BUG/MEDIUM: spoe: Never create new spoe applet if there is no server up

This test was already performed when a new message is queued into the
sending queue. However not when the last applet is released, in
spoe_release_appctx(). It is a quite old bug. It was introduced by commit
6f1296b5c7 ("BUG/MEDIUM: spoe: Create a SPOE applet if necessary when the
last one is released").

Because of this bug, new SPOE applets may be created and quickly released
because there is no server up, in loop and while there is at least one
message in the sending queue, consuming all the CPU. It is pretty visible if
the processing timeout is high.

To fix the bug, conditions to create or not a SPOE applet are now
centralized in spoe_create_appctx(). The test about the max connections per
second and about number of active servers are moved in this function.

This patch must be backported to all stable versions.

diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index e8f33834919a3e327d5484bb64f117baa1498265..70ea2bab6707cd1ef8ac345066eb71383a6a9597 100644 (file)
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -2018,16 +2018,35 @@ struct applet spoe_applet = {
 static struct appctx *
 spoe_create_appctx(struct spoe_config *conf)
 {
+       struct spoe_agent *agent = conf->agent;
        struct spoe_appctx *spoe_appctx;
        struct appctx *appctx;
 
+       /* Do not try to create a new applet if there is no server up for the
+        * agent's backend. */
+       if (!agent->b.be->srv_act && !agent->b.be->srv_bck) {
+               SPOE_PRINTF(stderr, "%d.%06d [SPOE/%-15s] %s: don't create SPOE appctx: no server up\n",
+                           (int)date.tv_sec, (int)date.tv_usec, agent->id, __FUNCTION__);
+               goto out;
+       }
+
+       /* Do not try to create a new applet if we have reached the maximum of
+        * connection per seconds */
+       if (agent->cps_max > 0) {
+               if (!freq_ctr_remain(&agent->rt[tid].conn_per_sec, agent->cps_max, 0)) {
+                       SPOE_PRINTF(stderr, "%d.%06d [SPOE/%-15s] %s: don't create SPOE appctx: max CPS reached\n",
+                                   (int)date.tv_sec, (int)date.tv_usec, agent->id, __FUNCTION__);
+                       goto out;
+               }
+       }
+
        spoe_appctx = pool_zalloc(pool_head_spoe_appctx);
        if (spoe_appctx == NULL)
                goto out_error;
 
-       spoe_appctx->agent           = conf->agent;
+       spoe_appctx->agent           = agent;
        spoe_appctx->version         = 0;
-       spoe_appctx->max_frame_size  = conf->agent->max_frame_size;
+       spoe_appctx->max_frame_size  = agent->max_frame_size;
        spoe_appctx->flags           = 0;
        spoe_appctx->status_code     = SPOE_FRM_ERR_NONE;
        spoe_appctx->buffer          = BUF_NULL;
@@ -2043,6 +2062,10 @@ spoe_create_appctx(struct spoe_config *conf)
        if (appctx_init(appctx) == -1)
                goto out_free_appctx;
 
+       /* Increase the per-process number of cumulated connections */
+       if (agent->cps_max > 0)
+               update_freq_ctr(&agent->rt[tid].conn_per_sec, 1);
+
        appctx_wakeup(appctx);
        return appctx;
 
@@ -2052,6 +2075,11 @@ spoe_create_appctx(struct spoe_config *conf)
  out_free_spoe_appctx:
        pool_free(pool_head_spoe_appctx, spoe_appctx);
  out_error:
+       SPOE_PRINTF(stderr, "%d.%06d [SPOE/%-15s] %s: failed to create SPOE appctx\n",
+                   (int)date.tv_sec, (int)date.tv_usec, agent->id, __FUNCTION__);
+       send_log(&conf->agent_fe, LOG_EMERG, "SPOE: [%s] failed to create SPOE applet\n", agent->id);
+ out:
+
        return NULL;
 }
 
@@ -2060,7 +2088,6 @@ spoe_queue_context(struct spoe_context *ctx)
 {
        struct spoe_config *conf = FLT_CONF(ctx->filter);
        struct spoe_agent  *agent = conf->agent;
-       struct appctx      *appctx;
        struct spoe_appctx *spoe_appctx;
 
        /* Check if we need to create a new SPOE applet or not. */
@@ -2073,44 +2100,7 @@ spoe_queue_context(struct spoe_context *ctx)
                    (int)date.tv_sec, (int)date.tv_usec, agent->id, __FUNCTION__,
                    ctx->strm);
 
-       /* Do not try to create a new applet if there is no server up for the
-        * agent's backend. */
-       if (!agent->b.be->srv_act && !agent->b.be->srv_bck) {
-               SPOE_PRINTF(stderr, "%d.%06d [SPOE/%-15s] %s: stream=%p"
-                           " - cannot create SPOE appctx: no server up\n",
-                           (int)date.tv_sec, (int)date.tv_usec, agent->id,
-                           __FUNCTION__, ctx->strm);
-               goto end;
-       }
-
-       /* Do not try to create a new applet if we have reached the maximum of
-        * connection per seconds */
-       if (agent->cps_max > 0) {
-               if (!freq_ctr_remain(&agent->rt[tid].conn_per_sec, agent->cps_max, 0)) {
-                       SPOE_PRINTF(stderr, "%d.%06d [SPOE/%-15s] %s: stream=%p"
-                                   " - cannot create SPOE appctx: max CPS reached\n",
-                                   (int)date.tv_sec, (int)date.tv_usec, agent->id,
-                                   __FUNCTION__, ctx->strm);
-                       goto end;
-               }
-       }
-
-       appctx = spoe_create_appctx(conf);
-       if (appctx == NULL) {
-               SPOE_PRINTF(stderr, "%d.%06d [SPOE/%-15s] %s: stream=%p"
-                           " - failed to create SPOE appctx\n",
-                           (int)date.tv_sec, (int)date.tv_usec, agent->id,
-                           __FUNCTION__, ctx->strm);
-               send_log(&conf->agent_fe, LOG_EMERG,
-                        "SPOE: [%s] failed to create SPOE applet\n",
-                        agent->id);
-
-               goto end;
-       }
-
-       /* Increase the per-process number of cumulated connections */
-       if (agent->cps_max > 0)
-               update_freq_ctr(&agent->rt[tid].conn_per_sec, 1);
+       spoe_create_appctx(conf);
 
   end:
        /* The only reason to return an error is when there is no applet */