投稿時間:2022-01-27 01:33:42 RSSフィード2022-01-27 01:00 分まとめ(36件)

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python	Pythonタグが付けられた新着投稿 - Qiita	【Django】IIS 利用時に python を all users でインストールしなかった場合の対処	https://qiita.com/tsk1000/items/62791d124b74a8d9fee4		2022-01-27 00:47:34
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python	Pythonタグが付けられた新着投稿 - Qiita	データ解析のための統計モデリング入門 7章 教科書中の図をPythonで再現してみた	https://qiita.com/shinji_komine/items/89932a2607912d7f6d13	GLMMの分布を確認する個体差をモデル化して二項分布と混合することで、生存種子数の分布がどのように変化するのかを確認します。	2022-01-27 00:10:23
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海外TECH	Ars Technica	European court overturns 12-year-old €1.06 billion fine against Intel	https://arstechnica.com/?p=1828496	intel	2022-01-26 15:12:35
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海外TECH	DEV Community	1 line of code: How to reverse all words of a string	https://dev.to/martinkr/1-line-of-code-how-to-reverse-all-words-of-a-string-n26	line of code How to reverse all words of a stringconst reverseWords str gt str split map word gt word reverse join join Returns the string with all words reversed The repository amp npm packageYou can find the all the utility functions from this series at github com martinkr onelinecodeThe library is also published to npm as onelinecode for your convenience The code and the npm package will be updated every time I publish a new article Follow me on Twitter martinkr and consider to buy me a coffeePhoto by zoo monkey on Unsplash	2022-01-26 15:40:55
海外TECH	DEV Community	Designing MQTT Topics for AWS IoT Core | AWS White Paper Summary	https://dev.to/awsmenacommunity/designing-mqtt-topics-for-aws-iot-core-aws-white-paper-summary-pkm	Designing MQTT Topics for AWS IoT Core AWS White Paper SummaryThis whitepaper focuses on best practices for MQTT topic design in Amazon Web Services AWS Internet of Things IoT It covers how developing an optimal MQTT topic schema can improve the overall architecture and efficiency of your IoT solutions It does so by providing greater visibility into cloud to device communication providing more fine grained security permissions and enhancing integration options with other AWS IoT Core services such as the AWS IoT Rules Engine AWS IoT Device Shadow AWS IoT Device Management and AWS IoT Analytics This whitepaper is intended for technical architects IoT cloud engineers and application architects This paper assumes that the reader understands fundamental MQTT concepts and terminology IntroductionAWS IoT Core supports Message Queuing Telemetry Transport MQTT a widely adopted lightweight messaging protocol designed for constrained devices MQTT participants receive information organized through MQTT topics An MQTT topic acts as a matching mechanism between publishers and subscribers Conceptually an MQTT topic behaves like an ephemeral notification channel For AWS IoT one of the first considerations when using MQTT is the design strategy of your MQTT topics MQTT topics must balance current device communications cloud side operations and future device capabilities Therefore it can be challenging to design an ideal MQTT topic structure that creates enough of a schema to enforce least privilege communication but does not create a rigid structure that makes it challenging to support future device deployments This document provides you with MQTT topic design best practices and guidance It outlines a set of commonly used MQTT topic structures that can be implemented to solve various device message patterns then applies several example design patterns using different AWS IoT services MQTT communication patternsIoT applications support multiple communication scenarios such as device to device device to cloud cloud to device and device to or from users Although the range of patterns can significantly vary a majority of MQTT communication models derive from three MQTT patterns point to point broadcast and fan in Point to pointA point to point communication pattern is one of the basic building blocks of how devices commonly send and receive messages in MQTT Two devices use a single MQTT topic as the communication channel The device that receives the event subscribes to an MQTT topic The thing that sends the message publishes to the same known MQTT topic This approach is common in smart home scenarios where an end user receives updates about the thing in the home In the following example the room occupancy publishes a message on a topic subscribed to by an application running on the digital display outside the screening room One to one messaging in point to point communicationPoint to point communication is not limited to one to one communication between devices Point to point is also used in one to many communication where a single publisher can publish to individual devices using a different MQTT topic per device This approach is common in notification scenarios where an administrator sends distinct updates to specific devices In the following example the repair service uses a set of point to point communications to programmatically loop through a list of appliances and publish a message One to many messaging in point to point communication BroadcastBroadcast patterns are used for one to many messaging The broadcast pattern sends the same message to a large fleet of devices In a broadcast multiple devices subscribe to the same MQTT topic and the sender publishes a message to that topic A typical use of a broadcast pattern is to send a notification to devices based on the category or group of the device For example a weather station transmits a broadcast message based on a topic based on its geolocation The following illustration depicts an example where a broadcast pattern sends a message on a weather topic that all delivery vehicles in the state subscribe to The message includes weather conditions and detailed location coordinates Based on the current location of the vehicle it can ignore the message or take some action One to many messaging in broadcast communication Fan InThe fan in pattern is a many to one communication pattern and can be thought of as the reverse of the broadcast pattern Multiple devices publish on a shared or similar topic with a single subscriber to that topic With the fan in pattern the subscriber may use wildcards as the publishers all use a similar but unique MQTT topics The fan in pattern is commonly used to aggregate telemetry data In the following example each device publishes to an MQTT topic containing a known group identifier The AWS IoT Rules Engine uses a wildcard subscription to receive the messages and route them to an Amazon Kinesis stream Specifically the air quality sensors publish on a fan in topic associated with a specific building LAX The administrative system receives all updates for