Critical error All management server resource pool

Question

I just receive critical error: All management server resource pool in scom 2012 management console.
Alert detail:
Alert subscription data source module encountered errors while running: Alert subscription data source module was unable to find alerts that match the subscription because of database errors.
The following error(s) were encountered:
Exception Message: ExecuteScalar requires an open and available Connection. The connection's current state is closed.
One or more workflows were affected by this.
Workflow name: Subscription3f818422_f4a1_42aa_b1b3_8bc14eb54cd8
Instance name: Alert Notification Subscription Server
Instance ID: {E07E3FAB-53BC-BC14-1634-5A6E949F9230}
Management group: SCOM_2012
What is problem and how to fix it ? I haven't changed any setting in scom !!

Answer 1

Only found some of error and warning in operation manager event log.
Error:
Source: Health Service Modules
Event ID: 22406
Task Category: NOne
The PowerShell script failed with below exception
System.Management.Automation.CmdletInvocationException: The following error occurred while loading the extended type data file:
Microsoft.PowerShell, C:\Program Files\System Center Operations Manager 2012\Powershell\OperationsManager\.\OM10.CoreCommands\Microsoft.EnterpriseManagement.Core.Cmdlets.Types.ps1xml : File skipped because it was already present from "Microsoft.PowerShell".
At line:8 char:66
+               if (!(Get-Module OperationsManager)) {Import-module <<<<  $SCOMModulePath}
   at System.Management.Automation.Internal.PipelineProcessor.SynchronousExecuteEnumerate(Object input, Hashtable errorResults, Boolean enumerate)
   at System.Management.Automation.PipelineNode.Execute(Array input, Pipe outputPipe, ArrayList& resultList, ExecutionContext context)
   at System.Management.Automation.StatementListNode.ExecuteStatement(ParseTreeNode statement, Array input, Pipe outputPipe, ArrayList& resultList, ExecutionContext context)
Script Name: Discover Agent Versions
One or more workflows were affected by this. 
Workflow name: ManagementGroupDiscoveryAgentVersions
Instance name: Operations Manager Management Group
Instance ID: {6B1D1BE8-EBB4-B425-08DC-2385C5930B04}
Management group: SCOM_2012
Error:
Source: HealthService
Event ID: 15002
Task Category: Pool Manager
The pool member cannot send a lease request to acquire ownership of managed objects assigned to the pool because half
or fewer members of the pool acknowledged the most recent initialization check request. The pool member will continue
to send an initialization check request.
Management Group: SCOM_2012
Management Group ID: {56D0B0FE-FB03-2A6C-E3F6-54287D96855D}
Pool Name: AD Assignment Resource Pool
Pool ID: {529CF61E-A357-5AED-73CC-81D48E4327CA}
Pool Version: 7607127134982980644
Number of Pool Members: 2
Number of Observer Only Pool Members: 1
Number of Instances: 1
Error:
Source: HealthService
Event ID: 15002
Task Category: Pool Manager
The pool member cannot send a lease request to acquire ownership of managed objects assigned to the pool because half
or fewer members of the pool acknowledged the most recent initialization check request. The pool member will continue
to send an initialization check request.
Management Group: SCOM_2012
Management Group ID: {56D0B0FE-FB03-2A6C-E3F6-54287D96855D}
Pool Name: Notifications Resource Pool
Pool ID: {3F9F97EA-E584-B0EE-A4C9-78A86FB4F21F}
Pool Version: 7607127134982980644
Number of Pool Members: 2
Number of Observer Only Pool Members: 1
Number of Instances: 1
Error:
Source: HealthService
Event ID: 15002
Task Category: Pool Manager
The pool member cannot send a lease request to acquire ownership of managed objects assigned to the pool because half
or fewer members of the pool acknowledged the most recent initialization check request. The pool member will continue
to send an initialization check request.
Management Group: SCOM_2012
Management Group ID: {56D0B0FE-FB03-2A6C-E3F6-54287D96855D}
Pool Name: All Management Servers Resource Pool
Pool ID: {4932D8F0-C8E2-2F4B-288E-3ED98A340B9F}
Pool Version: 7607127134982980644
Number of Pool Members: 2
Number of Observer Only Pool Members: 1
Number of Instances: 116
Warning:
Source: Health Service Modules
Event ID: 10103
Task Category: None
The Windows Event Log Provider has resumed processing the Operations Manager event log on computer 'HKWOMM01.ap.zurich.com' after recovering from errors.
One or more workflows were affected by this. 
Workflow name: Microsoft.SystemCenter.CM.AEM.Modules.EventCollection
Instance name: HKWOMM01.ap.zurich.com
Instance ID: {BF86169C-4A71-C728-9649-338260E86093}
Management group: SCOM_2012
Warning:
Source: Health Service Modules
Event ID: 10103
Task Category: None
In PerfDataSource, could not resolve counter instance OpsMgr DW Writer Module, Avg. Batch Processing Time, ms, All Instances. Module will not be unloaded.
One or more workflows were affected by this. 
Workflow name: Microsoft.SystemCenter.DataWarehouse.CollectionRule.Performance.Writer.AvgBatchProcessingTime
Instance name: HKWOMM01.ap.zurich.com
Instance ID: {BF86169C-4A71-C728-9649-338260E86093}
Management group: SCOM_2012
Warning:
Source: Health Service Modules
Event ID: 10103
Task Category: None
In PerfDataSource, could not resolve counter instance OpsMgr DW Writer Module, Batches/sec, All Instances. Module will not be unloaded.
One or more workflows were affected by this. 
Workflow name: Microsoft.SystemCenter.DataWarehouse.CollectionRule.Performance.Writer.BatchesPerSecond
Instance name: HKWOMM01.ap.zurich.com
Instance ID: {BF86169C-4A71-C728-9649-338260E86093}
Management group: SCOM_2012
Warning:
Source: Health Service Modules
Event ID: 10103
Task Category: None
In PerfDataSource, could not resolve counter instance LogicalDisk, Current Disk Queue Length,
\\?\Volume{9470dbf8-09e8-11e1-887f-806e6f6e6963}. Module will not be unloaded.
One or more workflows were affected by this. 
Workflow name: Microsoft.Windows.Server.2008.LogicalDisk.CurrentDiskQueueLength.Collection
Instance name:
\\?\Volume{9470dbf8-09e8-11e1-887f-806e6f6e6963}
Instance ID: {80A7A920-B571-987C-9B3B-DE2164998AB9}
Management group: SCOM_2012
Warning:
Source: Health Service Modules
Event ID: 10103
Task Category: None
In PerfDataSource, could not resolve counter instance OpsMgr DW Synchronization Module, Avg. Batch Processing Time, ms, All Instances. Module will not be unloaded.
One or more workflows were affected by this. 
Workflow name: Microsoft.SystemCenter.DataWarehouse.CollectionRule.Performance.Synchronization.AvgBatchProcessingTime
Instance name: b9e5cd4c-1b78-4530-b93f-69806d14d7f3
Instance ID: {E6A569EF-6527-2B26-8345-2E16F0979064}
Management group: SCOM_2012