Time's Up!

[SlightlyLoony]

Discovery's probes all do the same thing using different technologies: they ask a question, get the answer, and send it back to your Service-now.com instance. They also all do something that may not be obvious until you think about it: after asking the question, they wait for some period of time for the answer — and if no answer is forthcoming, they "time out".

We've selected default timeout values for all the probes that are long enough that you're not likely to hit them unless something is truly not working. But...your environment may have higher-than-average responsiveness, and those longer timeout values may be slowing your Discovery down unnecessarily. Or perhaps your environment includes older, slower network gear and servers, and they need an even longer timeout value. How can you adjust these?

All the probe types include timeout parameters of various kinds. To adjust them, all you have to do is create the parameter (if it isn't there already) and set it's value to what you need. The example at left shows a timeout parameter that has been added to the Ping probe. You can do the same thing for any other probe as well. The list below shows all the available timeout-related parameters for each probe type, along with the default values for them:

• SSHCommand: Parameter "timeout" sets the timeout in milliseconds; the default value is 30000 (30 seconds).
• Ping: Parameter "timeout" sets the timeout in milliseconds; the default value is 2000 (2 seconds).
• SNMP: Parameter "timeout" sets the timeout in milliseconds for initially establishing a session; the default value is 1500 (1.5 seconds). Once an SNMP session has been established, the timeout is set by parameter "established_session_timeout" sets the timeout in milliseconds for an established session; the default value is 15000 (15 seconds).
• WMI: Parameter "wmi_timeout" sets the timeout in iseconds for WMI queries to respond; the default value is 900 (15 minutes) and the maximum value is 999 seconds. Parameter "process_timeout" sets the timeout for the entire WMI script session in seconds; the default value 3600 (60 minutes).
• Shazzam:
  
  • HTTP Scanner: Parameter "HTTP_waitForConnectMS" sets the timeout in milliseconds for initially establishing an HTTP connection; the default value is 500 (0.5 seconds). Parameter "HTTP_waitForResponseMS" sets the timeout in milliseconds for a response to be received; the default value is 500 (0.5 seconds).
  • TCP Scanner: Parameter "GenericTCP_waitForConnectMS" sets the timeout in milliseconds for initially establishing an HTTP connection; the default value is 500 (0.5 seconds).
  • NBT Scanner: Parameter "NBT_waitForResponseMS" sets the timeout in milliseconds for receiving a NetBIOS query response; the default value is 1000 (1 second).
  • SNMP Scanner: Parameter "SNMP_waitForResponseMS" sets the timeout in milliseconds for receiving an SNMP query response; the default value is 1000 (1 second).
  • DNS Scanner: Parameter "DNS_waitForResponseMS" sets the timeout in milliseconds for receiving a DNS query response; the default value is 1000 (1 second).
  
  
• PortScanner: Parameter "timeout" sets the timeout in milliseconds for a TCP connection to be established; the default value is 1500 (1.5 seconds). Parameter "snmp_timeout" sets the timeout in milliseconds for a response to an SNMP query to be received; the default value is 1500 (1.5 seconds).