Computer Scan Timeout

The number in minutes to wait for each individual computer's scan to end before timing out and aborting. The default is 10 minutes.

WMI Timeout

The timeout, in seconds, to be used for all WMI queries on target computers. If computers are reporting WMI timeout errors this number should be increased. The default is 90 seconds.

IMPORTANT: The WMI timeout applies to each WMI call individually. WMI calls consist of the query and the enumeration of each result.

Concurrent Scans

The maximum number of scans that can be run concurrently. The higher the number, the greater the use of server memory, CPU resources, and network bandwidth.

Once this limit is reached, additional computers to be scanned are placed in a queued state until a connection is available.

The default is 32.

Note: This setting also controls the number of concurrent Wake-on-LAN sessions that can occur.

Service Manager TCP Connection

Microsoft’s service control manager (SCM) is a remote procedure call (RPC) server that allows PDQ Inventory to connect to remote service managers. SCM supports procedure calls over both Transmission Control Protocol (TCP) and named pipes (NP).

The following settings manage how the Windows SCM connects to target computers to perform scans.

Note: These are Windows settings and, as such, are system wide. They cannot be set per process or application. Be aware that changing these values will affect other applications that use remote service manager connections and the Windows service control. If another application (such as PDQ Deploy) or process (such as GPO) changes this setting, then PDQ Inventory uses the changed value.

Default

Lets Windows manage the RPC connection settings.

By default, Windows first attempts the RPC over TCP. If the TCP connection isn’t successful, Windows times out the connection for 21 seconds, then retries the connection over named pipes.

The default TCP timeout of 21 seconds will cause remote connections to be slow if firewall settings prevent access to the RPC ports. Blocking RPC/TCP is quite common, so if scans are typically in the “Connecting” state for longer than 20 seconds, then lowering the timeout or disabling TCP may be in order. Click Disabled to disable RPC/TCP connections and use only named pipes; click Timeout to redefine the timeout interval.

Another point to consider is that, unlike named pipes, TCP uses the credentials of the connecting process instead of the credentials of an SCM connection. This can cause Access Denied to Service Manager errors when connecting to computers in different domains (or non-Domain computers). To fix this, click Disabled to disable RPC/TCP and use only named pipes.

Disabled

Disables RPC over TCP and uses only named pipe (RCP/NP) connections.

Timeout

Redefines the timeout interval for the Default setting.

The Windows default timeout is 21 seconds. Decreasing the interval may improve performance if scans are typically in the “Connecting” state for longer than 20 seconds.

When selected, the default timeout setting is 10 seconds.