Compatible with NMIS9

Tabled of Contents

Introduction

NMIS8 is a powerful network management system, but NMIS is not only a network management system: it performs Windows and Unix server monitoring out of the box if your server supports SNMP. NMIS8 works well with Windows servers and especially with the popular NET-SNMP SNMP daemon, which is widely used on Linux and other Unix systems.

The core of NMIS server management is the Host Resources MIB, which is standardised in RFC2790, both the NET-SNMP, Windows SNMP and VMware ESXi daemons implement the Host Resources MIB. But NMIS is not relying on SNMP exclusively; it has capabilities for performance and fault management of servers, as well as service (application) monitoring running on servers.

This document describes a few common approaches towards service monitoring with or without using SNMP; There is a companion document named Service Monitoring Examples which shows a number  of practical example service monitoring setups.

NMIS8 collects and stores the following performance data from servers:

• Processor load
• Physical memory usage (not currently available from VMware ESXi)
• Virtual memory usage (not currently available from VMware ESXi)
• Disk usage (capacity and used)
• Network interface usage

Service Monitoring

• Checks Host Resources MIB for service status
• Performs poll of TCP/UDP port
• Runs send/expect scripts which return status (can perform full transaction over system and is highly extensible)
• Run external programs which return status (and optionally extra values)

You can download NMIS from the Opmantek webpage.

Windows Server Support

Depends on Windows SNMP Service (often referred to as agentless server monitoring).  NMIS will collect the following information from Windows Servers in addition to the already described information.

• IP Utilisation
• Server Memory Pages per Sec
• CPU Interrupts
• Memory Stats (commited and available bytes)
• Number of Users 

All of these information requires no Agent to be installed onto the Windows server other than the freely available Windows SNMP Service (part of the Windows installation and setup).

For more details about installing the SNMP Service on Windows, please see the following:

• Enabling SNMP Management on Windows 2008 Server
• HOW TO: Configure the Simple Network Management Protocol (SNMP) Service in Windows Server 2003
• TechNet: How to Install SNMP Remotely

Unix Server Support

Depends on NET-SNMP daemon being installed and configured, usually installed by default on most Unix platforms.  Instructions for installing the NET-SNMP daemon are included in the NMIS 8 Installation Guide (up to Version 8.5.4G).

Quickstart Chart of a Service Definition

Configuring NMIS to Monitor Services - Step By Step

An updated services file "Services.nmis" was distributed with later NMIS8 versions, and is attached to this page Services.nmis, this is compatible with earlier versions of NMIS8.  This file includes definitions for using the script method to poll HTTP, as well as monitoring for a MySQL daemon, and various ports using NMAP connections.  Once Services.nmis is copied to /usr/local/nmis8/conf, you should verify that you have the scripts folder in nmis8, this is included in the install directory. Running cp -r /usr/local/nmis8/install/scripts /usr/local/nmis8/conf will ensure the service definition files are available.

When a service "outage" is detected you will receive NMIS events and notifications if NMIS has been configured to do so.

Step 1

From the NMIS Menu, navigate to "System -> System Configuration -> Nodes (devices)"

Step 2

From the list of nodes, select "edit" from the server you want to monitor services on.

Step 3

From the services box, select the services you want to monitor, you can select several services.

Step 4

When you are done, select "Edit and Update Node", after the next poll cycle runs, within about 5 minutes you will see that the services are now being monitored

Step 5

You can also now select "Services" from the node menu bar and see a graph of all the monitored services.

Starting with version 8.4.10G the service graphs also include the response time (as number and and graph) which is the elapsed time of the service test.

Defining new SNMP based Services to Monitor

This is how to define a new services based on using SNMP for the status of the service.

This feature requires the device to support the HOST-RESOURCES-MIB, and specifically the hrSWRun instrumentation which provides "The (conceptual) table of software running on the host."

Step 1

Determine the name of the service process you want to monitor, for example to Monitor MongoDB on Windows, the process name is mongod.exe. As the MongoDB server state is reported as an attribute for the named process, you'll have to tell NMIS what process to look for.

Step 2

From the NMIS Menu, navigate to "System -> System Configuration -> Services"

Step 3

Then select add or edit to add a new service or edit an existing service monitoring definition.

Step 4

Give the service a (display) name, for Windows we call them service and for Unix we call them daemons. Insert the appropriate process name in the Service Name field, and select the Service Type service to tell NMIS that this is an SNMP-monitored service.

