From: wessels <>
Date: Tue, 5 Dec 2000 13:24:00 +0000 (+0000)
Subject: A feature to limit the number of connections that we make to
X-Git-Tag: SQUID_3_0_PRE1~1748
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c7f9eb6d11790300237552ace51f554b666a4b73;p=thirdparty%2Fsquid.git

A feature to limit the number of connections that we make to
a neighbor cache.
---

diff --git a/src/cache_cf.cc b/src/cache_cf.cc
index 73157e1b69..4c06a59913 100644
--- a/src/cache_cf.cc
+++ b/src/cache_cf.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: cache_cf.cc,v 1.357 2000/12/04 20:40:36 wessels Exp $
+ * $Id: cache_cf.cc,v 1.358 2000/12/05 06:24:00 wessels Exp $
  *
  * DEBUG: section 3     Configuration File Parsing
  * AUTHOR: Harvest Derived
@@ -1106,6 +1106,8 @@ parse_peer(peer ** head)
 #endif
 	} else if (!strcasecmp(token, "allow-miss")) {
 	    p->options.allow_miss = 1;
+	} else if (!strcasecmp(token, "max-conn=")) {
+	    p->max_conn = atoi(token + 9);
 	} else {
 	    debug(3, 0) ("parse_peer: token='%s'\n", token);
 	    self_destruct();
diff --git a/src/forward.cc b/src/forward.cc
index 63628285cf..39e00a15c7 100644
--- a/src/forward.cc
+++ b/src/forward.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: forward.cc,v 1.75 2000/11/01 04:03:14 wessels Exp $
+ * $Id: forward.cc,v 1.76 2000/12/05 06:24:00 wessels Exp $
  *
  * DEBUG: section 17    Request Forwarding
  * AUTHOR: Duane Wessels
@@ -49,6 +49,7 @@ static void fwdStartFail(FwdState *);
 static void fwdLogReplyStatus(int tries, http_status status);
 static OBJH fwdStats;
 static STABH fwdAbort;
+static peer *fwdStateServerPeer(FwdState *);
 
 #define MAX_FWD_STATS_IDX 9
 static int FwdReplyCodes[MAX_FWD_STATS_IDX + 1][HTTP_INVALID_HEADER + 1];
@@ -58,6 +59,16 @@ static void fwdLog(FwdState * fwdState);
 static Logfile *logfile = NULL;
 #endif
 
+static peer *
+fwdStateServerPeer(FwdState * fwdState)
+{
+    if (NULL == fwdState)
+	return NULL;
+    if (NULL == fwdState->servers)
+	return NULL;
+    return fwdState->servers->peer;
+}
+
 static void
 fwdServerFree(FwdServer * fs)
 {
@@ -71,6 +82,7 @@ fwdStateFree(FwdState * fwdState)
 {
     StoreEntry *e = fwdState->entry;
     int sfd;
+    peer *p;
     debug(17, 3) ("fwdStateFree: %p\n", fwdState);
     assert(e->mem_obj);
 #if URL_CHECKSUM_DEBUG
@@ -92,6 +104,7 @@ fwdStateFree(FwdState * fwdState)
     }
     if (storePendingNClients(e) > 0)
 	assert(!EBIT_TEST(e->flags, ENTRY_FWD_HDR_WAIT));
+    p = fwdStateServerPeer(fwdState);
     fwdServersFree(&fwdState->servers);
     requestUnlink(fwdState->request);
     fwdState->request = NULL;
@@ -106,6 +119,8 @@ fwdStateFree(FwdState * fwdState)
 	fwdState->server_fd = -1;
 	debug(17, 3) ("fwdStateFree: closing FD %d\n", sfd);
 	comm_close(sfd);
+	if (p)
+	    p->stats.conn_open--;
     }
     cbdataFree(fwdState);
 }
@@ -188,6 +203,8 @@ fwdConnectDone(int server_fd, int status, void *data)
 	err->dnsserver_msg = xstrdup(dns_error_message);
 	err->request = requestLink(request);
 	fwdFail(fwdState, err);
+	if (fs->peer)
+	    fs->peer->stats.conn_open--;
 	comm_close(server_fd);
     } else if (status != COMM_OK) {
 	assert(fs);
@@ -202,8 +219,10 @@ fwdConnectDone(int server_fd, int status, void *data)
 	}
 	err->request = requestLink(request);
 	fwdFail(fwdState, err);
-	if (fs->peer)
+	if (fs->peer) {
 	    peerConnectFailed(fs->peer);
+	    fs->peer->stats.conn_open--;
+	}
 	comm_close(server_fd);
     } else {
 	debug(17, 3) ("fwdConnectDone: FD %d: '%s'\n", server_fd, storeUrl(fwdState->entry));
@@ -228,6 +247,7 @@ fwdConnectTimeout(int fd, void *data)
     FwdState *fwdState = data;
     StoreEntry *entry = fwdState->entry;
     ErrorState *err;
+    peer *p = fwdStateServerPeer(fwdState);
     debug(17, 2) ("fwdConnectTimeout: FD %d: '%s'\n", fd, storeUrl(entry));
     assert(fd == fwdState->server_fd);
     if (entry->mem_obj->inmem_hi == 0) {
@@ -242,6 +262,8 @@ fwdConnectTimeout(int fd, void *data)
 	    if (fwdState->servers->peer)
 		peerConnectFailed(fwdState->servers->peer);
     }
+    if (p)
+	p->stats.conn_open--;
     comm_close(fd);
 }
 
