Yes lots of times, the clear events are key, what events are you using?

Hi Jeavon,

I'm using the below to clear off the cache. Do i need to change it for a load balance environment? Thanks

public class OutputCacheClearerEvents : IApplicationEventHandler
    {
        public void OnApplicationInitialized(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
        { }

        public void OnApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
        {
            content.AfterRefreshContent += ContentServiceOnEvent;
            ContentService.Published += ContentServiceOnEvent;
            ContentService.UnPublished += ContentServiceOnEvent;
            ContentService.Deleted += ContentServiceOnEvent;
            ContentService.Moved += ContentServiceOnEvent;
            ContentService.Trashed += ContentServiceOnEvent;
            MediaService.Saved += MediaServiceOnEvent;
        }

        public void OnApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
        { }


        private static void ContentServiceOnEvent(object sender, object e)
        {
            ClearCache();
        }

        private static void MediaServiceOnEvent(object sender, object e)
        {
            ClearCache();
        }

        private static void ClearCache()
        {
            try
            {
                var cacheManager = new OutputCacheManager();
                cacheManager.RemoveItems();
            }
            catch (Exception ex)
            {
                LogHelper.Error(typeof(OutputCacheClearerEvents), "Error clearing cache", ex);
            }
        }
    }

Those events are not going to occur on all servers. Instead you should use the cache events as shown below (you should also be using ApplicationEventHandler)

namespace MyProject.Events
{
    using System;

    using Umbraco.Core.Cache;
    using Umbraco.Core.Logging;
    using Umbraco.Web.Cache;
    using Umbraco.Core;

    using DevTrends.MvcDonutCaching;

    public class UmbracoEvents : ApplicationEventHandler
    {
        protected override void ApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
        {
            CacheRefresherBase<PageCacheRefresher>.CacheUpdated += this.CachePageEvents_CacheUpdated;
            CacheRefresherBase<DictionaryCacheRefresher>.CacheUpdated += this.CacheDictionaryEvents_CacheUpdated;
            CacheRefresherBase<MediaCacheRefresher>.CacheUpdated += this.CacheMediaEvents_CacheUpdated;
        }

        private void CacheMediaEvents_CacheUpdated(MediaCacheRefresher sender, CacheRefresherEventArgs e)
        {
            ClearDonutOutputCache();
        }

        private void CacheDictionaryEvents_CacheUpdated(DictionaryCacheRefresher sender, CacheRefresherEventArgs e)
        {
            ClearDonutOutputCache();
        }

        private void CachePageEvents_CacheUpdated(PageCacheRefresher sender, CacheRefresherEventArgs e)
        {
            ClearDonutOutputCache();
        }

        private void ClearDonutOutputCache()
        {
            var cacheManager = new OutputCacheManager();
            cacheManager.RemoveItems();
            LogHelper.Info<UmbracoEvents>(string.Format("Donut Output Cache Cleared On Server:{0} AppDomain:{1}", Environment.MachineName, System.AppDomain.CurrentDomain.FriendlyName));
        }
    }
}

Nice. Thanks Jeavon ;)

Hey Jeavon,

Quick question, is there a way i can check for a certain document type to be excluded from the CachePageEvents_CacheUpdated?

Thanks

The reason is I've got a feed that update and publish a node every 20 minutes. So wanted to detect and exclude that node from clearing the cache if it's possible.

Thanks

You're a superstar Jeavon ;)

Hey Jeavon quick question,

Have you came across a way to rebuild indexes on a distributed environments?

Eg when the Developer Section > Examine Management index gets rebuild on a single environment and it rebuilds on the rest of the environments

Can't find anything in the forum

Thanks

Hey Tommy,

Just saw this. You mean rebuild the entire indexes on individual load balancing environment?

Reminded me, I did build a simple tool for this, it's on GitHub (no package currently) https://github.com/CrumpledDog/ExamineDistributedDashboard

Hi,

Is there any way to achieve Donut caching but not clear all cache items everytime we publish? Wont this cause an overhead on servers which are constantly publishing?

Poornima

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