Explanation
If the class that wraps the external resource is shareable and thread-safe, create a shared singleton instance or a
pool of reusable instances of the class.
The following example uses a static HttpClient instance, thus sharing the connection across all requests.
public class SingleHttpClientInstanceController : ApiController
{
private static readonly HttpClient httpClient;
static SingleHttpClientInstanceController()
{
httpClient = new HttpClient();
}
// This method uses the shared instance of HttpClient for every call to GetProductAsync.
public async Task<Product> GetProductAsync(string id)
{
var hostName = HttpContext.Current.Request.Url.Host;
var result = await httpClient.GetStringAsync(string.Format("http://{0}:8080/api/...", hostName));
return new Product { Name = result };
}
}
References: https://docs.microsoft.com/en-us/azure/architecture/antipatterns/improper-instantiation/