Techniques are provided for tracking a number of transactions-of-interest in a transaction-recording blockchain using a control blockchain. A transaction-of-interest is a transactions that is in a particular state. A request to perform an action is received. Upon receiving the request and determining that the action corresponds to a new transaction-of-interest, a control blockchain is checked to determine the current number of transactions-of-interest in the transaction-recording blockchain and maximum allowed number of transaction-of-interest for the transaction-recording blockchain. In response to determining that the current number of transaction-of-interest in the transaction-recording blockchain are less than the maximum allowed: allowing the action to occur, adding a new block to the transaction-recording blockchain, and updating the control blockchain to indicate the new number of transaction-of-interest. In response to determining that the current number of transaction-of-interest are at least at the maximum allowed number, prohibiting the addition of a new block to the transaction-recording blockchain.