TestClusterHash.cc

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  @section license License

  Licensed to the Apache Software Foundation (ASF) under one
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  regarding copyright ownership.  The ASF licenses this file
  to you under the Apache License, Version 2.0 (the
  "License"); you may not use this file except in compliance
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      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
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/****************************************************************************

  TestClusterHash.cc
 ****************************************************************************/
#include "Cluster.h"
#include "libts.h"


//
// This test function produces the table included
// in Memo.ClusterHash
//

void
test()
{
  int n[CLUSTER_MAX_MACHINES];
  int i;
  Machine *m;
  int j;
  ink_hrtime t, t2;
  int total;
  int high, low, share;
  int version = 7;

  while (version > -1) {

    // the select the version
    //
    machineClusterHash = !!(version & 1);
    boundClusterHash = !!(version & 2);
    randClusterHash = !!(version & 4);

    // fabricate fake cluster

    clusterProcessor.this_cluster = new Cluster;
    ClusterConfiguration *cc = new ClusterConfiguration;
    cc->n_machines = 1;
    cc->machines[0] = this_cluster_machine();
    memset(cc->hash_table, 0, CLUSTER_HASH_TABLE_SIZE);
    clusterProcessor.this_cluster->configurations.push(cc);

    ClusterConfiguration *c = this_cluster()->current_configuration();

    printf("hash by %s - %s - %s\n",
           (machineClusterHash ? "MACHINE" : "BUCKET"),
           (boundClusterHash ? "BOUNDED" : "UNBOUND"), (randClusterHash ? "RAND" : "LINEAR CONGUENCE"));

    // from 1 to 32 machines

    for (i = 1; i < 32; i++) {
      m = new ClusterMachine(*this_cluster_machine());
      m->ip += i;
      t = ink_get_hrtime();
      cc = configuration_add_machine(c, m);
      t2 = ink_get_hrtime();

      //
      // Compute new distribution
      //
      high = 0;
      low = CLUSTER_HASH_TABLE_SIZE + 1;
      for (j = 0; j < cc->n_machines; j++)
        n[j] = 0;
      for (j = 0; j < CLUSTER_HASH_TABLE_SIZE; j++) {
        ink_assert(cc->hash_table[j] < cc->n_machines);
        n[cc->hash_table[j]]++;
      }
      total = CLUSTER_HASH_TABLE_SIZE;
      for (j = 0; j < cc->n_machines; j++) {
        total -= n[j];
        if (low > n[j])
          low = n[j];
        if (high < n[j])
          high = n[j];
      }
      ink_assert(!total);
      printf("n = %d:", i);
      printf(" high = %d low = %d high/low = %f", high, low, (float) high / (float) low);

      //
      // Compute sharing with n-1
      //
      share = 0;
      for (j = 0; j < CLUSTER_HASH_TABLE_SIZE; j++) {
        if (c->machines[c->hash_table[j]] == cc->machines[cc->hash_table[j]])
          share++;
      }
      printf(" shared = %d %%%6.2f", share, (float) share / (float) CLUSTER_HASH_TABLE_SIZE);

      printf(" time = %f secs\n", ((float) (t2 - t) / (float) HRTIME_SECONDS(1)));
      c = cc;
    }

    version--;
  }
}