My understanding from the documentation is that not all dimensions and the metrics have its baseline calculated (when I configure alert for loss rate and rtt I can't, so the way I see this is that, baseline is not calculated for these two metrics.)
But then out of curiosity, I create a DMI and found out this: It seems that actually baseline is calculated (because using different data source I get different value)
So what's the thing I got wrong? I hope can I can configure alert using rtt and loss rate. Currently I am using network time, but it doesn't seems to be a good enough metric for alerting-e-mail.
Any idea or comment on this is appreciated.
You should be able to configure alerts using RTT and loss rate. These are basic metrics and should work just fine.
Regarding the metric choice: Network TIme is definitely not a good metric to alert on, as its value would depend on transaction size. RTT makes sense when you know that new TCP connections are established frequently enough, so the RTT measurement can be done. If this is true, then Network Performance may be a good metric as well, it combines RTT and retransmissions relative to baseline (and it’s configurable what this metric entails). If TCP connections are not established frequently (e.g. once a day only), then ACK RTT may be abetter choice as a metric that represents latency. But first you need to verify on time-series charts whether in your environment the ACK RTT is predictable enough.
A few additional comments:.
Baselines: baseline calculations are performed for RTT and loss rate and alerts can use them. In fact baselines are calculated for nearly all metrics, so there should be no mer-metric visibility issue. However, there are two different DMI data views that expose the calculations: software services data view looks at all traffic that reaches software services or servers, while internetwork traffic data view looks at traffic that goes in and out of a location, so it excludes intra-location traffic (traffic between nodes that belong to a location IP address range). This may influence what you see on the DMI reports.
Dimensions for which baselines are calculated: indeed there are several dimension combinations for which baselines are calculated, but not all. However, all typical combinations of server, software service, location are enabled by default, so you should see baselines for sure.
If it still doesn’t work, perhaps a Support call may be needed to find out what’s not working in there.