In Steem, most of the blocks are produced by chosen witnesses rather than miners, in a system called DPOS. More detail can found on the bitshares.org article Delegated Proof-of-Stake Consensus written about it.
Live Visualization
I had created a tool to show the production of blocks as it happens, along with many other interesting things. Here's what it looks like:
Details
There are three lists in boxes that show various information.
Also, at the top of each list shows when the data in them is last refreshed.
Witness Schedule
This box shows the current round's schedule.
As you can see, every round consists of 21 3-second blocks. This includes the top 19 witnesses, a miner witness, and a backup witness.
Every row has the rank of the witness, what kind of witness they are, the name of the witness, and the block number of the block that the witness produced as it happens.
When a new block is added to the blockchain, the corresponding line is highlighted in green. Past blocks are then grayed out.
At the bottom is the next_shuffle_block_num. This is when the current list will be shuffled. The current_virtual_time is used to aid in choosing the next witness.
Top 100 Witnesses
This is a list of the top 100 witnesses by rank. There is an option to show 200 if desired, but 100 is good for most cases.
This list is sorted ascendingly by virtual_scheduled_time. The closer a witness is to the current_virtual_time, the sooner they will be scheduled for the next round.
The top 19 witnesses are shown in silver as they will always be scheduled and shuffled in the next round.
Disabled witnesses with the deactivated signing key of STM1111111111111111111111111111111114T1Anm are filtered out and not shown.
When there is a new witness schedule list at the end of the round, you will see that the next backup witness is picked from the top of this list. There is a chance that there is a witness outside of this top 100 list that is before the top of this list, but you'll only see that happen rarely.
Miner Queue
This shows the list of miners that are queued up to be included in a future schedule.
These miners have already broadcasted a proof-of-work, or POW, to the blockchain that demonstrate that they have done the necessary work. When that happens, they get inserted into the bottom of the queue.
When there is a new witness schedule, the one from the top of the list is included in the next round.
As rabbit and supercomputing accounts have dominated this list, if there are accounts with names that don't start with rabbit or supercomputing, they will be shown in orange. Occasionally, it happens.
Link
Just go to my personal site at bitcoiner.me and click on the link button at the top that says Witness Schedule Live Visualization.
Or you can go directly to bitcoiner.me/schedule.
With this tool, you can now see the blockchain in action and the witnesses at work!
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