res_pjsip: Add global option to limit the maximum time for initial qualifies

Currently when Asterisk starts initial qualifies of contacts are spread out
randomly between 0 and qualify_timeout to prevent network and system overload.
If a contact's qualify_frequency is 5 minutes however, that contact may be
unavailable to accept calls for the entire 5 minutes after startup.  So while
staggering the initial qualifies is a good idea, basing the time on
qualify_timeout could leave contacts unavailable for too long.

This patch adds a new global parameter "max_initial_qualify_time" that sets the
maximum time for the initial qualifies.  This way you could make sure that all
your contacts are initialy, randomly qualified within say 30 seconds but still
have the contact's ongoing qualifies at a 5 minute interval.

If max_initial_qualify_time is > 0, the formula is initial_interval =
min(max_initial_interval, qualify_timeout * random().  If not set,
qualify_timeout is used.

The default is "0" (disabled).

ASTERISK-24863 #close

Change-Id: Ib80498aa1ea9923277bef51d6a9015c9c79740f4
Tested-by: George Joseph <george.joseph@fairview5.com>

CHANGES

@@ -147,6 +147,10 @@ res_pjsip
    unavailable.  When any contact becomes available, the endpoint will status
    will change back to "Reachable".
 
+ * A new global option has been added: "max_initial_qualify_time", which
+   sets the maximum amount of time from startup that qualifies should be
+   attempted on all contacts.
+
 res_ari_channels
 ------------------
  * Two new events, 'ChannelHold' and 'ChannelUnhold', have been added to the

configs/samples/pjsip.conf.sample

@@ -869,7 +869,10 @@
             ; The order by which endpoint identifiers are given priority.
             ; Identifier names are derived from res_pjsip_endpoint_identifier_*
             ; modules. (default: ip,username,anonymous)
-
+;max_initial_qualify_time=4 ; The maximum amount of time (in seconds) from
+                              startup that qualifies should be attempted on all
+                              contacts.  If greater than the qualify_frequency
+                              for an aor, qualify_frequency will be used instead.
 
 ; MODULE PROVIDING BELOW SECTION(S): res_pjsip_acl
 ;==========================ACL SECTION OPTIONS=========================

contrib/ast-db-manage/config/versions/a541e0b5e89_add_pjsip_max_initial_qualify_time.py

@@ -0,0 +1,20 @@
+"""add pjsip max_initial_qualify_time
+
+Revision ID: a541e0b5e89
+Revises: 461d7d691209
+Create Date: 2015-04-15 14:37:36.424471
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'a541e0b5e89'
+down_revision = '461d7d691209'
+
+from alembic import op
+import sqlalchemy as sa
+
+def upgrade():
+    op.add_column('ps_globals', sa.Column('max_initial_qualify_time', sa.Integer))
+
+def downgrade():
+    op.drop_column('ps_globals', 'max_initial_qualify_time')

include/asterisk/res_pjsip.h

@@ -1995,4 +1995,12 @@ char *ast_sip_get_endpoint_identifier_order(void);
  */
 unsigned int ast_sip_get_keep_alive_interval(void);
 
+/*!
+ * \brief Retrieve the system max initial qualify time.
+ *
+ * \retval the maximum initial qualify time.
+ */
+unsigned int ast_sip_get_max_initial_qualify_time(void);
+
+
 #endif /* _RES_PJSIP_H */

res/res_pjsip.c

@@ -1229,6 +1229,10 @@
 				<configOption name="keep_alive_interval" default="0">
 					<synopsis>The interval (in seconds) to send keepalives to active connection-oriented transports.</synopsis>
 				</configOption>
+				<configOption name="max_initial_qualify_time" default="0">
+					<synopsis>The maximum amount of time from startup that qualifies should be attempted on all contacts.
+					If greater than the qualify_frequency for an aor, qualify_frequency will be used instead.</synopsis>
+				</configOption>
 				<configOption name="type">
 					<synopsis>Must be of type 'global'.</synopsis>
 				</configOption>

res/res_pjsip/config_global.c

@@ -33,6 +33,7 @@
 #define DEFAULT_OUTBOUND_ENDPOINT "default_outbound_endpoint"
 #define DEFAULT_DEBUG "no"
 #define DEFAULT_ENDPOINT_IDENTIFIER_ORDER "ip,username,anonymous"
+#define DEFAULT_MAX_INITIAL_QUALIFY_TIME 0
 
 static char default_useragent[256];
 
@@ -50,6 +51,8 @@ struct global_config {
 	unsigned int max_forwards;
 	/* The interval at which to send keep alive messages to active connection-oriented transports */
 	unsigned int keep_alive_interval;
+	/* The maximum time for all contacts to be qualified at startup */
+	unsigned int max_initial_qualify_time;
 };
 
 static void global_destructor(void *obj)
@@ -161,6 +164,21 @@ unsigned int ast_sip_get_keep_alive_interval(void)
 	return interval;
 }
 
+unsigned int ast_sip_get_max_initial_qualify_time(void)
+{
+	unsigned int time;
+	struct global_config *cfg;
+
+	cfg = get_global_cfg();
+	if (!cfg) {
+		return DEFAULT_MAX_INITIAL_QUALIFY_TIME;
+	}
+
+	time = cfg->max_initial_qualify_time;
+	ao2_ref(cfg, -1);
+	return time;
+}
+
 /*!
  * \internal
  * \brief Observer to set default global object if none exist.
@@ -271,6 +289,9 @@ int ast_sip_initialize_sorcery_global(void)
 	ast_sorcery_object_field_register(sorcery, "global", "keep_alive_interval",
 		__stringify(DEFAULT_KEEPALIVE_INTERVAL),
 		OPT_UINT_T, 0, FLDSET(struct global_config, keep_alive_interval));
+	ast_sorcery_object_field_register(sorcery, "global", "max_initial_qualify_time",
+		__stringify(DEFAULT_MAX_INITIAL_QUALIFY_TIME),
+		OPT_UINT_T, 0, FLDSET(struct global_config, max_initial_qualify_time));
 
 	if (ast_sorcery_instance_observer_add(sorcery, &observer_callbacks_global)) {
 		return -1;

res/res_pjsip/pjsip_options.c

@@ -994,14 +994,20 @@ 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;
+	int max_time = ast_sip_get_max_initial_qualify_time();
 
 	contact->qualify_frequency = aor->qualify_frequency;
 	contact->qualify_timeout = aor->qualify_timeout;
 	contact->authenticate_qualify = aor->authenticate_qualify;
 
 	/* 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());
+	if (max_time && max_time < contact->qualify_frequency) {
+		initial_interval = max_time;
+	} else {
+		initial_interval = contact->qualify_frequency;
+	}
+
+	initial_interval = (int)((initial_interval * 1000) * ast_random_double());
 
 	if (contact->qualify_frequency) {
 		schedule_qualify(contact, initial_interval);