Multi-Region ASP. In this, the ASP. NET Session State is not replicated across sites and instead is kept at the location of its creation. But, if you move any traffic from one region data center to another, the ASP.
NET Session State moves with it. This allows you to have two or more active regions data centers , keep most of the traffic to its own datacenter but occasionally overflow to the other datacenter if you want. And, you can also bring down one datacenter without causing any interruptions for the users because their sessions will be accessible by other datacenters. Additionally, it implements various advanced features to let you handle complex situations in your applications in the ConfigureServices IServiceCollection services method.
NET Core session locking behavior is that the session is never locked. As a result, you may corrupt the session if you try to update it simultaneously. NET Session State where if a session is locked, another request for it waits for 90 seconds configurable and at the end force-unlocks the session.
You can specify this locking option as following properties in the "configuration":. NET Core application, you may have robots scraping data and using the same session id for hundreds or thousands of requests simultaneously. In this case, you cannot afford standard session locking option because waiting for 90 seconds could tie up all your available sockets.
Instead, you want to return the request quickly to indicate a failure. You can specify this as following:. This makes 5 retries at half-second intervals and then returns an empty session to signify a failure. Even throwing an exception here is costly. That is why an empty session is implemented. This behavior was originally implemented on a request from a high traffic airline website.
Cloud Software Download Pricing Software. Technical Use Cases. This can occur if the link is passed through a search engine, through an e-mail message, or through another program.
You can reduce the chance of session data being shared by configuring the application not to recycle session identifiers.
To do this, set the regenerateExpiredSessionId attribute of the sessionState configuration element to true. This generates a new session ID when a cookieless session request is made with an expired session ID. This is because ASP. You can implement a custom class to supply and validate SessionID values. For an example, see the example provided for the CreateSessionID method. For example, you might have a Web application that associates a unique identifier with non-ASP.
NET session state. If your custom class supports cookieless session identifiers, you must implement a solution for sending and retrieving session identifiers in the URL. NET session state supports several storage options for session variables.
Each option is identified as a session-state Mode type. The default behavior is to store session variables in the memory space of the ASP. NET worker process. However, you can also specify that session state should be stored in a separate process, in a SQL Server database, or in a custom data source.
If you do not want session state enabled for your application, you can set the session mode to Off. NET provides two events that help you manage user sessions. Session events are specified in the Global. If the Global. NET application is modified, the application will be restarted and any values stored in application state or session state will be lost. Be aware that some anti-virus software can update the last-modified date and time of the Global. For more information, see Session-State Events.
Session state is configured by using the sessionState element of the system. You can also configure session state by using the EnableSessionState value in the Page directive. The session Timeout value. Supporting values that are based on the session Mode setting. The following example shows a sessionState element that configures an application for SQLServer session mode. It sets the Timeout value to 30 minutes, and specifies that session identifiers are stored in the URL. You can disable session state for an application by setting the session-state mode to Off.
If you want to disable session state for only a particular page of an application, you can set the EnableSessionState value in the Page directive to false. The EnableSessionState value can also be set to ReadOnly to provide read-only access to session variables. Access to ASP. NET session state is exclusive per session, which means that if two different users make concurrent requests, access to each separate session is granted concurrently.
However, if two concurrent requests are made for the same session by using the same SessionID value , the first request gets exclusive access to the session information. The second request executes only after the first request is finished. The second session can also get access if the exclusive lock on the information is freed because the first request exceeds the lock time-out.
NET Core maintains session state by providing a cookie to the client that contains a session ID, which is sent to the app with each request.
The app uses the session ID to fetch the session data. A session might not be restricted to a single user—the next user might continue to browse the app with the same session cookie.
Session package, which is included in the Microsoft. App metapackage , provides middleware for managing session state. To enable the session middleware, Startup must contain:. For more information, see Middleware Ordering. Http namespace add a using Microsoft.
Http; statement to gain access to the extension methods when the Microsoft. Extensions package is referenced by the project. Both packages are included in the Microsoft. App metapackage. Keep String and Peek string methods can be used to examine the data without deletion at the end of the request.
TempData is particularly useful for redirection when data is required for more than a single request. TempData is implemented by TempData providers using either cookies or session state.
Refreshing the page displays TempData["Message"]. Because the cookie is chunked, the single cookie size limit found in ASP. NET Core 1. Most web clients such as web browsers enforce limits on the maximum size of each cookie, the total number of cookies, or both. If targeting. Session package to the project. In addition to unintended sharing, including data in query strings can create opportunities for Cross-Site Request Forgery CSRF attacks, which can trick users into visiting malicious sites while authenticated.
Attackers can then steal user data from the app or take malicious actions on behalf of the user. Any preserved app or session state must protect against CSRF attacks. In the following example, middleware adds isVerified to the Items collection. For middleware that's only used by a single app, string keys are acceptable. Middleware shared between app instances should use unique object keys to avoid key collisions. Be careful not to cache user-specific data that may be retrieved by other users' requests.
Use Dependency Injection to make data available to all users:. Define a service containing the data. For example, a class named MyAppData is defined:.
This is usually caused by failing to configure at least one IDistributedCache implementation. In the event that the session middleware fails to persist a session for example, if the backing store isn't available , the middleware logs the exception and the request continues normally.
This leads to unpredictable behavior. CommitAsync ; from app code when the app is done writing to the session. LoadAsync throws under the same conditions where the data store is unavailable. Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services. Privacy policy. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Session and state management in ASP.
View or download sample code how to download State management State can be stored using several approaches. Each approach is described later in this topic. May include data stored using server-side app code. Session state Session state is an ASP. The cookie session ID: Is sent to the app with each request. Is used by the app to fetch the session data. Session state exhibits the following behaviors: The session cookie is specific to the browser. Sessions aren't shared across browsers.
Session cookies are deleted when the browser session ends. If a cookie is received for an expired session, a new session is created that uses the same session cookie.
Empty sessions aren't retained. The session must have at least one value set to persist the session across requests. When a session isn't retained, a new session ID is generated for each new request. The app retains a session for a limited time after the last request. The app either sets the session timeout or uses the default value of 20 minutes. Session state is ideal for storing user data: That's specific to a particular session.
Where the data doesn't require permanent storage across sessions. Session data is deleted either when the ISession. Clear implementation is called or when the session expires. There's no default mechanism to inform app code that a client browser has been closed or when the session cookie is deleted or expired on the client.
Session state cookies aren't marked essential by default. Session state isn't functional unless tracking is permitted by the site visitor. Warning Don't store sensitive data in session state. Note Most web clients such as web browsers enforce limits on the maximum size of each cookie, the total number of cookies, or both. Important If targeting. Is this page helpful? Yes No.
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