Performance Counters Functions
Performance counters are based on several predefined JavaScript functions:
SNMPMonitor() - JavaScript
function for performance counters which use the SNMP protocol
WMIMonitor() - JavaScript
function for performance counters which use the WMI protocol
ApacheMonitor() - JavaScript
function for Apache server performance counters which use the HTTP protocol
SQLMonitor() - JavaScript
function for performance counters which use the ODBC interface
Each counter should be based on one of these functions.
A value returned by this function is counter's value displayed in reports and graphs.
Inside the SNMPMonitor(), WMIMonitor(),
ApacheMonitor() and SQLMonitor()
you can use the following functions:
counter.SNMPGetValue(<oid_name>) - gets
the value of the counter with the OID equal to <oid_name>.
counter.SNMPGetNextValue(<oid_name>) - gets
the value of the next counter, which stays after the counter with the OID equal to <oid_name>.
counter.WMIGetValue(<wql_query>, <name>, <number>) - makes an sql query
<wql_query> and returns the value from the <name> column and <number> string of the table
which is the result of query execution.
counter.lastValue - returns the previous value of the counter.
counter.lastOIDName - returns the OID of the last SNMP request.
counter.ApacheGetValue(<ParamName>) - gets
the value of <ParamName> parameter from the Apache server statistics file.
counter.SQLGetValue(<sql_query>) - returns the value stored in the first column of
the first string of the table which is the result of <sql_query> execution.
Example of usage
function WMIMonitor()
{
var freeSpace = (counter.WMIGetValue("SELECT PercentFreeSpace FROM Win32_PerfRawData_PerfDisk_LogicalDisk WHERE Name='_Total'", "PercentFreeSpace", 0)-0);
var freeSpaceBase = (counter.WMIGetValue("SELECT PercentFreeSpace_Base FROM Win32_PerfRawData_PerfDisk_LogicalDisk WHERE Name='_Total'", "PercentFreeSpace_Base", 0)-0);
if(freeSpaceBase > 0)
{
var diskUsage = (freeSpace * 100 / freeSpaceBase);
return 100 - diskUsage;
}
return 0;
}
