The patch reported as cause is:
https://gerrit.ovirt.org/#/c/93345/10 - engine : Add finer grained monitoring thresholds for memory consumption on Hypervisors

Ravi, can you please check this issue?

You can see the logs here:

https://jenkins.ovirt.org/job/ovirt-master_change-queue-tester/10187/artifact/basic-suite.el7.x86_64/test_logs/basic-suite-master/

Here is the error:

2018-09-11 02:08:44,511-04 WARN  [org.ovirt.engine.core.bll.AddClusterCommand] (default task-2) [1362d97c-9d55-40d2-9b03-ebe93ae2fe67] Validation of action 'AddCluster' failed for user admin@internal-authz. Reasons: VAR__TYPE__CLUSTER,VAR
__ACTION__CREATE,must be greater than or equal to 1,$groups [Ljava.lang.Class;@29a040fc,$message {javax.validation.constraints.Min.message},$payload [Ljava.lang.Class;@64094510,$value 1,ACTION_TYPE_FAILED_ATTRIBUTE_PATH,$path cluster.logM
axMemoryUsedThreshold,$validatedValue 0
2018-09-11 02:08:44,511-04 DEBUG [org.ovirt.engine.core.common.di.interceptor.DebugLoggingInterceptor] (default task-2) [1362d97c-9d55-40d2-9b03-ebe93ae2fe67] method: runAction, params: [AddCluster, ManagementNetworkOnClusterOperationPara
meters:{commandId='e5eb6cf6-4e3d-4f50-be6a-9fe18bfc4d97', user='null', commandType='Unknown'}], timeElapsed: 56ms
2018-09-11 02:08:44,516-04 ERROR [org.ovirt.engine.api.restapi.resource.AbstractBackendResource] (default task-2) [] Operation Failed: [must be greater than or equal to 1, Attribute: cluster.logMaxMemoryUsedThreshold]
2018-09-11 02:08:44,533-04 DEBUG [org.ovirt.engine.core.aaa.filters.SsoRestApiAuthFilter] (default task-2) [] Entered SsoRestApiAuthFilter

Thanks,

Dafna