validation_pool: reduce the throttling backoff lookback threshold
If we start failing a lot of runs in a row, the exponential backoff of
CLs picked up gets so agressive as to make the CQ basically useless.
Reduce the history lookback so that this is less aggressive.
BUG=None
TEST=None
Change-Id: I4de48194630e4893969bff3ebc18583e31dd3e0e
Reviewed-on: https://chromium-review.googlesource.com/446624
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Trybot-Ready: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Ningning Xia <nxia@chromium.org>
diff --git a/cbuildbot/validation_pool.py b/cbuildbot/validation_pool.py
index ee4f46d..198439b 100644
--- a/cbuildbot/validation_pool.py
+++ b/cbuildbot/validation_pool.py
@@ -196,9 +196,9 @@
REJECTION_GRACE_PERIOD = 30 * 60
# How many CQ runs to go back when making a decision about the CQ health.
- # Note this impacts the max exponential fallback (2^10=1024 max exponential
+ # Note this impacts the max exponential fallback (1.5^4 ~= 5 max exponential
# divisor)
- CQ_SEARCH_HISTORY = 10
+ CQ_SEARCH_HISTORY = 4
def __init__(self, overlays, build_root, build_number, builder_name,
