投稿時間:2021-10-31 14:14:19 RSSフィード2021-10-31 14:00 分まとめ(18件)

カテゴリー等	サイト名等	記事タイトル・トレンドワード等	リンクURL	頻出ワード・要約等/検索ボリューム	登録日
TECH	Engadget Japanese	「GFX50S II」レビュー、どんな場所にも連れていけるラージフォーマット	https://japanese.engadget.com/gfx-50-s-ii-044746202.html	gfxsii	2021-10-31 04:47:46
TECH	Engadget Japanese	新生iMac Pro、M1 Pro/Maxや27型ミニLED画面搭載で2022年発売のウワサ	https://japanese.engadget.com/new-imacpro-m1max-27-miniled-20221h-044007868.html	imacpro	2021-10-31 04:40:07
TECH	Engadget Japanese	DIYに大活躍！ ボッシュ(BOSCH)の電動工具がセール価格に｜Amazonタイムセール祭り	https://japanese.engadget.com/timesale-bosch-electric-tools-042520100.html	amazon	2021-10-31 04:25:20
python	Pythonタグが付けられた新着投稿 - Qiita	【Python】pandas_datareaderで株価取得	https://qiita.com/atchicken/items/f3532f01eb409105dde3	pandasdatareader	2021-10-31 13:58:05
python	Pythonタグが付けられた新着投稿 - Qiita	発想力を測定するWebアプリをWord2Vecを使って作ってみた	https://qiita.com/IzumiSatoshi/items/a026015275124cc0e9cf	コーパスに含まれていない単語はどのように処理されるのだろうか点を超えるのがかなり難しいように感じたが、それはなぜか二つ以上の名詞がつながった複合名詞の測定はどうなっているのかまた、本来であれば、この測定器の信ぴょう性を検証するため、その他の発想力テストやIQテストなどとの相関関係を調べるのが良いと思われるが、今回はこれ以上は踏み込まないことにする。	2021-10-31 13:10:05
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	DialogflowのIntent複製を行いたい。	https://teratail.com/questions/367062?rss=all	DialogflowのIntent複製を行いたい。	2021-10-31 13:52:14
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	GLFWマウスが動いたかどうかを取得する方法が知りたい。	https://teratail.com/questions/367061?rss=all	GLFWマウスが動いたかどうかを取得する方法が知りたい。	2021-10-31 13:39:44
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	インデックスエラーについて	https://teratail.com/questions/367060?rss=all		2021-10-31 13:30:46
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	シンクライアント環境におけるVSCodeの設定	https://teratail.com/questions/367059?rss=all	シンクライアント環境におけるVSCodeの設定前提・実現したいことシンクライアント環境で、VSCodeとPythonをインストールし利用することを考えています。	2021-10-31 13:24:52
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	縦横比を維持したまま画像を希望のサイズにリサイズしたい	https://teratail.com/questions/367058?rss=all	縦横比を維持したまま画像を希望のサイズにリサイズしたい標題の通り、画像を縦横比を維持したままリサイズするプログラムを作っています。	2021-10-31 13:12:22
Azure	Azureタグが付けられた新着投稿 - Qiita	AzureとのSite to Site VPNでFQDNがサポートされた	https://qiita.com/hidekko/items/6ea27e158b531fad3418	検証するに至った経緯実際はNSGでWindowsUpdateを許可する方法では不要なのですが、なんとなく久しぶりにAzureとインターネットVPNを張ってみたくなりか月ぶりにAzureのVPN設定画面を眺めているとなんとマ、マジか・・・このパラメータを発見したときは、ほんとに漫画の集中線みたいになりました。	2021-10-31 13:43:00
Ruby	Railsタグが付けられた新着投稿 - Qiita	rails6 bootstrap5導入方法	https://qiita.com/mocomou_/items/95f1be13c9b0aafc422b	筆者の環境MacbookAirMmacOSBigAurバージョンrubyprevisiondbfarmdarwinRails①gemを入れるbootstrapではgembootstrapsassを入れていましたが、bootstrapではつ入れるそうです。	2021-10-31 13:21:03
海外TECH	DEV Community	20 JavaScript One-Liners That Will Help You Code Like a Pro	https://dev.to/jdk/20-javascript-one-liners-that-will-help-you-code-like-a-pro-30lc	JavaScript One Liners That Will Help You Code Like a Pro JavaScript keeps growing and growing JavaScript One Liners That Will Help You Code Like opening doors for new “to be tech geeks in the market as it s one of the easiest languages to start is it really It s true that JavaScript can do a lot of blazing things and there is just so much to learn And whether you re new to JavaScript or more of a professional developer it s always good to learn something new I m gonna go over some really helpful one liners Bonus that can help you boost your productivity and can help in debugging code  Read More JavaScript One Liners That Will Help You Code Like a Pro	2021-10-31 04:32:55
海外TECH	DEV Community	40+ JavaScript Projects for Beginners – Easy Ideas to Get Started Coding JS [Beginners to Advance]🔥	https://dev.to/jdk/40-javascript-projects-for-beginners-easy-ideas-to-get-started-coding-js-beginners-to-advance-37h9	JavaScript Projects for Beginners Easy Ideas to Get Started Coding JS Beginners to Advance The best way to learn a new programming language is to build projects I have created a list of beginner friendly project tutorials in Vanilla JavaScript React and TypeScript My advice for tutorials would be to watch the video build the project break it apart and rebuild it your own way Experiment with adding new features or using different methods That will test if you have really learned the concepts or not You can click on any of the projects listed below to jump to that section of the article Read More JavaScript Projects for Beginners Easy Ideas to Get Started Coding JS	2021-10-31 04:30:54
