clickhouse-web: drop the filesystem cache before the cold try, not every try

clickhouse-web/flush-caches

@@ -0,0 +1,11 @@
+#!/bin/bash
+# Drop the web disk's filesystem cache so the cold try is really cold.
+#
+# bench_flush_caches calls this while the server is stopped, so
+# SYSTEM DROP FILESYSTEM CACHE is not available — delete the files directly.
+# The cache lives in tmpfs, which the kernel's drop_caches does not touch.
+#
+# ./install bind-mounts /dev/shm/clickhouse onto the cache directory, so
+# remove the contents and leave the mount point itself alone. The server owns
+# these files (it runs as the clickhouse user), hence sudo.
+sudo find /dev/shm/clickhouse -mindepth 1 -delete

clickhouse-web/query

@@ -4,9 +4,9 @@
 # Stderr: query runtime in fractional seconds on the last line (from --time).
 # Exit non-zero on error.
 #
-# The web-disk cache is dropped before the query so timings are cold.
+# The web-disk cache is dropped by ./flush-caches, which the harness runs
+# once per query before the cold try — not here, or every try would be cold.
 set -e
 
 query=$(cat)
-clickhouse-client --query "SYSTEM DROP FILESYSTEM CACHE" >/dev/null
 clickhouse-client --time --format=Pretty --query="$query"

clickhouse-web/results/20260726/c6a.2xlarge.json

@@ -9,52 +9,52 @@
       "tags": ["C++","column-oriented","ClickHouse derivative","stateless"],
       "load_time": 1,
       "data_size": 14557009492,
-      "concurrent_qps": 0.703,
-      "concurrent_error_ratio": 0.062,
+      "concurrent_qps": 0.788,
+      "concurrent_error_ratio": 0.564,
       "result": [
         [0.002, 0.001, 0.001],
-        [0.112, 0.105, 0.06],
-        [0.397, 0.213, 0.2],
-        [0.38, 0.314, 1.133],
-        [0.812, 0.71, 0.683],
-        [1.597, 1.516, 1.562],
-        [0.106, 0.045, 0.036],
-        [0.101, 0.055, 0.052],
-        [1.07, 0.99, 0.995],
-        [1.268, 1.103, 1.124],
-        [1.141, 1.266, 1.235],
-        [1.149, 1.582, 1.387],
-        [1.349, 1.112, 1.167],
-        [2.156, 2.095, 2.018],
-        [1.679, 1.603, 1.606],
-        [0.98, 0.652, 0.667],
-        [3.395, 3.184, 3.311],
-        [2.522, 2.301, 2.381],
-        [7.636, 7.502, 7.108],
-        [1.05, 0.143, 0.153],
-        [7.748, 7.465, 6.856],
-        [7.053, 2.661, 2.667],
-        [10.472, 6.835, 6.773],
-        [5.409, 2.736, 2.579],
-        [1.221, 0.894, 0.818],
-        [0.846, 0.79, 0.742],
-        [1.212, 0.926, 0.844],
-        [7.042, 6.886, 6.906],
-        [6.636, 6.078, 5.899],
-        [0.396, 0.362, 0.237],
-        [2.008, 1.723, 1.707],
-        [4.307, 4.339, 5.19],
-        [12.138, 12.009, 12.199],
-        [9.613, 9.462, 9.837],
-        [10.002, 9.839, 9.701],
-        [0.79, 0.526, 0.517],
-        [0.378, 0.227, 0.221],
-        [0.289, 0.156, 0.116],
-        [0.312, 0.205, 0.207],
-        [0.544, 0.254, 0.253],
-        [0.312, 0.128, 0.126],
-        [0.234, 0.083, 0.081],
-        [0.244, 0.146, 0.103]
+        [0.132, 0.013, 0.014],
+        [0.264, 0.039, 0.04],
+        [0.332, 0.054, 0.046],
+        [0.859, 0.473, 0.466],
+        [1.725, 1.121, 1.117],
+        [0.088, 0.013, 0.013],
+        [0.168, 0.017, 0.017],
+        [1.357, 0.625, 0.635],
+        [1.328, 0.749, 0.751],
+        [1.294, 0.181, 0.185],
+        [1.195, 0.232, 0.226],
+        [1.241, 0.504, 0.523],
+        [1.944, 1.008, 1.063],
+        [1.793, 0.782, 0.727],
+        [0.964, 0.459, 0.456],
+        [3.589, 2.26, 2.231],
+        [2.625, 1.448, 1.358],
+        [7.507, 6.426, 6.338],
+        [1.097, 0.003, 0.002],
+        [7.596, 0.404, 0.401],
+        [7.589, 0.099, 0.098],
+        [8.903, 0.599, 0.604],
+        [4.378, 0.44, 0.15],
+        [0.906, 0.096, 0.086],
+        [0.846, 0.233, 0.226],
+        [0.969, 0.151, 0.079],
+        [7.115, 0.748, 0.754],
+        [5.801, 2.127, 2.129],
+        [0.291, 0.039, 0.039],
+        [2.029, 0.55, 0.537],
+        [4.112, 0.928, 0.908],
+        [12.805, 11.364, 11.31],
+        [12.972, 6.456, 6.252],
+        [12.44, 6.31, 6.455],
+        [0.815, 0.419, 0.377],
+        [0.402, 0.048, 0.046],
+        [0.252, 0.035, 0.03],
+        [0.332, 0.028, 0.025],
+        [0.618, 0.089, 0.107],
+        [0.253, 0.02, 0.018],
+        [0.426, 0.015, 0.014],
+        [0.242, 0.013, 0.014]
 ]
   } 
 

