Increase timeout in the rndc deadlock test

The timeout originally picked for "rndc status" invocations (2 seconds)
in the test attempting to reproduce a deadlock caused by running
multiple "rndc addzone", "rndc modzone", and "rndc delzone" commands
concurrently causes intermittent failures of the "addzone" system test
in GitLab CI.  Increase the timeout to 10 seconds to make such failures
less probable.  Adjust code comments accordingly.

diff --git a/bin/tests/system/addzone/tests_rndc_deadlock.py b/bin/tests/system/addzone/tests_rndc_deadlock.py
index 4e1e1090ba9784a2a1e3329f507335647a9d9f9f..43318d38bb0e5492398e919afdfe64a49eace121 100755 (executable)
--- a/bin/tests/system/addzone/tests_rndc_deadlock.py
+++ b/bin/tests/system/addzone/tests_rndc_deadlock.py
@@ -17,7 +17,7 @@ import time
 
 def run_rndc(server, rndc_command):
     '''
-    Send the specified 'rndc_command' to 'server' with a timeout of 2 seconds
+    Send the specified 'rndc_command' to 'server' with a timeout of 10 seconds
     '''
     rndc = os.getenv('RNDC')
     port = os.getenv('CONTROLPORT')
@@ -25,7 +25,7 @@ def run_rndc(server, rndc_command):
     cmdline = [rndc, '-c', '../common/rndc.conf', '-p', port, '-s', server]
     cmdline.extend(rndc_command)
 
-    subprocess.check_output(cmdline, stderr=subprocess.STDOUT, timeout=2)
+    subprocess.check_output(cmdline, stderr=subprocess.STDOUT, timeout=10)
 
 
 def rndc_loop(test_state, domain):
@@ -73,8 +73,9 @@ def test_rndc_deadlock():
             domain = 'example%d' % i
             executor.submit(rndc_loop, test_state, domain)
 
-        # Run "rndc status" in 1-second intervals for a maximum of 10 seconds.
-        # If any "rndc status" command fails, the loop will be interrupted.
+        # Run "rndc status" 10 times, with 1-second pauses between attempts.
+        # Each "rndc status" invocation has a timeout of 10 seconds.  If any of
+        # them fails, the loop will be interrupted.
         server_is_responsive = True
         attempts = 10
         while server_is_responsive and attempts > 0: