* health checks sent to servers configured with identical intervals
were sent in perfect synchronisation because the initial time was
the same for all. This could induce high load peaks when fragile
servers were hosting tens of instances for the same application.
Now the load is spread evenly across the smallest interval amongst
a listener.
diff --git a/haproxy.c b/haproxy.c
index 6907776..94839ff 100644
--- a/haproxy.c
+++ b/haproxy.c
@@ -412,6 +412,7 @@
#define SRV_BACKUP 2 /* this server is a backup server */
#define SRV_MAPPORTS 4 /* this server uses mapped ports */
#define SRV_BIND_SRC 8 /* this server uses a specific source address */
+#define SRV_CHECKED 16 /* this server needs to be checked */
/* what to do when a header matches a regex */
#define ACT_ALLOW 0 /* allow the request */
@@ -5033,7 +5034,16 @@
task_queue(t); /* restore t to its place in the task list */
return tv_remain2(&now, &t->expire);
}
-
+
+ /* we don't send any health-checks when the proxy is stopped or when
+ * the server should not be checked.
+ */
+ if (!(s->state & SRV_CHECKED) || s->proxy->state == PR_STSTOPPED) {
+ tv_delayfrom(&t->expire, &now, s->inter);
+ task_queue(t); /* restore t to its place in the task list */
+ return tv_remain2(&now, &t->expire);
+ }
+
/* we'll initiate a new check */
s->result = 0; /* no result yet */
if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) != -1) {
@@ -6822,8 +6832,6 @@
}
if (do_check) {
- struct task *t;
-
if (!newsrv->check_port && !(newsrv->state & SRV_MAPPORTS))
newsrv->check_port = realport; /* by default */
if (!newsrv->check_port) {
@@ -6831,23 +6839,7 @@
file, linenum, newsrv->id);
return -1;
}
-
- if ((t = pool_alloc(task)) == NULL) {
- Alert("parsing [%s:%d] : out of memory.\n", file, linenum);
- return -1;
- }
-
- t->next = t->prev = t->rqnext = NULL; /* task not in run queue yet */
- t->wq = LIST_HEAD(wait_queue); /* but already has a wait queue assigned */
- t->state = TASK_IDLE;
- t->process = process_chk;
- t->context = newsrv;
-
- if (curproxy->state != PR_STSTOPPED) {
- tv_delayfrom(&t->expire, &now, newsrv->inter); /* check this every ms */
- task_queue(t);
- task_wakeup(&rq, t);
- }
+ newsrv->state |= SRV_CHECKED;
}
curproxy->nbservers++;
@@ -7424,6 +7416,7 @@
char *args[MAX_LINE_ARGS];
int arg;
int cfgerr = 0;
+ int nbchk, mininter;
int confsect = CFG_NONE;
struct proxy *curproxy = NULL;
@@ -7543,6 +7536,9 @@
* Now, check for the integrity of all that we have collected.
*/
+ /* will be needed further to delay some tasks */
+ tv_now(&now);
+
if ((curproxy = proxy) == NULL) {
Alert("parsing %s : no <listen> line. Nothing to do !\n",
file);
@@ -7646,6 +7642,57 @@
curproxy->errmsg.msg504 = (char *)HTTP_504;
curproxy->errmsg.len504 = strlen(HTTP_504);
}
+
+ /* now we'll start this proxy's health checks if any */
+ /* 1- count the checkers to run simultaneously */
+ nbchk = 0;
+ mininter = 0;
+ newsrv = curproxy->srv;
+ while (newsrv != NULL) {
+ if (newsrv->state & SRV_CHECKED) {
+ if (!mininter || mininter > newsrv->inter)
+ mininter = newsrv->inter;
+ nbchk++;
+ }
+ newsrv = newsrv->next;
+ }
+
+ /* 2- start them as far as possible from each others while respecting
+ * their own intervals. For this, we will start them after their own
+ * interval added to the min interval divided by the number of servers,
+ * weighted by the server's position in the list.
+ */
+ if (nbchk > 0) {
+ struct task *t;
+ int srvpos;
+
+ newsrv = curproxy->srv;
+ srvpos = 0;
+ while (newsrv != NULL) {
+ /* should this server be checked ? */
+ if (newsrv->state & SRV_CHECKED) {
+ if ((t = pool_alloc(task)) == NULL) {
+ Alert("parsing [%s:%d] : out of memory.\n", file, linenum);
+ return -1;
+ }
+
+ t->next = t->prev = t->rqnext = NULL; /* task not in run queue yet */
+ t->wq = LIST_HEAD(wait_queue); /* but already has a wait queue assigned */
+ t->state = TASK_IDLE;
+ t->process = process_chk;
+ t->context = newsrv;
+
+ /* check this every ms */
+ tv_delayfrom(&t->expire, &now,
+ newsrv->inter + mininter * srvpos / nbchk);
+ task_queue(t);
+ //task_wakeup(&rq, t);
+ srvpos++;
+ }
+ newsrv = newsrv->next;
+ }
+ }
+
curproxy = curproxy->next;
}
if (cfgerr > 0) {