[MAJOR] first limited implementation of connection queueing.
There is no timeout yet, and the server UP/DOWN events are not used
to export/import list of connections yet. It seems that the process
can sometimes eat lots of user CPU (~50%) if a maxconn is set on an
overloaded server.
diff --git a/haproxy.c b/haproxy.c
index 5b96681..10cb6e5 100644
--- a/haproxy.c
+++ b/haproxy.c
@@ -405,6 +405,8 @@
/* various other session flags, bits values 0x400000 and above */
#define SN_MONITOR 0x00400000 /* this session comes from a monitoring system */
+#define SN_ASSIGNED 0x00800000 /* no need to assign a server to this session */
+#define SN_ADDR_SET 0x01000000 /* this session's server address has been set */
/* different possible states for the client side */
@@ -448,6 +450,13 @@
#define SRV_BIND_SRC 8 /* this server uses a specific source address */
#define SRV_CHECKED 16 /* this server needs to be checked */
+/* function which act on servers need to return various errors */
+#define SRV_STATUS_OK 0 /* everything is OK. */
+#define SRV_STATUS_INTERNAL 1 /* other unrecoverable errors. */
+#define SRV_STATUS_NOSRV 2 /* no server is available */
+#define SRV_STATUS_FULL 3 /* the/all server(s) are saturated */
+#define SRV_STATUS_QUEUED 4 /* the/all server(s) are saturated but the connection was queued */
+
/* what to do when a header matches a regex */
#define ACT_ALLOW 0 /* allow the request */
#define ACT_REPLACE 1 /* replace the matching header */
@@ -622,6 +631,8 @@
int srvtimeout; /* server I/O timeout (in milliseconds) */
int contimeout; /* connect timeout (in milliseconds) */
char *id; /* proxy id */
+ struct list pendconns; /* pending connections with no server assigned yet */
+ int nbpend; /* number of pending connections with no server assigned yet */
int nbconn; /* # of active sessions */
unsigned int cum_conn; /* cumulated number of processed sessions */
int maxconn; /* max # of active sessions */
@@ -1781,57 +1792,94 @@
/*********************************************************************/
/*
- * returns the first pending connection of server <s> or NULL if none.
+ * Detaches pending connection <p>, decreases the pending count, and frees
+ * the pending connection. The connection might have been queued to a specific
+ * server as well as to the proxy. The session also gets marked unqueued.
*/
-static inline struct pendconn *pendconn_peek(struct server *s) {
+static void pendconn_free(struct pendconn *p) {
+ LIST_DEL(&p->list);
+ p->sess->pend_pos = NULL;
+ if (p->srv)
+ p->srv->nbpend--;
+ else
+ p->sess->proxy->nbpend--;
+ pool_free(pendconn, p);
+}
+
+/* Returns the first pending connection for server <s>, which may be NULL if
+ * nothing is pending.
+ */
+static inline struct pendconn *pendconn_from_srv(struct server *s) {
if (!s->nbpend)
return NULL;
return LIST_ELEM(s->pendconns.n, struct pendconn *, list);
}
-/*
- * Detaches pending connection <p>, decreases the pending count, and frees
- * the pending connection.
+/* Returns the first pending connection for proxy <px>, which may be NULL if
+ * nothing is pending.
*/
-static inline void pendconn_free(struct pendconn *p) {
- LIST_DEL(&p->list);
- p->sess->pend_pos = NULL;
- p->srv->nbpend--;
- pool_free(pendconn, p);
+static inline struct pendconn *pendconn_from_px(struct proxy *px) {
+ if (!px->nbpend)
+ return NULL;
+
+ return LIST_ELEM(px->pendconns.n, struct pendconn *, list);
}
-/* detaches the first pending connection for server <s> and returns its
- * associated session. If no pending connection is found, NULL is returned.
+/* Detaches the next pending connection for either current session's server or
+ * current session's proxy, and returns its associated session. If no pending
+ * connection is found, NULL is returned. Note that cur->srv cannot be NULL.
