Hubble: Performance Debugging with In-Production, Just-In-Time Method Tracing on Android

Hubble is a method-tracing system shipped on all supported and upcoming Android devices manufactured by Huawei, in order to aid in debugging performance problems. Hubble instruments every non-inlined bytecode method's entry and exit to record the method's name and a timestamp. Instead of persisting all data, trace points are recorded into an in-memory ring buffer where older data is constantly overwritten. This data is only persisted when a performance problem is detected, giving engineers access to invaluable, detailed runtime data Just-In-Time before the detected anomaly. Hubble is highly efficient, with its tracing inducing negligible overhead in realworld usage and each trace point taking less than one nanosecond in our microbenchmark. Hubble significantly eases the debugging of user-experienced performance problems and has enabled engineers to quickly resolve many bug tickets that were open for months before Hubble was available.