ToR Agent Performance - monitor request

Issue:
------
During initial response for monitor request, we end up
generating too many partial update for Physical port
entries causing lots of unneccessary processing on half
baked data. resulting in bad performance.

Fix:
----
Delay Creation of Physical Port entries, to be done
after processing of initial response to monitor request
is complete. This avoids processing triggers for partial
updates on physical port entries. Once we unable physical
port creation it will create physical port and stale
entries for vlan port bindings with completed information.

Partial-Bug: #1456284
Change-Id: I03984ac9749cea6197feb1f8c43c87cdfe48833d
(cherry picked from commit 06b82cb)

src/vnsw/agent/ovs_tor_agent/ovsdb_client/ovsdb_client_idl.cc

@@ -259,6 +259,11 @@ bool OvsdbClientIdl::ProcessMessage(OvsdbMsg *msg) {
             // after processing the response to monitor request
             // connect to oper db.
             if (connect_oper_db) {
+                // enable physical port updation, before connect to
+                // Oper DB, to allow creation of stale entries for
+                // vlan port bindings.
+                physical_switch_table_->StartUpdatePorts();
+
                 ConnectOperDB();
             }
         }

src/vnsw/agent/ovs_tor_agent/ovsdb_client/physical_switch_ovsdb.cc

@@ -78,7 +78,7 @@ void PhysicalSwitchEntry::SendTrace(Trace event) const {
 }
 
 PhysicalSwitchTable::PhysicalSwitchTable(OvsdbClientIdl *idl) :
-    OvsdbObject(idl) {
+    OvsdbObject(idl), update_ports_(false) {
     idl->Register(OvsdbClientIdl::OVSDB_PHYSICAL_SWITCH,
                   boost::bind(&PhysicalSwitchTable::Notify, this, _1, _2));
 }
@@ -91,18 +91,11 @@ void PhysicalSwitchTable::Notify(OvsdbClientIdl::Op op,
     PhysicalSwitchEntry key(this, ovsdb_wrapper_physical_switch_name(row));
     PhysicalSwitchEntry *entry =
         static_cast<PhysicalSwitchEntry *>(FindActiveEntry(&key));
-    PhysicalPortTable *p_table = client_idl()->physical_port_table();
     if (op == OvsdbClientIdl::OVSDB_DEL) {
         if (entry != NULL) {
             entry->SendTrace(PhysicalSwitchEntry::DEL);
-            PhysicalSwitchEntry::InterfaceList::iterator it =
-                entry->intf_list_.begin();
-            while (it != entry->intf_list_.end()) {
-                // trigger del notify for ovs idl row
-                p_table->DeletePortEntry(*it);
-                entry->intf_list_.erase(it);
-                it = entry->intf_list_.begin();
-            }
+            entry->ovs_entry_ = NULL;
+            UpdatePorts(entry);
             Delete(entry);
         }
     } else if (op == OvsdbClientIdl::OVSDB_ADD) {
@@ -111,26 +104,11 @@ void PhysicalSwitchTable::Notify(OvsdbClientIdl::Op op,
             entry->SendTrace(PhysicalSwitchEntry::ADD);
         }
         entry->set_tunnel_ip(ovsdb_wrapper_physical_switch_tunnel_ip(row));
-        std::size_t count = ovsdb_wrapper_physical_switch_ports_count(row);
-        struct ovsdb_idl_row *ports[count];
-        ovsdb_wrapper_physical_switch_ports(row, ports, count);
-        PhysicalSwitchEntry::InterfaceList old = entry->intf_list_;
-        std::size_t i = 0;
-        entry->intf_list_.clear();
-        while (i < count) {
-            entry->intf_list_.insert(ports[i]);
-            if (old.erase(ports[i]) == 0) {
-                // if entry was not present eariler trigger Add.
-                p_table->CreatePortEntry(ports[i], entry->name());
-            }
-            i++;
-        }
-        PhysicalSwitchEntry::InterfaceList::iterator it = old.begin();
-        while (it != old.end()) {
-            // trigger del notify for ovs idl row
-            p_table->DeletePortEntry(*it);
-            old.erase(it);
-            it = old.begin();
+        entry->ovs_entry_ = row;
+
+        // check if we need to skip ports updation
+        if (update_ports_) {
+            UpdatePorts(entry);
         }
     } else {
         assert(0);
@@ -144,6 +122,46 @@ KSyncEntry *PhysicalSwitchTable::Alloc(const KSyncEntry *key, uint32_t index) {
     return entry;
 }
 
