icmp datasource
The icmp datasource uses ICMP to send packets (pings) to the hosts you specify and creates metric data points, entities, and events. Both IPv4 and IPv6 host addresses are supported.
Metrics
Most of the following metrics rely on the round-trip time of a ping. A round-trip time starts when Virtana Service Observability agent sends a ping to a target host and ends when Virtana Service Observability agent receives the target host’s acknowledgement of the ping, if the target can send one.
Name | Units | Description |
|---|---|---|
ping.icmp.up | boolean | 1 if target is up, 0 if down (see Availability metric) |
ping.icmp.min_rtt | ms | The minimum round-trip time among all performed pings per cycle |
ping.icmp.max_rtt | ms | The maximum round-trip time among all performed pings per cycle |
ping.icmp.mean_rtt | ms | The average round-trip time of all performed pings per cycle |
ping.icmp.std_dev | ms | The average variance of each ping’s round-trip time from the mean round-trip time |
ping.icmp.packet_loss | percentage | The percentage of sent packets that did not reach the destination |
ping.icmp.packet_loss_count | packets | The count of sent packets that did not reach the destination |
ping.icmp.jitter | ms | The variation among round-trip times (see Jitter metric) |
Availability metric
Either value of ping.icmp.up generates an event:
When
ping.icmp.upis 1 (true), an icmpAvailability UP event is sent.When
ping.icmp.upis 0 (false), an icmpAvailability DOWN event is sent, and onlyping.icmp.packet_lossandping.icmp.packet_loss_countare gathered. All other metrics are set to 0.
The value is 0 in the following circumstances:
When the Virtana Service Observability agent or its inbound gateway determine that the destination is unreachable.
When the value of
ping.icmp.packet_loss_countis greater than the value of the @lp(spec.datasource.config.packets_loss_critical_amount) configuration property.
Jitter metric
Jitter is the average time between successive round-trip times divided by the number of computed values. For example, five successive round-trip times (136, 184, 115, 148, 125) are computed four times:
136 - 184 = 48 184 - 115 = 69 115 - 148 = 33 148 - 125 = 23
Then, the sum of the computed values (48+69+33+23) is divided by the number of computed values (4) for a jitter value of 43.25.
Entities
This datasource either creates one entity for each monitoring target or uses existing entities. Specify the properties of each target’s entity in the configuration file. Virtana Service Observability associates metrics and events with each target’s entity.
Events
Health event
This datasource sends an icmpHealth event of severity WARNING in the following circumstances:
(Degraded) The value of
ping.icmp.packet_loss_countis greater than 0 but less than the value of the @lp(spec.datasource.config.packets_loss_critical_amount) configuration property.(Degraded) The value of
ping.icmp.mean_rttgrows abnormally.The previous ping attempt resulted in one of the preceding events, but the current ping attempt passes all health checks, so a new event is sent to clear the previous event.
Availability event
This datasource sends an icmpAvailability event of severity CRITICAL in the following circumstances:
(UP) All health checks pass.
(DOWN) The value of
ping.icmp.packet_loss_countis greater than the value of the @lp(spec.datasource.config.packets_loss_critical_amount) configuration property.(DOWN) The target is unreachable (
ping.icmp.packet_lossis equal to 100%).