*/
-static inline struct session *pendconn_get(struct server *s) {
+static struct session *pendconn_get_next_sess(struct session *cur) {
struct pendconn *p;
struct session *sess;
- p = pendconn_peek(s);
- if (!p)
- return NULL;
+ p = pendconn_from_srv(cur->srv);
+ if (!p) {
+ p = pendconn_from_px(cur->proxy);
+ if (!p)
+ return NULL;
+ p->sess->srv = cur->srv;
+ }
sess = p->sess;
pendconn_free(p);
return sess;
}
+/* Checks if other sessions are waiting for the same server, and wakes the
+ * first one up. Note that cur->srv cannot be NULL.
+ */
+void offer_connection_slot(struct session *cur) {
+ struct session *sess;
+
+ sess = pendconn_get_next_sess(cur);
+ if (sess == NULL)
+ return;
+ task_wakeup(&rq, sess->task);
+}
+
-/* adds the session <sess> to the pending connection list of server <srv>.
- * All counters and back pointers are updated accordingly. Returns NULL if
- * no memory is available, otherwise the pendconn itself.
+/* Adds the session <sess> to the pending connection list of server <sess>->srv
+ * or to the one of <sess>->proxy if srv is NULL. All counters and back pointers
+ * are updated accordingly. Returns NULL if no memory is available, otherwise the
+ * pendconn itself.
*/
-static struct pendconn *pendconn_add(struct server *srv, struct session *sess) {
+static struct pendconn *pendconn_add(struct session *sess) {
struct pendconn *p;
p = pool_alloc(pendconn);
if (!p)
return NULL;
- LIST_ADDQ(&srv->pendconns, &p->list);
- p->sess = sess;
- p->srv = srv;
sess->pend_pos = p;
- srv->nbpend++;
+ p->sess = sess;
+ p->srv = sess->srv;
+ if (sess->srv) {
+ LIST_ADDQ(&sess->srv->pendconns, &p->list);
+ sess->srv->nbpend++;
+ } else {
+ LIST_ADDQ(&sess->proxy->pendconns, &p->list);
+ sess->proxy->nbpend++;
+ }
return p;
}
@@ -1860,7 +1908,7 @@
/*
* frees the context associated to a session. It must have been removed first.
*/
-static inline void session_free(struct session *s) {
+static void session_free(struct session *s) {
if (s->pend_pos)
pendconn_free(s->pend_pos);
if (s->req)
@@ -2053,60 +2101,99 @@
/*
- * This function initiates a connection to the current server (s->srv) if (s->direct)
- * is set, or to the dispatch server if (s->direct) is 0.
- * It can return one of :
- * - SN_ERR_NONE if everything's OK
- * - SN_ERR_SRVTO if there are no more servers
- * - SN_ERR_SRVCL if the connection was refused by the server
- * - SN_ERR_PRXCOND if the connection has been limited by the proxy (maxconn)
- * - SN_ERR_RESOURCE if a system resource is lacking (eg: fd limits, ports, ...)
- * - SN_ERR_INTERNAL for any other purely internal errors
- * Additionnally, in the case of SN_ERR_RESOURCE, an emergency log will be emitted.
+ * This function marks the session as 'assigned' in direct or dispatch modes,
+ * or tries to assign one in balance mode, according to the algorithm. It does
+ * nothing if the session had already been assigned a server.
+ *
+ * It may return :
+ * SRV_STATUS_OK if everything is OK.
+ * SRV_STATUS_NOSRV if no server is available
+ * SRV_STATUS_FULL if all servers are saturated
+ * SRV_STATUS_INTERNAL for other unrecoverable errors.
+ *
+ * Upon successful return, the session flag SN_ASSIGNED to indicate that it does
+ * not need to be called anymore. This usually means that s->srv can be trusted
+ * in balance and direct modes. This flag is not cleared, so it's to the caller
+ * to clear it if required (eg: redispatch).
