Merge "Fix flow sampling threshold value from overflowing." into R3.0

src/vnsw/agent/vrouter/flow_stats/flow_export_info.cc

@@ -3,25 +3,22 @@
 
 FlowExportInfo::FlowExportInfo() :
     flow_(), setup_time_(0), teardown_time_(0), last_modified_time_(0),
-    bytes_(0), packets_(0), prev_diff_bytes_(0), prev_diff_packets_(0),
-    underlay_source_port_(0), changed_(false),
+    bytes_(0), packets_(0), underlay_source_port_(0), changed_(false),
     tcp_flags_(0), delete_enqueue_time_(0), evict_enqueue_time_(0),
     exported_atleast_once_(false) {
 }
 
 FlowExportInfo::FlowExportInfo(const FlowEntryPtr &fe) :
     flow_(fe), setup_time_(0), teardown_time_(0), last_modified_time_(0),
-    bytes_(0), packets_(0), prev_diff_bytes_(0), prev_diff_packets_(0),
-    underlay_source_port_(0), changed_(true),
+    bytes_(0), packets_(0), underlay_source_port_(0), changed_(true),
     tcp_flags_(0), delete_enqueue_time_(0), evict_enqueue_time_(0),
     exported_atleast_once_(false) {
 }
 
 FlowExportInfo::FlowExportInfo(const FlowEntryPtr &fe, uint64_t setup_time) :
     flow_(fe), setup_time_(setup_time),
     teardown_time_(0), last_modified_time_(setup_time),
-    bytes_(0), packets_(0), prev_diff_bytes_(0), prev_diff_packets_(0),
-    underlay_source_port_(0), changed_(true),
+    bytes_(0), packets_(0), underlay_source_port_(0), changed_(true),
     tcp_flags_(0), delete_enqueue_time_(0), evict_enqueue_time_(0),
     exported_atleast_once_(false) {
 }

src/vnsw/agent/vrouter/flow_stats/flow_export_info.h

@@ -27,10 +27,6 @@ class FlowExportInfo {
     void set_bytes(uint64_t value) { bytes_ = value; }
     uint64_t packets() const { return packets_; }
     void set_packets(uint64_t value) { packets_ = value; }
-    uint64_t prev_diff_bytes() const { return prev_diff_bytes_; }
-    void set_prev_diff_bytes(uint64_t value) { prev_diff_bytes_ = value; }
-    uint64_t prev_diff_packets() const { return prev_diff_packets_; }
-    void set_prev_diff_packets(uint64_t value) { prev_diff_packets_ = value; }
     uint16_t underlay_source_port() const { return underlay_source_port_; }
     void set_underlay_source_port(uint16_t port) {
         underlay_source_port_ = port;
@@ -61,12 +57,6 @@ class FlowExportInfo {
     uint64_t last_modified_time_; //used for aging
     uint64_t bytes_;
     uint64_t packets_;
-    /* When flow samples are dropped the diff stats for that sample is
-     * accumulated in the following fields. This used to compute aggregate diff
-     * when the flow is being sent again. On successful send the following
-     * fields are reset */
-    uint64_t prev_diff_bytes_;
-    uint64_t prev_diff_packets_;
     //IP address of the src vrouter for egress flows and dst vrouter for
     //ingress flows. Used only during flow-export
     //Underlay IP protocol type. Used only during flow-export

src/vnsw/agent/vrouter/flow_stats/flow_stats.sandesh

@@ -177,6 +177,6 @@ request sandesh DeleteAgingConfig {
 traceobject sandesh FlowExportStatsTrace {
     1: u32 export_rate;
     2: u32 export_rate_without_sampling;
-    3: u32 old_threshold;
-    4: u32 new_threshold;
+    3: u64 old_threshold;
+    4: u64 new_threshold;
 }

src/vnsw/agent/vrouter/flow_stats/flow_stats_collector.cc

@@ -769,11 +769,6 @@ void FlowStatsCollector::ExportFlow(FlowExportInfo *info,
         return;
     }
 
-    /* Compute diff stats by adding the previous diff stats of sample that
-     * was dropped */
-    diff_bytes += info->prev_diff_bytes();
-    diff_pkts += info->prev_diff_packets();
-
     /* Subject a flow to sampling algorithm only when all of below is met:-
      * a. if Log is not configured as action for flow
      * b. actual flow-export-rate is >= 80% of configured flow-export-rate. This
@@ -801,8 +796,6 @@ void FlowStatsCollector::ExportFlow(FlowExportInfo *info,
             /* Do not export the flow, if the random number generated is more
              * than the diff_bytes */
             flow_stats_manager_->flow_export_sampling_drops_++;
-            info->set_prev_diff_bytes(diff_bytes);
-            info->set_prev_diff_packets(diff_pkts);
             /* The second part of the if condition below is not required but
              * added for better readability. It is not required because
              * exported_atleast_once() will always be false if teardown time is
@@ -822,10 +815,6 @@ void FlowStatsCollector::ExportFlow(FlowExportInfo *info,
             diff_pkts = diff_pkts/probability;
         }
     }
-    /* Reset diff stats since flow will be exported now */
-    info->set_prev_diff_bytes(0);
-    info->set_prev_diff_packets(0);
-
     /* Mark the flow as exported */
     info->set_exported_atleast_once(true);
 
