How to read server statistic correctly

Question

I need a better understanding about reading server stats.

I have like a total of 10-12 map services. All hosted on AWS, single server.

I monitor all of them by reading their Total Request, Maximum Running Instances, Average Response Time and Maximum Response Time.

Here is the data:

My biggest question is how on earth "Map Svc A"with Total Request of 831 at Time 1 has Average response time of under 1 second whereas "Map Svc B" with Total Request of just 31 has max Response Tme of 221 seconds ? At time 4, all  both Map Services A and B are really slow.

What is going on ? How to read the server stats correctly ?

Here is some graphics to give general idea.

The graphic below shows the Max Running Instances, Total Request and Average Response of ALL Map services at both times, 1 and 4.

The graphic below shows that Service Maximum Running Instances all 0.

Here is the graphic about Total Request of Map Service A and B at two different times:

Here is a graphic about Average Response Time:

Any explanation welcome. I want to understand it better..

Thanks

berniejconnors · Answer

I rarely look at the Maximum Running Instance stats.  I have never found it useful and it does not appear to align with the other stats I am seeing.  We use very few feature services - we use map services and image services.  Here are charts of our most popular map service.  This service depicts our tax parcels (~450,000 polygons) and it receives about 270,000 hits per day.  It is configured for min=1 and max=6 instances and it is running on a site with three machines.  So the true min is 3 and the true max is 18.

This was captured at 9 am on a Thursday morning showing the last 24 hours. You can see the running instances drops to 1 during the quietest part of the day and is frequently at 6 during the busiest part of the day.  I don't understand why your Max Running Instances is showing 0 - it should be showing 2 if your feature services are using dedicated instances with min = 2.

And don't forget the number of running instances are tied to several timeout settings.  Once an instance is activated it will hang around in an idle state until the timeout value expires:

You asked a similar question last summer.  Perhaps you should contact Esri support for clarification.

Bernie.

yockee · Answer

berniejconnors HenryLindemann

Okey. Thanks for the reply.

Being hit by heavy Total Request, why the Service Maximum Running Instance lie flat 0 for both Map Services A and B ? Shouldn't they be picking up the request ? Or may be there is no available instances to process the request ? I set the instances to a fixed number. For Map Service A : min 2 max  5; Map Service B : min 2 max 4.

By the way, Service Maximum Running Instance is the number of instances that you set to handle the request. Those map service A and B are feature services and being accessed by mobile apps and desktop, possibly concurrently, but not all the time.

berniejconnors · Answer

Esri's low-code / no-code app builders make it really easy to build apps that look very polished.  But looking polished does not equate to fast and efficient use of your ArcGIS Server services.  You still have to ensure the apps are configured properly or you will have poor performance >> slow apps and busy servers.