How do you resolve concurrency issues in C#?

The general approach to handle a concurrency conflicts is:

1. Catch DbUpdateConcurrencyException during SaveChanges .
2. Use DbUpdateConcurrencyException.
3. Refresh the original values of the concurrency token to reflect the current values in the database.
4. Retry the process until no conflicts occur.

What are the concurrency issues?

The five concurrency problems that can occur in the database are: Temporary Update Problem. Incorrect Summary Problem. Lost Update Problem.

How do you handle concurrency issues?

Possible Solutions

1. Ignore It. The simplest technique is to just ignore it, hoping it will never happen; or if it does happen, that there won’t be a terrible outcome.
2. Locking. Another popular technique for preventing lost update problems is to use locking techniques.
3. Read Before Write.
4. Timestamping.

What is concurrency C#?

Concurrency. Doing more than one thing at a time. I hope it’s obvious how concurrency is helpful. End-user applications use concurrency to respond to user input while writing to a database. Server applications use concurrency to respond to a second request while finishing the first request.

How can we handle concurrency in LINQ?

LINQ gives three ways by which we can handle concurrency conflicts. To handle concurrency conflicts, we need to wrap the LINQ to SQL code in a TRY block and catch the ChangeConflictException . We can then loop through the ChangeConflicts collection to specify how we want the conflict to be resolved.

How does Web API handle concurrency?

How to handle concurrency in ASP.NET Core Web API. Create an empty project and update the Startup class to add services and middleware for MVC. Add a controller with GET and PUT to demonstrate concurrency. Send a GET request and observe the ETag header (using Postman).

What are the three trouble concurrency?

Concurrency Control Problems The three main problems are lost updates, uncommitted data, and inconsistent retrievals.

What are the 3 possible cases of trouble concurrency?

Problems of Concurrency Control : The concurrency control has the following three main problems: Lost updates. Dirty read (or uncommitted data). Unrepeatable read (or inconsistent retrievals).

What are the three 3 main problems in concurrency control?

The concurrency control has the following three main problems:

• Lost updates.
• Dirty read (or uncommitted data).
• Unrepeatable read (or inconsistent retrievals).

What is difference between concurrency and multithreading?

Unit of Concurrency Multitasking – Multiple tasks/processes running concurrently on a single CPU. The operating system executes these tasks by switching between them very frequently. The unit of concurrency, in this case, is a Process. Multithreading – Multiple parts of the same program running concurrently.

What is concurrent update?

The concurrent update problem is something that can happen when multiple database sessions are permitted to update the same data at the same time – which is why it’s called the concurrent update problem. Whenever a database user connects to the database, a new session is created.

How does ASP net handle concurrent users?

Implementation

1. Step 1: Add a timestamp column to the targeted table(s) that you want to handle concurrent updates.
2. Step 2: Modify the SELECT statements to get the timestamps along with other data.
3. Step 3: Modify the Save procedure accordingly.
4. Step 4: .

How do you handle concurrent requests?

Handling Concurrent Requests in a RESTful API

1. User A requests resource 1 via a GET endpoint.
2. User B requests resource 1 via a GET endpoint.
3. User A makes changes on resource 1 and saves its changes via a PUT request.
4. User B makes changes on resource 1, on the same fields as user A, and saves its changes via a PUT request.

How many concurrent requests can a Web API handle?

With a single CPU core, a web server can handle around 250 concurrent requests at one time, so with 2 CPU cores, your server can handle 500 visitors at the same time. Getting the balance right between performance and cost is crucial as your site grows in popularity.

What is dirty read and phantom read?

Dirty reads: read UNCOMMITED data from another transaction. Non-repeatable reads: read COMMITTED data from an UPDATE query from another transaction. Phantom reads: read COMMITTED data from an INSERT or DELETE query from another transaction.

What is phantom problem?

The so-called phantom problem occurs within a transaction when the same query produces different sets of rows at different times. For example, if a SELECT is executed twice, but returns a row the second time that was not returned the first time, the row is a “phantom” row.

What are the causes of trouble concurrency?

Concurrency control is important because the simultaneous execution of transactions over a shared database can create several data integrity and consistency problems. The three main problems are lost updates, uncommitted data, and inconsistent retrievals.

What are three common problems with concurrent transaction execution?

If concurrency control is not maintained, three serious problems may be caused by concurrent transaction execution: lost updates, uncommitted data, and inconsistent retrievals.