[MEDIUM] only consider slow checks when looking for the common interval
When one server in one backend has a very low check interval, it imposes
its value as the minimal interval, causing all other servers to start
their checks close to each other, thus partially voiding the benefits of
the spread checks.
The solution consists in ignoring intervals lower than a given value
(SRV_CHK_INTER_THRES = 1000 ms) when computing the minimal interval,
and then assigning them a start date relative to their own interval
and not the global one.
With this change, the checks distribution clearly looks better.
diff --git a/include/common/defaults.h b/include/common/defaults.h
index 198288f..2c757d2 100644
--- a/include/common/defaults.h
+++ b/include/common/defaults.h
@@ -115,4 +115,14 @@
#define DEFAULT_MAXCONN SYSTEM_MAXCONN
#endif
+/* Minimum check interval for spread health checks. Servers with intervals
+ * greater than or equal to this value will have their checks spread apart
+ * and will be considered when searching the minimal interval.
+ * Others will be ignored for the minimal interval and will have their checks
+ * scheduled on a different basis.
+ */
+#ifndef SRV_CHK_INTER_THRES
+#define SRV_CHK_INTER_THRES 1000
+#endif
+
#endif /* _COMMON_DEFAULTS_H */