+ *
*/
-int connect_server(struct session *s) {
- int fd;
+int assign_server(struct session *s) {
#ifdef DEBUG_FULL
- fprintf(stderr,"connect_server : s=%p\n",s);
+ fprintf(stderr,"assign_server : s=%p\n",s);
#endif
- if (s->flags & SN_DIRECT) { /* srv cannot be null */
- s->srv_addr = s->srv->addr;
- }
- else if (s->proxy->options & PR_O_BALANCE) {
- /* Ensure that srv will not be NULL */
- if (!s->proxy->srv_act && !s->proxy->srv_bck)
- return SN_ERR_SRVTO;
+ if (s->pend_pos)
+ return SRV_STATUS_INTERNAL;
- if (s->proxy->options & PR_O_BALANCE_RR) {
- struct server *srv;
+ if (!(s->flags & SN_ASSIGNED)) {
+ if ((s->proxy->options & PR_O_BALANCE) && !(s->flags & SN_DIRECT)) {
+ if (!s->proxy->srv_act && !s->proxy->srv_bck)
+ return SRV_STATUS_NOSRV;
- srv = get_server_rr_with_conns(s->proxy);
- if (!srv)
- srv = get_server_rr(s->proxy);
- s->srv_addr = srv->addr;
- s->srv = srv;
+ if (s->proxy->options & PR_O_BALANCE_RR) {
+ s->srv = get_server_rr_with_conns(s->proxy);
+ if (!s->srv)
+ return SRV_STATUS_FULL;
+ }
+ else if (s->proxy->options & PR_O_BALANCE_SH) {
+ int len;
+
+ if (s->cli_addr.ss_family == AF_INET)
+ len = 4;
+ else if (s->cli_addr.ss_family == AF_INET6)
+ len = 16;
+ else /* unknown IP family */
+ return SRV_STATUS_INTERNAL;
+
+ s->srv = get_server_sh(s->proxy,
+ (void *)&((struct sockaddr_in *)&s->cli_addr)->sin_addr,
+ len);
+ }
+ else /* unknown balancing algorithm */
+ return SRV_STATUS_INTERNAL;
}
- else if (s->proxy->options & PR_O_BALANCE_SH) {
- struct server *srv;
- int len;
+ s->flags |= SN_ASSIGNED;
+ }
+ return SRV_STATUS_OK;
+}
- if (s->cli_addr.ss_family == AF_INET)
- len = 4;
- else if (s->cli_addr.ss_family == AF_INET6)
- len = 16;
- else /* unknown IP family */
- return SN_ERR_INTERNAL;
+/*
+ * This function assigns a server address to a session, and sets SN_ADDR_SET.
+ * The address is taken from the currently assigned server, or from the
+ * dispatch or transparent address.
+ *
+ * It may return :
+ * SRV_STATUS_OK if everything is OK.
+ * SRV_STATUS_INTERNAL for other unrecoverable errors.
+ *
+ * Upon successful return, the session flag SN_ADDR_SET is set. This flag is
+ * not cleared, so it's to the caller to clear it if required.
