Clients going offline


#1

I’m having trouble with certain clients going offline after some amount of time. The clients begin online and are able to successfully complete a backup, but eventually they go offline and are no longer functional. Restarting the client machine or reinstalling the agent temporarily resolves the issue, but eventually they go offline again.

All clients are on the local network. The affected clients are Windows 7 x64. I’m using Server 2.3.7 and client 2.3.4. This was happening with the previous 2.2 server and client version as well. I can ping the affected clients from the server, so I don’t believe it’s a network connectivity issue.

How can I begin troubleshooting this issue?

Thank you!


#2

Additional info:

  • Restarting the agent on the client does not bring the client back online
  • Restarting the client machine does bring the client back online
  • Does not seem to affect every Windows 7 machine in the environment, just a couple
  • Firewalls on the server and on the clients disabled

Affected clients are yellow04 and yellow05.

Server log:
Server urbackup.log (465.1 KB)

Yellow04 client log (note: I grabbed this log file after restarting the client, so the client is online at the time of the log, but was showing offline before that):
debug.log (3.3 MB)

Yellow05 client log (Note: I grabbed this log file while the client was showing offline):
debug.log (3.5 MB)


#3

And in case it’s helpful, here’s the log from a Windows 7 client that’s not experiencing the issue (my own personal machine, NHFS10):
debug.log (1.9 MB)


#4

Did I read the log right:
2018-11-02 11:08:43: ERROR: Error while enumerating user groups: 2453
2018-11-02 11:08:43: ERROR: Error while enumerating DC user groups: 2221

You have 2453 Users, and you’re using the LDAP integration (which is beta only atm)?

Are server and workstation on same subnet? If you have that many users you must have multiple subnets or super-subnetting or something else. Client finds server with UDP discovery, check traffic routing.

On your server your database upgraded to 56 on 10/26/2018

but then did upgrade 57-59 on 12/28/2018?

Can’t tell when you’re having the client disconnect issues, do you have a date/time range in mind?

Delete problem clients and the saved data on the client machines associated with urbackup then reinitialize Urbackup and see if you still have errors.


#5

A client debug log would be interesting.

Also look for something that is different/same with the affected machines. For example network drivers. How many network interfaces of what type do they have? Some kind of virtual interfaces (VMs)?

Also the output of netstat -abno on a client while it is not working would be interesting. UrBackupClientBackend.exe should listen on UDP port 35622.


#6

@silversword, Thanks for responding.

Nope, we have 48 active user accounts and 71 groups. We’re very small. We are not using LDAP integration:

Server and workstations are all on the same subnet.

As mentioned in my second post, both clients (yellow04 and yellow05 were offline yesterday (31/12/18). Yellow05 was offline at the time I grabbed the log file, and Yellow04 had also been offline, but I restarted it and brought it back online just before I grabbed the log. I’m not sure when they went offline, but it would have been the same day. I’ll keep an eye on them and try to give a better indication of when they go offline.

When you say delete the problem clients, do you mean remove them from the console and uninstall the agent? Will I lose their current backups?

Thanks!


#7

@uroni, @silversword

I think the problem is solved, and it turns I may just be an idiot :slight_smile:

At least one of the clients was using an incorrect DNS server. Changing the DNS server and restarting the urBackup service immediately brought the client back online.

I’m pretty confident that was the issue, but if it continues to occur I’ll update this thread.

Thank you both!


#8

That might fix the AD issue (the client enumerates AD users; the server side thing is something different). Though I doubt it’ll fix the discoverability issue.

Another thing: You said reinstalling the client helps but restarting the client service doesn’t? If yes, then it is wierd (if you reinstall the same version all it does is restarting the service).


#9

The client being unable to resolve the server address wouldn’t cause an issue?

Yup, that seemed to be the case.

We’ll see what happens going forward!


#10

@uroni, @silversword

No client issues since fixing my DNS issues :slight_smile: Sorry again for wasting your time!