the building using an MQTT wildcard Rule Select environment building lax airqual Many to one communication in a fan in patternWhen devices communicate via the cloud using MQTT avoid using the fan in pattern to a single subscribing end device because this routing may hit a non adjustable limit on a single device MQTT connection Instead use the fan in pattern to route a large fleet of messages to your IoT application via the AWS IoT Rules Engine For large scale fan in scenarios combine the Rules Engine with a wildcard subscription pattern and a Rules Engine action to route to Amazon Kinesis Data Streams Amazon Kinesis Data Firehose or Amazon Simple Queue Service Amazon SQS Communication workflowsThe three common communication workflows are device to device device to cloud and cloud to device Each workflow determines the topic structure of topic hierarchy In the case of device to device MQTT topics should contain identifiers for either the sender or receiver of a message For device to cloud MQTT messages should include information about the target application The target application is responsible for augmenting any MQTT messages with internal metadata about the device Last for cloud to device communication MQTT messages should contain session information for tracking acknowledgment of any critical messages MQTT design best practices General best practicesAlthough there are numerous combinations of IoT communication patterns that share common approaches there are several best practices that apply to any message pattern irrespective of how a device is publishing or receiving a message This section articulates several overall best practices for you to review and implement as you design your MQTT topic structures Review the AWS IoT Core default service limits Design your communication pattern so that it aligns with any adjustable IoT service limits AWS IoT has several adjustable and non adjustable limits associated with using the AWS IoT Core service As part of your topic review review the AWS IoT limits and ensure your MQTT topic and device communication do not conflict with any service limits The maximum number of forward slashes in the MQTT topic name for AWS IoT Core is seven You should not prefix the topic with a forward slash as it counts towards the topic levels and may introduce confusion when building AWS IoT policies This excludes the first three slashes in the mandatory segments for Basic Ingest topics AWS rules rule name The topic passed to AWS IoT Core when sending a publish request can be no larger than bytes of UTF encoded characters This excludes the first three mandatory segments for Basic Ingest topics AWS rules rule name Define a consistent naming standard for MQTT topic levels Since MQTT topics are case sensitive it is important to use a standard set of naming conventions when designing MQTT topics For this reason customers should only use lowercase letters numbers and dashes when creating each topic level Customers should avoid camel casing and using hard to debug characters such as spaces Publish Topic names cannot contain wildcards Topics that start with are reserved by AWS IoT Core They are not supported for publishing and subscribing except for using the specific topic names defined by AWS IoT Core services for example the AWS IoT Device Shadow service Ensure MQTT topic levels structure follows a general to specific pattern As topic scheme flows left to right the topic levels flow general to specific For example an HVAC system is associated with an IoT platform named hv is located in the basement of building bld and has a Thing Name of hvac The topic structure begins with the general group in this case the name of the IoT platform and ends with the most specific identity the Thing Name This example creates the following topic level structure Include any relevant routing information in the MQTT topic Relevant routing information includes but is not limited to the IoT application identifier any groups the device may be a part of such as installed location and the unique identity of your IoT device To continue with the previous HVAC system example the MQTT topic hv bld basement hvac includes all relevant routing information Based on this MQTT topic you can design a system that captures any data related to the entire application using the identifier hv but also can target different areas of interest for subscribing to messages such as the building location Prefix your MQTT topics to distinguish data topics from command topics Make sure that your MQTT topics do not overlap between commands and data messages By reserving the first topic level to denote data and command topics you are more easily able to create fine grained permissions using IoT policies and monitor the status of commands and command responses separately from passive telemetry commands For example use the AWS IoT Device Shadow service for tracking reported and desired states and use a separate data topic for passive real time telemetry data Document proposed MQTT topic structures as part of your operations practice The document should include all topics available for publishing subscribing or receiving data along with the intended producers and consumers of the data Review the document to ensure it adheres to any AWS IoT limits internal security requirements and any application use cases Include the Thing Name of the device in any MQTT topic the device uses for publishing or subscribing to its data To track messages destined for a particular device include the Thing Name as part of any MQTT message that is published by the device or sent to a specific device The Thing Name should appear near or at the end of the MQTT topic after any routing topic information Include additional contextual information about a specific message in the payload of the MQTT message This contextual information includes but is not limited to a session identifier the requestor identifier logging information or the return topic on which a device is expecting to receive a response Although the MQTT specification does not require specific payload attributes we recommend you include relevant tracking information inside of the MQTT payload By creating a standard structure including fields such as session identifier and success or error codes you can more easily analyze trends in device behavior Standardizing the communication schema also strengthens a shared vernacular of device use cases across IoT teams Avoid MQTT communication patterns that result in a sizeable fan in scenario to a single device Some AWS IoT limits cannot be raised as part of a limit increase and frequently correlate to per device actions such as maximum publish in on a single MQTT connection Do not allow a single device to subscribe to a shared topic