The OneAgent version 1.221 release, rolled out on July 26, 2021, introduces several updates and deprecations, such as removing a deprecated OneAgent startup parameter and adding new binaries to the Linux installer package. This version enhances Java support by adding OpenTracing 0.31 and marks the initial release of z/OS Connect Enterprise Edition tracing support, while also introducing support for NGINX versions 1.20.1 and 1.21.0, limited to 64-bit platforms. The release includes various resolved issues across multiple components, including Java, .NET, and Infrastructure Monitoring, along with improvements such as enhanced error recovery for z/OS and better communication for mobile OneAgent for iOS. Additionally, the release outlines changes to technology and operating system support, with several platforms and OpenTelemetry versions being phased out by future versions. The updates also address stability and performance issues, such as fixing application crashes, memory usage problems, and encoding issues in JavaScript, while ensuring compatibility with various technologies and platforms.