retire.md

Retiring a Stake Pool

After having seen how to register a stake pool, we want to deregister one in this tutorial.

We assume that we have a registered stake pool with cold keys node.vkey and node.skey, a payment address with sufficient funds (for the transaction fees) pay and an associated payment signing key pay.skey. We furthermore assume the our node socket path is relay-db/node-socket and that our genesis file is ff-genesis.json.

In order to retire our pool, we need to create a deregistration certificate and attach it to a transaction that we submit to the blockchain.

1. The deregistration certificate contains the epoch in which we want to retire the pool. This epoch must be after the current epoch and not later than eMax epochs in the future, where eMax is a protocol parameter.

   So we first need to figure out the current epoch. The number of slots per epoch is recorded in the genesis file, and we can get it with

   cat ff-genesis.json | grep epoch
   > "epochLength": 21600,
   

   So one epoch lasts for 21600 slots. We get the current slot by querying the tip:

   export CARDANO_NODE_SOCKET_PATH=relay-db/node-socket
   cardano-cli shelley query tip --testnet-magic 42
   > Tip (SlotNo {unSlotNo = 856232}) ...
   

   This gives us

   expr 856232 / 21600
   > 39
   

   So we are currently in epoch 39.

   We can look up eMax by querying the current protocol parameters:

   cardano-cli shelley query protocol-parameters \
       --testnet-magic 42 \
       --out-file params.json
   cat params.json | grep eMax
   > "eMax": 100,
   

   This means the earlist epoch for retirement is 40 (one in the future), and the latest is 139 (current epoch plus eMax). So for example, we can decide to retire in epoch 41.

2. Now we can create the deregistration certificate and save it as pool.dereg:

   cardano-cli shelley stake-pool deregistration-certificate \
       --cold-verification-key-file node.vkey \
       --epoch 41 \
       --out-file pool.dereg
   

3. Finally, we need to create a transaction containing the certificate and submit it. We calculate fees:

   cardano-cli shelley transaction calculate-min-fee \
       --tx-in-count 1 \
       --tx-out-count 1 \
       --ttl 860000 \
       --testnet-magic 42 \
       --signing-key-file pay.skey \
       --signing-key-file node.skey \
       --certificate pool.dereg \
       --protocol-params-file params.json
   > 171309
   

   We query our address for a suitable UTxO to use as input:

   cardano-cli shelley query utxo \
       --address $(cat pay) \
       --testnet-magic 42
   
   
   
          TxHash             TxIx        Lovelace
   ------------------------------------------------
   9db6cf...                    0      999999267766
   

   We calculate our change:

   expr 999999267766 - 171309
   > 999999096457
   

   Build the raw transaction:

   cardano-cli shelley transaction build-raw \
       --tx-in 9db6cf...#0 \
       --tx-out $(cat pay)+999999096457 \
       --ttl 860000 \
       --fee 171309 \
       --out-file tx.raw \
       --certificate-file pool.dereg
   

   Sign it with both the payment signing key and the cold signing key (the first signature is necessary because we are spending funds from pay, the second because the certificate needs to be signed by the pool owner):

   cardano-cli shelley transaction sign \
       --tx-body-file tx.raw \
       --signing-key-file pay.skey \
       --signing-key-file node.skey \
       --testnet-magic 42 \
       --out-file tx.signed
   

   And submit to the blockchain:

   cardano-cli shelley transaction submit \
       --tx-file tx.signed \
       --testnet-magic 42
   

   And we are done. The pool will retire at the end of epoch 40. If we change our mind, we can create and submit a new registration certificate before epoch 41, which will then overrule the deregistration certificate.