that is being published to by a large number of other devices By avoiding this pattern you are more likely to avoid hitting a single connection device limit particularly a throughput per connection per second limit Never allow a device to subscribe to all topics using and only use multi level wildcard subscriptions in IoT rules By using multi level wildcards you can create unintended consequences when you inadvertently add new topics to the hierarchy that may not be intended for that particular device Instead reserve use of multi level wildcards as part of the IoT rules engine and use single level wildcards for device subscriptions Best practices for telemetryTelemetry is read only data that is transmitted by the device and processed in the cloud It follows the device to cloud pattern along with the fan in pattern for communication Telemetry does not require an acknowledge message back from the MQTT broker beyond optionally setting a higher quality of service QoS level Since telemetry is a passive activity the MQTT topic for telemetry should not overlap with any MQTT topics for active workflows such as command and control messages A telemetry topic supports more complex devices that publish telemetry on behalf of other devices such as an edge gateway or a mesh network with a single coordinator In AWS IoT you have the ability to use different AWS IoT services to support telemetry communication patterns We recommend that you use a combination of AWS IoT Basic Ingest and standard MQTT topics to support your telemetry use cases Using AWS IoT Basic Ingest for telemetryBasic Ingest optimizes data flow for high volume data ingestion workloads by removing the pub sub Message Broker from the ingestion path As a result you have a more cost effective option to send device data to other AWS services while continuing to benefit from all the security and data processing features of AWS IoT Core In cases where devices do not require the publish and subscribe functionality of the Message Broker Basic Ingest enables you to send data to cloud services through the Rules Engine Basic Ingest is an ideal use case for telemetry when the only interested subscriber for an IoT message is your backend IoT application Basic Ingest uses a reserved MQTT topic structure that is associated to a particular AWS IoT Rule A device can publish to the reserved topic associated to a specific AWS IoT Rule and Basic Ingest will trigger the IoT Rule for the matching Rule Name The MQTT topic structure for Basic Ingest follows a similar syntax as the following example aws rules lt rule name gt lt optional customer defined segments gt Where the field rule name matches the name of the AWS IoT Rule that should be invoked and optional customer defined segments includes any additional topic levels a customer may use for routing or logging as part of the AWS IoT Rule Action Best practices for using AWS IoT Basic IngestInclude any additional routing information after the rule name in the Basic Ingest MQTT Topic As a best practice AWS recommends you use the optional segments that can appear after the rule name in the MQTT topic to include relevant additional information that can be used by the AWS IoT Rule for features such as Substitution Templates IoT Rule SQL Functions and Where Clauses Similar to the overall best practice for MQTT topics any fields that can be used for IoT Rule evaluation such as application Identifier or device Identifier should be appended to the end of the Basic Ingest topic The following example would be publishing to an AWS IoT Rule named BuildingSecurity followed by customer defined segments aws rules BuildingSecurity buildings warehouse section motionChoose short descriptive rule names for Basic Ingest When AWS IoT Rules are used directly by devices via Basic Ingest AWS recommends that you ensure the rule name follows MQTT topic best practices for consistency Since the rule will link directly to a reserved MQTT topic ensure that the rule name is short descriptive of the underlying use case of the rule and adheres to the syntax rules described in the section General best practices Using the MQTT topics for telemetryIn addition to using Basic Ingest you can also leverage traditional MQTT topics These types of MQTT messages are passive AWS IoT data that may be subscribed to by other devices now or in the future For example a device that sends its current status may expect its data to be routed not only to your internal application but also to a user who needs the device s current status To achieve this level of flexibility you can use standard MQTT topics for sending and receiving telemetry MQTT telemetry topic syntaxThe following example and sections provide the MQTT topic structure for telemetry dt lt application gt lt context gt lt thing name gt lt dt type gt dt Set prefix that refers to the type of message For a telemetry topic we use dt short for data All telemetry topics use this top level prefix for an application By reusing the same value for telemetry you can identify the intent of a message by referring to the initial prefixed value In this case any dt topic is a telemetry topic application Identifies the overall IoT application associated with the device Commonly used application attributes include device hardware version or an internal identifier for a cloud application that is the primary ingestion point for a message The IoT application is associated with an internal name for your overarching IoT product or relates specifically to the type of hardware of your device Because the application topic portion correlates to a group of device messages and is immutable the application prefix portion of the telemetry MQTT topic is placed immediately after the dt message type context Single or multiple levels of additional contextual data about the message a device is publishing Contextual information is related to information that is set during device provisioning For example contextual information in a factory setting could include the current physical location of a device in the facility Another example of contextual information is a group id in the MQTT topic The group id denotes when multiple devices have an inherent relationship based on specific attributes such as buying a package of smart light bulbs to control lighting in a room The group id enables numerous devices to coordinate activities as a single unit thing name Identifies which device is transmitting a telemetry message dt type optional Associates a message with a particular subcomponent of a device or for edge gateways any downstream devices A complex device often has multiple subcomponents with specific tasks such as sensors actuators or separate system on chips SOCs The dt type allows you to associate each subcomponent of a