clickhouse-web/results/20260726/c6a.4xlarge.json

@@ -9,52 +9,52 @@
       "tags": ["C++","column-oriented","ClickHouse derivative","stateless"],
       "load_time": 1,
       "data_size": 14557009492,
-      "concurrent_qps": 1.047,
-      "concurrent_error_ratio": 0.583,
+      "concurrent_qps": 1.1320000000000001,
+      "concurrent_error_ratio": 0.598,
       "result": [
         [0.002, 0.001, 0.001],
-        [0.134, 0.126, 0.067],
-        [0.847, 0.206, 0.158],
-        [0.42, 0.272, 0.26],
-        [0.549, 0.485, 0.505],
-        [1.283, 0.915, 0.855],
-        [0.109, 0.034, 0.041],
-        [0.137, 0.076, 0.054],
-        [0.793, 0.689, 0.696],
-        [0.927, 0.777, 0.76],
-        [0.682, 0.651, 0.625],
-        [0.704, 0.615, 0.656],
-        [0.871, 0.808, 1.301],
-        [1.688, 1.426, 1.311],
-        [1.192, 0.981, 0.964],
-        [0.774, 0.617, 0.543],
-        [2.198, 2.178, 2.046],
-        [1.691, 1.523, 1.665],
-        [4.182, 3.589, 3.366],
-        [0.574, 0.346, 0.334],
-        [5.412, 4.079, 3.838],
-        [4.326, 1.831, 1.65],
-        [6.464, 4.07, 3.779],
-        [6.164, 2.655, 2.242],
-        [0.607, 0.609, 1.222],
-        [0.733, 0.48, 0.484],
-        [1.271, 0.678, 0.634],
-        [4.189, 4.219, 4.019],
-        [4.791, 3.308, 3.356],
-        [0.241, 0.164, 0.164],
-        [1.325, 1.339, 1.243],
-        [2.681, 2.369, 2.429],
-        [5.184, 4.875, 5.081],
-        [5.255, 6.014, 5.179],
-        [6.704, 6.044, 5.555],
-        [0.555, 0.418, 0.455],
-        [0.382, 0.199, 0.16],
-        [0.228, 0.174, 0.166],
-        [0.324, 0.139, 0.137],
-        [0.499, 0.268, 0.197],
-        [0.236, 0.106, 0.168],
-        [0.279, 0.097, 0.12],
-        [0.29, 0.108, 0.118]
+        [0.117, 0.01, 0.009],
+        [0.246, 0.026, 0.028],
+        [0.332, 0.027, 0.028],
+        [0.487, 0.271, 0.264],
+        [0.969, 0.611, 0.611],
+        [0.074, 0.012, 0.01],
+        [0.108, 0.012, 0.011],
+        [0.738, 0.428, 0.456],
+        [1.07, 0.498, 0.508],
+        [0.766, 0.126, 0.13],
+        [0.635, 0.165, 0.166],
+        [0.8, 0.419, 0.398],
+        [1.245, 0.612, 0.569],
+        [1.105, 0.48, 0.487],
+        [0.661, 0.377, 0.377],
+        [2.241, 1.617, 1.628],
+        [1.673, 0.938, 1.11],
+        [3.932, 2.91, 2.753],
+        [0.588, 0.003, 0.003],
+        [3.733, 0.335, 0.343],
+        [4.535, 0.085, 0.082],
+        [5.037, 0.595, 0.584],
+        [4.064, 0.229, 0.231],
+        [0.683, 0.106, 0.034],
+        [0.572, 0.153, 0.154],
+        [0.637, 0.138, 0.044],
+        [3.976, 0.387, 0.385],
+        [3.52, 1.621, 1.647],
+        [0.204, 0.031, 0.031],
+        [1.192, 0.364, 0.373],
+        [2.252, 0.654, 0.668],
+        [4.84, 4.147, 4.051],
+        [5.377, 2.245, 2.15],
+        [4.945, 2.241, 2.163],
+        [0.533, 0.304, 0.29],
+        [0.3, 0.035, 0.032],
+        [0.25, 0.029, 0.023],
+        [0.416, 0.019, 0.019],
+        [0.432, 0.082, 0.08],
+        [0.208, 0.017, 0.015],
+        [0.267, 0.011, 0.011],
+        [0.247, 0.01, 0.049]
 ]
   } 
 