海外TECH	DEV Community	[Looking for feedback.] Janky: Templates and Raw Types.	https://dev.to/baenencalin/looking-for-feedback-janky-templates-and-raw-types-3onn	Looking for feedback Janky Templates and Raw Types Feedback What are you giving feedback on How I plan on implementing templates similar to C s template arguments and raw types in Janky All feedback good or bad as long as it s constructive and non sarcastic is accepted and I ll be trying to respond and take as many notes as possible Thanks in advance Templates Templates act like C s template arguments but they look like Java s generics here s what I m thinking they ll look like Should the type keyword be optional here Type identifiers can also be used here so I thought I should ask struct MyType lt type T gt MyType T v this value v T value Legal MyType lt int gt MyType lt MyType gt MyType lt void gt This is a special case MyType lt T gt Illegal MyType lt null gt MyType lt gt MyType lt MyType gt MyType lt new MyType gt void s special case Fun fact did you know you can run this snippet of C legally without any errors or warnings template lt typename T gt T create return T create lt void gt T value create lt T gt NOTE Expansion to T val T return val causes multiple errors if you pass void Yeah Passing in void works But What does this mean for object members in my language This means they ll act as if they ve be en removed from the object Note if void is generic then it may take any number of arguments for its constructors consisting of any type Raw Types Love em or hate em they have to come they re too useful in the most niche of situations For example if you want a heterogeneous array of a template type MyType so instead of MyType lt type T gt you could use raw MyType raw would be its own keyword to A Avoid any confusion ambiguity between raw types and types with default template arguments B To make sure types aren t accidentally raw Regarding the type safety of Raw Types in Janky I know when it comes to raw datatypes types whose generic type arguments aren t specified have some type safety concerns and such concerns are valid because these types CAN be dangerous and aren t afraid to help create nasty bugs But I ve put some forethought into the matter and I ll discuss these briefly Where can Raw Types be passed Raw types raw MyType can be passed to functions methods constructors and other callables just like how any other kind of types MyType lt T gt can There s a catch though the type qualifiers for the MyType lt T gt in the parameter signature should include raw meaning this void f raw MyType value Do stuff void g raw MyType lt int gt value We ll talk about this in a minute void h MyType value Illegal function definition MyType must include a n type argument for T void j MyType lt int gt value Do stuff raw MyType rawval MyType lt int gt The lt int gt is required MyType lt int gt cookedval MyType lt int gt The second lt int gt is optional f cookedval Fine It just uncooks the value g cookedval Fine No uncooking needed j cookedval Fine f rawval This is okay obviously g rawval This is fine In this case j rawval Not fine Raw and cooked types are not compatible What is the elusive raw MyType lt T gt Maybe you ve figured it out from the last example maybe you haven t Anyways The these types that are both cooked but have the raw type qualifier are called undercooked types Though I think a more accurate and beautiful name for them may be baked types Feedback for which name to use if this should be implemented is welcome So what are baked types Well as the last line of my elaborate example says Raw and cooked types are not compatible Meaning that even if a raw MyType contains an int it still isn t compatible with MyType lt int gt But I ve decided to allow this cooking of the raw type on one condition and that s if MyType lt T gt has the raw qualifier this is a safety mechanism to stop types from being cooked accidentally Wrapping up So Those were my ideas for Templates and Raw Types in Janky Tell me your thoughts below	2021-10-31 04:16:10
海外TECH	DEV Community	Amazon Aurora MySQL Database Administrator’s Handbook | AWS White Paper Summary	https://dev.to/awsmenacommunity/amazon-aurora-mysql-database-administrators-handbook-aws-white-paper-summary-310o	Amazon Aurora MySQL Database Administrator s Handbook AWS White Paper SummaryThis paper outlines the best practices for managing database connections setting server connection parameters and configuring client programs drivers and connectors It s a recommended read for Amazon Aurora MySQL Database Administrators DBAs and application developers IntroductionAmazon Aurora MySQL Aurora MySQL is a managed relational database engine wire compatible with MySQL and Most of the drivers connectors and tools that you currently use with MySQL can be used with Aurora MySQL with little or no