan to move daily?**
 
@@ -28,9 +28,9 @@ Each IoT Hub tier is available in three sizes, based around how much data throug
 
 The standard tier of IoT Hub enables all features, and is required for any IoT solutions that want to make use of the bi-directional communication capabilities. The basic tier enables a subset of the features and is intended for IoT solutions that only need uni-directional communication from devices to the cloud. Both tiers offer the same security and authentication features.
 
-Only one type of [edition](https://azure.microsoft.com/pricing/details/iot-hub/) within a tier can be chosen per IoT Hub. For example, you can create an IoT Hub with multiple units of S1, but not with a mix of units from different editions, such as S1 and S2.
+Only one type of [IoT Hub edition](https://azure.microsoft.com/pricing/details/iot-hub/) within a tier can be chosen per IoT hub. For example, you can create an IoT hub with multiple units of S1. However, you can't create an IoT hub with a mix of units from different editions, such as S1 and B3 or S1 and S2.
 
-| Capability | Basic tier | Free/Standard tier |
+| Capability | Basic tier | Standard/Free tier |
 | ---------- | ---------- | ------------- |
 | [Device-to-cloud telemetry](iot-hub-devguide-messaging.md) | Yes | Yes |
 | [Per-device identity](iot-hub-devguide-identity-registry.md) | Yes | Yes |
@@ -39,18 +39,18 @@ Only one type of [edition](https://azure.microsoft.com/pricing/details/iot-hub/)
 | [Device Provisioning Service](../iot-dps/about-iot-dps.md) | Yes | Yes |
 | [Monitoring and diagnostics](monitor-iot-hub.md) | Yes | Yes |
 | [Cloud-to-device messaging](iot-hub-devguide-c2d-guidance.md) |   | Yes |
-| [Device twins](iot-hub-devguide-device-twins.md), [Module twins](iot-hub-devguide-module-twins.md), and [Device management](iot-hub-device-management-overview.md) |   | Yes |
+| [Device twins](iot-hub-devguide-device-twins.md), [module twins](iot-hub-devguide-module-twins.md), and [device management](iot-hub-device-management-overview.md) |   | Yes |
 | [Device streams (preview)](iot-hub-device-streams-overview.md) |   | Yes |
 | [Azure IoT Edge](../iot-edge/about-iot-edge.md) |   | Yes |
 | [IoT Plug and Play](../iot-develop/overview-iot-plug-and-play.md) |   | Yes |
 
-IoT Hub also offers a free tier that is meant for testing and evaluation. It has all the capabilities of the standard tier, but limited messaging allowances. You cannot upgrade from the free tier to either basic or standard.
+IoT Hub also offers a free tier that is meant for testing and evaluation. It has all the capabilities of the standard tier, but includes limited messaging allowances. You can't upgrade from the free tier to either the basic or standard tier.
 
 ## Partitions
 
-Azure IoT Hubs contain many core components of [Azure Event Hubs](../event-hubs/event-hubs-features.md), including [Partitions](../event-hubs/event-hubs-features.md#partitions). Event streams for IoT Hubs are generally populated with incoming telemetry data that is reported by various IoT devices. The partitioning of the event stream is used to reduce contentions that occur when concurrently reading and writing to event streams.
+Azure IoT hubs contain many core components from [Azure Event Hubs](../event-hubs/event-hubs-features.md), including [partitions](../event-hubs/event-hubs-features.md#partitions). Event streams for IoT hubs are populated with incoming telemetry data that is reported by various IoT devices. The partitioning of the event stream is used to reduce contentions that occur when concurrently reading and writing to event streams.
 
-The partition limit is chosen when IoT Hub is created, and cannot be changed. The maximum partition limit for basic tier IoT Hub and standard tier IoT Hub is 32. Most IoT hubs only need 4 partitions. For more information on determining the partitions, see the Event Hubs FAQ [How many partitions do I need?](../event-hubs/event-hubs-faq.yml#how-many-partitions-do-i-need-)
+The partition limit is chosen when an IoT hub is created, and can't be changed. The maximum limit of device-to-cloud partitions for basic tier and standard tier IoT hubs is 32. Most IoT hubs only need four partitions. For more information on determining the partitions, see the [How many partitions do I need?](../event-hubs/event-hubs-faq.yml#how-many-partitions-do-i-need-) question in the [FAQ](../event-hubs/event-hubs-faq.yml) for [Azure Event Hubs](../event-hubs/index.yml).
 
 ## Tier upgrade
 
@@ -59,13 +59,13 @@ Once you create your IoT hub, you can upgrade from the basic tier to the standar
 The partition configuration remains unchanged when you migrate from basic tier to standard tier.
 
 > [!NOTE]
-> The free tier does not support upgrading to basic or standard.
+> The free tier does not support upgrading to basic or standard tier.
 
