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Cache, Write-through, and Write-backDB/InMemory 2019. 9. 29. 12:36
1. Overview A caching method in which modifications to data in the cache aren't copied to the cache source until absolutely necessary. Write-back caching is available on many microprocessors, including all Intel processors since the 80486. With these microprocessors, data modifications (e.g., write operations) to data stored in the L1 cache aren't copied to main memory such as RAM. until absolut..
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Event bubbling and capturingWeb/DOMBrowser 2019. 9. 29. 01:40
1. Overview 1.1 Event Bubbling When an event happens on an element, it first runs the handlers on it, then on its parent, then all the way up on other ancestors. 1.2 Event Capturing There’s another phase of event processing called “capturing”. It is rarely used in real code, but sometimes can be useful. 2. Event Bubbling Description 2.1 Example Let’s say we have 3 nested elements FORM > DIV > P ..
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Event delegationWeb/DOMBrowser 2019. 9. 29. 01:40
1. Overview Capturing and bubbling allow us to implement one of the most powerful event handling patterns called event delegation. The idea is that if we have a lot of elements handled in a similar way, then instead of assigning a handler to each of them – we put a single handler on their common ancestor. In the handler we get event.target, see where the event actually happened and handle it. 2...
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Spring Bean ScopesFramework/SPRING 2019. 9. 29. 00:01
1. Overview The scope of a bean defines the life cycle and visibility of that bean in the contexts in which it is used. The latest version of Spring framework defines 6 types of scopes singleton prototype request session application WebSocket global session 2. Description 2.1 Singleton Scope The container creates a single instance of that bean, and all requests for that bean name will return the..
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DispatcherServlet in SpringFramework/SPRING 2019. 9. 28. 23:46
1. Overview In the Front Controller design pattern, a single controller is responsible for directing incoming HTTP requests to all of an application's other controllers and handlers. Spring's DispatcherServlet implements this pattern and is responsible for correctly coordinating the HTTP requests to their right handlers. It is inherited from javax.servlet.http.HttpServlet, it is typically config..
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Domain Name Server (DNS), Iterative, and Recursive DNS QueryWeb/Network 2019. 9. 28. 23:37
1. Overview There are two types of queries of Domain name resolution(DNS) to issue a request for the IP address of a hostname. Then local resolver formulates a DNS query to the name server of the host. Name server checks if it is authorized to answer the query. If it is, it responds. Otherwise, it will query other name servers, starting at the root tree. When the name server has the answer it se..
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Eventual consistency and strict consistencyModeling/TheoremParadigm 2019. 9. 28. 21:23
1. Overview Let’s define eventual consistency vs strict consistency. 2. Description 2.1 Strict consistency(or immediate or strong) For any incoming write operation, once a write is acknowledged to the client, the updated value is visible on reading from any replicated node (server) in the system Guaranteed data resiliency Once a write is acknowledged to the client the update is protected from no..
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HTTP keepalive(HTTP persistent connection)Web/Protocol 2019. 9. 28. 17:41
1. Overview HTTP keep-alive, a.k.a., HTTP persistent connection, is an instruction that allows a single TCP connection to remain open for multiple HTTP requests/responses. By default, HTTP connections close after each request. When someone visits your site, their browser needs to create new connections to request each of the files that make up your web pages (e.g. images, Javascript, and CSS sty..