change Aurora MySQL database DB clusters provide advanced features such as One primary instance that supports read write operations and up to Aurora Replicas that support read only operations Each of the Replicas can be automatically promoted to the primary role if the current primary instance fails A cluster endpoint that automatically follows the primary instance in case of failover A reader endpoint that includes all Aurora Replicas and is automatically updated when Aurora Replicas are added or removed Ability to create custom DNS endpoints containing a user configured group of database instances within a single cluster Internal server connection pooling and thread multiplexing for improved scalability DNS endpointsAn Aurora DB cluster consists of one or more instances and a cluster volume that manages the data for those instances There are two types of instances Primary instance Supports read and write statements Currently there can be one primary instance per DB cluster Aurora Replica Supports read only statements A DB cluster can have up to Aurora Replicas The Aurora Replicas can be used for read scaling and are automatically used as failover targets in case of a primary instance failure Amazon Aurora supports the following types of Domain Name System DNS endpoints Cluster endpoint Connects you to the primary instance and automatically follows the primary instance in case of failover that is when the current primary instance is demoted and one of the Aurora Replicas is promoted in its place Reader endpoint Includes all Aurora Replicas in the DB cluster under a single DNS CNAME You can use the reader endpoint to implement DNS round robin load balancing for read only connections Instance endpoint Each instance in the DB cluster has its own individual endpoint You can use this endpoint to connect directly to a specific instance Custom endpoints User defined DNS endpoints containing a selected group of instances from a given cluster Connection handling in Aurora MySQL and MySQLMySQL Community Edition manages connections in a one thread per connection fashion This means that each individual user connection receives a dedicated operating system thread in the mysqld process Issues with this type of connection handling include Relatively high memory use when there is a large number of user connections even if the connections are completely idle Higher internal server contention and context switching overhead when working with thousands of user connections Common misconceptionsThe following are common misconceptions for database connection management If the server uses connection pooling you don t need a pool on the application side This isn t true for workloads where connections are opened and torn down very frequently and clients run relatively few statements per connection Idle connections don t use memory This isn t true because the operating system and the database process both allocate an in memory descriptor for each user connection What is typically true is that Aurora MySQL uses less memory than MySQL Community Edition to maintain the same number of connections However memory usage for idle connections is still not zero even with Aurora MySQL Downtime depends entirely on database stability and database features This isn t true because the application design and configuration play an important role in determining how fast user traffic can recover following a database event Best practicesThe following are best practices for managing database connections and configuring connection drivers and pools Using smart driversThe cluster and reader endpoints abstract the role changes and topology changes occurring in the DB cluster However DNS updates are not instantaneous In addition they can sometimes contribute to a slightly longer delay between the time a database event occurs and the time it s noticed and handled by the application Aurora MySQL exposes near real time metadata about DB instances in the INFORMATION SCHEMA REPLICA HOST STATUS table mysql gt select server id if session id MASTER SESSION ID writer reader as role replica lag in milliseconds frominformation schema replica host status server id role replica lag in milliseconds aurora node uswa writer aurora node uswb reader rows in set sec For the purpose of this whitepaper a smart driver is a database driver or connector with the ability to read DB cluster topology from the metadata table It can route new connections to individual instance endpoints without relying on high level cluster endpoints A smart driver is also typically capable of load balancing read