Enterprise Search Problems : SharePoint Web Services Round Robin Service Load Balancer Event: EndpointFailure / Service too busy

Hi,

We are using Searh for local sites only, no search centre is created. so all search is scoped either at site level (OOB) or at library level(OOB).

We are getting following two errors very frequently. Please suggest solution and expected Search topology and search service location to start the service depending on provided farm details.  (Farm details are available after error description)

1. EndPointFaliure

SharePoint Web Services Round Robin Service Load Balancer Event: EndpointFailure

Process Name: w3wp

Process ID: 5552

AppDomain Name: /LM/W3SVC/1456599822/ROOT-1-129854037160725674

AppDomain ID: 2

Service Application Uri: urn:schemas-microsoft-com:sharepoint:service:01361a703232485b80439ddd2a6747f3#authority=urn:uuid:a74ce0713bc642bc874ae0352edc7d4f&authority=https://WFE1:32844/Topology/topology.svc

Active Endpoints: 3

Failed Endpoints:1

Affected Endpoint: http://APP1:32843/01361a703232485b80439ddd2a6747f3/SearchService.svc

2. Service too busy

The Execute method of job definition Microsoft.Office.Server.Search.Monitoring.TraceDiagnosticsProvider (ID ef82820a-9558-4552-a79b-a4687962a4ac) threw an exception. More information is included below. 

The HTTP service located at http://APP1:32843/01361a703232485b80439ddd2a6747f3/SearchService.svc is too busy.

3. Null reference exception in ULS Logs

The Execute method of job definition Microsoft.Office.Server.Search.Monitoring.TraceDiagnosticsProvider (ID ef82820a-9558-4552-a79b-a4687962a4ac) threw an exception. More information is included below. 

My farm setup is as given below:

Farm Setup

I have Sharepoint Farm with following topology.

WFE : WFE1, WFE2

App: APP1, APP2

DB : DB1

Sercvice run on All WFE and APP servers : Search Query and Site Settings service, SharePoint Server Search

Event log for endpoint initialization:

http://WFE1:32843/01361a703232485b80439ddd2a6747f3/SearchService.svc

http://APP1:32843/01361a703232485b80439ddd2a6747f3/SearchService.svc

http://WFE2:32843/01361a703232485b80439ddd2a6747f3/SearchService.svc

http://APP2:32843/01361a703232485b80439ddd2a6747f3/SearchService.svc

Search server topoloty

Search Admin component: WFE1

Crawl Component: APP1

All DB : DB1

Index partion 0 - Query Component 1  on WFE1

                          - Query Component 2 on WFE2 (Mirrered)

Thanks in advance,

Vikas Patel.

Regards, Vikas Patel