Merge pull request #23791 from ericgribkoff/unconditional_wait_for_propagation
Deflake fail_on_failed_rpc xDS test cases
diff --git a/tools/run_tests/run_xds_tests.py b/tools/run_tests/run_xds_tests.py
index 6908067..95241b5 100755
--- a/tools/run_tests/run_xds_tests.py
+++ b/tools/run_tests/run_xds_tests.py
@@ -1718,6 +1718,21 @@
metadata_to_send = '--metadata=""'
if test_case in _TESTS_TO_FAIL_ON_RPC_FAILURE:
+ # TODO(ericgribkoff) Unconditional wait is recommended by TD
+ # team when reusing backend resources after config changes
+ # between test cases, as we are doing here. This should address
+ # flakiness issues with these tests; other attempts to deflake
+ # (such as waiting for the first successful RPC before failing
+ # on any subsequent failures) were insufficient because, due to
+ # propagation delays, we may initially see an RPC succeed to the
+ # expected backends but due to a stale configuration: e.g., test
+ # A (1) routes traffic to MIG A, then (2) switches to MIG B,
+ # then (3) back to MIG A. Test B begins running and sees RPCs
+ # going to MIG A, as expected. However, due to propagation
+ # delays, Test B is actually seeing the stale config from step
+ # (1), and then fails when it gets update (2) unexpectedly
+ # switching to MIG B.
+ time.sleep(200)
fail_on_failed_rpc = '--fail_on_failed_rpc=true'
else:
fail_on_failed_rpc = '--fail_on_failed_rpc=false'
