FAQs
Developer FAQs
FAQs for developers
Developer FAQs
How do I speed up my self-hosted instance?
How do I speed up my self-hosted instance?
BlockScout can be resource intensive. If your instance is running slowly:
-
Clear the cache - the application cache is cleared on restart by running:
sudo systemctl restart explorer.service - Increase the memory limit for indexers if indexing is slow. See the indexer configuration for details.
- Increase the number of CPUs if CPU is running at 100% on the web app server
- Increase the memory if memory consumption is high on the web app server
- Increase the number of CPUs or/and increase the memory on the database server if consumption is high.
How do I customize the coin symbol / name?
How do I customize the coin symbol / name?
Exchange Rates Coin NameFor instance, in case of POA instance of Blockscout:
- Specify coin name for exchange rates fetcher with the
COINENV variables
COIN environment variable which pulls the associated market data from the Coinmarketcap.com API or CoinGecko API to provide pricing data throughout the application.Displayed Coin SymbolIn order to set displayed coin symbol, instance maintainer should set COIN_NAME runtime environment variable:How do I manage deployment with AWS CodeDeploy?
How do I manage deployment with AWS CodeDeploy?
- Visit CodeDeploy in AWS. You will see a list of your deployments. Select the deployment id to view details at https://console.aws.amazon.com/codesuite/codedeploy/deployments?region=us-east-1
-
Deployment status consists of several steps. Once step 2 is complete (application is installed on replacement instances), you manually reroute traffic. Click the
Reroute trafficbutton to initiate.
- Once traffic is rerouted, you’ll be asked to terminate the original instance. Click the Terminate button to initiate.
- Once complete, use the public DNS address of the Amazon EC2 instance to view in a web browser. (To get the public DNS value, choose your Amazon EC2 instance in the Amazon EC2 console, and look for the value in Public DNS in the Description tab).
What's the best way to deploy to AWS?
What's the best way to deploy to AWS?
Currently the best existing way is through docker compose.We are currently working on deployment through Kubernetes (K8s) and other methods for easily spinning up an instance on AWS.
How do I replace missing assets/version numbers?
How do I replace missing assets/version numbers?
Missing Assets
- Find the public ip of corresponding Blockscout instance in the EC2 -> Instances of AWS Dashboard.
-
Connect to the host via SSH
ssh -i <host.pem> ec2-user@<public_ip>, where<host.pem>is host’s private key file,<public_ip>is the public ip of the host, that can be found in the AWS dashboard. -
Go to assets folder
cd /opt/app/apps/block_scout_web/priv/static -
Add missing assets there or to
./imagesfolder depending on what is missing. Refresh Blockscout instance page. For example, iffavicon.icois missing in./imagesfolder, just copy it from the root assets foldercp favicon.ico ./images/. You should see now the missing assets.
Missing Version in Footer
The app version number should be in the footer of BlockScout instance
- Find the public ip of corresponding Blockscout instance in the EC2 -> Instances of AWS Dashboard
-
Connect to the host via SSH
ssh -i <host.pem> ec2-user@<public_ip>, where<host.pem>is host’s private key file,<public_ip>is the public ip of the host, that can be found in the AWS dashboard. -
Go to layout folder
/opt/app/apps/block_scout_web/lib/block_scout_web/templates/layout -
Open
_footer.html.eexfooter template in the favorite text editor. For examplenano ./_footer.html.eexand fix the line<% version = version() %>(it is in the bottom of the file) with the hardcoded new version, for example,<% version = 'v1.3.3-beta' %>and save. -
Restart the Blockscout instance with
sudo systemctl restart explorer.service
How do I fix the Gettext.Error?
How do I fix the Gettext.Error?
You may receive this error after making changes to a specific BlockScout application.
(Gettext.Error) translation with msgid '...<msg_here>...' has a non-empty msgstrTo update gettext, run the following command in the app’s folder where the changes were made.-
Go to the
./apps/{name_of_app}folder where the changes were made. -
Run
mix gettext.extract --merge - Repeat for other app folders as required.
How do I update the UI?
How do I update the UI?
See the Branding configs page for details related to different UI elements.For updates like adding elements/links etc you will need to change .eex templates. When changing .eex templates you don’t need to rebuild. Run the application in dev mode (MIX_ENV=dev), and change the template. You’ll see changes on-the-fly. When changing js/scss while running the application, you need to run
mix phx.digest to apply the changes.How can I view smart contracts using RPC?
How can I view smart contracts using RPC?
Use the JSON RPC
listcontracts endpoint. For example, to view verified contracts, use the following query. Pagination is availableWhy are Market Cap/Token Price stats wrong?
Why are Market Cap/Token Price stats wrong?
One reason may be related to the CoinGecko API refusing Blockscout requests without an API key.If impacted, apply this pull request to your instance:https://github.com/blockscout/blockscout/pull/5613It implements CoinGecko API key management and alternative CoinMarketCap exchange rates.
How do I verify contracts via an API?
How do I verify contracts via an API?
There are several ways:
- Use the API v2 endpoints
- Use the RPC endpoints for verification
How do I disable exchange rates?
How do I disable exchange rates?
Change the Explorer.ExchangeRates variable from See the configuration file for more details.
enabled: true to enabled: falseHow can I migrate verified contracts between databases?
How can I migrate verified contracts between databases?
You may want to do this if you are creating a new instance or resyncing a new node.
-
Backup the
smart_contractstable - Restore this table following the resync.
Which Linux distro do I use for manual deployment?
Which Linux distro do I use for manual deployment?
Ubuntu 18.04 has been configured in Blockscout CI.
Can I set RPC variable to a normal http(s) url?
Can I set RPC variable to a normal http(s) url?
Yes you can. The
ethereum_json_rpc_http variable can be set to any url, it does not need to be a localhost. Client variant env variable should be specified in either case.Do I need to enable ws?
Do I need to enable ws?
No, it is not required. If ws is disabled, leave the
ETHEREUM_JSONRPC_WS_URL env var empty or unset it.How to fix error message "execution timeout at `pushGasToTopCall`"?
How to fix error message "execution timeout at `pushGasToTopCall`"?
Try increasing time for the
ETHEREUM_JSONRPC_DEBUG_TRACE_TRANSACTION_TIMEOUT ENV variable. The default is 5 sec.How do I fix Unknown Private Network error?
How do I fix Unknown Private Network error?
In a self-hosted or locally deployed instance, when attempting to do a write transaction on a verified contract, the following errors may appear:Unauthorized“You connected to Unknown Private Network chain in the wallet, but the current instance of Blockscout is for Unknown Private Network chain”“No “from” address specified in neither the give options, nor the default options.”To Troubleshoot:
-
Check that you set the correct
CHAIN_IDenv variable -
Check correct variable for
NETWORK_ID