JonCole

ThreadPool Growth: Some Important Details

The CLR ThreadPool has two types of threads - "Worker" and "I/O Completion Port" (aka IOCP) threads.

• Worker threads are used when for things like processing Task.Run(…) or ThreadPool.QueueUserWorkItem(…) methods. These threads are also used by various components in the CLR when work needs to happen on a background thread.
• IOCP threads are used when asynchronous IO happens (e.g. reading from the network).

The thread pool provides new worker threads or I/O completion threads on demand (without any throttling) until it reaches the "Minimum" setting for each type of thread. By default, the minimum number of threads is set to the number of processors on a system.

Once the number of existing (busy) threads hits the "minimum" number of threads, the ThreadPool will throttle the rate at which is injects new threads to one thread per 500 milliseconds. This means that if your system gets a burst of work needing an IOCP thread, it will proces

JonCole

The Symptom

An application is using StackExchange.Redis to connect to their Redis instance and everything is working fine until suddenly exceptions like this start happening.

It was not possible to connect to the redis server(s); to create a disconnected multiplexer, disable AbortOnConnectFail.
at StackExchange.Redis.ConnectionMultiplexer.ConnectImpl(Func`1 multiplexerFactory, TextWriter log)
at MyApp.Web.Redis.StackExchangeClientConnection..ctor(ProviderConfiguration configuration)
at MyApp.Web.Data.GetInventoryData()

The Cause

JonCole

Diagnosing Redis errors on the server side

The content from this GIST has been moved to official Azure Cache for Redis Documentation. The new location is https://docs.microsoft.com/azure/azure-cache-for-redis/cache-how-to-troubleshoot#server-side-troubleshooting

Please update your bookmarks.

JonCole

Diagnosing Redis errors on the client side

Content moved

The content from this GIST has been moved to official Azure Cache for Redis Documentation. The new location is https://docs.microsoft.com/azure/azure-cache-for-redis/cache-troubleshoot-client

Please update your bookmarks.

JonCole

When contacting us with questions, please provide the following information to enable us to best help you.

Required Information

• Cache Name

• Date&Time when issue started and ended. Note: A 1-2 hour time window is ideal. If the issue is intermittent, please provide exact times for a few of the errors so that we can correlate with our logs.

  Important: Please Specify whether times are in UTC or some other Time > Zone. If you do not clarify the time zone, we don't know what time

JonCole

using System;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;

namespace System.Diagnostics
{
    public static class CrashDumpHelper
    {
        /// <summary>

JonCole

Content Moved

The content from this article has been moved to a happier home on our official documentation site - please update your bookmarks.

JonCole

using System;

namespace StackExchange.Redis
{
    static class RedisKeyspaceNotifications
    {
        /// <summary>
        /// NOTE: For this sample to work, you need to go to the Azure Portal and configure keyspace notifications with "Kxge$" to
        ///       1) turn on expiration notifications (x), 
        ///       2) general command notices (g) and 

JonCole

Contents Moved

The contents of this article have moved to a new, happier home https://aka.ms/Redis/DataLoss

JonCole

namespace StackExchange.Redis
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Net;

    public static class StackExchangeRedisExtensions
    {
        public static IEnumerable<IServer> GetMasterServers(this IConnectionMultiplexer connection)