particular device to an individual MQTT topic One example of this is a subcomponent that measures geolocation and direction of a vehicle That subcomponent would have a dt type value of geo to distinguish its geolocation messages from other components of the car such as the accelerometer Best practices for commandsIn IoT applications command topics are used to control a device remotely and to acknowledge successful command executions Unlike telemetry command topics are not read only Commands are a back and forth workflow that can occur between two devices or between the cloud and devices Because commands are actionable messages isolate the MQTT topic for command messages from telemetry topics Several services are available for you to implement command and control operations on AWS IoT With the capability to store the desired and reported states in the cloud the AWS IoT Shadow is the preferred AWS IoT service for implementing individual device commands AWS IoT Device Jobs should be used for fleet wide operations as it provides extra benefits such as Amazon CloudWatch metrics for Job tracking and the ability to track multiple in transit Jobs for a single device You can use a combination of the AWS IoT Shadow AWS IoT Jobs and standard MQTT topics to support your command use cases Using the AWS IoT Shadow for commandsThe AWS IoT Device Shadow service acts as a state intermediary allowing devices and applications to retrieve and update a device s shadow state You can use the shadow to get and set the state of a device over MQTT or HTTP The shadow includes the following individual state properties that support command and control desired state Applications that have permissions to send commands to a device can write the requested state changes to the desired portion of the shadow document By updating the desired state the AWS IoT Shadow service stores the desired state change in the AWS cloud and then sends an MQTT message to the device using a reserved shadow topic When a device receives a shadow request it can execute the changes required from the desired state reported state The reported state of the AWS IoT Thing s shadow stores the last published attributes published by a device Devices write to this portion of the document to record their new state while applications read this portion of the Shadow to determine the state of a specific device Because shadows are stored by AWS in the cloud they can collect and report device state data from apps and other cloud services whether the device is connected or not Use the AWS IoT Shadow in situations where a command persists for later use even if the device is currently offline For example if a GPS system is sent a new destination through the Shadow desired state but is not immediately reachable the new coordinates remain in the GPS IoT Shadow Once the GPS system regains connectivity it can actively request its last shadow state and retrieve the new coordinates The shadow is also ideal for storing the last reported state for attributes of the device Best practices for using the AWS IoT Classic Shadow or Named ShadowsThe AWS IoT is a mechanism for command and control along with storing the reported state of a specific device The following list of best practices offers advice on maximizing the efficiency of commands through the shadow IoT devices should not share shadows To separate commands for each device make sure that each device has permissions to its own shadow and that devices do not share a single shadow For complex scenarios like edge gateways or large device assets with multiple subcomponents the primary asset should use multiple IoT Things and shadows individually associated with the downstream devices Consider using Named Shadows to create logical groups of properties You can create a unique access policy for each Named Shadow therefore controlling what applications or services can view or update that group of properties An example of this would be the device management team viewing the firmware battery health or WiFi signal strength but not having access to the data being published by the sensors on said devices Use the shadow for state or commands that have a medium to low transaction per second TPS The shadow is an ideal fit for infrequent updates that occur in minutes hours or days as the shadow publishes on additional topics to acknowledge an action was successful For a high frequency or throughput commands that do not require the updates to the shadow consider publishing to a MQTT command topic Use the shadow for storing status metrics of a device Store informational data about the current health of the device including but not limited to connectivity the status of device sensors and control units and any error information about those subcomponents If you know the current status of the device you can make actionable decisions during command requests Use the AWS IoT Device Shadow service to catalog the current firmware version The shadow is an ideal location for a device to report the firmware version installed on the hardware The firmware should be a simple attribute such as a field that highlights the major minor patch version of the service Use the optional clientToken field with AWS IoT Device Shadow service updates to track the sender of a shadow message The clientToken is a field in the Shadow that enables a subscriber to associate the responses with requests in your MQTT application If a device sets the clientToken during a shadow update request the AWS IoT Shadow service includes that same clientToken in the associated shadow output events Using AWS IoT Jobs for CommandsAWS IoT Jobs is a service that allows you to define a set of remote operations that are sent to and executed on one or more things connected to AWS IoT For command use cases Jobs allows applications to run tasks that require executing multiple steps An AWS IoT Job contains instructions that the thing must run to complete its transaction AWS IoT Jobs are the recommended feature for fleet wide operational tasks such as software updates that are only executed by trusted administrators of the entire IoT application Best practices for using AWS IoT JobsUse thing groups to organize devices for AWS IoT Jobs Create multiple thing groups organized by common device attributes such as the current firmware version hardware version or deployment environments for example staging or production Thing groups should also have common hierarchical structures such as business units or locations During deployments you can use thing groups as the deployment target for a specific IoT job Use staged rollouts to deploy commands using Device Jobs Device Jobs are the ideal solution for delivering fleet wide operations to devices Create multiple smaller deployments first to