/*
- * $Id: carp.cc,v 1.20 2002/10/13 20:34:59 robertc Exp $
+ * $Id$
*
* DEBUG: section 39 Cache Array Routing Protocol
* AUTHOR: Henrik Nordstrom
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
- *
+ *
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
- *
+ *
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
*/
#include "squid.h"
+#include "CacheManager.h"
#include "Store.h"
-#if USE_CARP
-
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
static int n_carp_peers = 0;
static int
peerSortWeight(const void *a, const void *b)
{
- const peer *const *p1 = a, *const *p2 = b;
+ const peer *const *p1 = (const peer *const *)a;
+ const peer *const *p2 = (const peer *const *)b;
return (*p1)->weight - (*p2)->weight;
}
+static void
+carpRegisterWithCacheManager(void)
+{
+ CacheManager::GetInstance()->
+ registerAction("carp", "CARP information", carpCachemgr, 0, 1);
+}
+
void
carpInit(void)
{
peer **P;
char *t;
/* Clean up */
+
for (k = 0; k < n_carp_peers; k++) {
- cbdataReferenceDone(carp_peers[k]);
+ cbdataReferenceDone(carp_peers[k]);
}
+
safe_free(carp_peers);
n_carp_peers = 0;
+
+ /* initialize cache manager before we have a chance to leave the execution path */
+ carpRegisterWithCacheManager();
+
/* find out which peers we have */
+
for (p = Config.peers; p; p = p->next) {
- if (!p->options.carp)
- continue;
- assert(p->type == PEER_PARENT);
- if (p->weight == 0)
- continue;
- n_carp_peers++;
- W += p->weight;
+ if (!p->options.carp)
+ continue;
+
+ assert(p->type == PEER_PARENT);
+
+ if (p->weight == 0)
+ continue;
+
+ n_carp_peers++;
+
+ W += p->weight;
}
+
if (n_carp_peers == 0)
- return;
- carp_peers = xcalloc(n_carp_peers, sizeof(*carp_peers));
+ return;
+
+ carp_peers = (peer **)xcalloc(n_carp_peers, sizeof(*carp_peers));
+
/* Build a list of the found peers and calculate hashes and load factors */
for (P = carp_peers, p = Config.peers; p; p = p->next) {
- if (!p->options.carp)
- continue;
- if (p->weight == 0)
- continue;
- /* calculate this peers hash */
- p->carp.hash = 0;
- for (t = p->host; *t != 0; t++)
- p->carp.hash += ROTATE_LEFT(p->carp.hash, 19) + (unsigned int) *t;
- p->carp.hash += p->carp.hash * 0x62531965;
- p->carp.hash = ROTATE_LEFT(p->carp.hash, 21);
- /* and load factor */
- p->carp.load_factor = ((double) p->weight) / (double) W;
- if (floor(p->carp.load_factor * 1000.0) == 0.0)
- p->carp.load_factor = 0.0;
- /* add it to our list of peers */
- *P++ = cbdataReference(p);
+ if (!p->options.carp)
+ continue;
+
+ if (p->weight == 0)
+ continue;
+
+ /* calculate this peers hash */
+ p->carp.hash = 0;
+
+ for (t = p->name; *t != 0; t++)
+ p->carp.hash += ROTATE_LEFT(p->carp.hash, 19) + (unsigned int) *t;
+
+ p->carp.hash += p->carp.hash * 0x62531965;
+
+ p->carp.hash = ROTATE_LEFT(p->carp.hash, 21);
+
+ /* and load factor */
+ p->carp.load_factor = ((double) p->weight) / (double) W;
+
+ if (floor(p->carp.load_factor * 1000.0) == 0.0)
+ p->carp.load_factor = 0.0;
+
+ /* add it to our list of peers */
+ *P++ = cbdataReference(p);
}
+
/* Sort our list on weight */
qsort(carp_peers, n_carp_peers, sizeof(*carp_peers), peerSortWeight);
+
/* Calculate the load factor multipliers X_k
*
* X_1 = pow ((K*p_1), (1/K))
* simplified to have X_1 part of the loop
*/
K = n_carp_peers;
+
P_last = 0.0; /* Empty P_0 */
+
