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Commit 29b9e038 authored by Chad Barb's avatar Chad Barb
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Now in 3-D!!! 

Added loss metric (-3 switch; must be used after -2 switch.)..
Also added -1 switch to specify latency weight.
parent 4cec1c24
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tbsetup/wanlinksolve.cc
View file @ 29b9e038
/****
wanlinksolve -
A Reasonably Effective Algorithm for Genetically Assigning Nodes.
Resilient Overlay Network
Reasonably Effective Algorithm for Genetically Assigning Nodes.
Chad Barb, May 3, 2002
Applies a standard genetic algorithm (with crossover and elitism)
......@@ -8,7 +10,7 @@
into a larger "physical" graph, such that the actual
weights between acquired nodes are similar to desired weights.
The penalty function is the sum of error square roots.
The penalty function is the sum of error square roots (for the first dimension).
For the application this was designed for,
"weights" are values of latency time in milliseconds.
......@@ -17,6 +19,10 @@
-v Extra verbosity
-v -v Jumbo verbosity
-1 <weight>
Multiply penalty for latency by <weight>.
(optional, default weight is 1.0)
-2 <weight>
Solve for 2nd (bandwidth) dimension;
Penalty for error is sum of differences of natural logs,
......@@ -24,6 +30,12 @@
A good weight seems to be around 7, but the appropriate
value is pretty much application-dependent.
-3 <weight>
Solve for 3rd (loss) dimension
Penalty for error is difference of %% (10 * percent) loss,
multiplied by <weight>.
-2 must be specified first.
-m <plexpenalty>
Handle multiple virtual->physical mapping.
For each vnode beyond 1 assigned to a pnode, <plexpenalty> will be assessed.
......@@ -53,6 +65,7 @@
this is a P x P matrix of the _actual_ weight from pnodes to
pnodes. For latencies, there are zeros along the diagonal.
? 'p' lines, a P x P matrix of actual bandwidth ('-2' switch only)
? 'p' lines, a P x P matrix of actual loss ('-3' switch only)
* One line containing a single number 'v'-- the number of virtual nodes.
......@@ -66,6 +79,7 @@
If link weights are symmetrical, this matrix will be its own
transpose (symmetric over the diagonal.)
? 'v' lines, a V x V matrix of desired bandwidth ('-2' switch only)
? 'v' lines, a V x V matrix of desired loss ('-3' switch only)
output format:
......@@ -82,7 +96,6 @@
Holland 75
J. Holland. Adaptation In Natural and Artificial Systems. The University of Michigan Press, Ann Arbour, 1975.
****/
......@@ -101,7 +114,7 @@
// accommodate up to MAX_NODES nodes.
// These could be changed to STL vectors in the future.
#define MAX_NODES 32
#define MAX_DIMENSIONS 2
#define MAX_DIMENSIONS 3
// default rounds to keep going without finding a better solution.
#define DEFAULT_ROUNDS 512
......@@ -168,7 +181,7 @@ static int userSpecifiedMultiplex = 0;
static int fixed[MAX_NODES];
static int dimensions;
static float d2weight;
static float d1weight, d2weight, d3weight;
static int verbose = 0;
......@@ -179,6 +192,7 @@ static bool himutate = false;
class Solution
{
public:
// the beef, as it were.
int vnode_mapping[MAX_NODES];
// Keep around a list of how many times each physical node is used
......@@ -186,7 +200,11 @@ public:
// (which is often.)
unsigned char pnode_uses[MAX_NODES];
// calculated penalty
float error;
// probability of selecting this particular one (or any before it)
// out of MAXINT
unsigned int prob;
};
......@@ -196,6 +214,8 @@ public:
static Solution pool[SOLUTIONS];
static Solution pool2[SOLUTIONS];
const char dimName[3][12] = { "latency", "bandwidth", "loss" };
// determines probabilities of selecting each solution.