subsets of the fleet letting the devices apply your changes and then rolling out the commands to a greater number of devices over time By allowing changes to progress over weeks and months you can have more confidence that there are fewer unforeseen issues and you can react more quickly if there is an issue during an earlier rollout Using the MQTT topics for commands MQTT command topic syntaxIn some scenarios you may want to design your command communication using the standard MQTT publish and subscribe model These types of situations may occur when a device must execute a command that is temporal that is can only be processed at this current type and should fail if the device is unavailable or run a single command across multiple devices simultaneously It is also possible in a brownfield environment where a device may be incapable of leveraging higher level AWS IoT services You may also require the flexibility to choose your own set of MQTT topics to define commands to and responses from devices In cases where you are using a separate set of command topics follow similar best practices for MQTT command topics as described for telemetry A command topic should have flexibility for complex devices that publish or relay commands to other devices Command topics should also provide visibility into essential attributes MQTT command topics should be designed in a way that can answer operational questions based on the MQTT topic and payload Who is the originator of the command Who is the intended receiver of the command Was the command processed successfully What is the current status of the command If the command was not processed successfully what is the error In addition to these questions you may also want to determine when a command was requested when a device responded and to monitor the state of any single request among the fleet in the cloud When you design MQTT topics for command requests follow this structure cmd lt application gt lt context gt lt destination id gt lt req type gt Since commands are two way communication patterns design a similar MQTT topic structure for responding to commands such as the following cmd lt application gt lt context gt lt destination id gt lt res type gt Because telemetry topic design is similar to command topic design this section provides only the portions of the IoT topic for command requests and responses that differ cmd Prefix that refers to the type of message Command topics use cmd which is short for command By prefixing all commands with cmd and all telemetry with dt telemetry and commands are isolated on separate MQTT topics req type Classifies the command For simple request and response patterns the req type attribute should be a single command request static value such as req In cases of limited command types the MQTT message includes the additional data in the payload In more complex systems where a device is orchestrating multiple devices actuators or subcomponents the req type attribute relates to each subcomponent available to receive commands For example if a device is mobile you may want to steer the device remotely or receive navigational information about the device s surroundings This type of subcomponent would have a req type of nav where commands are sent steering in single or multiple planes destination id Identifies the destination device or application for this message By including the destination id the target device can subscribe to its own set of command topics and receive any command requests res type Denotes command responses and identifies responses that are related to a previously sent command The res type enables a single device to use one single level wildcard subscription for all incoming command acknowledgments If a device has limited commands the response topic can use a static field such as res MQTT command payload syntaxIn addition to creating a clear MQTT topic structure for commands make sure that you generate a schema for message payloads MQTT payload information is parsed by the receiving device or IoT application to inform it of any additional logic it may need to complete its operation For MQTT commands include the following fields with the command message payload session id Identifies a unique session The requestor generates the session id for the command and includes it in the request payload The response topic uses the session id upon command completion By using a session id the AWS IoT Rules Engine can store and track the status of commands and determine if a request is still in transit successful or in error Devices can also keep track of in transit requests when communicating with multiple devices response topic In a command there is a request for an action to happen and then a response that indicates the status of the command successful or error To avoid hard coding response topics we recommend that for any MQTT command the command request payload includes a field that has a response topic The device publishes its response payload using the response topic For example consider the following command topic cmd security device cert rotation In the payload of this request the IoT application includes a field that denotes where the device device should send its response and a session identifier for tracking See the following example for this command s payload structure session id session res topic cmd security app res Applications on AWSThe following sections provide use cases for implementing MQTT topic best practices using AWS IoT MQTT command topics exampleFor a smart door lock application a user must be able to submit a command to the lock that initiates a temporary key to be issued for an approved visitor The temporary key consists of a TTL code and information about the authorized user The ability to create a temporary key allows another individual to open the lock for a specified period This use case would apply in scenarios such as visiting family member arriving at the home while the primary owner is at work More Details about MQTT command examples can be found here MQTT telemetry topics exampleThis section is an example of aggregating telemetry from a set of occupancy sensors that are placed throughout a building to monitor room usage The occupancy sensors communicate to a local gateway that is running AWS IoT Greengrass AWS IoT Greengrass AWS IoT Greengrass then delivers all sensor metrics on an MQTT topic to AWS IoT Core Because this use case is focused on telemetry a response topic is not needed between AWS IoT Greengrass and AWS IoT Core either locally or upstream More Details about MQTT telemetry examples can be found here Best practices for using MQTT topics in the AWS IoT Rules EngineThe AWS IoT Rules Engine enables you to define how messages sent to AWS IoT Core can interact