@@ -302,6 +324,14 @@ fwdConnectStart(void *data)
     }
     fwdState->server_fd = fd;
     fwdState->n_tries++;
+    /*
+     * stats.conn_open is used to account for the number of
+     * connections that we have open to the peer, so we can limit
+     * based on the max-conn option.  We need to increment here,
+     * even if the connection may fail.
+     */
+    if (fs->peer)
+	fs->peer->stats.conn_open++;
     comm_add_close_handler(fd, fwdServerClosed, fwdState);
     commSetTimeout(fd,
 	ctimeout,
@@ -338,7 +368,7 @@ fwdStartFail(FwdState * fwdState)
 static void
 fwdDispatch(FwdState * fwdState)
 {
-    peer *p;
+    peer *p = NULL;
     request_t *request = fwdState->request;
     StoreEntry *entry = fwdState->entry;
     ErrorState *err;
@@ -400,6 +430,11 @@ fwdDispatch(FwdState * fwdState)
 	     * transient (network) error; its a bug.
 	     */
 	    fwdState->flags.dont_retry = 1;
+	    /*
+	     * this assertion exists because if we are connected to
+	     * a peer, then we need to decrement p->stats.conn_open.
+	     */
+	    assert(NULL == p);
 	    comm_close(fwdState->server_fd);
 	    break;
 	}
diff --git a/src/neighbors.cc b/src/neighbors.cc
index 6e8e20f7e8..7a742213f5 100644
--- a/src/neighbors.cc
+++ b/src/neighbors.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: neighbors.cc,v 1.288 2000/11/07 22:04:38 wessels Exp $
+ * $Id: neighbors.cc,v 1.289 2000/12/05 06:24:00 wessels Exp $
  *
  * DEBUG: section 15    Neighbor Routines
  * AUTHOR: Harvest Derived
@@ -189,6 +189,9 @@ peerHTTPOkay(const peer * p, request_t * request)
 	return 0;
     if (!neighborUp(p))
 	return 0;
+    if (p->max_conn)
+	if (p->stats.conn_open >= p->max_conn)
+	    return 0;
     return 1;
 }
 
@@ -1242,6 +1245,7 @@ dump_peers(StoreEntry * sentry, peer * peers)
 	storeAppendPrintf(sentry, "Status     : %s\n",
 	    neighborUp(e) ? "Up" : "Down");
 	storeAppendPrintf(sentry, "AVG RTT    : %d msec\n", e->stats.rtt);
+	storeAppendPrintf(sentry, "OPEN CONNS : %d\n", e->stats.conn_open);
 	storeAppendPrintf(sentry, "LAST QUERY : %8d seconds ago\n",
 	    (int) (squid_curtime - e->stats.last_query));
 	storeAppendPrintf(sentry, "LAST REPLY : %8d seconds ago\n",
diff --git a/src/structs.h b/src/structs.h
index 0254c55834..de87fce53a 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1,6 +1,6 @@
 
 /*
- * $Id: structs.h,v 1.361 2000/11/13 12:25:13 adrian Exp $
+ * $Id: structs.h,v 1.362 2000/12/05 06:24:00 wessels Exp $
  *
  *
  * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
@@ -1043,6 +1043,7 @@ struct _peer {
 	time_t last_connect_failure;
 	time_t last_connect_probe;
 	int logged_state;	/* so we can print dead/revived msgs */
+	int conn_open;		/* current opened connections */
     } stats;
     struct {
 	int version;
@@ -1109,6 +1110,7 @@ struct _peer {
 #endif
     char *login;		/* Proxy authorization */
     time_t connect_timeout;
+    int max_conn;
 };
 
 struct _net_db_name {