clickhouse-web/results/20260726/c6a.large.json

@@ -9,52 +9,52 @@
       "tags": ["C++","column-oriented","ClickHouse derivative","stateless"],
       "load_time": 0,
       "data_size": 14557009492,
-      "concurrent_qps": 0.158,
-      "concurrent_error_ratio": 0.882,
+      "concurrent_qps": 0.247,
+      "concurrent_error_ratio": 0.864,
       "result": [
         [0.002, 0.001, 0.002],
-        [0.31, 0.191, 0.202],
-        [0.618, 0.536, 0.57],
-        [1.311, 1.348, 1.475],
-        [3.16, 3.104, 3.684],
-        [6.376, 6.514, 6.339],
-        [0.209, 0.171, 0.228],
-        [0.281, 0.2, 0.211],
-        [4.482, 4.696, 4.543],
-        [6.056, 5.91, 6.572],
-        [3.861, 4.17, 4.041],
-        [4.332, 4.218, 4.282],
-        [6.05, 6.192, 5.802],
-        [13.614, 14.654, 13.969],
-        [11.022, 11.132, 10.765],
-        [3.68, 4.012, 3.319],
-        [24.608, 24.863, 24.773],
-        [17.479, 18.01, 18.074],
-        [45.804, 45.554, 46.028],
-        [1.762, 0.209, 0.219],
-        [31.439, 29.207, 27.822],
-        [32.86, 8.451, 7.959],
-        [38.32, 29.253, 27.033],
-        [10.341, 6.228, 6.361],
-        [3.177, 3.06, 3.02],
-        [3.473, 3.67, 3.297],
-        [2.948, 3.113, 2.798],
-        [30.609, 29.472, 30.457],
-        [40.166, 38.403, 39.172],
-        [0.464, 0.438, 0.415],
-        [7.387, 6.831, 7.215],
-        [20.244, 20.105, 19.189],
-        [62.38, 59.699, 59.617],
-        [62.186, null, null],
-        [61.456, 61.255, 61.436],
-        [2.328, 2.089, 2.363],
-        [0.663, 0.564, 0.489],
-        [0.274, 0.205, 0.242],
-        [0.573, 0.358, 0.391],
-        [1.053, 0.862, 0.813],
-        [0.282, 0.187, 0.22],
-        [0.244, 0.123, 0.127],
-        [0.242, 0.191, 0.15]
+        [0.317, 0.144, 0.14],
+        [0.729, 0.355, 0.353],
+        [1.516, 0.527, 0.533],
+        [3.085, 2.357, 2.837],
+        [6.636, 5.549, 5.48],
+        [0.193, 0.151, 0.136],
+        [0.3, 0.158, 0.159],
+        [4.744, 3.998, 3.784],
+        [5.806, 4.661, 4.554],
+        [5.041, 1.684, 1.503],
+        [4.281, 1.886, 2.106],
+        [5.288, 4.818, 3.89],
+        [12.766, 10.813, 11.318],
+        [11.157, 8.624, 8.603],
+        [3.689, 2.766, 2.695],
+        [25.941, 27.214, 22.063],
+        [18.004, 14.709, 18.147],
+        [44.482, 51.634, 49.824],
+        [1.688, 0.004, 0.004],
+        [32.064, 40.116, 29.884],
+        [35.273, 8.551, 1.632],
+        [37.585, 44.497, 55.686],
+        [9.491, 5.132, 2.051],
+        [3.013, 0.662, 0.638],
+        [3.551, 2.835, 3.181],
+        [3.274, 0.662, 0.653],
+        [28.448, 39.609, 40.281],
+        [41.779, 61.26, 50.596],
+        [0.42, 0.225, 0.226],
+        [8.143, 4.191, 4.337],
+        [19.172, 12.597, 10.538],
+        [55.473, 65.824, 65.194],
+        [57.832, 84.09, 84.136],
+        [59.257, 86.058, 84.506],
+        [2.269, 1.631, 1.624],
+        [0.532, 0.276, 0.268],
+        [0.386, 0.134, 0.13],
+        [0.443, 0.083, 0.083],
+        [1.068, 0.575, 0.577],
+        [0.3, 0.047, 0.044],
+        [0.266, 0.037, 0.037],
+        [0.282, 0.039, 0.04]
 ]
   }