static inline void prepick( Solution * currentPool )
{
......@@ -292,24 +312,32 @@ static inline void calcError( Solution * t )
float errDelta;
if (z == 0) {
errDelta = sqrtf((float)(abs(should - is)));
} else {
errDelta = d1weight * sqrtf((float)(abs(should - is)));
} else if (z == 1) {
errDelta = d2weight * (float)(abs(should - is));
if (should < is) { errDelta *= 0.5f; }
} else {
errDelta = d3weight * (float)(abs( should - is ));
}
if (verbose) {
if (z == 0) {
printf("%s -> %s latency (ms) should be %i; is %i (err [sqrt |a-b|] %4.3f)\n",
printf("%s -> %s latency (ms) should be %i; is %i (err [wt * sqrt |a-b|] %4.3f)\n",
vnodeNames[x].c_str(), vnodeNames[y].c_str(),
should, is, errDelta );
} else {
} else if (z == 1) {
printf("%s -> %s bandwidth (kB/s) should be ~%i; is ~%i (err [wt %s* ln (a/b)] %4.3f)\n",
vnodeNames[x].c_str(), vnodeNames[y].c_str(),
(int)expf((float)should / 1000.0f),
(int)expf((float)is / 1000.0f),
(should < is) ? "* 0.5 " : "",
errDelta );
} else {
printf("%s -> %s loss should be %1.4f; is %1.4f (err [wt * |a-b|] %4.3f)\n",
vnodeNames[x].c_str(), vnodeNames[y].c_str(),
(float)should / 65536.0f,
(float)is / 65536.0f,
errDelta );
}
}
err += errDelta;
......@@ -374,15 +402,6 @@ static inline void mutate( Solution * t )
}
} else {
// reassign mutation
/*
int pnode_uses[MAX_NODES];
bzero( pnode_uses, sizeof( pnode_uses ) );
for (int i = 0; i < vnodes; i++) {
++pnode_uses[ t->vnode_mapping[i] ];
}
*/
int a, b;
// find which vnode to remap
......@@ -533,13 +552,17 @@ void usage( char * appname )
{
fprintf(stderr,
"Usage:\n"
"%s [-v] [-2 <weight>] [-r <minrounds>] [-R <maxrounds>]\n\n"
"%s [-v [-v]] [-m <penalty>] [-s <seed>] [-1 <weight>]\n"
"\t[-2 <weight> [-3 <weight>]] [-r <minrounds>] [-R <maxrounds>]\n\n"
" -v extra verbosity\n"
" -v -v jumbo verbosity\n"
" -m <penalty> enable many-to-one virtual to physical mappings\n"
" -s <seed> seed the random number generator with a specific value\n"
" -1 <weight> assign weight to latency penalty (optional; default 1.0)\n"
" -2 <weight> enable solving for bandwidth;\n"
" multiply bandwidth penalties by <weight>.\n"
" -3 <weight> enable solving for loss.\n"
" (must specify -2 first)\n"
" -r <minrounds> number of rounds to go without a solution before stopping\n"
" default: %i\n"
" -R <maxrounds> set maximum rounds\n"
......@@ -565,14 +588,16 @@ int main( int argc, char ** argv )
verbose = 0;
dimensions = 1;
d1weight = 1.0f;
d2weight = 1.0f / 1000.0f;
d3weight = 1.0f / 65536.0f;
minrounds = DEFAULT_ROUNDS;
maxrounds = -1;
int ch;
while ((ch = getopt(argc, argv, "v2:r:R:s:m:")) != -1) {
while ((ch = getopt(argc, argv, "v1:2:3:r:R:s:m:")) != -1) {
switch (ch) {
case 's':
srand( atoi( optarg ) );
......@@ -584,10 +609,22 @@ int main( int argc, char ** argv )
plexPenalty = atof( optarg );
userSpecifiedMultiplex++;
break;
case '1':
d1weight = atof( optarg );
break;
