Add comment about "avgtime" usage

diff --git a/src/ceph.c b/src/ceph.c
index 488680a..bfd95e8 100644 (file)
--- a/src/ceph.c
+++ b/src/ceph.c
@@ -518,6 +518,12 @@ static int parse_keys(char *buffer, size_t buffer_size, const char *key_str) {
   size_t tmp_size = sizeof(tmp);
   const char *cut_suffixes[] = {".type", ".avgcount", ".sum", ".avgtime"};
 
+  /* The "avgtime" metric reports ("sum" / "avgcount"), i.e. the average time
+   * per request since the start of the Ceph daemon. Report this only when the
+   * user has configured "long running average". Otherwise, use the rate of
+   * "sum" and "avgcount" to calculate the current latency.
+   */
+
   if (buffer == NULL || buffer_size == 0 || key_str == NULL ||
       strlen(key_str) == 0)
     return EINVAL;