Yet another "How many service instances?" thread....

02-24-2016 08:25 AM
MVP Frequent Contributor

I know this gets asked a lot, but here it is in different context: If the number of CPU cores and RAM was not a limiting factor, how many service instances can a single ArcGIS Server push?

I have a single-server site, with a bottomless supply of cores and bytes, with 50-ish map/feature services, and 10-ish cached image services. I  push 2 minimum, 10 max instances on each service. There is no hard number I've found yet, but when I start pushing some of the more popular services to 5 min, 10 max, server stability fails and often data store corruption occurs.

I've heard 250-500 is the max number of service instances ArcGIS Server will handle. Does this call for adding GIS Server nodes to a cluster? Which is a bad idea. Does ArcGIS on RH Linux push more service instances? The IT guys are telling me that threads are running out of control on this server.

I'm needing to spool up more minimum instances, as the amount of time it takes for a new instance to spool up when min instances is exceeded causes the client to time out. And frankly, if I can call upon limitless CPU cores, then dang it, I should be able to push as many instances as I want.

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3 Replies
MVP Esteemed Contributor

Not to be a spoiler.....but you may need to see what your license allows.

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MVP Frequent Contributor


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Occasional Contributor III

Is there any other business systems running on the server?  We have a similar setup to you guys and we never see an issue with CPU.  We did see some stability issues when we were running SQL and ArcGIS server on the same machine, because SQL would try to chew up all the memory during a cache process and there would be memory contention.  We just throttled back the max memory consumption in the interim until we got a new server for SQL to off load that load.

The only instability that I have seen is from the above, or the javaw.exe ArcGIS server process that runs and grabs a bunch of memory that will bring a site to a crawl.  This has not been an issue since upgrading to 10.3.1. 

All of our instability is due to memory consumption, definitely not CPU intensive unless a cache process is taking place.  We never have issues with allocating more instances to a service within the means of our allotted memory on the server, we are even starting to increase min instances on our popular services to the max that ArcGIS server statistics have shown spun up at any one time.

All of our services have a max of 40 which is higher than I have ever seen used by any one service as one of the old ESRI guys Tom Brenneman mentioned in his blog to allocate as many instances as possible to each service for best performance.

He has a lot of server knowledge

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