A number in parentheses after an agent name indicates that the name has been indexed because when the agent connected there was already an agent connected that has the same name that this new agent would receive, sometimes caused after a restart when the agent reconnects before it has fully disconnected from the server.
Does that help?
Any disconnected agents (even the ones that are just indexed) will disappear from the overview after 72 hours I believe.
To avoid the indexing completely there is actually a debug flag the you can set on the collector which is pretty common:
One reason we use this is so that for the incident "application process unavailable" start and end alerts are more accurate and don't get confused by the indexing.
Is there any way to decrease this 72 hour timeout without removing the index number entirely?
My current client wants to prevent indexing for servers that restart but wants to keep the indexing for other reasons.
The 72 hours isn't really a timeout it's just how long the overview will continue to show disconnected agents it is not directly related to indexing. I'm not aware of any way to adjust this.
And I believe indexing is an all or nothing thing, although as of 6.5 it seems you can just set that flag on the server itself to prevent indexing but I have not tried that yet.
One comment I want to add on top of what James has accurately pointed out. Yes, the debug flag used to be on the Collector but if you're on 6.5, that debug flag is actually now part of the Server.ini file (went through this at my client site as well).
Here is a link to the doc about it -> https://community.dynatrace.com/community/display/...
Hope that helps,