connmon Spikes in latency because of spdMerlin?

[MvW]

I noticed I was having latency spikes every 30 minutes in connmon. Then I realised I have spdMerlin performing its speedtests at regular intervals. Now I've been shifting with the set intervals and now my spikes are gone and the latency is far more consistent, which I imagine, if they're measured by connmon, they affect my whole LAN.

I'm not sure if others are aware of this and I was wondering, as the ping test takes 60 seconds by default and the speedtests probably a little under a minute plus some additional time to refresh the data and the charts, causing a short cpu load, is there any way to prevent them from running at the same time? Maybe with a lock file? As you can see below, after I shifted the 30 minute interval a bit (it was bit trial and error over the past two days, but I can't think of anything else causing the spikes), the spikes are now completely gone as of 2pm this afternoon. I've set the speed test interval to 10 and 40 minutes after the hour, but of course, as soon as I reboot and connmon will automatically start when it's active, it might be active again, as it doesn't run on set times, only intervals (3 min default). It would be nice if both scripts could work together to not get in each others way, assuming the spikes are indeed cause by the overlap in activity of both scripts.

 

[Jack Yaz]

spdMerlin will be getting new defaults when i port over the scheduling update from connmon so out of the box there won't be an overlap.

Until then, there's enough flexibility for you to configure things to not overlap.

 

[Wistuplu]

Hello,

FWIW,
In my view, the overlap is a nice feature and not a weakness.
It is very interesting to have some feedback about the latency under load.
I have actually defined the duration of my connmon to 26 seconds, roughly the duration of my speedtests, to ensure overlap during the whole ping test of connmon. And therefore, a more accurate report of the latency under load.

and the latency is far more consistent, which I imagine, if they're measured by connmon, they affect my whole LAN.

I'm not sure I understand MvW fully. Your LAN is still affected in the same way, just as when you run any speedtest.
connmon doesn't impact latency. It just allows to visualize/measure the condition.

I was under the impression that despite reboots, with the default settings, connmon will always run at the hour, hour and 3 minutes, hour and 6 minutes etc. I thought that setting the spdMerlin to start at h:11 (and h:41), you would avoid the overlap with connmon in a reliable fashion. (Well, except if you choose 11 minutes as interval for connmon ;-) )

HIH
Take care
Best regards
W.

 

[DanNuke86]

Hello,

FWIW,
In my view, the overlap is a nice feature and not a weakness.
It is very interesting to have some feedback about the latency under load.
I have actually defined the duration of my connmon to 26 seconds, roughly the duration of my speedtests, to ensure overlap during the whole ping test of connmon. And therefore, a more accurate report of the latency under load.




I'm not sure I understand MvW fully. Your LAN is still affected in the same way, just as when you run any speedtest.
connmon doesn't impact latency. It just allows to visualize/measure the condition.

I was under the impression that despite reboots, with the default settings, connmon will always run at the hour, hour and 3 minutes, hour and 6 minutes etc. I thought that setting the spdMerlin to start at h:11 (and h:41), you would avoid the overlap with connmon in a reliable fashion. (Well, except if you choose 11 minutes as interval for connmon ;-) )

HIH
Take care
Best regards
W.

I agree with this. Latency under load is bufferbloat, which no one wants.. Doing It this way, overlapping conmon with spdmerlin is a crude but effective way of monitoring this.

Setting up connmon so it misses latency under load doesn't make sense. Surely you want to pick up these things that could indicate issues on your network/router?

Changes in my latency under load have come from changing the server for spdmerlin. My other one suddenly became unavailable. It definitely helps being able to compare the difference between ping unloaded and ping under load.