+ *
+ */
+int assign_server_address(struct session *s) {
+#ifdef DEBUG_FULL
+ fprintf(stderr,"assign_server_address : s=%p\n",s);
+#endif
+
+ if (s->flags & SN_DIRECT || s->proxy->options & PR_O_BALANCE) {
+ /* A server is necessarily known for this session */
+ if (!(s->flags & SN_ASSIGNED))
+ return SRV_STATUS_INTERNAL;
+
+ s->srv_addr = s->srv->addr;
- srv = get_server_sh(s->proxy,
- (void *)&((struct sockaddr_in *)&s->cli_addr)->sin_addr,
- len);
- s->srv_addr = srv->addr;
- s->srv = srv;
+ /* if this server remaps proxied ports, we'll use
+ * the port the client connected to with an offset. */
+ if (s->srv->state & SRV_MAPPORTS) {
+ struct sockaddr_in sockname;
+ socklen_t namelen = sizeof(sockname);
+
+ if (!(s->proxy->options & PR_O_TRANSP) ||
+ get_original_dst(s->cli_fd, (struct sockaddr_in *)&sockname, &namelen) == -1)
+ getsockname(s->cli_fd, (struct sockaddr *)&sockname, &namelen);
+ s->srv_addr.sin_port = htons(ntohs(s->srv_addr.sin_port) + ntohs(sockname.sin_port));
}
- else /* unknown balancing algorithm */
- return SN_ERR_INTERNAL;
}
else if (*(int *)&s->proxy->dispatch_addr.sin_addr) {
/* connect to the defined dispatch addr */
@@ -2118,21 +2205,102 @@
if (get_original_dst(s->cli_fd, &s->srv_addr, &salen) == -1) {
qfprintf(stderr, "Cannot get original server address.\n");
- return SN_ERR_INTERNAL;
+ return SRV_STATUS_INTERNAL;
}
}
- /* if this server remaps proxied ports, we'll use
- * the port the client connected to with an offset. */
- if (s->srv != NULL && s->srv->state & SRV_MAPPORTS) {
- struct sockaddr_in sockname;
- socklen_t namelen = sizeof(sockname);
+ s->flags |= SN_ADDR_SET;
+ return SRV_STATUS_OK;
+}
- if (!(s->proxy->options & PR_O_TRANSP) ||
- get_original_dst(s->cli_fd, (struct sockaddr_in *)&sockname, &namelen) == -1)
- getsockname(s->cli_fd, (struct sockaddr *)&sockname, &namelen);
- s->srv_addr.sin_port = htons(ntohs(s->srv_addr.sin_port) + ntohs(sockname.sin_port));
+/* This function assigns a server to session <s> if required, and can add the
+ * connection to either the assigned server's queue or to the proxy's queue.
+ *
+ * Returns :
+ *
+ * SRV_STATUS_OK if everything is OK.
+ * SRV_STATUS_NOSRV if no server is available
+ * SRV_STATUS_QUEUED if the connection has been queued.
+ * SRV_STATUS_FULL if the server(s) is/are saturated and the
+ * connection could not be queued.
+ * SRV_STATUS_INTERNAL for other unrecoverable errors.
+ *
+ */
+int assign_server_and_queue(struct session *s) {
+ struct pendconn *p;
+ int err;
+
+ if (s->pend_pos)
+ return SRV_STATUS_INTERNAL;
+
+ if (s->flags & SN_ASSIGNED) {
+ /* a server does not need to be assigned, perhaps because we're in
+ * direct mode, or in dispatch or transparent modes where the server
+ * is not needed.
+ */
+ if (s->srv &&
+ s->srv->maxconn && s->srv->cur_sess >= s->srv->maxconn) {
+ p = pendconn_add(s);
+ if (p)
+ return SRV_STATUS_QUEUED;
+ else
+ return SRV_STATUS_FULL;
+ }
+ return SRV_STATUS_OK;
+ }
+
+ /* a server needs to be assigned */
+ err = assign_server(s);
+ switch (err) {
+ case SRV_STATUS_OK:
+ /* in balance mode, we might have servers with connection limits */
+ if (s->srv != NULL &&
+ s->srv->maxconn && s->srv->cur_sess >= s->srv->maxconn) {
+ p = pendconn_add(s);
+ if (p)
+ return SRV_STATUS_QUEUED;
+ else
+ return SRV_STATUS_FULL;
+ }
+ return SRV_STATUS_OK;
+
+ case SRV_STATUS_FULL:
+ /* queue this session into the proxy's queue */
+ p = pendconn_add(s);
+ if (p)
+ return SRV_STATUS_QUEUED;
+ else
+ return SRV_STATUS_FULL;
+
+ case SRV_STATUS_NOSRV:
+ case SRV_STATUS_INTERNAL:
+ return err;
+ default:
+ return SRV_STATUS_INTERNAL;
}
+}
+
+
+/*
+ * This function initiates a connection to the server assigned to this session
+ * (s->srv, s->srv_addr). It will assign a server if none is assigned yet.