Step 5

Click "Add" or "Edit" to save the new service and then you can assign this to a device as described above in "Configuring NMIS Services to Monitor".

Process Selection Details

In NMIS 8.6 we refined the process selection mechanism to improve its flexibility, and you can now check more of the process properties reported by SNMP.
(Up to Version 8.5.12G only Service Name is matched against the Process Name).

• Your given "Service Name" is used  (as regular expression) to check the Process Name,
• and your given "Service Parameters" value is used (again as regular expression) to check the Process Path and Process Arguments.

You have to provide at least one of the two, and a blank value will be interpreted as 'match anything'.

Note that the Service Name regular expression cannot contain the anchors "^" or "$", whereas the Service Parameters one can.

For example, if you want to check a particular Java application, you would set the Service Name to java and the Service Parameters to some identifying property for this particular application. To figure out what exactly might distinguish this application from others, have a look at the Service List page for that node, and the Service and Parameters columns in particular:

In this example, the Java process happens to be the one for the Confluence application, and the mingetty is the one covering the second terminal.

The following simple configuration would match just those two processes:

  'confluence' => {
    'Name' => 'confluence',
    'Service_Type' => 'service',
    'Poll_Interval' => '5m',
    'Service_Name' => 'java',
    'Service_Parameters' => '/opt/confluence',
  },
  'secondterminal' => {
    'Name' => 'secondterminal',
    'Service_Type' => 'service',
    'Poll_Interval' => '5m',
    'Service_Name' => '(min|a)getty',
    'Service_Parameters' => 'tty2',
  },

You can also be more specific or loose if needed, as both Service Name and Parameters allow regular expressions: The example above will also accept "agetty" processes serving the second terminal.

Defining new TCP or UDP Ports to Monitor

Assuming you only want to check if a server listens for network connections on a particular TCP or UDP port (without actually exchanging application-level data with that service), then this is how to instruct NMIS to do that:

• Select Service Type port
  
• Give the appropriate port and protocol in the form of udp:123 (that would be NTP) or tcp:22 (that's SSH)
• Ignore Service Name and all program-related settings

Please note that the open/reachable/closed status for UDP ports is unreliable due to the nature of the protocol; doing end-to-end service-specific tests is recommended for UDP.

Defining DNS Server Monitoring

NMIS also supports monitoring of DNS servers out of the box:

• Service Type is dns.
• Up to version 8.4.10G inclusive, the builtin dns monitor requires the node's Name/IP Address setting to hold the node's fully qualified domain name. NMIS then requests DNS info for this FQDN from the node that is marked for dns service monitoring. The Service Name is ignored.
• After version 8.4.10G, you must specify the DNS query target as the Service Name. This can be either an IP address or a fully qualified domain name (host or domain). Again it is the node marked for dns monitoring that is asked for DNS info, but you've got control over what is requested.

Defining new (sapi-)Script based Services to Monitor

This is how to define a new services based on using a sapi script to connect to the socket and send some data, looking for the correct response.

Please note that this service type does not cover scripts written in a general-purpose programming language (e.g. perl, python, php): use Service Type program for those.

Sapi scripts are extremely similar to expect scripts and documented at the end of /usr/local/nmis8/lib/sapi.pm; they're very simple but also quite limited capability-wise.

Step 1

Determine the name of the service you want to monitor.

In the example below we call the service "nmis" and we check that the NMIS web application is running and answering.

Note that the script file must be named the same as the Name given to the service.

Step 2 and Step 3

Same as above, 

From the NMIS Menu, navigate to "System -> System Configuration -> Services"

Then select add or edit to add a new service or edit an existing service monitoring definition.

cp /usr/local/nmis8/conf/scripts/http /usr/local/nmis8/conf/scripts/nmis

send: HEAD /nmis8/ HTTP/1.0
send: 
expect: 200 OK

HTTP/1.1 200 OK
Date: Tue, 01 Apr 2014 05:19:19 GMT
Server: Apache/2.2.15 (CentOS)
Last-Modified: Thu, 21 Mar 2013 05:14:21 GMT
ETag: "a233b-67c-4d8686950cd27"
Accept-Ranges: bytes
Content-Length: 1660
Vary: Accept-Encoding
Connection: close
Content-Type: text/html; charset=UTF-8

    'nmis_executable' => '(/(bin|admin)/[a-zA-Z0-9_\\.-]+|\\.pl|\\.sh)$',