The error “BigQueryException: Connection has closed: javax.net.ssl.SSLException: Connection reset” usually indicates that the network connection to BigQuery was terminated unexpectedly. This can be caused by various network issues such as transient disruptions or restrictive network configurations like firewalls or proxies that terminate idle connections.
Here are some strategies to manage and potentially resolve this issue:
Implement a Retry Mechanism:
Use a retry mechanism with exponential backoff to handle connection resets gracefully. When a connection reset occurs, catch the exception, wait for a progressively increasing interval, and then retry the operation. This is especially useful for transient network issues.
Utilize Streaming for Large Result Sets:
Instead of attempting to load all results at once, process the results in smaller batches. Use the getQueryResults method with pagination tokens to handle large datasets efficiently. This reduces memory consumption and minimizes the impact of any single network disruption.
Adjust Network and Client Timeouts:
Increase the timeout settings in your BigQuery client configuration to allow longer periods for your operations to complete, particularly for queries that return large datasets or are known to take a long time.
Review Firewall and Proxy Configurations:
Ensure that any firewalls or proxy servers in your network path are configured to allow long-lived connections as required by your BigQuery operations. These systems might be closing connections that appear idle for too long.
Batch Processing with Pagination:
If persistent issues occur, consider breaking your query into smaller chunks. You can modify your query to retrieve subsets of the data and process each subset separately. This approach limits the impact of any single query failure.
Example (Handling Large Queries with Pagination and Retry):
String pageToken = null;
int retryCount = 0;
final int MAX_RETRIES = 5;
while (true) {
try {
TableResult tableResult = bigquery.getQueryResults(jobId, BigQuery.QueryResultsOption.pageToken(pageToken));
for (FieldValueList row : tableResult.iterateAll()) {
// Process each row here
}
pageToken = tableResult.getNextPageToken();
if (pageToken == null) {
break; // All pages have been processed
}
retryCount = 0; // Reset retry count after a successful batch
} catch (BigQueryException e) {
if (e.getCause() instanceof SSLException && e.getMessage().contains("Connection reset")) {
if (retryCount < MAX_RETRIES) {
retryCount++;
int waitTime = 1000 * (int) Math.pow(2, retryCount); // Exponential backoff calculation
System.err.println("Connection reset. Retrying after " + waitTime + " ms...");
Thread.sleep(waitTime);
continue; // Retry the operation
} else {
throw new RuntimeException("Maximum retries reached, unable to recover from SSLException", e);
}
} else {
throw e; // Rethrow if it's not a recoverable SSLException
}
}
}