# Example 781 — The capacity was sufficient and one hour a week was not `the_capacity_was_sufficient_and_one_hour_a_week_was_not.eml` - Capacity planning has shown comfortable headroom for fourteen months, and the planning is careful. What the headroom is an average over is computed below. ## EML ```eml # Self-authored for the EML case corpus (no external origin). Capacity planning # has shown comfortable headroom for fourteen months, and the planning is # careful. What the headroom is an average over is computed below. # # The planning is done properly. Utilisation is measured on the containers that # actually run rather than on the nodes they sit on; the figure includes the # sidecars, which are usually forgotten; growth is projected from the last four # quarters rather than from the best one; and a review that finds headroom below # the floor triggers a purchase rather than a conversation. # # Utilisation is the mean over the week. 4800 => cores_provisioned 4100 => mean_utilisation_per_myriad 9800 => peak_utilisation_per_myriad 5000 => headroom_floor_per_myriad 168 => hours_in_a_week 3 => hours_a_week_above_the_floor 14 => months_of_comfortable_headroom 42000000 => requests_a_week 1900000 => requests_in_those_three_hours 61000 => requests_shed_in_those_three_hours 4 => capacity_reviews_a_year_that_read_the_mean 0 => capacity_reviews_a_year_that_read_the_peak hours_in_a_week - hours_a_week_above_the_floor => hours_a_week_below_the_floor peak_utilisation_per_myriad - mean_utilisation_per_myriad => the_distance_between_peak_and_mean capacity_reviews_a_year_that_read_the_mean - capacity_reviews_a_year_that_read_the_peak => reviews_that_read_only_the_mean int(requests_shed_in_those_three_hours * 10000 / requests_a_week) => shed_over_the_week_per_myriad int(requests_shed_in_those_three_hours * 10000 / requests_in_those_three_hours) => shed_inside_those_hours_per_myriad int(requests_in_those_three_hours * 10000 / requests_a_week) => traffic_in_those_hours_per_myriad "cores provisioned : " + str(cores_provisioned) ^0 "mean utilisation : " + str(mean_utilisation_per_myriad) + " per ten thousand" ^0 "headroom floor : " + str(headroom_floor_per_myriad) + " per ten thousand" ^0 "months of comfortable headroom : " + str(months_of_comfortable_headroom) ^0 "" ^0 "hours in a week : " + str(hours_in_a_week) ^0 " above the floor : " + str(hours_a_week_above_the_floor) ^0 " below it : " + str(hours_a_week_below_the_floor) ^0 "peak utilisation : " + str(peak_utilisation_per_myriad) + " per ten thousand" ^0 " distance from the mean : " + str(the_distance_between_peak_and_mean) + " per ten thousand" ^0 "" ^0 "requests a week : " + str(requests_a_week) ^0 " in those three hours : " + str(requests_in_those_three_hours) ^0 " traffic in those hours : " + str(traffic_in_those_hours_per_myriad) + " per ten thousand" ^0 "requests shed in those hours : " + str(requests_shed_in_those_three_hours) ^0 " shed, over the week : " + str(shed_over_the_week_per_myriad) + " per ten thousand" ^0 " shed, inside those hours : " + str(shed_inside_those_hours_per_myriad) + " per ten thousand" ^0 "" ^0 "capacity reviews a year" ^0 " that read the mean : " + str(capacity_reviews_a_year_that_read_the_mean) ^0 " that read the peak : " + str(capacity_reviews_a_year_that_read_the_peak) ^0 " that read only the mean : " + str(reviews_that_read_only_the_mean) ^0 "" ^0 # ---- what the planning verified ---- "the capacity review" ^0 " what utilisation is measured on : the containers that" ^0 " run, not the nodes they sit on" ^0 " sidecars : included, which is the part usually" ^0 " forgotten" ^0 " growth : projected from four quarters, not the best" ^0 " one" ^0 " headroom below the floor : triggers a purchase, not a" ^0 " conversation" ^0 " months comfortable : " + str(months_of_comfortable_headroom) ^0 " verdict : SUFFICIENT" ^0 "" ^0 " counting the sidecars is the part almost nobody does," ^0 " and it is why " + str(mean_utilisation_per_myriad) + " per ten thousand is not an" ^0 " understatement" ^0 "" ^0 # ---- what a mean over a week holds ---- "the same week, two ways" ^0 " as a mean : " + str(mean_utilisation_per_myriad) + " per ten thousand, comfortably" ^0 " under the floor of " + str(headroom_floor_per_myriad) ^0 " at its peak : " + str(peak_utilisation_per_myriad) + " per ten thousand" ^0 " the distance : " + str(the_distance_between_peak_and_mean) + " per ten thousand" ^0 " hours spent up there : " + str(hours_a_week_above_the_floor) + " of " + str(hours_in_a_week) ^0 " hours spent below : " + str(hours_a_week_below_the_floor) ^0 "" ^0 " a hundred and sixty-five quiet hours are enough to" ^0 " average away three loud ones, and the three are when" ^0 " the work arrives" ^0 "" ^0 # ---- what happens in the three hours ---- "inside the peak" ^0 " traffic there : " + str(traffic_in_those_hours_per_myriad) + " per ten thousand of the week" ^0 " requests shed there : " + str(requests_shed_in_those_three_hours) ^0 " shed as a share of the week : " ^0 " " + str(shed_over_the_week_per_myriad) + " per ten thousand" ^0 " shed as a share of those hours : " ^0 " " + str(shed_inside_those_hours_per_myriad) + " per ten thousand" ^0 " which of those two the capacity review reads : " ^0 " neither; it reads the mean utilisation" ^0 " reviews that read the peak : " ^0 " " + str(capacity_reviews_a_year_that_read_the_peak) ^0 "" ^0 # ---- null control ---- # The same planning, with the floor applied to the ninety-ninth percentile hour # of the week instead of to the mean. 4100 => nc_mean_utilisation_per_myriad 9800 => nc_percentile_hour_utilisation_per_myriad 1 => nc_reviews_that_would_have_triggered_a_purchase "null control - apply the floor to the busiest hour" ^0 " mean utilisation : " + str(nc_mean_utilisation_per_myriad) + ", unchanged" ^0 " the hour the floor now reads : " ^0 " " + str(nc_percentile_hour_utilisation_per_myriad) + " per ten thousand" ^0 " reviews that would have triggered a purchase : " ^0 " " + str(nc_reviews_that_would_have_triggered_a_purchase) ^0 " no container changed and no hour got busier; the" ^0 " statistic the floor is applied to stopped being the one" ^0 " the quiet hours dominate" ^0 "" ^0 # ---- the rule ---- "what comfortable headroom guarantees" ^0 " mean utilisation is under the floor : exactly," ^0 " measured on the containers, sidecars included," ^0 " projected from four quarters, " + str(months_of_comfortable_headroom) + " months" ^0 " the system has enough capacity : not addressed; the" ^0 " mean is taken over " + str(hours_in_a_week) + " hours and the shedding" ^0 " happens in " + str(hours_a_week_above_the_floor) + " of them" ^0 "" ^0 "a mean is a statement about a period and none about any" ^0 "moment in it; where demand is concentrated the average is" ^0 "lowest exactly because most of the period is idle" ^0 "" ^0 "Utilisation is measured on the containers with sidecars counted, growth comes" ^0 "from four quarters, and a breach buys hardware - " + str(mean_utilisation_per_myriad) + " per ten thousand against a" ^0 "floor of " + str(headroom_floor_per_myriad) + ", " + str(months_of_comfortable_headroom) + " months. It is a mean over " + str(hours_in_a_week) + " hours, so the " + str(hours_a_week_above_the_floor) + " that reach " ^0 "" + str(peak_utilisation_per_myriad) + " shed " + str(requests_shed_in_those_three_hours) + " requests - " + str(shed_inside_those_hours_per_myriad) + " per ten thousand of what arrives then and " ^0 "" + str(shed_over_the_week_per_myriad) + " per ten thousand of the week - across " + str(capacity_reviews_a_year_that_read_the_peak) + " reviews that read the peak." ^0 ``` ## Python (deterministic transpilation) ```python cores_provisioned = 4800 mean_utilisation_per_myriad = 4100 peak_utilisation_per_myriad = 9800 headroom_floor_per_myriad = 5000 hours_in_a_week = 168 hours_a_week_above_the_floor = 3 months_of_comfortable_headroom = 14 requests_a_week = 42000000 requests_in_those_three_hours = 1900000 requests_shed_in_those_three_hours = 61000 capacity_reviews_a_year_that_read_the_mean = 4 capacity_reviews_a_year_that_read_the_peak = 0 hours_a_week_below_the_floor = hours_in_a_week - hours_a_week_above_the_floor the_distance_between_peak_and_mean = peak_utilisation_per_myriad - mean_utilisation_per_myriad reviews_that_read_only_the_mean = capacity_reviews_a_year_that_read_the_mean - capacity_reviews_a_year_that_read_the_peak shed_over_the_week_per_myriad = int(requests_shed_in_those_three_hours * 10000 / requests_a_week) shed_inside_those_hours_per_myriad = int(requests_shed_in_those_three_hours * 10000 / requests_in_those_three_hours) traffic_in_those_hours_per_myriad = int(requests_in_those_three_hours * 10000 / requests_a_week) print("cores provisioned : " + str(cores_provisioned)) print("mean utilisation : " + str(mean_utilisation_per_myriad) + " per ten thousand") print("headroom floor : " + str(headroom_floor_per_myriad) + " per ten thousand") print("months of comfortable headroom : " + str(months_of_comfortable_headroom)) print("") print("hours in a week : " + str(hours_in_a_week)) print(" above the floor : " + str(hours_a_week_above_the_floor)) print(" below it : " + str(hours_a_week_below_the_floor)) print("peak utilisation : " + str(peak_utilisation_per_myriad) + " per ten thousand") print(" distance from the mean : " + str(the_distance_between_peak_and_mean) + " per ten thousand") print("") print("requests a week : " + str(requests_a_week)) print(" in those three hours : " + str(requests_in_those_three_hours)) print(" traffic in those hours : " + str(traffic_in_those_hours_per_myriad) + " per ten thousand") print("requests shed in those hours : " + str(requests_shed_in_those_three_hours)) print(" shed, over the week : " + str(shed_over_the_week_per_myriad) + " per ten thousand") print(" shed, inside those hours : " + str(shed_inside_those_hours_per_myriad) + " per ten thousand") print("") print("capacity reviews a year") print(" that read the mean : " + str(capacity_reviews_a_year_that_read_the_mean)) print(" that read the peak : " + str(capacity_reviews_a_year_that_read_the_peak)) print(" that read only the mean : " + str(reviews_that_read_only_the_mean)) print("") print("the capacity review") print(" what utilisation is measured on : the containers that") print(" run, not the nodes they sit on") print(" sidecars : included, which is the part usually") print(" forgotten") print(" growth : projected from four quarters, not the best") print(" one") print(" headroom below the floor : triggers a purchase, not a") print(" conversation") print(" months comfortable : " + str(months_of_comfortable_headroom)) print(" verdict : SUFFICIENT") print("") print(" counting the sidecars is the part almost nobody does,") print(" and it is why " + str(mean_utilisation_per_myriad) + " per ten thousand is not an") print(" understatement") print("") print("the same week, two ways") print(" as a mean : " + str(mean_utilisation_per_myriad) + " per ten thousand, comfortably") print(" under the floor of " + str(headroom_floor_per_myriad)) print(" at its peak : " + str(peak_utilisation_per_myriad) + " per ten thousand") print(" the distance : " + str(the_distance_between_peak_and_mean) + " per ten thousand") print(" hours spent up there : " + str(hours_a_week_above_the_floor) + " of " + str(hours_in_a_week)) print(" hours spent below : " + str(hours_a_week_below_the_floor)) print("") print(" a hundred and sixty-five quiet hours are enough to") print(" average away three loud ones, and the three are when") print(" the work arrives") print("") print("inside the peak") print(" traffic there : " + str(traffic_in_those_hours_per_myriad) + " per ten thousand of the week") print(" requests shed there : " + str(requests_shed_in_those_three_hours)) print(" shed as a share of the week : ") print(" " + str(shed_over_the_week_per_myriad) + " per ten thousand") print(" shed as a share of those hours : ") print(" " + str(shed_inside_those_hours_per_myriad) + " per ten thousand") print(" which of those two the capacity review reads : ") print(" neither; it reads the mean utilisation") print(" reviews that read the peak : ") print(" " + str(capacity_reviews_a_year_that_read_the_peak)) print("") nc_mean_utilisation_per_myriad = 4100 nc_percentile_hour_utilisation_per_myriad = 9800 nc_reviews_that_would_have_triggered_a_purchase = 1 print("null control - apply the floor to the busiest hour") print(" mean utilisation : " + str(nc_mean_utilisation_per_myriad) + ", unchanged") print(" the hour the floor now reads : ") print(" " + str(nc_percentile_hour_utilisation_per_myriad) + " per ten thousand") print(" reviews that would have triggered a purchase : ") print(" " + str(nc_reviews_that_would_have_triggered_a_purchase)) print(" no container changed and no hour got busier; the") print(" statistic the floor is applied to stopped being the one") print(" the quiet hours dominate") print("") print("what comfortable headroom guarantees") print(" mean utilisation is under the floor : exactly,") print(" measured on the containers, sidecars included,") print(" projected from