Redis cluster cause Null Reference in Dashboard.Instances.cshtml

[fdjy1234]

I've Redis clusters configured, 6 nodes cluster with 3 masters and 3 slaves

I'm getting a NullReference exception on line 199 in Opserver\Opserver\Views\Redis\Dashboard.Instances.cshtml

Line 199: @Helpers.PollNow(mastersWithSlaves.Union(mastersWithSlaves.SelectMany(s => s.GetAllSlavesInChain())))

Full stacktrace:
   System.Linq.<SelectManyIterator>d__16`2.MoveNext() +216
   System.Linq.<UnionIterator>d__66`1.MoveNext() +230
   System.Linq.<DistinctIterator>d__63`1.MoveNext() +60
   System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +460
   System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
   StackExchange.Opserver.Data.Redis.RedisInstance.GetAllSlavesInChain() in C:\Users\099042\AppData\Local\GitHub\TutorialRepository_fdbf2020839cde135ff9dbed7d503f8e03fa3ab4\new-repo\Opserver\Opserver.Core\Data\Redis\RedisInstance.Info.cs:127
   ASP.<>c.<Execute>b__6_11(RedisInstance s) in C:\Users\099042\AppData\Local\GitHub\TutorialRepository_fdbf2020839cde135ff9dbed7d503f8e03fa3ab4\new-repo\Opserver\Opserver\Views\Redis\Dashboard.Instances.cshtml:199
   System.Linq.<SelectManyIterator>d__16`2.MoveNext() +188
   System.Linq.<UnionIterator>d__66`1.MoveNext() +230
   System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +190
   System.Web.Script.Serialization.JavaScriptSerializer.SerializeEnumerable(IEnumerable enumerable, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat) +139
   System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember) +1335
   System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember) +196
   System.Web.Script.Serialization.JavaScriptSerializer.Serialize(Object obj, StringBuilder output, SerializationFormat serializationFormat) +29
   System.Web.Script.Serialization.JavaScriptSerializer.Serialize(Object obj, SerializationFormat serializationFormat) +64
   System.Web.Helpers.Json.Encode(Object value) +93
   ASP.<>c__DisplayClass3_0.<PollNow>b__0(TextWriter __razor_helper_writer) in C:\Users\099042\AppData\Local\GitHub\TutorialRepository_fdbf2020839cde135ff9dbed7d503f8e03fa3ab4\new-repo\Opserver\Opserver\App_Code\Helpers.cshtml:23
   System.Web.WebPages.HelperResult.WriteTo(TextWriter writer) +10
   System.Web.WebPages.WebPageBase.Write(HelperResult result) +80
   ASP._Page_Views_Redis_Dashboard_Instances_cshtml.Execute() in C:\Users\099042\AppData\Local\GitHub\TutorialRepository_fdbf2020839cde135ff9dbed7d503f8e03fa3ab4\new-repo\Opserver\Opserver\Views\Redis\Dashboard.Instances.cshtml:199
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +197
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +105
   System.Web.WebPages.StartPage.RunPage() +17
   System.Web.WebPages.StartPage.ExecutePageHierarchy() +64
   System.Web.WebPages.StartPage.RunPage() +17
   System.Web.WebPages.StartPage.ExecutePageHierarchy() +64
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +78
   System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +235
   System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +107
   StackExchange.Profiling.Mvc.WrappedView.Render(ViewContext viewContext, TextWriter writer) +121
   System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +291
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +56
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +420
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +52
   System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +173
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +100
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +13
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +36
   System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller) +12
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +22
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +21
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +577
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +157

my RedisSettings.json

{
    "allServers": {
        "name": "Localhost",
        "instances": [
                {
                    "name": "cluser_6380",
                    "port": "6380"
                },
                {
                    "name": "cluser_6381",
                    "port": "6381"
                },
                {
                    "name": "cluser_6382",
                    "port": "6382"
                },
                {
                    "name": "cluser_6383",
                    "port": "6383"
                },
                {
                    "name": "cluser_6384",
                    "port": "6384"
                },
                {
                    "name": "cluser_6385",
                    "port": "6385"
                }
            ]
    },
    "Servers": [
        { "name": "Localhost" }
    ]
}

[NickCraver]

Just checking - you're on the overhaul branch, correct?

[NickCraver]

@fdjy1234 pull latest and give it a try from overhaul please!

[fdjy1234]

i got overhaul and try. i get exception on line 23 in Helpers.cshtml, NullReferenceException

line 23: <a href="#" class="pull-right hover-pulsate js-reload-link" data-type="@(nodes.FirstOrDefault()?.NodeType)" data-uk="@Json.Encode(nodes.Select(i => i.UniqueKey))"><span class="glyphicon glyphicon-refresh"></span> <span class="js-text">Poll Now</span></a>

Full stacktrace:
ASP.<>c.<PollNow>b__3_1(PollNode i) in C:\github_project\Opserver\Opserver\App_Code\Helpers.cshtml:23
   System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +164
   System.Web.Script.Serialization.JavaScriptSerializer.SerializeEnumerable(IEnumerable enumerable, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat) +138
   System.Web.Script.Serialization.JavaScriptSerializer.SerializeValueInternal(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember) +1335
   System.Web.Script.Serialization.JavaScriptSerializer.SerializeValue(Object o, StringBuilder sb, Int32 depth, Hashtable objectsInUse, SerializationFormat serializationFormat, MemberInfo currentMember) +195
   System.Web.Script.Serialization.JavaScriptSerializer.Serialize(Object obj, StringBuilder output, SerializationFormat serializationFormat) +29
   System.Web.Script.Serialization.JavaScriptSerializer.Serialize(Object obj, SerializationFormat serializationFormat) +64
   System.Web.Helpers.Json.Encode(Object value) +93
   ASP.<>c__DisplayClass3_0.<PollNow>b__0(TextWriter __razor_helper_writer) in C:\github_project\Opserver\Opserver\App_Code\Helpers.cshtml:23
   System.Web.WebPages.HelperResult.WriteTo(TextWriter writer) +10
   System.Web.WebPages.WebPageBase.Write(HelperResult result) +80
   ASP._Page_Views_Redis_Dashboard_Instances_cshtml.Execute() in C:\github_project\Opserver\Opserver\Views\Redis\Dashboard.Instances.cshtml:199
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +197
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +105
   System.Web.WebPages.StartPage.RunPage() +17
   System.Web.WebPages.StartPage.ExecutePageHierarchy() +64
   System.Web.WebPages.StartPage.RunPage() +17
   System.Web.WebPages.StartPage.ExecutePageHierarchy() +64
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +78
   System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +235
   System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +107
   StackExchange.Profiling.Mvc.WrappedView.Render(ViewContext viewContext, TextWriter writer) +121
   System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +291
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +56
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +420
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +52
   System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +173
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +100
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +13
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +36
   System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller) +12
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +22
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +21
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +577
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +157

[NickCraver]

All of these symptoms point to a null node in the list...and I'm not sure how that's happening without setting up a cluster here. I'll try and find time to do so in the coming weeks.