Understanding Rapid Recovery Core-Level Performance Tuning Settings (4034266)

In Rapid Recovery, you can modify several settings to tune the timeout values for different jobs and configurations.  You can change the values using the Registry Editor, however; some of these settings can also be found in the Core GUI

CAUTION:  This document should only be used as a reference to understand the purpose and function of each parameter on a high level, and should not be used as a best practice guide for general use.  Changing these settings could have dramatic effects on your Rapid Recovery environment and performance, however; it can be used to alleviate some environmental issues such as network timeout and connectivity problems

NOTE:  Making changes to the following Registry keys will only take affect after restarting the Core Service

Client Connection Timeout Settings:

These settings can be found in the following Windows Registry path:

HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\CoreSettings

\ClientTimeoutSettings

ConnectionTimeout:  Timeout value used for Agent-Core connection for protected agents and for Core-Core during Replication.  Increasing this value for example to 15 min (00:15:00) would be useful to workaround some environmental timeout issues

ReadWriteTmeout:  Timeout value for reading and writing data from the agent to the core during transfer as well as for replication from the source to the target core.  Increasing this value (for example to 15 min “00:15:00”) would be useful to alleviate some transfer error due to network timeout issues

ConnectionUITimeout:  Timeout value to keep the connection session alive between the core UI and protected agent during collecting the metadata, and between the source and target core to update the UI with core information and agents status.  Increasing this value (for example to 15 min “00:15:00”) would be useful if there are environmental issues that could cause failure to collect agent metadata

ReadWriteUITimeout:  Timeout value for reading and writing data to maintain core UI information with transferring progress and information.  Increasing this value for example (to 15 min “00:15:00”) would be useful if there are environmental issues that could cause sporadic timeout errors between the agent and the core machines

Replication Service Timeout Settings:

These settings can be found in the following Windows Registry path:

HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\Replication\ReplicationService

MaxParallelStreams:  This setting configures the number of streams per one replication job, the higher the number the more the data will be pushed over the network which would provide faster transfer rate, however; for slower WAN connections higher value would saturate the connection and cause replication job to fail with a timeout error.  “8” is the default value which considered ideal for average network speed.  You can tune this value to a lower number (for example to 4, 2, or 1 respectively) to see which one provides the best performance and success rate in case replication fails due to environmental network timeout issue

RemoteReplicationSyncJobTimeout:  Timeout value allowed by both replication cores to keep the connection alive while checking recovery points metadata during the Synchronization phase.  Increasing this value (for example to 30 min “00:30:00”) would be useful to work around some replication errors due to environmental network timeout issue

VolumeImageSessionTimeout:  Timeout value allowed by both replication cores to keep the connection alive during transferring the data for volume images (a recovery point consist of one or more volume images).  If no activity is happening due to network issues for that period of time the replication job will fail.  Increasing this value (for example to 60 min “01:00:00”) would be useful to resolve some replication errors due to environmental network timeout issue

AAVdisk Mount Driver Timeout Settings:

These settings can be found in the following Windows Registry path:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\AAVdisk\Parameters\

AsyncNetworkTimeout:  Timeout value for the Core mount driver (AAVdisk).   It sets the timeout limit for the I/O activities between the core service and the driver during mounting recovery points.  Increasing this value (should be in decimal value, for example to 60 sec “60000 millisecond”) might help as workaround errors if occur during manually mounting a Recovery Point or during Exchange Mountability or Checksum checks due to environmental network timeout

NetworkTimeout:  Timeout value for the Core mount driver (AAVdisk) during the process of enumerating the Recovery Point chain to a usable mounted volume(s).  Increasing this value (should be in decimal value, for example to 60 sec “60000 millisecond”) might help mounting very large volumes that fails with environmental timeout errors

AAVStor Mount Driver Timeout Settings:

These settings can be found in the following Windows Registry path:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\AAVStor\Parameters\

NetworkTimeout:  Timeout value for another mount driver (AAVStor) during the process of enumerating the Recovery Point chain to a usable mounted volume(s).  Increasing this value (should be in decimal value, for example to 60 sec “60000 millisecond”) might help mounting very large volumes that fails with environmental timeout errors

Exchange Mountability Check Timeout Settings:

These settings can be found in the following Windows Registry path:

HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\ExchangeServiceConfiguration

MountabilityCheckingProcessTimeoutMinutes: Timeout value allowed by the Core to process Exchange Mountability jobs.  Increasing this value (for example to 1440 min) would be a valid workaround if you notice Mountability check for Exchange fails due environmental timeout issues, especially if the Repository is stored on a slow storage, Recovery Point chain has large number or recovery points, or the Exchange database and logs are very large in size. 

Since mounting the recovery point chain is part of the Exchange Mountability job it is recommended to increase the mount driver's timeout period as mentioned above when you decide to increase the MountabilityCheckingProcessTimeoutMinutes value

Write Caching Policy Settings:

These settings can be found in the following Windows Registry path:

HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\Repositories\xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx\FileConfigurations\0\Specification\

WriteCachingPolicy:  Changing the value to “3” will turn off Write Caching Policy for the Repository files.  In some situations, this would improve the overall core machine performance.  For more details regarding this topic please refer to KB article: High Paged Pool RAM Utilization on Systems Running Rapid Recovery (4035226)

NOTE:  If the Repository consists of multiple “Extents” please make sure to change the “WriteCachingPolicy” value the same way for each Extent. The Registry branch for each Extent would look like the following path:

HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\Repositories\xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx\FileConfigurations\X=(Extent #)\Specification\

Repository Allocation Policy Settings:

These settings can be found in the following Windows Registry path:

HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\Repositories\ xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx \Specification\

AllocationPolicy:  Repository Allocation Policy setting is used to configure the way the core handle writing method to a Repository with multiple Extents.  The value “2” is Striped Writing which is set by default, and it writes the data in stripes across multiple Extents.  The value “1” will change the policy to Sequential Writing which will utilize one extent and use all of its space before going to the next Extent. 

Striped Writing is the default as it would suite the majority of environments, however; if you create a Repository with multiple Extents stored on the same storage changing the allocation policy to Sequential would avoid poor performance issues due to heavy I/O load resulted by the Striped Writing to multiple Extents on the same storage spindle

NOTE:  For detailed instructions on changing the above Registry keys values please refer to the the following KB articles:

Windows Registry Disclaimer:

Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 “Description of the Microsoft Windows registry” at Microsoft Support.