four quarters, " + str(months_of_comfortable_headroom) + " months") print(" the system has enough capacity : not addressed; the") print(" mean is taken over " + str(hours_in_a_week) + " hours and the shedding") print(" happens in " + str(hours_a_week_above_the_floor) + " of them") print("") print("a mean is a statement about a period and none about any") print("moment in it; where demand is concentrated the average is") print("lowest exactly because most of the period is idle") print("") print("Utilisation is measured on the containers with sidecars counted, growth comes") print("from four quarters, and a breach buys hardware - " + str(mean_utilisation_per_myriad) + " per ten thousand against a") print("floor of " + str(headroom_floor_per_myriad) + ", " + str(months_of_comfortable_headroom) + " months. It is a mean over " + str(hours_in_a_week) + " hours, so the " + str(hours_a_week_above_the_floor) + " that reach ") print("" + str(peak_utilisation_per_myriad) + " shed " + str(requests_shed_in_those_three_hours) + " requests - " + str(shed_inside_those_hours_per_myriad) + " per ten thousand of what arrives then and ") print("" + str(shed_over_the_week_per_myriad) + " per ten thousand of the week - across " + str(capacity_reviews_a_year_that_read_the_peak) + " reviews that read the peak.") ``` ## stdout (executed) ```text cores provisioned : 4800 mean utilisation : 4100 per ten thousand headroom floor : 5000 per ten thousand months of comfortable headroom : 14 hours in a week : 168 above the floor : 3 below it : 165 peak utilisation : 9800 per ten thousand distance from the mean : 5700 per ten thousand requests a week : 42000000 in those three hours : 1900000 traffic in those hours : 452 per ten thousand requests shed in those hours : 61000 shed, over the week : 14 per ten thousand shed, inside those hours : 321 per ten thousand capacity reviews a year that read the mean : 4 that read the peak : 0 that read only the mean : 4 the capacity review what utilisation is measured on : the containers that run, not the nodes they sit on sidecars : included, which is the part usually forgotten growth : projected from four quarters, not the best one headroom below the floor : triggers a purchase, not a conversation months comfortable : 14 verdict : SUFFICIENT counting the sidecars is the part almost nobody does, and it is why 4100 per ten thousand is not an understatement the same week, two ways as a mean : 4100 per ten thousand, comfortably under the floor of 5000 at its peak : 9800 per ten thousand the distance : 5700 per ten thousand hours spent up there : 3 of 168 hours spent below : 165 a hundred and sixty-five quiet hours are enough to average away three loud ones, and the three are when the work arrives inside the peak traffic there : 452 per ten thousand of the week requests shed there : 61000 shed as a share of the week : 14 per ten thousand shed as a share of those hours : 321 per ten thousand which of those two the capacity review reads : neither; it reads the mean utilisation reviews that read the peak : 0 null control - apply the floor to the busiest hour mean utilisation : 4100, unchanged the hour the floor now reads : 9800 per ten thousand reviews that would have triggered a purchase : 1 no container changed and no hour got busier; the statistic the floor is applied to stopped being the one the quiet hours dominate what comfortable headroom guarantees mean utilisation is under the floor : exactly, measured on the containers, sidecars included, projected from four quarters, 14 months the system has enough capacity : not addressed; the mean is taken over 168 hours and the shedding happens in 3 of them a mean is a statement about a period and none about any moment in it; where demand is concentrated the average is lowest exactly because most of the period is idle Utilisation is measured on the containers with sidecars counted, growth comes from four quarters, and a breach buys hardware - 4100 per ten thousand against a floor of 5000, 14 months. It is a mean over 168 hours, so the 3 that reach 9800 shed 61000 requests - 321 per ten thousand of what arrives then and 14 per ten thousand of the week - across 0 reviews that read the peak. ``` ## Round-trip `ok: true` — round-trip fixpoint reached (python1 == python2) ## Trace event types eml:run:start · eml:assign · eml:output · eml:run:done