These files are compressed by the Cowic library, which operates on each of their columns independently, unlike “parser-based” methods. A data structure partially named for these files utilizes Bloom filters to query a hierarchy of SSTables and is used instead of B-trees in many write-optimized database systems. They’re not keys, but the process of limiting the size of these files (-5[1])is termed their (15[1])namesake (15[1])“rotation.” A popular data analytics stack consists of Elasticsearch, a tool named for these files, and Kibana. (*) Journalctl (10[1])(“journal-CTL”) and Event Viewer (10[1])are tools used to view the contents of these files (10[2])on (10[1])Linux and Windows. In December 2021, Alibaba Cloud announced a zero-day vulnerability allowing arbitrary code execution in Java’s “4j” utility for these files. (10[2])Entries in these files are typically tagged with namesake levels, such as INFO, DEBUG, and WARN. (10[1])For 10 points, name these (10[1])append-only files used to monitor, (10[1])debug, and audit computer systems. ■END■ (10[1]0[3])