SLOs https://landing.google.com/sre/book/chapters/service- level-objectives.html • Latency: 99th percentile at edge (measured every 5 minutes) < 500 ms • Reliability: 99.99% of requests succeed (200-499 status code)
duration[s] * requests impacted[%] * (period weight) / 100 (60*60*24*30)[s] * (error budget[%]/100[%]) * 100 req during period length avg req period length during month period weight = Consumption Real Model
feature-change const feature_change = require('feature-change'); var options = { expected: function(cb){ search_v2(query, cb); }, actual: function(cb){ search_v3(query, cb); }, logAction: function(current_result, new_result){ // invoked when there is a difference in the results // (useful for logging) } }; feature_change(options, function(err, result){ // this is the original callback you were using for search v2 // err and result always come from search_v2 });