Troubleshooting common errors when using the Spark Cassandra Connector with Amazon Keyspaces

If you're using Amazon Virtual Private Cloud and you connect to Amazon Keyspaces, the most common errors experienced when using the Spark connector are caused by the following configuration issues.

• The IAM user or role used in the VPC lacks the required permissions to access the system.peers table in Amazon Keyspaces. For more information, see Populating system.peers table entries with interface VPC endpoint information.

• The IAM user or role lacks the required read/write permissions to the user table and read access to the system tables in Amazon Keyspaces. For more information, see Step 1: Configure Amazon Keyspaces for integration with the Apache Cassandra Spark Connector.

• The Java driver configuration doesn't disable hostname verification when creating the SSL/TLS connection. For examples, see Step 2: Configure the driver.

For detailed connection troubleshooting steps, see My VPC endpoint connection doesn't work properly.

In addition, you can use Amazon CloudWatch metrics to help you troubleshoot issues with your Spark Cassandra Connector configuration in Amazon Keyspaces. To learn more about using Amazon Keyspaces with CloudWatch, see Monitoring Amazon Keyspaces with Amazon CloudWatch.

The following section describes the most useful metrics to observe when you're using the Spark Cassandra Connector.

PerConnectionRequestRateExceeded

Amazon Keyspaces has a quota of 3,000 requests per second, per connection. Each Spark executor establishes a connection with Amazon Keyspaces. Running multiple retries can exhaust your per-connection request rate quota. If you exceed this quota, Amazon Keyspaces emits a PerConnectionRequestRateExceeded metric in CloudWatch.

If you see PerConnectionRequestRateExceeded events present along with other system or user errors, it's likely that Spark is running multiple retries beyond the allotted number of requests per connection.

If you see PerConnectionRequestRateExceeded events without other errors, then you might need to increase the number of connections in your driver settings to allow for more throughput, or you might need to increase the number of executors in your Spark job.

StoragePartitionThroughputCapacityExceeded

Amazon Keyspaces has a quota of 1,000 WCUs or WRUs per second/3,000 RCUs or RRUs per second, per-partition. If you're seeing StoragePartitionThroughputCapacityExceeded CloudWatch events, it could indicate that data is not randomized on load. For examples how to shuffle data, see Step 4: Prepare the source data and the target table in Amazon Keyspaces.

Common errors and warnings

If you're using Amazon Virtual Private Cloud and you connect to Amazon Keyspaces, the Cassandra driver might issue a warning message about the control node itself in the system.peers table. For more information, see Common errors and warnings. You can safely ignore this warning.