How to Resolve java.net.UnknownHostException: Unable to Resolve Host 'accounts.google.com' When Inserting Rows in BigQuery

What causes the java.net.UnknownHostException when trying to insert data into BigQuery?

// Sample Java code snippet for BigQuery insertion
BigQuery bigQuery = BigQueryOptions.getDefaultInstance().getService();
TableId tableId = TableId.of("dataset_id", "table_id");
InsertAllResponse response = bigQuery.insertAll(InsertAllRequest.newBuilder(tableId)
.addRow(rowId, rowContent)
.build());

The java.net.UnknownHostException occurs when a Java application cannot resolve a host name into an IP address. This can be problematic when trying to connect to services like Google BigQuery, particularly if your application relies on external DNS resolution.

// to check network connectivity
try {
    InetAddress address = InetAddress.getByName("accounts.google.com");
    System.out.println("Host IP Address: " + address.getHostAddress());
} catch (UnknownHostException e) {
    e.printStackTrace();
}

Causes

• The hostname may be incorrect or misspelled.
• Network connectivity issues, such as firewalls blocking access to the external DNS server.
• Issues with the local DNS resolver or network settings.
• Temporary unavailability of the target hostname.

Solutions

• Check and correct the hostname in your code. Ensure 'accounts.google.com' is spelled correctly.
• Verify your Internet connection and firewall settings to allow access to Google's servers.
• Try using a different DNS server or resetting your network settings.
• Check for any outages or issues with the hosting provider's services.

Mistake: Using an incorrect hostname in the BigQuery configuration.

Solution: Double-check and ensure the hostname is accurate.

Mistake: Not handling errors or exceptions properly in the code, leading to poor feedback.

Solution: Implement robust error handling to catch exceptions and log them adequately.