Xn = 1.0; /* Empty starting point of X_1 * X_2 * ... * X_{x-1} */
+
X_last = 0.0; /* Empty X_0, nullifies the first pow statement */
+
for (k = 1; k <= K; k++) {
- double Kk1 = (double) (K - k + 1);
- p = carp_peers[k - 1];
- p->carp.load_multiplier = (Kk1 * (p->carp.load_factor - P_last)) / Xn;
- p->carp.load_multiplier += pow(X_last, Kk1);
- p->carp.load_multiplier = pow(p->carp.load_multiplier, 1.0 / Kk1);
- Xn *= p->carp.load_multiplier;
- X_last = p->carp.load_multiplier;
- P_last = p->carp.load_factor;
+ double Kk1 = (double) (K - k + 1);
+ p = carp_peers[k - 1];
+ p->carp.load_multiplier = (Kk1 * (p->carp.load_factor - P_last)) / Xn;
+ p->carp.load_multiplier += pow(X_last, Kk1);
+ p->carp.load_multiplier = pow(p->carp.load_multiplier, 1.0 / Kk1);
+ Xn *= p->carp.load_multiplier;
+ X_last = p->carp.load_multiplier;
+ P_last = p->carp.load_factor;
}
- cachemgrRegister("carp", "CARP information", carpCachemgr, 0, 1);
}
peer *
-carpSelectParent(request_t * request)
+carpSelectParent(HttpRequest * request)
{
int k;
const char *c;
const char *key = NULL;
if (n_carp_peers == 0)
- return NULL;
+ return NULL;
key = urlCanonical(request);
/* calculate hash key */
- debug(39, 2) ("carpSelectParent: Calculating hash for %s\n", key);
+ debugs(39, 2, "carpSelectParent: Calculating hash for " << key);
+
for (c = key; *c != 0; c++)
- user_hash += ROTATE_LEFT(user_hash, 19) + *c;
+ user_hash += ROTATE_LEFT(user_hash, 19) + *c;
+
/* select peer */
for (k = 0; k < n_carp_peers; k++) {
- tp = carp_peers[k];
- combined_hash = (user_hash ^ tp->carp.hash);
- combined_hash += combined_hash * 0x62531965;
- combined_hash = ROTATE_LEFT(combined_hash, 21);
- score = combined_hash * tp->carp.load_multiplier;
- debug(39, 3) ("carpSelectParent: %s combined_hash %u score %.0f\n",
- tp->host, combined_hash, score);
- if ((score > high_score) && peerHTTPOkay(tp, request)) {
- p = tp;
- high_score = score;
- }
+ tp = carp_peers[k];
+ combined_hash = (user_hash ^ tp->carp.hash);
+ combined_hash += combined_hash * 0x62531965;
+ combined_hash = ROTATE_LEFT(combined_hash, 21);
+ score = combined_hash * tp->carp.load_multiplier;
+ debugs(39, 3, "carpSelectParent: " << tp->name << " combined_hash " << combined_hash <<
+ " score " << std::setprecision(0) << score);
+
+ if ((score > high_score) && peerHTTPOkay(tp, request)) {
+ p = tp;
+ high_score = score;
+ }
}
+
if (p)
- debug(39, 2) ("carpSelectParent: selected %s\n", p->host);
+ debugs(39, 2, "carpSelectParent: selected " << p->name);
+
return p;
}
peer *p;
int sumfetches = 0;
storeAppendPrintf(sentry, "%24s %10s %10s %10s %10s\n",
- "Hostname",
- "Hash",
- "Multiplier",
- "Factor",
- "Actual");
+ "Hostname",
+ "Hash",
+ "Multiplier",
+ "Factor",
+ "Actual");
+
for (p = Config.peers; p; p = p->next)
- sumfetches += p->stats.fetches;
+ sumfetches += p->stats.fetches;
+
for (p = Config.peers; p; p = p->next) {
- storeAppendPrintf(sentry, "%24s %10x %10f %10f %10f\n",
- p->host, p->carp.hash,
- p->carp.load_multiplier,
- p->carp.load_factor,
- sumfetches ? (double) p->stats.fetches / sumfetches : -1.0);
+ storeAppendPrintf(sentry, "%24s %10x %10f %10f %10f\n",
+ p->name, p->carp.hash,
+ p->carp.load_multiplier,
+ p->carp.load_factor,
+ sumfetches ? (double) p->stats.fetches / sumfetches : -1.0);
}
}
-
-#endif
projects / thirdparty / squid.git / blobdiff