* Tweak account XRP balance and sequence if needed before preclaim.
* Limit total fees in flight to minimum reserve / account balance.
* LastLedgerSequence must be at least 2 more than the current ledger to be queued.
* Limit 10 transactions per account in the queue at a time.
* Limit queuing multiple transactions after transactions that affect authentication.
* Zero base fee transactions are treated as having a fixed fee level of 256000 instead of infinite.
* Full queue: new txn can only kick out a tx if the fee is higher than that account's average fee.
* Queued tx retry limit prevents indefinitely stuck txns.
* Return escalation factors in server_info and _state when escalated.
* Update documentation.
* Update experimental config to only include the % increase.
* Convert TxQ metric magic numbers to experimental config.
Replace Journal public data members with member function accessors
in order to make Journal lighter weight. The change makes a
Journal cheaper to pass by value.
Also add missing stream checks (e.g., calls to JLOG) to avoid
text processing that ultimately will not be stored in the log.
* LastLedgerSequence
* Zero-fee txn has infinite fee level.
* Remove pseudo-transaction fee levels, since pseudos never get to the open ledger.
* preflight/preclaim failure cases
* Queued transaction failure handling.
The first few transactions are added to the open ledger at
the base fee (ie. 10 drops). Once enough transactions are
added, the required fee will jump dramatically. If additional
transactions are added, the fee will grow exponentially.
Transactions that don't have a high enough fee to be applied to
the ledger are added to the queue in order from highest fee to
lowest. Whenever a new ledger is accepted as validated, transactions
are first applied from the queue to the open ledger in fee order
until either all transactions are applied or the fee again jumps
too high for the remaining transactions.
Current implementation is restricted to one transaction in the
queue per account. Some groundwork has been laid to expand in
the future.
Note that this fee logic escalates independently of the load-based
fee logic (ie. LoadFeeTrack). Submitted transactions must meet
the load fee to be considered for the queue, and must meet both
fees to be put into open ledger.