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Understanding Dynamic Global Properties

Maintains global state information

Intro

Dynamic Global Properties represents a set of values that are calculated during normal chain operations and reflect the current values of global blockchain properties.

The API returns an object containing information that changes every block interval such as the head block number, the total vesting fund, etc.

Sections

head_block_number

Block height at the head of the blockchain. This represents the latest block produced by witnesses.

head_block_id

Used to implement TaPoS (Transaction as Proof of Stake). The first 4 bytes (8 hex digits) of the block ID represents the block number. E.g., 01709398 in hex is 24155032 in decimal.

time

Point in time (UTC) that the block was included in the chain.

Used to synchronize events like Hard Fork activation.

When attempting to calculate the validity of a transaction we need to lookup a past block and check its block hash and the time it occurred so we can calculate whether the current transaction is valid and at what time it should expire.

For new transactions, expirations originate from this time.

current_witness

Account name of the current witness.

total_powDeprecated

The total POW accumulated, aka the sum of num_pow_witness at the time new POW is added.

num_pow_witnessesDeprecated

The current count of how many pending POW witnesses there are, determines the difficulty of doing pow.

virtual_supply

The virtual supply is the supply of all STEEM + all SBD if all SBD were converted to STEEM at the current median price.

current_supply

STEEM currently in existence.

confidential_supply

Total asset held in confidential balances.

current_sbd_supply

SBD currently in existence.

confidential_sbd_supply

Total asset held in confidential balances.

total_vesting_fund_steem Deprecated

Now deprecated way to get STEEM that is invested in STEEM POWER (powered up).

Use condenser_api.get_reward_fund instead.

total_vesting_shares

VESTS that are invested in STEEM POWER (powered up).

total_reward_fund_steem

STEEM available in the reward pool.

total_reward_shares2 Deprecated

Now deprecated way to get the number of shares in the pool.

Use condenser_api.get_reward_fund instead.

sbd_interest_rate

This property defines the interest rate that SBD deposits receive.

maximum_block_size

Maximum block size is decided by the set of active witnesses which change every round. Each witness posts what they think the maximum size should be as part of their witness properties, the median size is chosen to be the maximum block size for the round.

Note: the minimum value for maximum_block_size is defined by the protocol to prevent the network from getting stuck by witnesses attempting to set this too low.

current_aslot

The current absolute slot number. Equal to the total number of slots since genesis. Also equal to the total number of missed slots plus head_block_number.

recent_slots_filled

Used to compute witness participation.

last_irreversible_block_num

The latest block number that has been confirmed by two thirds of all block producers and is thus irreversible.

vote_power_reserve_rate

The number of votes regenerated per day. Any user voting slower than this rate will be “wasting” voting power through spillover; any user voting faster than this rate will have their votes reduced.

average_block_size Removed

Removed in 0.20.6, see: #3029

Average block size is updated every block to be: average_block_size = (99 * average_block_size + new_block_size) / 100. This property is used to update the current_reserve_ratio to maintain approximately * 50% or less utilization of network capacity.

current_reserve_ratio Removed

Removed in 0.20.6, see: #3029

Any time average_block_size <= 50% maximum_block_size this value grows by 1 until it reaches STEEM_MAX_RESERVE_RATIO. Any time average_block_size is greater than 50% it falls by 1%. Upward adjustments happen once per round, downward adjustments happen every block.

max_virtual_bandwidth Removed

Removed in 0.20.6, see: #3029

The maximum bandwidth the blockchain can support is max_bandwidth = maximum_block_size * STEEM_BANDWIDTH_AVERAGE_WINDOW_SECONDS / STEEM_BLOCK_INTERVAL; The maximum virtual bandwidth is: max_bandwidth * current_reserve_ratio

Not Covered

Fields not covered in this recipe are:

Example Method Call

To retrieve the current results for condenser_api.get_dynamic_global_properties, we can retrieve the current state information using curl:

curl -s --data '{"jsonrpc":"2.0", "method":"condenser_api.get_dynamic_global_properties", "params":[], "id":1}' https://api.steemit.com

Example Output

{
   "id":1,
   "jsonrpc":"2.0",
   "result":{
      "head_block_number":24238248,
      "head_block_id":"0171d8a833dc369abd034b0c67d8725f96df9e5b",
      "time":"2018-07-16T22:41:24",
      "current_witness":"xeldal",
      "total_pow":514415,
      "num_pow_witnesses":172,
      "virtual_supply":"283434761.199 STEEM",
      "current_supply":"271729171.190 STEEM",
      "confidential_supply":"0.000 STEEM",
      "current_sbd_supply":"15498201.173 SBD",
      "confidential_sbd_supply":"0.000 SBD",
      "total_vesting_fund_steem":"192913644.627 STEEM",
      "total_vesting_shares":"391296886352.617261 VESTS",
      "total_reward_fund_steem":"0.000 STEEM",
      "total_reward_shares2":"0",
      "pending_rewarded_vesting_shares":"379159224.860656 VESTS",
      "pending_rewarded_vesting_steem":"185294.019 STEEM",
      "sbd_interest_rate":0,
      "sbd_print_rate":2933,
      "maximum_block_size":65536,
      "current_aslot":24315228,
      "recent_slots_filled":"340282366920938463463374607431768211400",
      "participation_count":128,
      "last_irreversible_block_num":24238230,
      "vote_power_reserve_rate":10
   }
}