Choosing EVEN distribution in Amazon Redshift is most appropriate in two primary circumstances. First, when the tables are highly denormalized and do not participate in frequent joins, the EVEN distribution helps in evenly distributing the data across the nodes without concern for join keys. Second, when a new table has been loaded and it is unclear how it will be joined to dimension tables, using EVEN distribution can help to ensure that the data is evenly spread out while the schema and data relationships are still being determined.
To optimize EMR job performance when handling large files, it is beneficial to use a compression algorithm that balances CPU usage and compression speed while also being splittable, which allows for parallel processing. Both bzip2 and Snappy offer these advantages over gzip. Bzip2 provides higher compression with reasonable speed and is splittable, enabling efficient processing of large datasets. Snappy, while not as compressive as bzip2, offers much faster compression and decompression speeds, making it suitable for frequent access scenarios. This approach improves EMR efficiency by allowing faster data processing and optimizing resource usage.
The most reliable and fault-tolerant technique for sending data to Amazon Kinesis with every click is to use the Amazon Kinesis PutRecord API along with an exponential back-off algorithm for retries until a successful response is received. This method handles potential throughput issues and ensures that retries do not overwhelm the system, providing a balanced approach to reliability and fault tolerance.
The most efficient DynamoDB table scheme to support querying for a given stream or server within a defined time range involves defining a primary key with StreamName as the partition key and TimeStamp followed by ServerName as the sort key. Additionally, a Global Secondary Index should be defined with ServerName as the partition key and TimeStamp followed by StreamName. This setup allows for querying based on either StreamName or ServerName within a specified time range, providing the flexibility needed to meet the requirements.
To enable a centralized metadata layer that can expose Amazon S3 objects as tables for teams using SQL queries with Hive, Spark-SQL, and Presto on Amazon EMR, configuring the Hive Metastore to use an Amazon RDS database is the best approach. By hosting the Hive Metastore in Amazon RDS, multiple EMR clusters can share a single, consistent, and centralized metadata store. This allows all analyst teams to access the same metadata from different clusters, ensuring that the S3 objects are represented consistently as tables across all teams. EMRFS consistent view and DynamoDB are primarily used for consistency of file operations in S3 and do not serve as a centralized metadata service.