Why Does Using a UNC Path Toss a Warning?

3385
13
06-28-2016 07:52 AM
JoeBorgione
MVP Esteemed Contributor

10.3.1 ArcGIS Server.

When I analyze a map service prior to publishing it, the analysis tosses a warning about using UNC paths.  Why is that?  Is there a more appropriate way to map to data stored on a network san?

can't wait to retire....
0 Kudos
13 Replies
DanPatterson_Retired
MVP Esteemed Contributor
MichaelMiller2
Regular Contributor

It's basically telling you that there may be reduced performance when using UNC data connections as opposed to direct connections. If you are sharing data on a network, really no way around it. Besides, the reduction in performance is very small if any, depending on your network.

JoeBorgione
MVP Esteemed Contributor

Thanks guys-  as far as performance goes, I can't imagine it being much of a hit for a couple reasons: The Map Service is only being read internally, and it's only being read by a third party application (9-1-1 dispatch CAD) to get data like dispatch zones and city of a given address point. So, no drawing involved per se.

Yes Dan,  when I expand the COde field it is 10027.

edit:  So I guess I'll just shine the warning.

Dan Patterson

Michael Miller

can't wait to retire....
0 Kudos
JoshuaBixby
MVP Esteemed Contributor

Accessing any data over a network, instead of locally on a machine, runs the risk that performance will be impacted, drawing or otherwise.  The point of the warning is to make a user aware that data is being accessed over a network, and that the user should probably check to see whether accessing that data over the network versus locally causes any performance problems.  If a user checks and doesn't notice a difference or is willing to accept the difference, the warning hasn't been ignored.  I strongly discourage users from ignoring the warning out of hand.

JoeBorgione
MVP Esteemed Contributor

Obviously, I haven't ignored the warning; I understand what it's about now, and consider it a non-issue for me.

can't wait to retire....
0 Kudos
VinceAngelo
Esri Esteemed Contributor

All access of data via network shares, either mounted or through a UNC is always slower.  In my benchmarking on two different gigabit networks, it was a consistent 50% performance penalty.  This has nothing to do with drawing (or even OS, since Linux had the same penalty).  My benchmarks were with both ArcPy and the FileGDB API, and no draw operations were a part of the tests.Local filesystem access is always fastest (unless you're using a USB2.0 protocol thumb drive).  I would recommend you evaluate the performance cost before considering it a non-issue.

JoeBorgione
MVP Esteemed Contributor

But....  All my machines are now virtural.  All my storage is on a san.  How does one get away from traversing networks?

can't wait to retire....
DanPatterson_Retired
MVP Esteemed Contributor

You are stuck by the fact that you aren't the only user of the data.

Quit sharing

0 Kudos
JoeBorgione
MVP Esteemed Contributor

Actually, I'm the only GIS guy and the data in question is being consumed by an internal, third party application (connected on a fiber network).  It's not like I have 200,000 AT&T iPhone users hitting the data and expecting a millisecond screen draw. The network guy sit down with me and we ran a few addresses through the CAD and the return was nearly simultaneous... 

can't wait to retire....
0 Kudos