only connections across the available Aurora Replicas in a round robin fashion The MariaDB Connector J is an example of a third party Java Database Connectivity JDBC smart driver with native support for Aurora MySQL DB clusters Application developers can draw inspiration from the MariaDB driver to build drivers and connectors for languages other than Java It s a good idea to evaluate the use of smart drivers in your setup Note that if a thirdparty driver contains Aurora MySQL specific functionality it doesn t mean that it has been officially tested validated or certified by AWS Also note that due to the advanced built in features and higher overall complexity smart drivers are likely to receive updates and bug fixes more frequently than traditional bare bones drivers You should regularly review the driver s release notes and use the latest available version whenever possible DNS cachingUnless you use a smart database driver you depend on DNS record updates and DNS propagation for failovers instance scaling and load balancing across Aurora Replicas Currently Aurora DNS zones use a short Time To Live TTL of five seconds Ensure that your network and client configurations don t further increase the DNS cache TTL Remember that DNS caching can occur anywhere from your network layer through the operating system to the application container For example Java virtual machines JVMs are notorious for caching DNS indefinitely unless configured otherwise Here are some examples of issues that can occur if you don t follow DNS caching best practices After a new primary instance is promoted during a failover applications continue to send write traffic to the old instance Data modifying statements will fail because that instance is no longer the primary instance After a DB instance is scaled up or down applications are unable to connect to it Due to DNS caching applications continue to use the old IP address of that instance which is no longer valid Aurora Replicas can experience unequal utilization for example one DB instance receiving significantly more traffic than the others Connection management and poolingAlways close database connections explicitly instead of relying on the development framework or language destructors to do it There are situations especially in container based or code as a service scenarios when the underlying code container isn t immediately destroyed after the code completes In such cases you might experience database connection leaks where connections are left open and continue to hold resources for example memory and locks Connection scalingThe most common technique for scaling web service capacity is to add or remove application instances in response to changes in user traffic Each application server can use a database connection pool This approach causes the total number of database connections to grow proportionally with the number of application instances For example application servers configured with database connections each would require a total of database connections If the application pool scales up to instances for example during peak hours the total connection count will reach Under a typical web application workload most of these connections are likely idle In extreme cases this can limit database scalability idle connections do take server resources and you re opening significantly more of them than you need Also the total number of connections is not easy to control because it s not something you configure directly but rather depends on the number of application servers Tune the connection pools on application instances Reduce the number of connections in the pool to the acceptable minimum This can be a stop gap solution but it might not be a long term solution as your application server fleet continues to grow Introduce a connection proxy between the database and the application On one side the proxy connects to the database with a fixed number of connections On the other side the proxy accepts application connections and can provide additional features such as query caching connection buffering query rewriting routing and load balancing Transaction management and autocommitWith autocommit enabled each SQL statement runs within its own transaction When the statement ends the transaction ends as well Between statements the client connection is not in transaction If you need a transaction to remain open for more than one statement you explicitly begin the transaction run the statements and then commit or roll back the transaction With autocommit disabled the connection is always in transaction