Monitoring Parameters

IPHost Network Monitor provides constant monitoring of your network's services and resources that are critically important for your company. Unlike many monitoring tools IPHost Network Monitor checks not only the availability of a resource but also its operability and performance characteristics.

The base element in IPHost Network Monitor is a monitor; it checks the availability of a resource on a remote computer and requests the value of a certain parameter. A monitor has parameters that determine:

1. What and how should be checked (monitoring parameters),

2. The levels of acceptable and problem values of the checking results (defining the conditions of the monitor's change of state),

3. Alerts to be performed when problems appear (alerting rule),

4. Additional parameters such as a link to the basic report on the monitor, dependence on the availability of another monitor, and comments.

Parameters of a Group of Monitors

Grouping monitors according to hosts and types of monitors provides a convenient way of specifying and changing parameters for a group of monitors at a time. For instance, by default a monitor uses conditions of its change of state as well as an alerting rule assigned for the type of the monitor. Accordingly, changing the values of parameters for the type of the monitor will automatically be reflected on their values for specific monitors of this type. Of course, any monitor can also have individual values of these parameters that are not dependent on the values set for the type.

Polling

Active monitors are polled (checked) with a regularity specified by the user. By default, monitors of the group "Basic connectivity" are checked every 30 seconds, all the rest - every minute. It is strongly recommended to set polling interval more than 15 seconds because more frequent checks are practically useless, besides, they can lead to a performance degradation of a network or monitored network resources, which contradicts the goal of monitoring.

The result of a check is either a value or an error message shown in the Log View pane. When checking fails, several repeated checks may be carried out (depending on the value in the Down State Timeout parameter). If the repeated checks do not succeed the monitor is switched to a Down state. If subsequent checks within the time period specified in the parameter Extended Down State Latency still persist in failing then the monitor is switched to the state Extended Down.

IPHost Network Monitor reacts to monitor transitions to problem states by executing alerts assigned by the user. The alerts are set in an alerting rule. The structure of the system of alerts and alerting rules is described here.

If checking succeeded then the value obtained as a result (mostly it is response time; other examples are the size of a file or free space, etc.) is compared with the levels of performance set by the user. For each monitor one can set two levels of performance, they define the conditions of monitor transition to the states Performance Warning and Performance Problem. A monitor switches to one of these states either based on the results of one check or additional checks may be required (using the parameters Number of Repetitions for Warning, Number of Repetitions for Problem).

The OK state means that checking has succeeded and yielded an acceptable result.

Passive Monitors

Unlike the active monitors the passive ones don't poll the device periodically but are called when something happens on the remote device. In response monitor may either change its state or trigger an event without changing state. Alerts are assigned to events via the alerting rules the same way as to monitor state transitions, so alert may be executed for any event occured.

Down State Timeout and Extended Down State Latency parameters may be used for passive monitors to automatically switch them to Down and Extended Down states if there are no any new events within the time period specified.

Example of passive monitor is the SNMP Generic Trap one described here.

Multilevel Checks

For most monitor types a possibility is provided to perform multilevel checks. For instance, for HTTP(S) type monitors a basic check is a call to a certain URL (GET or POST with optional parameters) while an additional check (second level) is the validation of a received page by means of checking for the presence or absence of a specified string on it. An example of a monitor with three levels of checking - SMTP:

1. Creating connection with an SMTP server;
2. User logging in;
3. Sending a test message.

Monitor States

At any moment of time a monitor can be in one of ten states. There are five states in which monitoring is performed, namely the above described:

1. OK
2. Performance Warning
3. Performance Problem
4. Down
5. Extended Down

There are five states, in which monitoring is not performed (no periodic checks are performed):

1. Discovered (a monitor has been found in the process of discovery and is waiting for review)
2. Stopped (monitoring has been terminated by the user)
3. Stopped by dependency (the monitor, on which this monitor depends, is in the state Down, Extended Down or Stopped by dependency)
4. Unknown (means that the monitoring service is stopped or down)
5. Maintenance (the user can select whether monitoring should be continued during maintenance or not)

One can start/stop monitoring of any monitor/host or an entire group as well as perform a check at any moment using the Monitor Control toolbar:

Dependencies

One can set the dependence of monitor checks on the state of another monitor. This means that the dependent monitor is checked only if the monitor on which it depends is in a state different from Down, Extended Down or Stopped by Dependency.

This facility can be of especial use to establish for instance the dependence of the monitors on particular hosts on the state of the router through which they are connected to the network. By default, a monitor depends on the monitor PING of its host.

Available Monitor Types

PING	Sends a standard PING to the host
TCP	Checks whether the host accepts connection at a specified port number
UDP	UDP datagram send/receive on a specific port
SMTP	Checks an SMTP server with optional authentication and may send a test message
POP3	Checks a POP3 server with optional authentication
IMAP	Checks an IMAP server with optional authentication
HTTP(S)	GET or POST HTTP/HTTPS request with optional response code and content validation
FTP	Checks an FTP server with optional authentication
Web Transaction Monitor	Checks an arbitrary Web application (makes a sequence of related HTTP(S) requests forming a complete transaction) with optional content validation
DNS	Checks a DNS server
WMI CPU load	Checks the current CPU load on a remote computer via WMI
WMI Available Memory	Checks the current volume of available memory on a remote computer via WMI
WMI Bytes Received/sec	Checks the current inbound throughput on a remote computer
WMI Bytes Send/sec	Checks the current outbound throughput on a remote computer
WMI Custom (run WMI script)	Runs a custom WMI script to check some value on a remote computer
SNMP Custom	Monitors the SNMP v1 / v2 / v3 performance counters such as network traffic or system resources on SNMP-enabled devices such as routers.
SNMP Generic Trap	Listens for the SNMP v1 / v2 traps sent by SNMP-enabled devices such as routers.
DISKSPACE	Monitors the free disk space of a local disk drive or a remote network share
FILE	Monitors a file on a local disk drive or a network share. It checks if the file exists and the file size is in a given range
Windows Service	Monitors the presence of any Windows service on a local machine or a computer in the network. You can restart the service using the Run program alert.
MS SQL Database	Checks a MS SQL database for availability with optional authentication and SQL expression execution.
MySQL Database	Checks a MySQL database for availability with optional authentication and SQL expression execution.
ODBC Database	Checks an ODBC data source for availability with optional authentication and SQL expression execution. You can use it to monitor MS Access, PostgreSQL, SQLite, Firebird, and other databases in case they have ODBC drivers implemented.
Oracle Database	Checks an Oracle database for availability with optional authentication and SQL expression execution.
Script or Program	Makes it easy to create your own custom monitors. Sample monitors for directory size, file content and HTTP response content are provided.
SSH (Remote Script or Program)	Allows running commands on other computers over SSH and integrating IPHost with other systems deployed remotely.