Summary:  Due to a kernel security exploit on system CPUs (Spectre and Meltdown), OS updates are required for all systems. The OS updates have performance implications. Cloudera is in the process of testing the impact across various Cloudera software services and workloads. Initial test results, based on the limited testing (a subset of services and workloads) we have completed as of January 12, indicate that the performance impact on Cloudera software is minor.   Users affected:  While we are not aware of customers who have been impacted by these CPU vulnerabilities, we understand and expect that all Cloudera customers will apply Spectre and Meltdown patches as they become available from their OS suppliers.  As such, Cloudera is performing basic functional testing to ensure that CDH works with the patches as well as determining performance impact on typical workloads.   Impact:  Cloudera’s initial testing has focused on a subset of commonly used CDH services. Based on the limited testing (a subset of services and workloads) we have completed as of January 12, these CDH services continue to function on patched systems and the performance impact on Cloudera software is minor. For example: MapReduce jobs run with 3 - 9% slowdown Impala queries run with 5 - 10% slowdown Hive on Spark queries run with up to 5% slowdown Spark jobs run with 0 - 12% slowdown HBase queries run with up to 5% slowdown Cloudera understands that the performance of your data clusters can affect important applications and may have business impact. As such, we are taking this situation seriously and treating this with urgency. Cloudera will provide additional performance results as soon as they are available.   Action required:  While we are not aware of customers who have been impacted by these CPU vulnerabilities, we understand and expect that all Cloudera customers will apply Spectre and Meltdown patches as they become available from their OS suppliers. ... View more