Multiple transactions per account in TxQ (RIPD-1048):

* 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.

doc/rippled-example.cfg

@@ -418,16 +418,77 @@
 #
 #       The queue will be limited to this <number> of average ledgers'
 #       worth of transactions. If the queue fills up, the transactions
-#       with the lowest fees will be dropped from the queue any time a
-#       transaction with a higher fee level is added. Default: 20.
+#       with the lowest fee levels will be dropped from the queue any
+#       time a transaction with a higher fee level is added.
+#       Default: 20.
 #
 #   retry_sequence_percent = <number>
 #
-#       If a client resubmits a transaction, the new transaction's fee
-#       must be more than <number> percent higher than the original
-#       transaction's fee, or meet the current open ledger fee to be
-#       considered. Default: 125.
+#       If a client replaces a transaction in the queue (same sequence
+#       number as a transaction already in the queue), the new
+#       transaction's fee must be more than <number> percent higher
+#       than the original transaction's fee, or meet the current open
+#       ledger fee to be considered. Default: 25.
 #
+#   multi_txn_percent = <number>
+#
+#       If a client submits multiple transactions (different sequence
+#       numbers), later transactions must pay a fee at least <number>
+#       percent higher than the transaction with the previous sequence
+#       number.
+#       Default: -90.
+#
+#   minimum_escalation_multiplier = <number>
+#
+#       At ledger close time, the median fee level of the transactions
+#       in that ledger is used as a multiplier in escalation
+#       calculations of the next ledger. This minimum value ensures that
+#       the escalation is significant. Default: 500.
+#
+#   minimum_txn_in_ledger = <number>
+#
+#       Minimum number of transactions that must be allowed into the
+#       ledger at the minimum required fee before the required fee
+#       escalates. Default: 5.
+#
+#   minimum_txn_in_ledger_standalone = <number>
+#
+#       Like minimum_txn_in_ledger when rippled is running in standalone
+#       mode. Default: 1000.
+#
+#   target_txn_in_ledger = <number>
+#
+#       Number of transactions allowed into the ledger at the minimum
+#       required fee that the queue will "work toward" as long as
+#       consensus stays healthy. The limit will grow quickly until it
+#       reaches or exceeds this number. After that the limit may still
+#       change, but will stay above the target. If consensus is not
+#       healthy, the limit will be clamped to this value or lower.
+#       Default: 50.
+#
+#   maximum_txn_in_ledger = <number>
+#
+#       (Optional) Maximum number of transactions that will be allowed
+#       into the ledger at the minimum required fee before the required
+#       fee escalates. Default: no maximum.
+#
+#   maximum_txn_per_account = <number>
+#
+#       Maximum number of transactions that one account can have in the
+#       queue at any given time. Default: 10.
+#
+#   minimum_last_ledger_buffer = <number>
+#
+#       If a transaction has a LastLedgerSequence, it must be at least
+#       this much larger than the current open ledger sequence number.
+#       Default: 2.
+#
+#   zero_basefee_transaction_feelevel = <number>
+#
+#       So we don't deal with infinite fee levels, treat any transaction
+#       with a 0 base fee (ie. SetRegularKey password recovery) as
+#       having this fee level.
+#       Default: 256000.
 #
 #
 #-------------------------------------------------------------------------------