Option to save latency measurements to a file.

LogHistogramSampler.h

@@ -8,6 +8,7 @@
 
 #include <vector>
 
+#include "mutilate.h"
 #include "Operation.h"
 
 #define _POW 1.1
@@ -16,6 +17,8 @@ class LogHistogramSampler {
 public:
   std::vector<uint64_t> bins;
 
+  std::vector<Operation> samples;
+
   double sum;
   double sum_sq;
 
@@ -28,6 +31,7 @@ public:
 
   void sample(const Operation &op) {
     sample(op.time());
+    if (args.save_given) samples.push_back(op);
   }
 
   void sample(double s) {
@@ -97,6 +101,8 @@ public:
 
     sum += h.sum;
     sum_sq += h.sum_sq;
+
+    for (auto i: h.samples) samples.push_back(i);
   }
 };
 

cmdline.ggo

@@ -38,7 +38,6 @@ option "depth" d "Maximum depth to pipeline requests." int default="1"
 option "roundrobin" R "Assign threads to servers in round-robin fashion.  \
 By default, each thread connects to every server."
 
-option "cork" - "Minimum timer interval, in usecs. (experimental)" int
 option "iadist" i "Inter-arrival distribution (distribution).  Note: \
 The distribution will automatically be adjusted to match the QPS given \
 by --qps." string default="exponential"
@@ -55,6 +54,7 @@ option "no_nodelay" - "Don't use TCP_NODELAY."
 
 option "warmup" w "Warmup time before starting measurement." int
 option "wait" W "Time to wait after startup to start measurement." int
+option "save" - "Record latency samples to given file." string
 
 option "search" - "Search for the QPS where N-order statistic < Xus.  \
 (i.e. --search 95:1000 means find the QPS where 95% of requests are \

mutilate.cc

@@ -610,6 +610,18 @@ int main(int argc, char **argv) {
     printf("TX %10" PRIu64 " bytes : %6.1f MB/s\n",
            stats.tx_bytes,
            (double) stats.tx_bytes / 1024 / 1024 / (stats.stop - stats.start));
+
+    if (args.save_given) {
+      printf("Saving latency samples to %s.\n", args.save_arg);
+
+      FILE *file;
+      if ((file = fopen(args.save_arg, "w")) == NULL)
+        DIE("--save: failed to open %s: %s", args.save_arg, strerror(errno));
+
+      for (auto i: stats.get_sampler.samples) {
+        fprintf(file, "%f %f\n", i.start_time - boot_time, i.time());
+      }
+    }
   }
 
   //  if (args.threads_arg > 1) 
@@ -963,6 +975,9 @@ void do_mutilate(const vector<string>& servers, options_t& options,
   }
 #endif
 
+  if (master && !args.scan_given && !args.search_given)
+    V("started at %f", get_time());
+
   start = get_time();
   for (Connection *conn: connections) {
     conn->start_time = start;
@@ -992,6 +1007,9 @@ void do_mutilate(const vector<string>& servers, options_t& options,
     else break;
   }
 
+  if (master && !args.scan_given && !args.search_given)
+    V("stopped at %f  options.time = %d", get_time(), options.time);
+
   // Tear-down and accumulate stats.
   for (Connection *conn: connections) {
     stats.accumulate(conn->stats);