 ## IoT Hub REST APIs
 
-The difference in supported capabilities between the basic and standard tiers of IoT Hub means that some API calls do not work with basic tier hubs. The following table shows which APIs are available:
+The difference in supported capabilities between the basic and standard tiers of IoT Hub means that some API calls don't work with basic tier IoT hubs. The following table shows which APIs are available:
 
-| API | Basic tier | Free/Standard tier |
+| API | Basic tier | Standard/Free tier |
 | --- | ---------- | ------------- |
 | [Delete device](/javascript/api/azure-iot-digitaltwins-service/registrymanager#azure-iot-digitaltwins-service-registrymanager-deletedevice) | Yes | Yes |
 | [Get device](/rest/api/iothub/service/devices/get-identity) | Yes | Yes |
@@ -107,7 +107,13 @@ The best way to size an IoT Hub solution is to evaluate the traffic on a per-uni
 * Cloud-to-device messages
 * Identity registry operations
 
-Traffic is measured for your IoT hub on a per-unit basis. When you create an IoT hub, you choose its tier and edition, and set the number of units available. You can purchase up to 200 units for the B1, B2, S1, or S2 edition, or up to 10 units for the B3 or S3 edition. After your IoT hub is created, you can change the number of units available within its edition, upgrade or downgrade between editions within its tier (B1 to B2), or upgrade from the basic to the standard tier (B1 to S1) without interrupting your existing operations. For more information, see [How to upgrade your IoT hub](iot-hub-upgrade.md).  
+Traffic is measured for your IoT hub on a per-unit basis. When you create an IoT hub, you choose its tier and edition, and set the number of units available. You can purchase up to 200 units for the B1, B2, S1, or S2 edition, or up to 10 units for the B3 or S3 edition. After you create your IoT hub, without interrupting your existing operations, you can:
+
+- Change the number of units available within its edition (for example, upgrading from one to three units of B1)
+- Upgrade or downgrade between editions within its tier (for example, upgrading from B1 to B2)
+- Upgrade from the basic to the standard tier (for example, upgrading from B1 to S1)
+ 
+For more information, see [How to upgrade your IoT hub](iot-hub-upgrade.md).  
 
 As an example of each tier's traffic capabilities, device-to-cloud messages follow these sustained throughput guidelines:
 
@@ -117,20 +123,20 @@ As an example of each tier's traffic capabilities, device-to-cloud messages foll
 | B2, S2 |Up to 16 MB/minute per unit<br/>(22.8 GB/day/unit) |Average of 4,167 messages/minute per unit<br/>(6 million messages/day per unit) |
 | B3, S3 |Up to 814 MB/minute per unit<br/>(1144.4 GB/day/unit) |Average of 208,333 messages/minute per unit<br/>(300 million messages/day per unit) |
 
-Device-to-cloud throughput is only one of the metrics you need to consider when designing an IoT solution. For more comprehensive information, see [IoT Hub quotas and throttles](iot-hub-devguide-quotas-throttling.md).
+Device-to-cloud throughput is only one of the metrics you need to consider when designing an IoT solution. For more comprehensive information, see [IoT Hub quotas and throttling](iot-hub-devguide-quotas-throttling.md).
 
 ### Identity registry operation throughput
 
-IoT Hub identity registry operations are not supposed to be run-time operations, as they are mostly related to device provisioning.
+IoT Hub identity registry operations aren't supposed to be run-time operations, as they're mostly related to device provisioning.
 
-For specific burst performance numbers, see [IoT Hub quotas and throttles](iot-hub-devguide-quotas-throttling.md).
+For more information about specific burst performance numbers, see [IoT Hub quotas and throttling](iot-hub-devguide-quotas-throttling.md).
 
 ## Auto-scale
 
-If you are approaching the allowed message limit on your IoT hub, you can use these [steps to automatically scale](https://azure.microsoft.com/resources/samples/iot-hub-dotnet-autoscale/) to increment an IoT Hub unit in the same IoT Hub tier.
+If you're approaching the allowed message limit on your IoT hub, you can use these [steps to automatically scale](https://azure.microsoft.com/resources/samples/iot-hub-dotnet-autoscale/) to increment an IoT Hub unit in the same IoT Hub tier.
 
 ## Next steps
 
-* For more information about IoT Hub capabilities and performance details, see [IoT Hub pricing](https://azure.microsoft.com/pricing/details/iot-hub) or [IoT Hub quotas and throttles](iot-hub-devguide-quotas-throttling.md).
+* For more information about IoT Hub capabilities and performance details, see [Azure IoT Hub pricing](https://azure.microsoft.com/pricing/details/iot-hub) or [IoT Hub quotas and throttling](iot-hub-devguide-quotas-throttling.md).
 
-* To change your IoT Hub tier, follow the steps in [Upgrade your IoT hub](iot-hub-upgrade.md).
+* To change your IoT Hub tier, follow the steps in [How to upgrade your IoT hub](iot-hub-upgrade.md).