case '2':
dimensions = 2;
d2weight = atof( optarg ) / 1000.0f;
break;
case '3':
if (dimensions != 2) {
fprintf(stderr, "Must specify -2 option first when using -3.\n");
exit(1);
} else {
dimensions = 3;
d3weight = atof( optarg ) / 65536.0f;
}
break;
case 'r':
minrounds = atoi( optarg );
break;
......@@ -596,6 +633,7 @@ int main( int argc, char ** argv )
break;
default:
usage( argv[0] );
break;
}
}
......@@ -634,19 +672,22 @@ int main( int argc, char ** argv )
for (int z = 0; z < dimensions; z++) {
if (verbose > 1) {
printf("Enter %ix%i grid o' actual %s.\n", pnodes, pnodes,
(z == 0) ? "latency" : "bandwidth");
printf("Enter %ix%i grid o' actual %s.\n", pnodes, pnodes, dimName[z]);
}
for (int y = 0; y < pnodes; y++) {
char * linePos = line;
gets( line );
while (*linePos == ' ') { linePos++; } // skip leading whitespace
for (int x = 0; x < pnodes; x++) {
float temp;
sscanf( linePos, "%i", &pLatency[z][x][y] );
if (z == 1) {
sscanf( linePos, "%f", &temp );
if (pLatency[z][x][y] != -1) {
pLatency[z][x][y] = (int)( logf(pLatency[z][x][y]) * 1000.0f );
}
if (z == 1) {
pLatency[z][x][y] = (int)( logf(pLatency[z][x][y]) * 1000.0f );
} else if (z == 2) {
pLatency[z][x][y] = (int)(temp * 65536.0f);
}
}
while (*linePos != ' ' && *linePos != '\n') { linePos++; }
while (*linePos == ' ') { linePos++; }
......@@ -695,17 +736,21 @@ int main( int argc, char ** argv )
for (int z = 0; z < dimensions; z++) {
if (verbose > 1) {
printf("Enter %ix%i grid o' desired %s (-1 is don't care.)\n", vnodes, vnodes,
(z == 0) ? "latency" : "bandwidth");
dimName[z]);
}
for (int y = 0; y < vnodes; y++) {
char * linePos = line;
gets( line );
while (*linePos == ' ') { linePos++; } // skip leading whitespace
for (int x = 0; x < vnodes; x++) {
float temp;
sscanf( linePos, "%i", &vDesiredLatency[z][x][y] );
if (z == 1) {
if (vDesiredLatency[z][x][y] != -1) {
sscanf( linePos, "%f", &temp );
if (vDesiredLatency[z][x][y] != -1) {
if (z == 1) {
vDesiredLatency[z][x][y] = (int)(logf(vDesiredLatency[z][x][y]) * 1000.0f);
} else if (z == 2) {
vDesiredLatency[z][x][y] = (int)(temp * 65536.0f);
}
}
while (*linePos != ' ' && *linePos != '\n') { linePos++; }
......@@ -733,9 +778,6 @@ int main( int argc, char ** argv )
himutate = false;
for (int i = 0; i != maxrounds && i < (highestFoundRound + minrounds); i++) {
/*
*/
float avg = 0.0f;
int xy;
......@@ -784,21 +826,7 @@ int main( int argc, char ** argv )
if (stddev < 0.1f) {
himutate = false;
}
/*
printf("NUKE!\n");
for (j = SOLUTIONS - 10; j != SOLUTIONS; j++) {
generateRandomSolution( &(nextPool[j]) );
}
}
*/
/*
for (int j = 0; j < CHILDREN_PER_ROUND; j++) {
// Overwrite a "bad" solution with the child of two "good" ones.
splice( &(pool[pickAWorst()]),
&(pool[pickABest()]),
&(pool[pickABest()]) );
}
*/
sortByError( nextPool );
Solution * temp = currentPool;
......
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