/* OVSDB IDL used to obtain configuration. */
static struct ovsdb_idl *idl;
+/* We want to complete daemonization, fully detaching from our parent process,
+ * only after we have completed our initial configuration, committed our state
+ * to the database, and received confirmation back from the database server
+ * that it applied the commit. This allows our parent process to know that,
+ * post-detach, ephemeral fields such as datapath-id and ofport are very likely
+ * to have already been filled in. (It is only "very likely" rather than
+ * certain because there is always a slim possibility that the transaction will
+ * fail or that some other client has added new bridges, ports, etc. while
+ * ovs-vswitchd was configuring using an old configuration.)
+ *
+ * We only need to do this once for our initial configuration at startup, so
+ * 'initial_config_done' tracks whether we've already done it. While we are
+ * waiting for a response to our commit, 'daemonize_txn' tracks the transaction
+ * itself and is otherwise NULL. */
+static bool initial_config_done;
+static struct ovsdb_idl_txn *daemonize_txn;
+
/* Most recently processed IDL sequence number. */
static unsigned int idl_seqno;
}
free(managers);
- if (done) {
- /* ovs-vswitchd has completed initialization, so allow the process that
- * forked us to exit successfully. */
- daemonize_complete();
- reconfiguring = false;
-
- VLOG_INFO_ONCE("%s (Open vSwitch) %s", program_name, VERSION);
- }
-
return done;
}
ofproto_free_ofproto_controller_info(&info);
}
+\f
+/* "Instant" stats.
+ *
+ * Some information in the database must be kept as up-to-date as possible to
+ * allow controllers to respond rapidly to network outages. We call these
+ * statistics "instant" stats.
+ *
+ * We wish to update these statistics every INSTANT_INTERVAL_MSEC milliseconds,
+ * assuming that they've changed. The only means we have to determine whether
+ * they have changed are:
+ *
+ * - Try to commit changes to the database. If nothing changed, then
+ * ovsdb_idl_txn_commit() returns TXN_UNCHANGED, otherwise some other
+ * value.
+ *
+ * - instant_stats_run() is called late in the run loop, after anything that
+ * might change any of the instant stats.
+ *
+ * We use these two facts together to avoid waking the process up every
+ * INSTANT_INTERVAL_MSEC whether there is any change or not.
+ */
+
+/* Minimum interval between writing updates to the instant stats to the
+ * database. */
+#define INSTANT_INTERVAL_MSEC 100
+
+/* Current instant stats database transaction, NULL if there is no ongoing
+ * transaction. */
+static struct ovsdb_idl_txn *instant_txn;
+
+/* Next time (in msec on monotonic clock) at which we will update the instant
+ * stats. */
+static long long int instant_next_txn = LLONG_MIN;
+
+/* True if the run loop has run since we last saw that the instant stats were
+ * unchanged, that is, this is true if we need to wake up at 'instant_next_txn'
+ * to refresh the instant stats. */
+static bool instant_stats_could_have_changed;
static void
-refresh_instant_stats(void)
+instant_stats_run(void)
{
- static struct ovsdb_idl_txn *txn = NULL;
+ enum ovsdb_idl_txn_status status;
+
+ instant_stats_could_have_changed = true;
- if (!txn) {
+ if (!instant_txn) {
struct bridge *br;
- txn = ovsdb_idl_txn_create(idl);
+ if (time_msec() < instant_next_txn) {
+ return;
+ }
+ instant_next_txn = time_msec() + INSTANT_INTERVAL_MSEC;
+ instant_txn = ovsdb_idl_txn_create(idl);
HMAP_FOR_EACH (br, node, &all_bridges) {
struct iface *iface;
struct port *port;
}
}
- if (ovsdb_idl_txn_commit(txn) != TXN_INCOMPLETE) {
- ovsdb_idl_txn_destroy(txn);
- txn = NULL;
+ status = ovsdb_idl_txn_commit(instant_txn);
+ if (status != TXN_INCOMPLETE) {
+ ovsdb_idl_txn_destroy(instant_txn);
+ instant_txn = NULL;
+ }
+ if (status == TXN_UNCHANGED) {
+ instant_stats_could_have_changed = false;
}
}
+static void
+instant_stats_wait(void)
+{
+ if (instant_txn) {
+ ovsdb_idl_txn_wait(instant_txn);
+ } else if (instant_stats_could_have_changed) {
+ poll_timer_wait_until(instant_next_txn);
+ }
+}
+\f
/* Performs periodic activity required by bridges that needs to be done with
* the least possible latency.
*
HMAP_FOR_EACH_SAFE (br, next_br, node, &all_bridges) {
bridge_destroy(br);
}
+ /* Since we will not be running system_stats_run() in this process
+ * with the current situation of multiple ovs-vswitchd daemons,
+ * disable system stats collection. */
+ system_stats_enable(false);
return;
} else if (!ovsdb_idl_has_lock(idl)) {
return;
}
if (reconfiguring) {
- if (cfg) {
- if (!reconf_txn) {
- reconf_txn = ovsdb_idl_txn_create(idl);
- }
- if (bridge_reconfigure_continue(cfg)) {
+ if (!reconf_txn) {
+ reconf_txn = ovsdb_idl_txn_create(idl);
+ }
+
+ if (bridge_reconfigure_continue(cfg ? cfg : &null_cfg)) {
+ reconfiguring = false;
+
+ if (cfg) {
ovsrec_open_vswitch_set_cur_cfg(cfg, cfg->next_cfg);
}
- } else {
- bridge_reconfigure_continue(&null_cfg);
+
+ /* If we are completing our initial configuration for this run
+ * of ovs-vswitchd, then keep the transaction around to monitor
+ * it for completion. */
+ if (!initial_config_done) {
+ initial_config_done = true;
+ daemonize_txn = reconf_txn;
+ reconf_txn = NULL;
+ }
}
}
reconf_txn = NULL;
}
+ if (daemonize_txn) {
+ enum ovsdb_idl_txn_status status = ovsdb_idl_txn_commit(daemonize_txn);
+ if (status != TXN_INCOMPLETE) {
+ ovsdb_idl_txn_destroy(daemonize_txn);
+ daemonize_txn = NULL;
+
+ /* ovs-vswitchd has completed initialization, so allow the
+ * process that forked us to exit successfully. */
+ daemonize_complete();
+
+ VLOG_INFO_ONCE("%s (Open vSwitch) %s", program_name, VERSION);
+ }
+ }
+
/* Refresh interface and mirror stats if necessary. */
if (time_msec() >= iface_stats_timer) {
if (cfg) {
}
run_system_stats();
- refresh_instant_stats();
+ instant_stats_run();
}
void
const char *type;
ovsdb_idl_wait(idl);
+ if (daemonize_txn) {
+ ovsdb_idl_txn_wait(daemonize_txn);
+ }
if (reconfiguring) {
poll_immediate_wake();
}
system_stats_wait();
+ instant_stats_wait();
}
/* Adds some memory usage statistics for bridges into 'usage', for use with
projects / cascardo / ovs.git / blobdiff