+ * It can return one of :
+ * - SN_ERR_NONE if everything's OK
+ * - SN_ERR_SRVTO if there are no more servers
+ * - SN_ERR_SRVCL if the connection was refused by the server
+ * - SN_ERR_PRXCOND if the connection has been limited by the proxy (maxconn)
+ * - SN_ERR_RESOURCE if a system resource is lacking (eg: fd limits, ports, ...)
+ * - SN_ERR_INTERNAL for any other purely internal errors
+ * Additionnally, in the case of SN_ERR_RESOURCE, an emergency log will be emitted.
+ */
+int connect_server(struct session *s) {
+ int fd, err;
+
+ if (!(s->flags & SN_ADDR_SET)) {
+ err = assign_server_address(s);
+ if (err != SRV_STATUS_OK)
+ return SN_ERR_INTERNAL;
+ }
if ((fd = s->srv_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
qfprintf(stderr, "Cannot get a server socket.\n");
@@ -3624,7 +3792,7 @@
if (srv->state & SRV_RUNNING || t->proxy->options & PR_O_PERSIST) {
/* we found the server and it's usable */
t->flags &= ~SN_CK_MASK;
- t->flags |= SN_CK_VALID | SN_DIRECT;
+ t->flags |= SN_CK_VALID | SN_DIRECT | SN_ASSIGNED;
t->srv = srv;
break;
} else {
@@ -3879,7 +4047,7 @@
if (srv->state & SRV_RUNNING || t->proxy->options & PR_O_PERSIST) {
/* we found the server and it's usable */
t->flags &= ~SN_CK_MASK;
- t->flags |= SN_CK_VALID | SN_DIRECT;
+ t->flags |= SN_CK_VALID | SN_DIRECT | SN_ASSIGNED;
t->srv = srv;
break;
} else {
@@ -3976,7 +4144,7 @@
if (srv->state & SRV_RUNNING || t->proxy->options & PR_O_PERSIST) {
/* we found the server and it's usable */
t->flags &= ~SN_CK_MASK;
- t->flags |= SN_CK_VALID | SN_DIRECT;
+ t->flags |= SN_CK_VALID | SN_DIRECT | SN_ASSIGNED;
t->srv = srv;
break;
} else {
@@ -4312,8 +4480,152 @@
return 0;
}
+/* This function turns the server state into the SV_STCLOSE, and sets
+ * indicators accordingly. Note that if <status> is 0, no message is
+ * returned.
+ */
+void srv_close_with_err(struct session *t, int err, int finst, int status, int msglen, char *msg) {
+ t->srv_state = SV_STCLOSE;
+ if (status > 0) {
+ t->logs.status = status;
+ if (t->proxy->mode == PR_MODE_HTTP)
+ client_return(t, msglen, msg);
+ }
+ if (!(t->flags & SN_ERR_MASK))
+ t->flags |= err;
+ if (!(t->flags & SN_FINST_MASK))
+ t->flags |= finst;
+}
+
+/*
+ * This function checks the retry count during the connect() job.
+ * It updates the session's srv_state and retries, so that the caller knows
+ * what it has to do. It uses the last connection error to set the log when
+ * it expires. It returns 1 when it has expired, and 0 otherwise.
+ */
+int srv_count_retry_down(struct session *t, int conn_err) {
+ /* we are in front of a retryable error */
+ t->conn_retries--;
+ if (t->conn_retries < 0) {
+ /* if not retryable anymore, let's abort */
+ tv_eternity(&t->cnexpire);
+ srv_close_with_err(t, conn_err, SN_FINST_C,
+ 503, t->proxy->errmsg.len503, t->proxy->errmsg.msg503);
+
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+ return 1;
+ }
+ return 0;
+}
/*
+ * This function performs the retryable part of the connect() job.
+ * It updates the session's srv_state and retries, so that the caller knows
+ * what it has to do. It returns 1 when it breaks out of the loop, or 0 if
+ * it needs to redispatch.
+ */
+int srv_retryable_connect(struct session *t) {
+ int conn_err;
+
+ /* This loop ensures that we stop before the last retry in case of a
+ * redispatchable server.
