Use dpinger defaults for send_interval and time_period

Update parameters to reflect existing defaults and correct the loss resolution calculation when using subsecond send intervals.

Makefile

@@ -1,8 +1,8 @@
-#CC=gcc
-#WARNINGS=-Wall -Wextra -Wformat=2 -Wno-unused-result
+CC=gcc
+WARNINGS=-Wall -Wextra -Wformat=2 -Wno-unused-result
 
-CC=clang
-WARNINGS=-Weverything -Wno-padded -Wno-disabled-macro-expansion -Wno-reserved-id-macro
+#CC=clang
+#WARNINGS=-Weverything -Wno-unsafe-buffer-usage -Wno-cast-function-type-strict -Wno-padded -Wno-disabled-macro-expansion -Wno-reserved-id-macro
 
 CFLAGS=${WARNINGS} -pthread -g -O2
 

NOTES.md

@@ -4,10 +4,10 @@ In general, dpinger works a bit differently than other latency monitors. Rather
 
 When the alert check is made, or a report is generated, dpinger goes through the array and examines each echo request. If a reply has been received, it is used as part of the overall latency calculation. If a reply has not yet been received, the amount of time since the request is compared against the loss interval. If it is greater than the loss interval, the request/reply is counted as lost in the current report. However the concept of the request/reply being lost is not a permanent decision. In subsequent reports, if a the missing reply has been received, its latency will be used instead of being counted as lost.
 
-It's important to keep in mind that latency and loss are reported as averages across the entire request set. The default time period for dpinger is 30 seconds, with an echo request being sent every 250 milliseconds. This means that the latency and loss will be reported as averages across 115-120 samples. The alert check runs every second by default. So each time, the 4 oldest entries in the set have been replaced by the 4 newest ones.
+It's important to keep in mind that latency and loss are reported as averages across the entire request set. The default time period for dpinger is 60 seconds, with an echo request being sent every 500 milliseconds. This means that the latency and loss will be reported as averages across 116-120 samples. The alert check runs every second by default. So each time, the 4 oldest entries in the set have been replaced by the 4 newest ones.
 
 Note that if you want accurate loss reporting, it is important that the number of samples be sufficient. In order to achieve 1% loss resolution, you have need more than 100 samples in the set. The calculation for loss resolution is:
 
-  100 * send_interval / (time_period - loss_interval)
+  100 / ((time_period - loss_interval) / send_interval)
 
 The default settings for dpinger report loss with an accuracy of 0.87%.

dpinger.c

@@ -606,7 +606,7 @@ alert_thread(
     sleeptime.tv_nsec = (alert_interval_msec % 1000) * 1000000;
 
     // Set number of alarm hold periods
-    alarm_hold_periods = (alarm_hold_msec + alert_interval_msec - 1) / alert_interval_msec;
+    alarm_hold_periods = (unsigned int) ((alarm_hold_msec + alert_interval_msec - 1) / alert_interval_msec);
 
     while (1)
     {
@@ -878,8 +878,8 @@ usage(void)
     fprintf(stderr, "    the output format is \"latency_avg latency_stddev loss_pct\"\n");
     fprintf(stderr, "    latency values are output in microseconds\n");
     fprintf(stderr, "    loss percentage is reported in whole numbers of 0-100\n");
-    fprintf(stderr, "    resolution of loss calculation is: 100 * send_interval / (time_period - loss_interval)\n\n");
-    fprintf(stderr, "    the alert_cmd is invoked as \"alert_cmd dest_addr alarm_flag latency_avg loss_avg\"\n");
+    fprintf(stderr, "    resolution of loss calculation is: 100 / ((time_period - loss_interval) / send_interval)\n\n");
+    fprintf(stderr, "    the alert_cmd is invoked as \"alert_cmd dest_addr alarm_flag latency_avg latency_stddev loss_pct\"\n");
     fprintf(stderr, "    alarm_flag is set to 1 if either latency or loss is in alarm state\n");
     fprintf(stderr, "    alarm_flag will return to 0 when both have have cleared alarm state\n");
     fprintf(stderr, "    alarm hold time begins when the source of the alarm retruns to normal\n\n");

influx/dpinger_influx_logger

@@ -41,7 +41,7 @@ influx_pass = os.getenv('INFLUX_PASS')
 # Set up dpinger command
 cmd = [dpinger_path, "-f"]
 cmd.extend(sys.argv)
-cmd.extend(["-s", "1s", "-t", "60s", "-r", "10s", target])
+cmd.extend(["-r", "10s", target])
 
 # Set up formats
 url = '{0}/write?db={1}'.format(influx_url, influx_db)