{'fraction_non_alphanumeric': 0.031914893617021274, 'fraction_numerical': 0.008274231678486997, 'mean_word_length': 4.841379310344828, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
When Does Fast Recovery Trump High Reliability

A widely accepted equation for availability is Availability=MTTF/(MTTF+MTTR), where MTTF is the mean time to failure of a system or subsystem (i.e. the reciprocal of reliability), MTTR is its mean time to recovery, and A is a number between 0 and 1. The equation suggests that to improve availability, a 10x decrease in MTTR (for example) is just as valuable as a 10x increase in MTTF, a founding observation of the Recovery-Oriented Computing (ROC) project [9]. In this paper, we argue that for interactive Internet applications, a decrease in MTTR is sometimes more valuable than the corresponding increase in MTTF to improve Availability by the same amount, and we make a case for adopting MTTR as the primary metric for reasoning about system availability and focusing designs on fast recovery.