PJSIP: Stagger outbound qualifies

This change staggers initiation of outbound qualify (OPTIONS) attempts
to reduce instantaneous server load and prevent network congestion.

Review: https://reviewboard.asterisk.org/r/4246/
ASTERISK-24342 #close
Reported by: Richard Mudgett

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@429127 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_pjsip/pjsip_options.c b/res/res_pjsip/pjsip_options.c
index 33f717498dd5d84a43d065c1e8f21d608142cf48..a3d9b0c1ea5153cf9e3144279a171103dd3d7d1e 100644 (file)
--- a/res/res_pjsip/pjsip_options.c
+++ b/res/res_pjsip/pjsip_options.c
@@ -418,14 +418,14 @@ static int qualify_contact_sched(const void *obj)
         * up the data object ref between self deletion and an external
         * deletion.
         */
-       return 1;
+       return data->contact->qualify_frequency * 1000;
 }
 
 /*!
  * \internal
  * \brief Set up a scheduled qualify contact check.
  */
-static void schedule_qualify(struct ast_sip_contact *contact)
+static void schedule_qualify(struct ast_sip_contact *contact, int initial_interval)
 {
        struct sched_data *data;
 
@@ -437,8 +437,8 @@ static void schedule_qualify(struct ast_sip_contact *contact)
        ast_assert(contact->qualify_frequency != 0);
 
        ao2_t_ref(data, +1, "Ref for qualify_contact_sched() scheduler entry");
-       data->id = ast_sched_add_variable(sched, contact->qualify_frequency * 1000,
-               qualify_contact_sched, data, 0);
+       data->id = ast_sched_add_variable(sched, initial_interval,
+               qualify_contact_sched, data, 1);
        if (data->id < 0) {
                ao2_t_ref(data, -1, "Cleanup failed scheduler add");
                ast_log(LOG_ERROR, "Unable to schedule qualify for contact %s\n",
@@ -482,7 +482,7 @@ static void qualify_and_schedule(struct ast_sip_contact *contact)
                        ao2_ref(contact, -1);
                }
 
-               schedule_qualify(contact);
+               schedule_qualify(contact, contact->qualify_frequency * 1000);
        } else {
                delete_contact_status(contact);
        }
@@ -951,11 +951,16 @@ static int qualify_and_schedule_cb(void *obj, void *arg, int flags)
 {
        struct ast_sip_contact *contact = obj;
        struct ast_sip_aor *aor = arg;
+       int initial_interval;
 
        contact->qualify_frequency = aor->qualify_frequency;
        contact->authenticate_qualify = aor->authenticate_qualify;
 
-       qualify_and_schedule(contact);
+       /* Delay initial qualification by a random fraction of the specified interval */
+       initial_interval = contact->qualify_frequency * 1000;
+       initial_interval = (int)(initial_interval * ast_random_double());
+
+       schedule_qualify(contact, initial_interval);
 
        return 0;
 }