@@ -964,7 +953,7 @@ bool FlowStatsManager::UpdateFlowThreshold() {
         (cfg_rate == prev_cfg_flow_export_rate_)) {
         return true;
     }
-    uint32_t cur_t = threshold(), new_t = 0;
+    uint64_t cur_t = threshold(), new_t = 0;
     // Update sampling threshold based on flow_export_rate_
     if (flow_export_rate_ < ((double)cfg_rate) * 0.8) {
         /* There are two reasons why we can be here.
@@ -975,20 +964,20 @@ bool FlowStatsManager::UpdateFlowThreshold() {
          * Threshold should be updated here depending on which of the above two
          * situations we are in. */
         if (!flows_sampled_atleast_once_) {
-            UpdateThreshold(kDefaultFlowSamplingThreshold);
+            UpdateThreshold(kDefaultFlowSamplingThreshold, false);
         } else {
             if (flow_export_rate_ < ((double)cfg_rate) * 0.5) {
-                UpdateThreshold((threshold_ / 4));
+                UpdateThreshold((threshold_ / 4), false);
             } else {
-                UpdateThreshold((threshold_ / 2));
+                UpdateThreshold((threshold_ / 2), false);
             }
         }
     } else if (flow_export_rate_ > (cfg_rate * 3)) {
-        UpdateThreshold((threshold_ * 4));
+        UpdateThreshold((threshold_ * 4), true);
     } else if (flow_export_rate_ > (cfg_rate * 2)) {
-        UpdateThreshold((threshold_ * 3));
+        UpdateThreshold((threshold_ * 3), true);
     } else if (flow_export_rate_ > ((double)cfg_rate) * 1.25) {
-        UpdateThreshold((threshold_ * 2));
+        UpdateThreshold((threshold_ * 2), true);
     }
     prev_cfg_flow_export_rate_ = cfg_rate;
     new_t = threshold();
@@ -997,7 +986,7 @@ bool FlowStatsManager::UpdateFlowThreshold() {
     return true;
 }
 
-uint32_t FlowStatsCollector::threshold() const {
+uint64_t FlowStatsCollector::threshold() const {
     return flow_stats_manager_->threshold();
 }
 

src/vnsw/agent/vrouter/flow_stats/flow_stats_collector.h

@@ -103,7 +103,7 @@ class FlowStatsCollector : public StatsCollector {
     void set_flow_tcp_syn_age_time(uint64_t interval) {
         flow_tcp_syn_age_time_ = interval;
     }
-    uint32_t threshold()  const;
+    uint64_t threshold()  const;
     boost::uuids::uuid rand_gen();
     bool Run();
     bool RunAgeingTask();

src/vnsw/agent/vrouter/flow_stats/flow_stats_manager.cc

@@ -34,7 +34,11 @@ SandeshTraceBufferPtr FlowExportStatsTraceBuf(SandeshTraceBufferCreate(
     "FlowExportStats", 3000));
 const uint8_t FlowStatsManager::kCatchAllProto;
 
-void FlowStatsManager::UpdateThreshold(uint32_t new_value) {
+void FlowStatsManager::UpdateThreshold(uint64_t new_value, bool check_oflow) {
+    if (check_oflow && new_value < threshold_) {
+        /* Retain the same value for threshold if it results in overflow */
+        return;
+    }
     if (new_value < kMinFlowSamplingThreshold) {
         threshold_ = kMinFlowSamplingThreshold;
     } else {

src/vnsw/agent/vrouter/flow_stats/flow_stats_manager.h

@@ -149,7 +149,7 @@ class FlowStatsManager {
         return flow_export_drops_;
     }
 
-    uint32_t threshold() const { return threshold_;}
+    uint64_t threshold() const { return threshold_;}
     bool delete_short_flow() const {
         return delete_short_flow_;
     }
@@ -173,15 +173,15 @@ class FlowStatsManager {
     friend class FlowStatsCollectorReq;
     friend class FlowStatsCollector;
     bool UpdateFlowThreshold(void);
-    void UpdateThreshold(uint32_t new_value);
+    void UpdateThreshold(uint64_t new_value, bool check_oflow);
     Agent *agent_;
     WorkQueue<boost::shared_ptr<FlowStatsCollectorReq> > request_queue_;
     FlowAgingTableMap flow_aging_table_map_;
     FlowAgingTablePtr default_flow_stats_collector_;
     tbb::atomic<uint32_t> flow_export_count_;
     uint64_t prev_flow_export_rate_compute_time_;
     uint32_t flow_export_rate_;
-    uint32_t threshold_;
+    uint64_t threshold_;
     tbb::atomic<uint64_t> flow_export_disable_drops_;
     tbb::atomic<uint64_t> flow_export_sampling_drops_;
     tbb::atomic<uint32_t> flow_export_without_sampling_;