Thold 'thold_fail_count' Logic

[yavin]

Hi, I trying to understand some of the logic behind how the threshold module increments numbers tracked in the database. I am running Thold v.0.4.3

Quick summary : I am polling the cacti database from a remote nagios server on values which thold is tracking and alerting in Nagios based on these values.

One example is : I have setup a 'time based' threshold to to monitor cpu usage on a server. The high threshold is set to 85 with a Breach count of 3 in a breach window of 20 minutes. As I understand it (and please correct me if wrong), every 5 minutes the service is being polled for its current cpu usage and this is recorded as in the thold 'lastread' field. But if I take snapshots of the database for this host every 5 minutes (as seen by the 'lastread_time' field) the 'thold_fail_count' number seems to vary up and down even though every read is above my threshold value of 85. In the output below I would expect this value to remain at 4 constantly (4 x 5min intervals = 20min breach window). Why would this value be dropping despite the lastread ouput not showing any drops below the threshold in the test window? Thanks!


thold_enabled: on
thold_type: 2
thold_hi: 85
thold_low:
time_hi: 85
time_low:
thold_fail_count: 3
time_fail_trigger: 3
thold_alert: 2
lastread: 97
lastread_time: 1352834523


thold_enabled: on
thold_type: 2
thold_hi: 85
thold_low:
time_hi: 85
time_low:
thold_fail_count: 3
time_fail_trigger: 3
thold_alert: 2
lastread: 100
lastread_time: 1352834823


thold_enabled: on
thold_type: 2
thold_hi: 85
thold_low:
time_hi: 85
time_low:
thold_fail_count: 4
time_fail_trigger: 3
thold_alert: 2
lastread: 100
lastread_time: 1352835123


thold_enabled: on
thold_type: 2
thold_hi: 85
thold_low:
time_hi: 85
time_low:
thold_fail_count: 3
time_fail_trigger: 3
thold_alert: 2
lastread: 99
lastread_time: 1352835423


thold_enabled: on
thold_type: 2
thold_hi: 85
thold_low:
time_hi: 85
time_low:
thold_fail_count: 3
time_fail_trigger: 3
thold_alert: 2
lastread: 100
lastread_time: 1352835723