+ */
+ do {
+ /* initiate a connection to the server */
+ conn_err = connect_server(t);
+ switch (conn_err) {
+
+ case SN_ERR_NONE:
+ //fprintf(stderr,"0: c=%d, s=%d\n", c, s);
+ t->srv_state = SV_STCONN;
+ return 1;
+
+ case SN_ERR_INTERNAL:
+ tv_eternity(&t->cnexpire);
+ srv_close_with_err(t, SN_ERR_INTERNAL, SN_FINST_C,
+ 500, t->proxy->errmsg.len500, t->proxy->errmsg.msg500);
+ /* release other sessions waiting for this server */
+ if (t->srv)
+ offer_connection_slot(t);
+ return 1;
+ }
+ /* ensure that we have enough retries left */
+ if (srv_count_retry_down(t, conn_err))
+ return 1;
+ } while (t->srv == NULL || t->conn_retries > 0 || !(t->proxy->options & PR_O_REDISP));
+
+ /* We're on our last chance, and the REDISP option was specified.
+ * We will ignore cookie and force to balance or use the dispatcher.
+ */
+ t->flags &= ~(SN_DIRECT | SN_ASSIGNED | SN_ADDR_SET);
+ t->srv = NULL; /* it's left to the dispatcher to choose a server */
+ if ((t->flags & SN_CK_MASK) == SN_CK_VALID) {
+ t->flags &= ~SN_CK_MASK;
+ t->flags |= SN_CK_DOWN;
+ }
+ return 0;
+}
+
+/* This function performs the "redispatch" part of a connection attempt. It
+ * will assign a server if required, queue the connection if required, and
+ * handle errors that might arise at this level. It can change the server
+ * state. It will return 1 if it encounters an error, switches the server
+ * state, or has to queue a connection. Otherwise, it will return 0 indicating
+ * that the connection is ready to use.
+ */
+
+int srv_redispatch_connect(struct session *t) {
+ int conn_err;
+
+ /* We know that we don't have any connection pending, so we will
+ * try to get a new one, and wait in this state if it's queued
+ */
+ conn_err = assign_server_and_queue(t);
+ switch (conn_err) {
+ case SRV_STATUS_OK:
+ break;
+
+ case SRV_STATUS_NOSRV:
+ tv_eternity(&t->cnexpire);
+ srv_close_with_err(t, SN_ERR_SRVTO, SN_FINST_C,
+ 503, t->proxy->errmsg.len503, t->proxy->errmsg.msg503);
+
+ /* FIXME-20060501: we should not need this once we flush every session
+ * when the last server goes down.
+ */
+ /* release other sessions waiting for this server */
+ if (t->srv)
+ offer_connection_slot(t);
+ return 1;
+
+ case SRV_STATUS_QUEUED:
+ t->srv_state = SV_STIDLE;
+ /* do nothing else and do not wake any other session up */
+ return 1;
+
+ case SRV_STATUS_FULL:
+ case SRV_STATUS_INTERNAL:
+ default:
+ tv_eternity(&t->cnexpire);
+ srv_close_with_err(t, SN_ERR_INTERNAL, SN_FINST_C,
+ 500, t->proxy->errmsg.len500, t->proxy->errmsg.msg500);
+ /* release other sessions waiting for this server */
+ if (t->srv)
+ offer_connection_slot(t);
+ return 1;
+ }
+ /* if we get here, it's because we got SRV_STATUS_OK, which also
+ * means that the connection has not been queued.
+ */
+ return 0;
+}
+
+
+/*
* manages the server FSM and its socket. It returns 1 if a state has changed
* (and a resync may be needed), 0 else.
