Missed slots

Hi, I’m a SPO and I just wondered, how many missed slots by BP is normal, if any. My pool gets about 20-30 missed slots in 24 hours.

1 Like

btw, Where do you see this info? since I am interested in this stat as well

cardano_node_metrics_slotsMissedNum_int

1 Like

keep it under monitoring, also u are running 1.25.1? I heard in 1.26.1 no more issues

It seems to be correlated to hardware performance. My pool runs on a Raspberry Pi, and if TraceMempool is enabled, it misses a few slots every hour. With that setting disabled, it misses very few slots a day.

Another pool operator (also Raspberry Pi) mentioned that if the BP was only connected to one relay it helped (vs two or more relays connected).

It seems that folks that have more powerful hardware (more RAM, faster Disk IO perhaps) have less of an issue. So if you are running a cloud instance, try upping the RAM or other resources and see how it affects the metric.

I’m on 1.26.1. BP and one Relay is in Germany and second Relay is in USA. I’m gonna labour with it and let you all know.

After some tries with settings it looks like the problem with missing slots was caused by my second relay, which is located in USA (high latency); BP and primary relay are located in Germany. Now, when the BP is not connected to USA relay, the problem with missed slots is gone (zero missed in about 8 hours).

1 Like

Thanks for sharing this - so it is indeed a good metrics to monitor the performance of the pool - and probably the solution is to add more relays to your block producer topology…

Exactly. And additionaly, it looks like that the closer your relays is located, the better for latency and thus the synchronization speeds BP will have. Cheers

I had the Producer in DE (when it was on cloud) and it was connected with my relays from USA, DE and RO and never had issues; indeed the RTT for USA relay was a little high but never has issues in creating the blocks.

And, by your mean, what is acceptable count of missed slots for staking pool?

I don’t know if it is acceptable but certainly you will not loss a block because of this… .anyway… your Producer has connections with 2 Relays right? so if the USA relay has issue the producer should receive the slots from the 2nd Relay right?

and I know were issues before 1.26.1 … I don’t know if were fixed

You’re right Alex, no doubt. The fact is (maybe coincidence), that my pool gets about 25-30 % less missed slots when the USA relay is offline. I have to play with it.

If you want to mint blocks and you miss slots while minting you’d loose that block - AFAIK. In other words missing blocks is not acceptable.

It’s not fixed in 1.26.1. Still seeing missed slots. Investigated for a couple of days now. Having not missed a slot for the last 5 hours, but for me it’s mostly happening over night. I.e., I’ll have to wait and see for some time to come.

@Alexd1985 how can I enable this metric - when making a query curl localhost:12798/metrics it does not show up…

This one?

cardano_node_metrics_slotsMissedNum_int

yes, I can not find among the metrics I got when making the query

Are u trying on Producer right?

yes, on producer.