Active Discovery and Filtering

Datasource Instance Filters control what objects are allowed to populate as instances on a device level. These filters are used to retain the desired alerting and data collection, but prevents LogicMonitor from creating alerts on non-critical infrastructure. From every object discovered by Active Discovery, only objects that satisfy the filter criteria will be added into monitoring. Filters can be found in the Active Discovery section of multi-instance Datasource definitions.

Use Case: Script instance filtering

The same method can apply to datasources that outputs instances in a different format. For example, the recently released VMware_vSphere_VMsnapshots. This datasource performs discovery through an embedded Groovy script, which will create and apply Instance Level Properties:

// Get props/ILP
def props_hash = ['auto.config.alternate_guest_os_Name': vm?.config?.alternateGuestName,
'auto.config.annotation' : vm?.config?.annotation,
'auto.config.firmware' : vm?.config?.firmware,
'auto.config.guest_os_full_Name' : vm?.config?.guestFullName,
'auto.config.guest_os_id' : vm?.config?.guestId,
'auto.config.managed_by' : vm?.config?.managedBy?.type ?: "false",
'auto.config.modified' : vm?.config?.modified?.getTime(),
'auto.config.template' : vm?.config?.template,
'auto.guest.guest_os_family' : vm?.guest?.guestFamily,
'auto.guest.guest_os_full_name' : vm?.guest?.guestFullName,
'auto.guest.guest_os_id' : vm?.guest?.guestId,
'auto.guest.hostname' : vm?.guest?.hostName,
'auto.guest.tools_version' : vm?.guest?.toolsVersion,
'auto.guest.tools_version_status' : vm?.guest?.toolsVersionStatus2,
'auto.hardware.memory_mb' : vm?.config?.hardware?.memoryMB ?: 0,
'auto.hardware.num_cpu' : vm?.config?.hardware?.numCPU ?: 0,
'auto.hardware.num_cores_per_socket' : vm?.config?.hardware?.numCoresPerSocket ?: 0,
'auto.hardware.num_virtual_disks' : vm?.summary?.config?.numVirtualDisks ?: 0,
'auto.hardware.num_ethernet_cards' : vm?.summary?.config?.numEthernetCards ?: 0,
'auto.resource_pool' : vm?.resourcePool?.name,
'auto.resource_pool_full_path' : resource_pool_array.reverse().join(' -> '),
'auto.snapshot_count' : vm?.layoutEx?.snapshot?.size() ?: 0,
'auto.cluster' : esxhost?.parent?.name,
'auto.cluster_full_path' : cluster_path_array.reverse().join(' -> '),
'' : esxhost?.name,
'auto.runtime.connection_state' : vm?.runtime?.connectionState,
'auto.runtime.power_state' : vm?.runtime?.powerState]

For reference, here is what the ILPs look like for an instance before filtering is applied.

Since each of these Instance Level Properties are provided with each instance that is discovered, LogicMonitor can call these properties using filters. As an example use case: “A customer was interested in excluding Virtual Machines from two lab resource pools. Since this customer was not interested in the alarms that were generated and did not want to collect data from the test environments.

Attribute Operation Value Comment
auto.resource_pool RegexNotMatch INFOSEC Excludes any instance with a resource pool name of either of these two labs

Use Case: Troubleshooting SNMP filtering

Sometimes a default filter can create confusion to a customer expecting an instance but not seeing it. For example, our

NetAppSnapVol contains the following filters:

Attribute Operation Value Comment
. RegexMatch \.snapshot|\.\. Volume name contains snapshot, or “..” if no snapdir is set.
. NotEqual 0 Ignore volumes of zero size.
. Contain /vol/ Include volumes only (not aggregates)

A common scenario is only seeing one snap volume displayed, when more are expected. Using the SNMP OID set on the datasource definition, perform a manual walk to get the full list of instances:

$ !snmpwalk SOMEHOST .
Walking OID . from host=SOMEHOST, version=v2c, port=161, timeout=3 seconds:
1 => aggr2
10 => /vol/cache1img3/.snapshot
11 => /vol/cache1img4/
12 => /vol/cache1img4/.snapshot
13 => /vol/cache1img5/
14 => /vol/cache1img5/.snapshot
15 => /vol/cache1img6/
16 => /vol/cache1img6/.snapshot
17 => /vol/cache1img7/
18 => /vol/cache1img7/.snapshot
19 => /vol/cache1img8/
2 => aggr2/.snapshot
20 => /vol/cache1img8/.snapshot
21 => /vol/cachepreprod/
22 => /vol/cachepreprod/.snapshot
23 => /vol/cache1imgtest/
24 => /vol/cache1imgtest/.snapshot
3 => /vol/new_root/
4 => /vol/new_root/.snapshot
5 => /vol/cache1img1/
6 => /vol/cache1img1/.snapshot
7 => /vol/cache1img2/
8 => /vol/cache1img2/.snapshot
9 => /vol/cache1img3/

Here there are indeed more than one potential instance for discovery, however, the middle filter in the table above checks volume size and only reports those that do not report a zero size from the OID .,

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