with AWS services An AWS IoT rule consists of a SQL SELECT statement a topic filter and a rule action The SQL SELECT statement can extract data from incoming MQTT messages The topic filter of an AWS IoT rule specifies which MQTT topics invoke an AWS IoT Rule Action The rules engine plays a pivotal role in intelligently directing messages to other AWS services or republishing to devices AWS IoT rules support use cases such as gathering operational metrics data enrichment data aggregation of device telemetry for analytics purpose and for troubleshooting errors Rules Engine integration with telemetry topicsWe recommend using a topic structure for telemetry similar to the following dt lt application prefix gt lt context gt lt thing name gt lt dt type gt The second field in the MQTT topic telemetry pattern defined as application prefix represents an immutable natural bifurcation between your devices in a fleet A common attribute for the application is the device hardware version or the name of the IoT application Using the telemetry MQTT structure you can create an IoT rule to capture all telemetry associated with a specific application version sql SELECT topic as applicationVersion topic ascontextIdentifier FROM dt awsIoTSqlVersion ruleDisabled false actions Because the MQTT topic structure mirrors a hierarchy this rule can select different parts of the MQTT topic hierarchy and inject it into the new payload These attributes provide further context as messages are processed and stored in other AWS services Rules Engine integration with command topicsThe Rules Engine can be used to capture insight into the success or failure of commands regardless of whether the commands are sent using the AWS IoT Device Shadow service AWS IoT Jobs or by using an MQTT command topic Tracking success of commandsThe AWS IoT Rules Engine can be used to track the success rates of individual commands The IoT rule extracts payload information such as the session identifier generates additional metadata in the rule select statement such as creating a time to live and temporarily stores the new message payload into a data store such as Amazon DynamoDB The rule that follows mirrors a common implementation of this use case for an AWS customer The IoT rule stores each session as an individual DynamoDB record and because the WHERE clause identifies this as an incoming command the rule adds a literal value named status that marks the command as In progress sql SELECT sessionId AS token timestamp as ttl topicId AS responseTopic clientId AS requestorID action type AS commandType In PRogress AS status FROM cmd series WHERE topic credentials actions dynamoDBv roleArn arn aws iam role service role dynamoDBrole putItem tableName command sessions table As command messages are published to the topic matching the rule the preceding rule maintains a record of all in transit commands By following the MQTT topic best practices the response topic includes overlapping information as the command itself for example the original session ID and the response topic used by the smart lock As an added capability the cloud application may have a second IoT rule that uses the session ID to update the status of a specific command using information from the response metadata Refer to the following example sql SELECT sessionId AS token timestamp as ttl topic AS responseTopic clientId AS requestorID res code AS response code Complete AS status FROM cmd series WHERE topic res actions dynamoDBv roleArn arn aws iam role service role dynamoDBrole putItem tableName command sessions table Aligning Rules Engine capabilities with MQTT topicsAs you define your use of the IoT rules review the following recommendations as you relate to MQTT topics and the AWS IoT Rules Engine Use the topic Decimal rule function to augment your MQTT messages with contextual information contained in your MQTT topics Use the timestamp rule function to include a timestamp that correlates the time that a message reached AWS IoT Core If your commands are in JSON reference any contextual payload metadata such as session ID in the SELECT and WHERE clause of the rules engine The additional payload information can be used to determine if and when a rule should initiate Use Substitution templates in your AWS IoT actions to express variables as part of the AWS IoT Rule action that is initiated Substitution expressions make it easier to scale and dynamically route to downstream IoT Rule actions To track the completion of a command or request use the AWS IoT Rules Engine to store the data and status in a service such as DynamoDB As messages are processed data can be automatically expired from DynamoDB using a TTL field In cases where commands are sent at a high throughput rate you can leverage the AWS IoT Rules Engine with Amazon Kinesis to buffer data before DynamoDB storage Use the AWS IoT Rules WHERE clause to filter messages that do not apply to an AWS IoT Action The WHERE clause can be used with the JSON payload or Rules Engine functions such as get thing shadow thingName roleARN or aws lambda functionArn inputJson After AWS IoT Core receives a message use AWS services like Amazon Kinesis or Amazon SQS to buffer the message payload along with the MQTT topic the message was published to Once messages are buffered you can run your own logic on AWS Lambda or Amazon Elastic Compute Cloud Amazon EC to map fields from the payload or the topic and enrich the payload with additional metadata related to the individual devices the type of device or the device group The topic decimal rule function can be used to enrich the payload with the entire topic when using topic If you want to enrich the payload with an serial number that is part of the MQTT topic shown below then you would use topic dt customer hub ConclusionMQTT is a simple secure flexible and robust IoT protocol It allows you to define communication networks between devices and the cloud that can tailor fit an increasingly large number of customer use cases To support you on your initial steps in using MQTT on AWS IoT this whitepaper has presented several best practices guidelines and considerations that can be used when reviewing how to implement IoT device communications AWS IoT enables the definition of several MQTT communication patterns point to point broadcast and fan in ーthat relate to different use cases In addition AWS IoT Services provide you with additional managed services including but not limited to AWS IoT Jobs AWS IoT Device Shadow service and the AWS IoT Rules Engine ReferenceOriginal paper	2022-01-26 15:29:36
海外TECH	DEV Community	How to visualize data	https://dev.to/aiflowltd/how-to-visualize-data-2462	How to visualize dataAs discussed in last week s article data is the core of every learning algorithm and we need lots of it to create a good intelligent product but most of the time the type of algorithm we are going to use highly depends on what kind of information we are dealing with To get some sense of the information we are working with we use data visualization techniques What is data visualization Data visualization refers to an efficient graphical representation of data or information for example taking a spreadsheet s content and converting it into a bar or line chart It is a particularly efficient way of communicating when the information we are dealing with is numerous or complex as for example a time series From a formal point of view the representation can be considered as a mapping between the original data usually numeric and graphic elements for example lines or points in a chart The mapping determines how the attributes of these elements vary according to the data like a bar chart is a mapping between the length of a bar and the magnitude of a variable Why do we visualize data To determine what s the best learning algorithm for our problem we need to understand our data Most of the time it s hard to have an intuition of the data we are working with and some algorithms only work on specific datasets For example a Linear Regression algorithm won t work on a dataset that is not Linearly Separable You likely heard about the old saying a picture is worth a thousand words but sometimes in the field of learning it s hard to find a compelling visualization for your data Visualization methodsAs we humans cannot visualize in more than dimensions although some mathematicians can gain intuition in dimensions we have to reduce the dimensions of our dataset so we can visualize it properly Two of the main methods to reduce dimensions are Principal Component Analysis PCA and t Distributed Stochastic Neighbor Embedding t SNE Principal Component Analysis PCA PCA is a dimensionality reduction method that is often used to reduce the dimensionality of large data sets by transforming a large set of variables into a smaller one that still contains most of the information in the large set The main steps of PCA are calculate the mean of each columncenter the value in each column by subtracting the mean column valuecalculate covariance matrix of centered matrixcalculate eigendecomposition of the covarianceSo PCA tries to reduce the number of variables of a dataset while preserving as much information as possible the only downside of PCA is that it works well with multidimensional data that is linearly separable If the dataset is not linearly separable PCA will often lose a lot of information t Distributed Stochastic Neighbor Embedding t SNE The main difference between t SNE and PCA is that t SNE is a non linear dimensionality reduction algorithm It takes a set of points in high dimensional data and converts it into low dimensional data It is a non linear method and adapts to underlying data performing different transformations in different regions It s incredibly flexible and often finds a structure where other dimensionality reduction algorithms can t These were just a few insights into data visualization At aiflow ltd we automatically create visualizations for your to make sure you get a sense of your data If you re curious to find out more subscribe to our newsletter and see our other articles References	2022-01-26 15:05:28
Apple	AppleInsider - Frontpage News	Best deals Jan. 26: 30% off Parallels Desktop 17 Pro, refurbished Apple Watch discounts, more!	https://appleinsider.com/articles/22/01/26/best-deals-jan-26-30-off-parallels-desktop-17-pro-refurbished-apple-watch-discounts-more?utm_medium=rss	Best deals Jan off Parallels Desktop Pro refurbished Apple Watch discounts more In addition to big savings on a one year Parallels Desktop Pro subscription Wednesday s best deals include off a W Anker USB C wall charger pack off SwitchBot for HomeKit off Bose Frames Alto and for a Tile pack Best deals January As we do every day we ve collected some of the best deals we could find on Apple products tech accessories and other items for the AppleInsider audience If an item is out of stock it may still be able to be ordered for delivery at a later date Read more	2022-01-26 15:34:03
Apple	AppleInsider - Frontpage News	Apple iCloud caused some services to be slow or unavailable for four hours on Tuesday	https://appleinsider.com/articles/22/01/26/apple-icloud-outage-causing-some-services-to-be-slow-or-unavailable?utm_medium=rss	Apple iCloud caused some services to be slow or unavailable for four hours on TuesdayApple was having issues with its iCloud servers with many users reporting that they cannot access Messages Apple Music files and more Social media reports show emergent issues with several iCloud services For example users have reported being logged out of their iCloud accounts or unable to access anything stored on iCloud servers This is what happens when your home goes all in on Apple products iPhone ipad Mac Apple TV etc when iCloud goes down Every device starts going off telling you to log in just to go in a continual loop ーKen Crockett Goodeye January Read more	2022-01-26 15:33:16
海外TECH	Engadget	Huawei is releasing the P50 Pro and Pocket outside China, but not in the US	https://www.engadget.com/huawei-p-50-pro-p-50-pocket-foldable-availability-europe-latin-america-asia-pacific-154632693.html?src=rss	Huawei is releasing the P Pro and Pocket outside China but not in the USHuawei is set to start selling the P Pro and foldable P Pocket smartphones it announced last year outside of China The flagship Pro device costs € and the P Pocket starts at € Those convert to around and respectively but don t expect to get your hands on these in the US Along with preventing Huawei devices from easily being sold in the US sanctions imposed by the country mean that the P Pro and P Pocket don t ship with Google apps and services such as Gmail Chrome Maps and the Play Store That s despite Huawei basing its HarmonyOS on an open source version of Android nbsp Sanctions also inhibit Huawei from sourcing G components so the P Pro and P Pocket are G handsets Those are significant tradeoffs that might make the P Pro and P Pocket hard sells given that they ll likely be more expensive than flagship Apple Samsung and Google devices in many markets The next Galaxy S devices are right around the corner too HuaweiThe P Pro has a inch OLED display with a resolution of x and a Hz refresh rate as well as support for billion colors There are four cameras on the rear a MP True Chroma main camera MP mono camera MP telephoto and MP ultrawide There s also a MP selfie camera The mAh battery supports up to W wired fast charging and W wireless charging The P Pro comes with GB RAM and GB of storage The P Pocket meanwhile has