misc/simulate_load.py: use a more realistic distribution of file sizes, and automate the formatting of the ascii art so that it fits in 70 columns and the number of files uploaded is properly marked

misc/simulate_load.py

@@ -20,8 +20,6 @@ SERVERS = 40
 K = 3
 N = 10
 
-MAXSHARESIZE = 2**34 / K
-
 def go(permutedpeerlist):
     servers = [ Server() for x in range(SERVERS) ]
     servers.sort(cmp=lambda x,y: cmp(x.si, y.si))
@@ -29,7 +27,7 @@ def go(permutedpeerlist):
     tick = 0
     fullservers = 0
     while True:
-        nextsharesize = random.randrange(40, MAXSHARESIZE)
+        nextsharesize = (2 ** random.randrange(8, 31)) / K
         if permutedpeerlist:
             random.shuffle(servers)
         else:
@@ -56,20 +54,43 @@ def go(permutedpeerlist):
 
         tick += 1
 
+def div_ceil(n, d):
+    """
+    The smallest integer k such that k*d >= n.
+    """
+    return (n/d) + (n%d != 0)
+
+DESIRED_COLUMNS = 70
+
 def test(permutedpeerlist, iters):
-    # the i'th element of the filledat list is how many servers got full on the tick numbered 4500 + i * 9
-    filledat = [0] * 77
+    # The i'th element of the filledat list is how many servers got full when the i'th file was uploaded.
+    filledat = []
     for test in range(iters):
         servers = go(permutedpeerlist)
         for server in servers:
-            fidx = (server.full_at_tick - 4500) / 9
-            if fidx >= len(filledat):
-                filledat.extend([0]*(fidx-len(filledat)+1))
+            fidx = server.full_at_tick
+            filledat.extend([0]*(fidx-len(filledat)+1))
             filledat[fidx] += 1
 
-    # the i'th element of the fullat list is how many servers were full by the tick numbered 4500 + i * 9 (on average)
-    fullat = [0] * 77
-    for idx, num in enumerate(filledat):
+    startfiles = 0
+    while filledat[startfiles] == 0:
+        startfiles += 1
+    filespercolumn = div_ceil(len(filledat) - startfiles, (DESIRED_COLUMNS - 3))
+
+    # The i'th element of the compressedfilledat list is how many servers got full when the filespercolumn files starting at startfiles + i were uploaded.
+    compressedfilledat = []
+    idx = startfiles
+    while idx < len(filledat):
+        compressedfilledat.append(0)
+        for i in range(filespercolumn):
+            compressedfilledat[-1] += filledat[idx]
+            idx += 1
+            if idx >= len(filledat):
+                break
+
+    # The i'th element of the fullat list is how many servers were full by the tick numbered startfiles + i * filespercolumn (on average).
+    fullat = [0] * len(compressedfilledat)
+    for idx, num in enumerate(compressedfilledat):
         for fidx in range(idx, len(fullat)):
             fullat[fidx] += num
 
@@ -79,7 +100,7 @@ def test(permutedpeerlist, iters):
     # Now print it out as an ascii art graph.
     import sys
     for serversfull in range(40, 0, -1):
-        sys.stdout.write("%2d" % serversfull)
+        sys.stdout.write("%2d " % serversfull)
         for numfull in fullat:
             if int(numfull) == serversfull:
                 sys.stdout.write("*")
@@ -90,8 +111,9 @@ def test(permutedpeerlist, iters):
     sys.stdout.write(" ^-- servers full\n")
     idx = 0
     while idx < len(fullat):
-        sys.stdout.write("%d--^ " % (4500 + idx * 9))
-        idx += 8
+        nextmark  = "%d--^ " % (startfiles + idx * filespercolumn)
+        sys.stdout.write(nextmark)
+        idx += len(nextmark)
 
     sys.stdout.write("\nfiles uploaded --> \n")