You can commit or roll back the current transaction at which point the server immediately opens a new one Running with autocommit disabled is not recommended because it encourages longrunning transactions where they re not needed Recommendations Always run with autocommit mode enabled Set the autocommit parameter to on the database side which is the default and on the application side which might not be the default Always double check the autocommit settings on the application side For example Python drivers such as MySQLdb and PyMySQL disable autocommit by default Manage transactions explicitly by using BEGIN START TRANSACTION and COMMIT ROLLBACK statements You should start transactions when you need them and commit as soon as the transactional work is done Connection handshakesA lot of work can happen behind the scenes when an application connector or a GUI tool opens a new database session Drivers and client tools commonly run series of statements to set up session configuration e g SET SESSION variable value This increases the cost of creating new connections and delays when your application can start issuing queries The cost of connection handshakes becomes even more important if your applications are very sensitive to latency OLTP or key value workloads that expect single digit millisecond latency can be visibly impacted if each connection is expensive to open For example if the driver runs six statements to set up a connection and each statement takes just one millisecond to run your application will be delayed by six milliseconds before it issues its first query Load balancing with the reader endpointBecause the reader endpoint contains all Aurora Replicas it can provide DNS based round robin load balancing for new connections Every time you resolve the reader endpoint you ll get an instance IP that you can connect to chosen in round robin fashion DNS load balancing works at the connection level not the individual query level You must keep resolving the endpoint without caching DNS to get a different instance IP on each resolution Designing for fault tolerance and quick recoveryIn large scale database operations you re statistically more likely to experience issues such as connection interruptions or hardware failures You must also take operational actions more frequently such as scaling adding or removing DB instances and performing software upgrades The only scalable way of addressing this challenge is to assume that issues and changes will occur and design your applications accordingly Server configurationThere are two major server configuration variables worth mentioning in the context of this whitepaper max connections and max connect errors Configuration variable max connectionsThe configuration variable max connections limits the number of database connections per Aurora DB instance The best practice is to set it slightly higher than the maximum number of connections you expect to open on each instance If you also enabled performance schema be extra careful with the setting The Performance Schema memory structures are sized automatically based on server configuration variables including max connections The higher you set the variable the more memory Performance Schema uses In extreme cases this can lead to out ofmemory issues on smaller instance types Configuration variable max connect errorsThe configuration variable max connect errors determines how many successive interrupted connection requests are permitted from a given client host If the client host exceeds the number of successive failed connection attempts the server blocks it ConclusionUnderstanding and implementing connection management best practices is critical to achieve scalability reduce downtime and ensure smooth integration between theapplication and database layers You can apply most of the recommendations provided in this whitepaper with little to no engineering effort The guidance provided in this whitepaper should help you introduce improvements in your current and future application deployments using Aurora MySQL DB clusters Reference Original paper	2021-10-31 04:13:04
海外科学	BBC News - Science & Environment	COP26: 'Moment of truth' as world meets for climate summit	https://www.bbc.co.uk/news/science-environment-59105878?at_medium=RSS&at_campaign=KARANGA	action	2021-10-31 04:38:04
金融	ニュース - 保険市場TIMES	アドバンスクリエイト、オンライン保険相談サービスの利用件数が50,000件突破！	https://www.hokende.com/news/blog/entry/2021/10/31/140000	アドバンスクリエイト、オンライン保険相談サービスの利用件数が件突破国内トップクラスの利用件数国内最大級の保険選びサイト「保険市場」を運営するアドバンスクリエイトは月日、同社オンライン保険相談サービスの利用件数が件を突破したと発表した。	2021-10-31 14:00:00