a clamshell foldable design akin to Samsung s Galaxy Z Flip devices When unfolded users can access the inch OLED display with a resolution of x and a Hz refresh rate along with support for billion colors and P wide color gamut HuaweiThere s a MP selfie camera and a triple camera array on the rear Along with the main MP True Chroma sensor there s a MP ultra spectrum camera and MP ultra wide lens One interesting feature in the Mirror app enables users to visualize their sunscreen application and check for spots they may not have covered up nbsp There s a small circular display positioned below the camera array which can display things like notifications and the weather It allows control over features like music playback and the cameras The foldable also comes with up to GB RAM and GB of storage The mAh battery supports W charging The two handsets both run on the Snapdragon G chipset They ll go on sale in quot key markets quot in Europe Asia Pacific the Middle East Africa and Latin America as part of phase one of an international rollout Huawei didn t disclose the specific markets or when exactly the phones will be available to purchase	2022-01-26 15:46:32
海外TECH	Engadget	Android apps come to Windows 11 in 'preview' next month	https://www.engadget.com/windows-11-android-apps-public-preview-release-date-152112952.html?src=rss	Android apps come to Windows in x preview x next monthYou won t have to run an unpolished beta to try Android apps on Windows Microsoft s Panos Panay has teased the release of a Windows public preview in February that will bring Android apps to the Microsoft Store The company didn t say how many apps would be available in this test but they ll be titles you would find in the Amazon Appstore The preview should still be helpful if you re content to stick to Windows apps You can expect taskbar upgrades that include call mute controls simpler window sharing and weather Microsoft has redesigned the Media Player and Notepad apps too You may want to hurry if you re still uncertain about upgrading to the new OS though Microsoft has warned the free Windows upgrade rollout is quot entering its final phase quot sooner than the originally planned mid target While that hints uptake has been strong it also suggests you might have to pay for the upgrade if you don t decide relatively soon Android app support was one of the headlining features for Windows at its reveal event but is only reaching mainstream users several months after the new Windows version s launch Nonetheless it might be an important addition for both Microsoft and users This will help if you d like to use common Android apps on your PC of course but it could also spark interest in both touchscreen Windows PCs and the Microsoft Store	2022-01-26 15:21:12
Cisco	Cisco Blog	Practicing Digital Hope, one clean drop of water at a time	https://blogs.cisco.com/internet-of-things/practicing-digital-hope-one-clean-drop-of-water-at-a-time	Practicing Digital Hope one clean drop of water at a time“It matters how we get there This phrase has become a mantra for me and the rest of the IoT team at Cisco Yes we are laser focused on helping our customers achieve their business objectives as well as achieving our own internal goals But we care about more than just the bottom line We	2022-01-26 15:50:08
海外科学	NYT > Science	An Extraordinary Iceberg Is Gone, but Not Forgotten	https://www.nytimes.com/2022/01/26/climate/iceberg-a68a-antarctica.html	An Extraordinary Iceberg Is Gone but Not ForgottenA chunk of Antarctic ice that was one of the biggest icebergs ever seen has met its end near South Georgia Scientists will be studying its effects on the ecosystem around the island for some time	2022-01-26 15:03:38
海外科学	NYT > Science	E.P.A. Chief Vows to ‘Do Better’ to Protect Poor Communities	https://www.nytimes.com/2022/01/26/climate/epa-environmental-justice-regan.html	E P A Chief Vows to Do Better to Protect Poor CommunitiesThe Environmental Protection Agency on Wednesday will announce stepped up enforcement and monitoring to help disadvantaged communities struggling with polluted air and water	2022-01-26 15:06:04
海外科学	NYT > Science	Even Low Levels of Soot Can Be Deadly to Older People, Research Finds	https://www.nytimes.com/2022/01/26/climate/air-pollution-study-epa.html	pollution	2022-01-26 15:52:25
金融	RSS FILE - 日本証券業協会	株主コミュニティの統計情報・取扱状況	https://www.jsda.or.jp/shiryoshitsu/toukei/kabucommunity/index.html	株主コミュニティ	2022-01-26 15:30:00
金融	ニュース - 保険市場TIMES	ぜんち共済・ミライロ・東京海上日動がデジタル障害者手帳を通じて「がん保険」を販売	https://www.hokende.com/news/blog/entry/2022/01/27/010000		2022-01-27 01:00:00
ニュース	ジェトロ ビジネスニュース（通商弘報）	中央銀行が外貨の優先配分先や取り扱い方法を変更	https://www.jetro.go.jp/biznews/2022/01/f8ac31561769293c.html	中央銀行	2022-01-26 15:40:00
ニュース	ジェトロ ビジネスニュース（通商弘報）	2021年GDP成長率は2.7％、ビオンテックがGDP押し上げに貢献	https://www.jetro.go.jp/biznews/2022/01/4f06ed937e18ecf2.html	押し上げ	2022-01-26 15:30:00
ニュース	ジェトロ ビジネスニュース（通商弘報）	遼寧省、政府機関の信用失墜行為の処罰に関する具体策を公布・施行	https://www.jetro.go.jp/biznews/2022/01/f2bba2abeea7f163.html	信用失墜	2022-01-26 15:20:00
ニュース	ジェトロ ビジネスニュース（通商弘報）	科学技術情報通信部、2022年の量子・半導体研究開発に87億円を計上	https://www.jetro.go.jp/biznews/2022/01/f81b2c97091fdc64.html	研究開発	2022-01-26 15:10:00
ニュース	BBC News - Home	Boris Johnson authorised Afghan animal evacuation, leaked email suggests	https://www.bbc.co.uk/news/uk-politics-60143279?at_medium=RSS&at_campaign=KARANGA	charity	2022-01-26 15:50:12
ニュース	BBC News - Home	Sainsbury's and John Lewis asks shoppers and staff to keep wearing masks	https://www.bbc.co.uk/news/business-60137428?at_medium=RSS&at_campaign=KARANGA	rules	2022-01-26 15:50:01
ニュース	BBC News - Home	Inflation measure shake-up amid Jack Monroe row	https://www.bbc.co.uk/news/business-60140858?at_medium=RSS&at_campaign=KARANGA	chiefs	2022-01-26 15:03:49
ニュース	BBC News - Home	One dead, dozens missing after boat capsizes off Florida	https://www.bbc.co.uk/news/world-us-canada-60135487?at_medium=RSS&at_campaign=KARANGA	floridaus	2022-01-26 15:30:48
ニュース	BBC News - Home	Premier League clubs must now prove four Covid cases to get postponements	https://www.bbc.co.uk/sport/football/60135824?at_medium=RSS&at_campaign=KARANGA	Premier League clubs must now prove four Covid cases to get postponementsPremier League clubs will have to prove they have at least four Covid cases to get matches called off under new guidance announced	2022-01-26 15:33:33
サブカルネタ	ラーブロ	担々麺専門店 まる鈴（〇鈴・MARUSUZU）＠神田	http://ra-blog.net/modules/rssc/single_feed.php?fid=195944	marusuzu	2022-01-26 15:00:51
北海道	北海道新聞	ワクチン接種、世界１００億回　日本６位、３回目は低調	https://www.hokkaido-np.co.jp/article/638264/	通信	2022-01-27 00:18:00
北海道	北海道新聞	まん延防止、１８道府県を追加　時短要請、２月２０日まで	https://www.hokkaido-np.co.jp/article/638262/	新型コロナウイルス	2022-01-27 00:15:00
北海道	北海道新聞	イタリア大統領３回目も決着せず　現職再登板に期待も	https://www.hokkaido-np.co.jp/article/638261/	登板	2022-01-27 00:06:00