ASP.NET Core: Saturating 10GbE at 7+ million request/s
In these “platform” comparisons that’s:
- x1.78 faster than ngnix
- x2.93 faster than Java’s Servlet (x7.76 faster than Servlet on Tomcat)
- x7.36 faster than Golang’s “net/http” package
- x8.06 faster than node.js running as a cluster of 28 processes (as node.js is single threaded)
Install-Package Microsoft.Extensions.Caching.StackExchangeRedis
public interface IResponseCacheService
{
Task CacheResponseAsync(string cacheKey, object response, TimeSpan timeToLive);
Task<string> GetCachedResponseAsync(string cacheKey);
} public class ResponseCacheService : IResponseCacheService, ISingletonDependency
{
private readonly IDistributedCache _distributedCache;
public ResponseCacheService(IDistributedCache distributedCache)
{
_distributedCache = distributedCache;
}
public async Task CacheResponseAsync(string cacheKey, object response, TimeSpan timeToLive)
{
if (response == null) return;
var serializedResponse = JsonConvert.SerializeObject(response);
await _distributedCache.SetStringAsync(cacheKey, serializedResponse, new DistributedCacheEntryOptions
{
AbsoluteExpirationRelativeToNow = timeToLive
});
}
public async Task<string> GetCachedResponseAsync(string cacheKey)
{
var cachedResponse = await _distributedCache.GetStringAsync(cacheKey);
return string.IsNullOrWhiteSpace(cachedResponse) ? null : cachedResponse;
}
} public class RedisCacheSettings
{
public bool Enabled { get; set; }
public string ConnectionString { get; set; }
public int DefaultSecondsToCache { get; set; }
} "RedisCacheSettings": {
"Enabled": true,
"ConnectionString": "192.168.1.107:6379,ssl=False,allowAdmin=True,abortConnect=False,defaultDatabase=0,connectTimeout=500,connectRetry=3",
"DefaultSecondsToCache": 600
}, public class CacheInstaller : IServiceInstaller
{
public void InstallServices(IServiceCollection services, AppSettings appSettings, Assembly startupProjectAssembly)
{
var redisCacheService = appSettings.RedisCacheSettings;
services.AddSingleton(redisCacheService);
if (!appSettings.RedisCacheSettings.Enabled) return;
services.AddStackExchangeRedisCache(options =>
options.Configuration = appSettings.RedisCacheSettings.ConnectionString);
// Below code applied with ISingletonDependency Interface
// services.AddSingleton<IResponseCacheService, ResponseCacheService>();
}
} [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
public class CachedAttribute : Attribute, IAsyncActionFilter
{
private readonly int _secondsToCache;
private readonly bool _useDefaultCacheSeconds;
public CachedAttribute()
{
_useDefaultCacheSeconds = true;
}
public CachedAttribute(int secondsToCache)
{
_secondsToCache = secondsToCache;
_useDefaultCacheSeconds = false;
}
public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
var cacheSettings = context.HttpContext.RequestServices.GetRequiredService<RedisCacheSettings>();
if (!cacheSettings.Enabled)
{
await next();
return;
}
var cacheService = context.HttpContext.RequestServices.GetRequiredService<IResponseCacheService>();
// Check if request has Cache
var cacheKey = GenerateCacheKeyFromRequest(context.HttpContext.Request);
var cachedResponse = await cacheService.GetCachedResponseAsync(cacheKey);
// If Yes => return Value
if (!string.IsNullOrWhiteSpace(cachedResponse))
{
var contentResult = new ContentResult
{
Content = cachedResponse,
ContentType = "application/json",
StatusCode = 200
};
context.Result = contentResult;
return;
}
// If No => Go to method => Cache Value
var actionExecutedContext = await next();
if (actionExecutedContext.Result is OkObjectResult okObjectResult)
{
var secondsToCache = _useDefaultCacheSeconds ? cacheSettings.DefaultSecondsToCache : _secondsToCache;
await cacheService.CacheResponseAsync(cacheKey, okObjectResult.Value,
TimeSpan.FromSeconds(secondsToCache));
}
}
private static string GenerateCacheKeyFromRequest(HttpRequest httpRequest)
{
var keyBuilder = new StringBuilder();
keyBuilder.Append($"{httpRequest.Path}");
foreach (var (key, value) in httpRequest.Query.OrderBy(x => x.Key))
{
keyBuilder.Append($"|{key}-{value}");
}
return keyBuilder.ToString();
}
} [Cached]
[HttpGet]
public IActionResult Get()
{
var rng = new Random();
var weatherForecasts = Enumerable.Range(1, 5).Select(index => new WeatherForecast
{
Date = DateTime.Now.AddDays(index),
TemperatureC = rng.Next(-20, 55),
Summary = Summaries[rng.Next(Summaries.Length)]
})
.ToArray();
return Ok(weatherForecasts);
} Working with SQL Server data in Power BI Desktop
