Special case NaN double values for GAUGE metrics.

JSON does not support NaN values and the Stackdriver POST requests are malformed becuase of cutting the request in the middle.
This change special-cases NaN values and prevents them from being written to the backend.

diff --git a/src/utils/format_stackdriver/format_stackdriver.c b/src/utils/format_stackdriver/format_stackdriver.c
index ccb1c77deed6920c2adbc291008286d6d6e32154..3c45aacb42192dd2e0522178168b0950691f807c 100644 (file)
--- a/src/utils/format_stackdriver/format_stackdriver.c
+++ b/src/utils/format_stackdriver/format_stackdriver.c
@@ -30,6 +30,7 @@
 #include "utils_cache.h"
 #include "utils_time.h"
 
+#include <math.h>
 #include <yajl/yajl_gen.h>
 #include <yajl/yajl_parse.h>
 #if HAVE_YAJL_YAJL_VERSION_H
@@ -411,6 +412,12 @@ static int format_time_series(yajl_gen gen, data_set_t const *ds,
     /* for cumulative metrics, the interval must not be zero. */
     return EAGAIN;
   }
+  if (ds_type == DS_TYPE_GAUGE) {
+    double d = (double)vl->values[ds_index].gauge;
+    if (isnan(d) || isinf(d)) {
+      return EAGAIN;
+    }
+  }
 
   yajl_gen_map_open(gen);
 
@@ -564,7 +571,7 @@ int sd_output_add(sd_output_t *out, data_set_t const *ds,
   for (size_t i = 0; i < ds->ds_num; i++) {
     int status = format_time_series(out->gen, ds, vl, i, out->res);
     if (status == EAGAIN) {
-      /* first instance of a cumulative metric */
+      /* first instance of a cumulative metric or NaN value */
       continue;
     }
     if (status != 0) {