+void PhysicalSwitchTable::StartUpdatePorts() {
+    if (update_ports_) {
+        return;
+    }
+    update_ports_ = true;
+    PhysicalSwitchEntry *entry = static_cast<PhysicalSwitchEntry *>(Next(NULL));
+    while (entry != NULL) {
+        // Trigger Update Ports to update pending physical port entries
+        UpdatePorts(entry);
+        entry = static_cast<PhysicalSwitchEntry *>(Next(entry));
+    }
+}
+
+void PhysicalSwitchTable::UpdatePorts(PhysicalSwitchEntry *entry) {
+    PhysicalPortTable *p_table = client_idl()->physical_port_table();
+    PhysicalSwitchEntry::InterfaceList old = entry->intf_list_;
+    entry->intf_list_.clear();
+    if (entry->ovs_entry_ != NULL) {
+        std::size_t count =
+            ovsdb_wrapper_physical_switch_ports_count(entry->ovs_entry_);
+        struct ovsdb_idl_row *ports[count];
+        ovsdb_wrapper_physical_switch_ports(entry->ovs_entry_, ports, count);
+        std::size_t i = 0;
+        while (i < count) {
+            entry->intf_list_.insert(ports[i]);
+            if (old.erase(ports[i]) == 0) {
+                // if entry was not present eariler trigger Add.
+                p_table->CreatePortEntry(ports[i], entry->name());
+            }
+            i++;
+        }
+    }
+    PhysicalSwitchEntry::InterfaceList::iterator it = old.begin();
+    while (it != old.end()) {
+        // trigger del notify for ovs idl row
+        p_table->DeletePortEntry(*it);
+        old.erase(it);
+        it = old.begin();
+    }
+}
 
 /////////////////////////////////////////////////////////////////////////////
 // Sandesh routines

src/vnsw/agent/ovs_tor_agent/ovsdb_client/physical_switch_ovsdb.h

@@ -9,14 +9,29 @@
 #include <ovsdb_object.h>
 
 namespace OVSDB {
+class PhysicalSwitchEntry;
+
 class PhysicalSwitchTable : public OvsdbObject {
 public:
     PhysicalSwitchTable(OvsdbClientIdl *idl);
     virtual ~PhysicalSwitchTable();
 
     void Notify(OvsdbClientIdl::Op, struct ovsdb_idl_row *);
     KSyncEntry *Alloc(const KSyncEntry *key, uint32_t index);
+
+    void StartUpdatePorts();
+
 private:
+    void UpdatePorts(PhysicalSwitchEntry *entry);
+
+    // By default update ports is set to false to avoid updation
+    // of physical port entries in ovsdb client context, which
+    // helps to ignore partial updates on physical ports from
+    // ovsdb library to avoid useless processing on half cooked
+    // information. once the initial monitor request processing
+    // is complete OvsdbClientIdl triggers StartUpdatePorts to
+    // update the pending ports and allow further ports updation
+    bool update_ports_;
     DISALLOW_COPY_AND_ASSIGN(PhysicalSwitchTable);
 };
 
@@ -40,10 +55,11 @@ class PhysicalSwitchEntry : public OvsdbEntry {
     bool IsLess(const KSyncEntry&) const;
     std::string ToString() const {return "Physical Switch";}
     KSyncEntry* UnresolvedReference();
+
 private:
+    friend class PhysicalSwitchTable;
     void SendTrace(Trace event) const;
 
-    friend class PhysicalSwitchTable;
     std::string name_;
     Ip4Address tunnel_ip_;
     InterfaceList intf_list_;