Daniel, I have a vague recollection you handled something similar with domains missing some/all of their connections?

(In reply to Yedidyah Bar David from comment #0)
> 
> The code doing this, in that test, is [2] (this is a link to a gerrit
> change, but that change does not touch the test code - so you can check
> he-basic-master code in current master):
> 
>  187     api.vms.get(VM0_NAME).snapshots.list()[-2].delete()
>  188     testlib.assert_true_within_short(
>  189         lambda:
>  190         (len(api.vms.get(VM0_NAME).snapshots.list()) == 2) and
>  191         (api.vms.get(VM0_NAME).snapshots.list()[-1].snapshot_status
>  192          == 'ok'),
>  193     )

The error [1] originated form GetVmConfigurationBySnapshotQuery, which is a part of the flow of retrieving snapshots (GetVmConfigurationBySnapshot). The snapshot is missing since it's being deleted. To avoid such races, the suggested patch ignores the result of GetVmConfigurationBySnapshot on failure.
This should fix the issue, however, I would suggest to simplify the test by checking the existence of the deleted snapshot. E.g. something like:

  snapshots_service = vm_service.snapshots_service()
  snapshot = snaps_service.list()[-2]
  snapshot_service = snapshots_service.snapshot_service(snapshot.id)
  snapshot_service.remove()
  testlib.assert_true_within_short(
      lambda:
      get_snapshot(snapshots_service, snapshot.id) == None
      ),
  )

  def get_snapshot(snapshots_service, id):
    try:
        return snapshots_service.snapshot_service('cc').get()
    except:
        return None


[1] [org.ovirt.engine.core.bll.GetVmConfigurationBySnapshotQuery] (default task-3) [37d73c43-ccb7-4f68-b684-7dbdccdf0b44] Snapshot '41e33b04-329c-4de5-acf4-7b9ab9bb4e5f' does not exist

Daniel, can you add steps to reproduce?

(In reply to Lilach Zitnitski from comment #3)
> Daniel, can you add steps to reproduce?

Steps are described in the description[*], it was encountered on OST.
In a nutshell, the scenario is: (using the api)
* Delete a snapshot
* Immediately get snapshots list

[*]
"
The code doing this, in that test, is [2] (this is a link to a gerrit change, but that change does not touch the test code - so you can check he-basic-master code in current master):

 187     api.vms.get(VM0_NAME).snapshots.list()[-2].delete()
 188     testlib.assert_true_within_short(
 189         lambda:
 190         (len(api.vms.get(VM0_NAME).snapshots.list()) == 2) and
 191         (api.vms.get(VM0_NAME).snapshots.list()[-1].snapshot_status
 192          == 'ok'),
 193     )
"

Daniel - looking at the patch, it seems this bug is not specific to the V3 API. Can you please confirm (and edit the title) or refute (and explain how I've got it wrong)?

(In reply to Allon Mureinik from comment #5)
> Daniel - looking at the patch, it seems this bug is not specific to the V3
> API. Can you please confirm (and edit the title) or refute (and explain how
> I've got it wrong)?

Indeed, it has been reproduced also in v4.

--------------------------------------
Tested with the following code:
----------------------------------------
rhvm-4.2.1.3-0.1.el7.noarch
vdsm-4.20.17-1.el7ev.x86_64

Tested with the following scenario:

Steps to Reproduce:
1. using API, remove snapshot
2. using API, get snapshot list

Actual results:
No errors appear in the log

Expected results:

Moving to VERIFIED!

This bugzilla is included in oVirt 4.2.1 release, published on Feb 12th 2018.

Since the problem described in this bug report should be
resolved in oVirt 4.2.1 release, it has been closed with a resolution of CURRENT RELEASE.

If the solution does not work for you, please open a new bug report.