Assigned performance is the percentage of blocks minted against leader slots assigned (not including stolen or ghosted blocks). Assigned performance is reduced by missing and invalid blocks which are nominally in the control of the operator.
We track a large number of metrics to ensure that the ADAvault stake pools are reliably minting blocks including:
- assigned leader slots,
- the ideal number of slots per epoch, based on pool stake,
- luck, which is the ratio of assigned leader slots to ideal;
- and lastly, the actual minted blocks confirmed on chain.
You will see in the data there is considerable variation in leader slots assigned to the pools. This is due to the Verifiably Random Function (VRF) used to assign blocks. The VRF will always average over time to 100% luck but there can be significant variance from this in the short term.
The graph shows slots as leader, ideal slot allocation based on stake, luck expressed as the percentage leader allocation against ideal; and lastly, the actual confirmed blocks which were minted on the Cardano blockchain. We present data for the last 20 epochs.
* M=Missed, G=Ghosted, S=Stolen, I=Invalid (see below for more details).
There were stolen and ghosted blocks in some Epochs where an assigned block was minted by another pool. This is a standard part of the Ouroboros Praos protocol decided based on a random function using the pool VRF key. See discussion on implementation here https://github.com/input-output-hk/ouroboros-network/issues/2014
ADV2 shows a similar overall performance profile as ADV which is expected given the pool has similar stake and runs on an equivalent hardware and software stack. Again, please note the ghosted and stolen blocks which are more likely given the pool is close to 100% saturation.
Slot leader allocation for ADV3 is more variable as the pool is smaller, average luck is consistent with the larger pools but with greater variance across epochs. There are far less stolen and ghosted blocks as the potential for VRF collisions with other pools is proportionately smaller.
Key to headings
Leader: Number of slots scheduled to lead and mint block
Ideal: Expected number of leader slots based on active stake
Luck: The percentage of leader slots assigned vs ideal
Confirmed: Number of blocks created and subsequently validated on-chain
Invalid: Node attempted but failed to create block (for unknown reasons)
Missed: Scheduled at slot but no record of it in cncli DB and no other pool has made a block for this slot
Ghosted: Block created but marked as orphaned and no other pool has made a valid block for this slot, possibly due to height battle or block propagation issue
Stolen: Another pool has a valid block registered on-chain for the same slot, possibly due to VRF contention and more than one pool assigned to the slot
Historic performance data is refreshed every hour, there will be some lag against the real time statistics for block production in the current epoch.
ADAvault uses Prometheus and Grafana to monitor the infrastructure that we operate, and collect data from node instances. Delegators have complete transparency on pool operation and performance, with access to a subset of the same real time monitoring dashboard as our Ops team.
Resource utilisation for memory network and CPU is low, and there is significant capacity on the existing hardware for transactions as smart contracts adoption increases. Performance tuning is carried out periodically for releases with a number of improvements recently implemented for time synchronisation and file systems (xfs from ext4).
Stake pool operational availability remains at 100% and the Cardano node software has proven to be very stable. We always allow for a comprehensive soak test on the passive nodes when compiling new releases.
ADAvault has very low latency measurements for connectivity to peers. This is important as it increases the likelihood that the blocks minted by the stake pools are adopted on chain. Real time details are available from PoolTool.io who measure propagation delays across all registered pools.
The important latency number is not the average (or median) at ~300ms, but the mode (or most frequently occurring latency) which is ~100ms. The reason the average is less relevant is that it is skewed by the very infrequent long tail which could be removed by connecting to close geographical peers, but has the side effect of making the network weaker and reducing global block propagation.
For comparison it takes approximately 200ms to send a ping request half way around the world. Therefore we can see that 100ms for the mode is towards the lower theoretical bound for latency.
We regularly review global peer connectivity, and are confident the pools have excellent performance characteristics for reliable block production.