*/
@@ -4340,51 +4652,37 @@
c == CL_STSHUTW ||
(c == CL_STSHUTR && t->req->l == 0)) { /* give up */
tv_eternity(&t->cnexpire);
- t->srv_state = SV_STCLOSE;
- if (!(t->flags & SN_ERR_MASK))
- t->flags |= SN_ERR_CLICL;
- if (!(t->flags & SN_FINST_MASK))
- t->flags |= SN_FINST_C;
+ srv_close_with_err(t, SN_ERR_CLICL, SN_FINST_C, 0, 0, NULL);
+
+ /* it might be possible that we have been granted an access to the
+ * server while waiting for a free slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
return 1;
}
- else { /* go to SV_STCONN */
- /* initiate a connection to the server */
- conn_err = connect_server(t);
- if (conn_err == SN_ERR_NONE) {
- //fprintf(stderr,"0: c=%d, s=%d\n", c, s);
- t->srv_state = SV_STCONN;
- }
- else { /* try again */
- while (t->conn_retries-- > 0) {
- if ((t->proxy->options & PR_O_REDISP) && (t->conn_retries == 0)) {
- t->flags &= ~SN_DIRECT; /* ignore cookie and force to use the dispatcher */
- t->srv = NULL; /* it's left to the dispatcher to choose a server */
- if ((t->flags & SN_CK_MASK) == SN_CK_VALID) {
- t->flags &= ~SN_CK_MASK;
- t->flags |= SN_CK_DOWN;
- }
- }
+ else {
+ /* Right now, we will need to create a connection to the server.
+ * We might already have tried, and got a connection pending, in
+ * which case we will not do anything till it's pending. It's up
+ * to any other session to release it and wake us up again.
+ */
+ if (t->pend_pos)
+ return 0;
- conn_err = connect_server(t);
- if (conn_err == SN_ERR_NONE) {
- t->srv_state = SV_STCONN;
- break;
- }
- }
- if (t->conn_retries < 0) {
- /* if conn_retries < 0 or other error, let's abort */
- tv_eternity(&t->cnexpire);
- t->srv_state = SV_STCLOSE;
- t->logs.status = 503;
- if (t->proxy->mode == PR_MODE_HTTP)
- client_return(t, t->proxy->errmsg.len503, t->proxy->errmsg.msg503);
- if (!(t->flags & SN_ERR_MASK))
- t->flags |= conn_err; /* report the precise connect() error */
- if (!(t->flags & SN_FINST_MASK))
- t->flags |= SN_FINST_C;
- }
- }
- return 1;
+ do {
+ /* first, get a connection */
+ if (srv_redispatch_connect(t))
+ return t->srv_state != SV_STIDLE;
+
+ /* try to (re-)connect to the server, and fail if we expire the
+ * number of retries.
+ */
+ if (srv_retryable_connect(t))
+ return t->srv_state != SV_STIDLE;
+
+ } while (1);
}
}
else if (s == SV_STCONN) { /* connection in progress */
@@ -4393,44 +4691,35 @@
return 0; /* nothing changed */
}
else if (t->res_sw == RES_SILENT || t->res_sw == RES_ERROR) {
+ /* timeout, asynchronous connect error or first write error */
//fprintf(stderr,"2: c=%d, s=%d\n", c, s);
- /* timeout, connect error or first write error */
- //FD_CLR(t->srv_fd, StaticWriteEvent);
+
fd_delete(t->srv_fd);
if (t->srv)
t->srv->cur_sess--;
- //close(t->srv_fd);
- t->conn_retries--;
- if (t->conn_retries >= 0) {
- if ((t->proxy->options & PR_O_REDISP) && (t->conn_retries == 0)) {
- t->flags &= ~SN_DIRECT; /* ignore cookie and force to use the dispatcher */
- t->srv = NULL; /* it's left to the dispatcher to choose a server */
- if ((t->flags & SN_CK_MASK) == SN_CK_VALID) {
- t->flags &= ~SN_CK_MASK;
- t->flags |= SN_CK_DOWN;
- }
- }
- conn_err = connect_server(t);
- if (conn_err == SN_ERR_NONE)
- return 0; /* no state changed */
- }
- else if (t->res_sw == RES_SILENT)
+
+ if (t->res_sw == RES_SILENT)
conn_err = SN_ERR_SRVTO; // it was a connect timeout.
else
- conn_err = SN_ERR_SRVCL; // it was a connect error.
+ conn_err = SN_ERR_SRVCL; // it was an asynchronous connect error.
