Database Reference
In-Depth Information
<Property NAME="command" SCOPE="GLOBAL">%perlBin%/perl</Property>
<Property NAME="script" SCOPE="GLOBAL">
%scriptsDir%/sample_host1/data_collector.pl --collect Response --fake "%fake%"
</Property>
<Property NAME="startsWith" SCOPE="GLOBAL">em_result=</Property>
<Property NAME="delimiter" SCOPE="GLOBAL">|</Property>
</QueryDescriptor>
</Metric>
The
Metric
element must have a
NAME
unique within the target type.
TYPE
is most frequently a
TABLE
but can
be some other value that I won't be looking at here. Each
Metric
element should include one
TableDescriptor
.
A
TableDescriptor
defines columns with names, types, and labels. Finally, a
QueryDescriptor
tag describes how to
collect metric values via one of the fetchlets. These are similar to metric extension adapters, but there are many more
fetchlet types available, and you have much more flexibility configuring them in XML. The order of the columns in a
TableDescriptor
is important because the fetchlet configured under the
QueryDescriptor
element must return the
values in that order.
The
TableDescriptor
element is a simple container for the multiple
ColumnDescriptor
elements (each
describing a column in the table, as you might have already guessed). Each column descriptor has the familiar
Display
element describing how this column is displayed in the user interface. Attributes of the column descriptor
define column names and types.
STRING
and
NUMBER
are two column types that you will be using most of the time. The
IS_KEY
attribute lets you specify whether this column is part of the unique key for the metrics, returning multiple rows
as in the multirow metrics you learned about in the section “Metric Extensions.”
For each target type, it's important to define a special metric with the name
Response
, of type
TABLE
, with a
column named
Status
. The EM12c framework will use this column for the target's up and down status and historical
availability statistics. You also must define a critical condition for this metric, as you will learn later. EM12c knows that
the target is down if the
Status
column of the
Response
metric generates a critical alert. One way to get the availability
history for a target is via the target's menu: choose the Target Information option and then click the availability
percentage. The example availability history for Sample Plug-in Host 1 is shown in Figure
10-10
.