"C:\Program Files\Microsoft SQL Server\120\LocalDB\Binn\\sqlservr.exe" -c -SMSSQL12E.LOCALDB -sLOCALDB#5657074F -d"C:\Users\Vahid\AppData\Local\Microsoft\Microsoft SQL Server Local DB\Instances\MSSQLLocalDB\master.mdf" -l"C:\Users\Vahid\AppData\Local\Microsoft\Microsoft SQL Server Local DB\Instances\MSSQLLocalDB\mastlog.ldf" -e"C:\Users\Vahid\AppData\Local\Microsoft\Microsoft SQL Server Local DB\Instances\MSSQLLocalDB\error.log"
msiexec /i SqlLocalDB.msi /qn IACCEPTSQLLOCALDBLICENSETERMS=YES
<connectionStrings> <add name="Sample35Context" connectionString="Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\test.mdf;Integrated Security=True;" providerName="System.Data.SqlClient" /> </connectionStrings>
C:\Users\your_user_name_here\AppData\Local\Microsoft\Microsoft SQL Server Local DB\Instances
For LocalDB SQL EXPRESS 2014 "C:\Program Files\Microsoft SQL Server\120\Tools\Binn\SqlLocalDB.exe" create "v12.0" 12.0 -s For LocalDB SQL Express 2012 "C:\Program Files\Microsoft SQL Server\110\Tools\Binn\SqlLocalDB.exe" create "v11.0" 11.0 -s
AppDomain.CurrentDomain.SetData("DataDirectory", AppDomain.CurrentDomain.BaseDirectory); AppDomain.CurrentDomain.SetData("DataDirectory", Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "db")); C:\Users\USERNAME\AppData\Local\Microsoft\Microsoft SQL Server Local DB\Instances C:\Users\USERNAME\AppData\Local\Microsoft\VisualStudio\SSDT
The database xyz cannot be opened because it is version 706. This server supports version 663 and earlier. A downgrade path is not supported.
<?xml version="1.0" encoding="utf-8"?> <configuration> <configSections> <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /> </configSections> <connectionStrings> <add name="Sample35Context" connectionString="Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\test.mdf;Integrated Security=True;" providerName="System.Data.SqlClient" /> </connectionStrings> <startup> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" /> </startup> <entityFramework> <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework"> <parameters> <parameter value="mssqllocaldb" /> </parameters> </defaultConnectionFactory> <providers> <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" /> </providers> </entityFramework> </configuration>
using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
using System.Diagnostics;
class Program
{
static void Main(string[] args)
{
using (var pdfDoc = new Document(PageSize.A4))
{
var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));
pdfDoc.Open();
var table1 = new PdfPTable(1);
table1.WidthPercentage = 100f;
table1.HeaderRows = 2;
table1.FooterRows = 1;
//header row
var headerCell = new PdfPCell(new Phrase("header"));
table1.AddCell(headerCell);
//footer row
var footerCell = new PdfPCell(new Phrase(" "));
table1.AddCell(footerCell);
//adding some rows
for (int i = 0; i < 400; i++)
{
var rowCell = new PdfPCell(new Phrase(i.ToString()));
table1.AddCell(rowCell);
}
// wrapping table1 in multiple columns
ColumnText ct = new ColumnText(pdfWriter.DirectContent);
ct.RunDirection = PdfWriter.RUN_DIRECTION_RTL;
ct.AddElement(table1);
int status = 0;
int count = 0;
int l = 0;
int columnsWidth = 100;
int columnsMargin = 7;
int columnsPerPage = 4;
int r = columnsWidth;
bool isRtl = true;
// render the column as long as it has content
while (ColumnText.HasMoreText(status))
{
if (isRtl)
{
ct.SetSimpleColumn(
pdfDoc.Right - l, pdfDoc.Bottom,
pdfDoc.Right - r, pdfDoc.Top
);
}
else
{
ct.SetSimpleColumn(
pdfDoc.Left + l, pdfDoc.Bottom,
pdfDoc.Left + r, pdfDoc.Top
);
}
var delta = columnsWidth + columnsMargin;
l += delta;
r += delta;
// render as much content as possible
status = ct.Go();
// go to a new page if you've reached the last column
if (++count > columnsPerPage)
{
count = 0;
l = 0;
r = columnsWidth;
pdfDoc.NewPage();
}
}
}
//open the final file with adobe reader for instance.
Process.Start("Test.pdf");
}
}
// Before
void Insert(string s) {
if (s is null) {
throw new ArgumentNullException(nameof(s));
}
...
}
// After
void Insert(string s!) {
...
} 
Last year a team of six researchers in Portugal from three different universities decided to investigate this question, ultimately releasing a paper titled “Energy Efficiency Across Programming Languages.”
SQL Server 2014 DML Triggers are often a point of contention between Developers and DBAs, between those who customize a database application and those who provides it. They are often the first database objects investigated when the performance degrades. They seem easy to write, but writing efficient Trigger, though complex have a very important characteristic: they allow solving problems that cannot be managed in any other application layer. Therefore, if you cannot work without them, in this article you will learn tricks and best practices for writing and managing them efficiently.
