Sync#

Before Sync#

Certain files will need to be absent or deleted prior to download. A quicksync replaces blockchain data with a customized snapshot. For most use cases a “pruned” version is adequate. Pruned versions will have certain transactions removed from the archive to make node performance smoother. If you are running a node for archival purposes, you will want an “archive” or “default” download.

After choosing the appropriate download type, examine your node and ensure that .terra/data is empty.

Example:

6:22PM INF Removed all blockchain history dir=/home/ubuntu/.terra/data

Warning

If you are a validator, ensure that you do not remove your private key.

Example of a removed private key:

6:22PM INF Reset private validator file to genesis state keyFile=/home/ubuntu/.terra/config/priv_validator_key.json stateFile=/home/ubuntu/.terra/data/priv_validator_state.json

If you have an address book downloaded, you may keep it. Otherwise, you will need to download the appropriate addressbook prior to running terrad start.

During Sync#

After Joining a public network, your node will begin to sync.

Sync start times

Nodes take at least an hour to start syncing. This wait is normal. Before troubleshooting a sync, please wait an hour for the sync to start.

Monitor the sync#

Your node is catching up with the network by replaying all the transactions from genesis and recreating the blockchain state locally. You can verify this process by checking the latest_block_height in the SyncInfo of the terrad status response:

  {
    "SyncInfo": {
        "latest_block_height": "42", <-----
        "catching_up"        : true
    },
  ...
  }

Compare this height to the Latest Blocks on stake.id to see your progress.

Quicksync#

You can significantly accelerate the synchronization process by providing terrad with a recent snapshot of the network state. Snapshots are made publicly available by the Terra community and can be downloaded at https://quicksync.io/networks/terra.html. Choose the snapshot corresponding to your network type (testnet/mainnet) and a mirror close to the location of your node server.

Before downloading a snapshot, make sure that you have the streaming and unpacking utilities installed:

apt-get install wget liblz4-tool aria2 -y

Copy the download URL

Don’t click the download link if you are using a separately hosted node, as this will not download to the correct machine. Instead, copy the link by right-clicking the Download button. Downloading locally is not recommended unless you are hosting your node on the same computer from which you are browsing.

The link in your clipboard should resemble the following:

https://dl2.quicksync.io/bombay-12-default.20220107.0510.tar.lz4

The archived snapshot contains the state and transactions of the network, which are stored in the ~/.terra/data/ folder by default. You should navigate exactly to the ~/.terra/ folder before proceeding to unpack it, or make sure that the contents of the archive are placed into ~/.terra/.

Download the snapshot.

# aria2c is a multi-source command-line download utility
# specify N cores(up to 16) to speed up the process via -xN (5 cores used below)
aria2c -x5 https://dl2.quicksync.io/bombay-12-default.20220107.0510.tar.lz4

Unpack the .lz4 archive:

lz4 -d bombay-12-default.20220107.0510.tar.lz4

Unpack the .tar archive into ~/.terra. Its contents must replace ~/.terra/data/:
```
tar -xvf bombay-12-default.20220107.0510.tar
```
Due to the size of the network, this may take some time.
After the snapshot is completely unpacked, start terrad:
```
terrad start
```

Sync Complete#

You can tell that your node is in sync with the network when SyncInfo.catching_up in the terrad status response returns false and the latest_block_height corresponds to the public network blockheight found on stake.id :

terrad status

Example:

  {
    "SyncInfo": {
        "latest_block_height": "7356350",
        "catching_up"        : false
    },
  ...
  }

Validators can view the status of the network using Terra Finder.

Verify the snapshot#

To verify the validity of the snapshot, use a sha512sum to check it against a cosmos validator’s registry of transactions.

Compare checksum with its on-chain version.#

For this example, use the following snapshot URL:

https://dl2.quicksync.io/bombay-12-default.20220107.0510.tar.lz4

To make things easier for checking, assign the URL to a variable:

URL=https://dl2.quicksync.io/bombay-12-default.20220107.0510.tar.lz4

Obtain the checksum for the snapshot:

wget $URL.checksum
# bombay-12-default.20220 100%[==============================>]  59.55K   215KB/   s    in 0.3s    
# 2022-01-08 07:30:06 (215 KB/s) - 'bombay-12-   default.20220107.0510.tar.lz4.checksum.1' saved [60984/60984]

Obtain the tx hash and assign it to a variable for brevity:

HASH=$(curl -s $URL.hash)   
# 80E12115FEA1B3A161A2FDE7367FC34B8714EF398DAE5B1396F9748BC6218DB1

Obtain the transaction profile and verify it:

curl -s https://lcd-cosmos.cosmostation.io/txs/$(curl -s $URL.hash) | jq -r    '.tx.value.memo'|sha512sum -c
# bombay-12-default.20220107.0510.tar.lz4.checksum: OK

Obtain the checksum script and verify the provided snapshot:

wget https://raw.githubusercontent.com/chainlayer/quicksync-playbooks/master/   roles/quicksync/files/checksum.sh
./checksum.sh $(basename $URL)

Sync faster during testing#

Sometimes you may want to sync faster by foregoing checks. This command should only be used by advanced users in non-production environments. To speed up the sync process during testing, use the following command:

terrad start --x-crisis-skip-assert-invariants

Congratulations!#

You’ve successfully joined a network as a full node operator. If you are a validator, continue to manage a Terra validator for the next steps.

Sync

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