aggregator: reduce splay to just a bunch of seconds

When large expiry windows are used, using a splay of up to a window is
just overkill.  We just want to avoid emptying all buckets at once, but
in the end, a little splay here should be enough.  If we really need to
stretch it out over the entire expiry windows, it means we're at max
capacity, and any random mishap, may go over the limit.

Closes: #435
Signed-off-by: Fabian Groffen <grobian@gentoo.org>

aggregator.c

@@ -261,10 +261,13 @@ aggregator_putmetric(
 				 * requested in issue #72.
 				 * For consistency with other tools/old carbon-aggregator
 				 * align the buckets to interval boundaries such that it is
-				 * predictable what intervals will be taken, issue #104. */
+				 * predictable what intervals will be taken, issue #104.
+				 * Reduce maximum splay to a couple of seconds at most,
+				 * issue #435. */
 				time(&now);
 				now = ((now - s->expire) / s->interval) * s->interval;
-				invocation->expire = s->expire + (rand() % s->interval);
+				invocation->expire = s->expire +
+					(rand() % s->interval < 10 ? s->interval : 10);
 
 				/* allocate enough buckets to hold the past + future */
 				invocation->buckets =