Server clock skew

Server clock skew is the difference between the PingDataMetrics server system clock and the monitored server clock, in seconds.

Correlating metric samples from multiple servers requires that the timestamp associated with each sample from each monitored server is synchronized. The PingDataMetrics server tracks system time information and makes it visible in the cn=Monitored Server <servername>,cn=monitor entry.

The system-clock-skew-seconds attribute indicates the difference between the PingDataMetrics server system clock and the monitored server clock, in seconds. The larger this skew value, the less precision there is when comparing changes in data across servers.

While it is not necessary to keep the PingDataMetrics server clock synchronized with all of the monitored servers, it can be convenient when issuing metric queries with time ranges specified by offsets. Because the offset is computed using the PingDataMetrics server system clock, if this clock is very different from the monitored servers' system clocks, the start and end time of a metric query will not match the expected boundaries.