24 Jan
2018
24 Jan
'18
10:20 a.m.
ID: 5605
Title: HW/SW Inventory: Status data can be integrated into HW/SW Inventory tree
Component: HW/SW Inventory
Level: 1
Class: New feature
Version: 1.5.0i3
The HW/SW Inventory system collects static information about hardware and
software of hosts which is displayed in the GUI as a tree below 'Inventory'
of each host which has installed the mk_inventory plugin and enabled the
rule 'Do hardware/software inventory'.
If any data changes the HW/SW Inventory system detects that and calculates
the differences which can be viewed below 'Inventory history'.
Now status data like free space of tablespace can be intergated into the
HW/SW Inventory tree. These kind of data may change after every check cycle
thus we do not calculate any differences as for the static inventory data
in order to avoid filling up inventory archive and therefore slowing down
the monitoring system.
We solve above problem by separating these two kind of data within the
inventory plugins.
- There's one tree which is filled up with inventory data and will be saved
to var/check_mk/inventory as before.
- A second tree for the status data will be created and saved to
tmp/check_mk/structured_data
Later in the web GUI both tree objects are merged and visible below 'Inventory'.
Inventory history is only calculated for the inventory data, not for the
status data.
In order to use this feature you have to enable the rule
'Do status data inventory' for a host. When it's enabled Check_MK does a
HW/Sw inventory for this host after every check cycle if and only if there's
a inventory plugin which fills up status data tree.
Notes for inventory plugin development:
Previously an inventory plugin used the functions inv_tree_list and inv_tree
for filling up the inventory tree, eg.
C+:
def inv_oracle_tablespaces(info):
node = inf_tree_list("software.applications.oracle.tablespaces:")
C-:
This behaviour will be still supported, but it's recommended to use the
new API, escpecially for new inventory plugins.
In order to use this new feature the inventory plugin takes the optional
arguments 'inventory_tree' or 'status_data_tree', eg.
C+:
def inv_oracle_tablespaces(info, inventory_tree, status_data_tree):
C-:
There are two methods for these tree objects 'get_dict' and 'get_list'
which
take a path as argument. This path defines where the data should be stored, eg.
C+:
path = "software.applications.oracle.tablespaces:"
inv_node = inventory_tree.get_list(path)
status_node = status_data_tree.get_list(path)
C-:
Especially if lists are filled up with inventory and status data, there must
be a so-called identifier in the entries of these lists in order to link the
related elements, eg.:
C+:
for sid, data in tablespaces:
inv_node.append({"sid": sid, "INV-KEY": data[INV-DATA]})
status_node.append({"sid": sid, "STATUS-KEY": data[STATUS-DATA]})
C-:
Both nodes, 'inv_node' and 'status_node', use 'sid' as an
identifier. Thereby
Check_MK knows which entries of both lists belong together.
If one identifier is not sufficient you can add more, eg.:
C+:
for sid, data in tablespaces:
inv_node.append({"sid": sid, "name" : name, "INV-KEY":
data[INV-DATA]})
status_node.append({"sid": sid, "name": name, "STATUS-KEY":
data[STATUS-DATA]})
C-:
Now Check_MK uses 'sid' and 'name' as identifier. These identifier have to
exist in
all entries of both lists. Otherwise there's no possibility to link these entries.
To make Check_MK know which inventory plugins calculate status data an
additional attribute 'has_status_data' must be added which has the
value 'True'.
C+:
inv_info['oracle_tablespaces'] = {
"inv_function": inv_oracle_tablespaces,
"has_status_data": True,
}
C-: