Simple Network Management Protocol (SNMP) is a protocol used to remotely manage and control nodes on a TCP/IP network. Using SNMP, one workstation running management software can monitor information being collected by routers, servers, and other workstations on the system. This information is used to determine the health and performance of the network. This appendix describes how you can set up and test SNMP to monitor the SilverStream Server.
NOTE The SilverStream SNMP implementation currently runs on the Windows NT platform only, and does not allow the SNMP service to control the SilverStream Server.
SilverStream implements SNMP using three components:
The SilverStream Extension Agent (
AgSNMP35.dll) implements the Windows NT SNMP Application Program Interface (API). The SNMP agent reads the SilverStream Server statistical information from a flat file named
AgSNMP.props that is located in the SilverStream\resources directory.
For a list of available statistics and object identifiers, see SilverStream ID and OIDs.
A SilverStream scheduled business object (
AgSNMPGetStats) updates the
AgSNMP.props file according to a scheduled interval. When the
scheduleReached event fires, the business object gets an instance of the
AgiServer object and calls the appropriate methods to build the data for the file. It then gets registry information from the server to determine the SilverStream path and writes the file to the resources directory.
On a GET request, if the update interval has elapsed, the Silverstream Extension Agent updates the MIB data by accessing the registry to get the SilverStream path and reading the
AgSNMP.props file in the resources directory. Otherwise, it returns the value that was stored the last time the file was read. If the timestamp in the file is not updated within the given interval, the "Server Responding" status is set to false, indicating a possible problem with the SilverStream Server.
The following figure shows how the SilverStream components work within the SNMP framework.
The following terms are used in an SNMP-enabled architecture:
This section describes how to set up SNMP as an NT service and run the software. Setting up SNMP involves the following steps:
If you are installing the SNMP software service on a machine that is currently running the SilverStream Server, first you need to stop the server. In addition, if SilverStream has already been installed, you will need to reinstall SilverStream after installing the service.
To install the SMNP Service:
Contact: Name of person or name of machine
Location: Any descriptive term
Community name: public (optional)
Trap destinations: IP address of the machine (optional)
After you have installed SNMP as a service, use the SilverStream Installation program to install SilverStream on the server to be managed. If you are reinstalling SilverStream, you must stop the SNMP Service first. Otherwise, the install program will not be able to write over the AgSNMPAgent.DLL file.
The SilverStream install process takes care of the required registry key entries and places the agent in the correct location. The required registry entries are as follows:
Software\SilverStream Software Inc.\SilverStream\version\SNMP\ExtensionAgents\AgSNMPAgent\CurrentVersion
HKEY_LOCAL_MACHINE\SOFTWARE\SilverStream Software Inc.\SilverStream\version\SNMP\ExtensionAgents\AgSNMPAgent\CurrentVersion
SilverStream Install Directory\bin\AgSNMPversion.dll
In the SilverMaster database, open the business object
AgSNMPGetStats and set the Trigger value for Enabled to True. If you want to change the time interval that the business object will fire, you must change it in two places:
m_fileUpdateIntervalto match the Schedule Interval.
SilverStream provides a tool that allows you to test the SNMP installation from a DOS prompt. First, open the file
SilverStream\bin\SilverSNMPGetStats.bat and change the
localhost parameter wherever it appears in the file to the host name on which your SilverStream Server is running. Then follow the next procedure.
To test the SNMP extension agent:
SilverSNMPGetStats.To get a list of available parameters, type:
The SilverStream Object Identifier is composed of an enterprise ID and the OID identifying each Managed Object (MIB). You will need the following information to set up access to the SilverStream Server OIDs from your SNMP Management node:
The following are the SilverStream OIDs. When accessing MIB data using
SNMPTool.exe, you must precede the OID with a period.