- /* if conn_retries < 0 or other error, let's abort */
- tv_eternity(&t->cnexpire);
- t->srv_state = SV_STCLOSE;
- t->logs.status = 503;
- if (t->proxy->mode == PR_MODE_HTTP)
- client_return(t, t->proxy->errmsg.len503, t->proxy->errmsg.msg503);
- if (!(t->flags & SN_ERR_MASK))
- t->flags |= conn_err;
- if (!(t->flags & SN_FINST_MASK))
- t->flags |= SN_FINST_C;
- /* TODO : check if there are pending connections on this server */
- return 1;
+ /* ensure that we have enough retries left */
+ if (srv_count_retry_down(t, conn_err))
+ return 1;
+
+ do {
+ /* Now we will try to either reconnect to the same server or
+ * connect to another server. If the connection gets queued
+ * because all servers are saturated, then we will go back to
+ * the SV_STIDLE state.
+ */
+ if (srv_retryable_connect(t))
+ return t->srv_state != SV_STCONN;
+
+ /* we need to redispatch the connection to another server */
+ if (srv_redispatch_connect(t))
+ return t->srv_state != SV_STCONN;
+ } while (1);
}
else { /* no error or write 0 */
t->logs.t_connect = tv_diff(&t->logs.tv_accept, &now);
@@ -4521,7 +4810,12 @@
Alert("Blocking cacheable cookie in response from instance %s, server %s.\n", t->proxy->id, t->srv->id);
send_log(t->proxy, LOG_ALERT, "Blocking cacheable cookie in response from instance %s, server %s.\n", t->proxy->id, t->srv->id);
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
}
@@ -4540,7 +4834,12 @@
t->flags |= SN_ERR_PRXCOND;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_H;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
@@ -4974,7 +5273,12 @@
t->flags |= SN_ERR_SRVCL;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_H;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
/* end of client write or end of server read.
@@ -5004,7 +5308,12 @@
t->flags |= SN_ERR_SRVTO;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_H;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
/* last client read and buffer empty */
@@ -5099,7 +5408,12 @@
t->flags |= SN_ERR_SRVCL;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_D;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
/* last read, or end of client write */
@@ -5208,7 +5522,12 @@
t->flags |= SN_ERR_SRVCL;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_D;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
else if ((c == CL_STSHUTR || c == CL_STCLOSE) && (req->l == 0)) {
@@ -5219,7 +5538,12 @@
t->srv->cur_sess--;
//close(t->srv_fd);
t->srv_state = SV_STCLOSE;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
else if (tv_cmp2_ms(&t->swexpire, &now) <= 0) {
@@ -5234,7 +5558,12 @@
t->flags |= SN_ERR_SRVTO;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_D;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
else if (req->l == 0) {
@@ -5271,7 +5600,12 @@
t->flags |= SN_ERR_SRVCL;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_D;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
else if (t->res_sr == RES_NULL || c == CL_STSHUTW || c == CL_STCLOSE) {
@@ -5282,7 +5616,12 @@
t->srv->cur_sess--;
//close(t->srv_fd);
t->srv_state = SV_STCLOSE;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
else if (tv_cmp2_ms(&t->srexpire, &now) <= 0) {
@@ -5297,7 +5636,12 @@
t->flags |= SN_ERR_SRVTO;
if (!(t->flags & SN_FINST_MASK))
t->flags |= SN_FINST_D;
- /* TODO : check if there are pending connections on this server */
+ /* We used to have a free connection slot. Since we'll never use it,
+ * we have to pass it on to another session.
+ */
+ if (t->srv)
+ offer_connection_slot(t);
+
return 1;
}
else if (rep->l == BUFSIZE) { /* no room to read more data */
@@ -6666,8 +7010,11 @@
Alert("parsing [%s:%d] : out of memory.\n", file, linenum);
return -1;
}
+
curproxy->next = proxy;
proxy = curproxy;
+ LIST_INIT(&curproxy->pendconns);
+
curproxy->id = strdup(args[1]);
/* parse the listener address if any */