[Lag 2] Allow lacp timing tests to retry limited times until succeeded

ansible/roles/test/files/acstests/lag_test.py

@@ -83,6 +83,7 @@ class LacpTimingTest(BaseTest,RouterUtility):
     @ param: timeout        -   time to expect the LACP packet.
     @ param: packet_timing         -   time between two packets.
     @ param: ether_type     -   Ethernet type of expected packet.
+    @ param: interval_count -   Number of intervals to collect.
     '''
 
     def __init__(self):
@@ -95,13 +96,46 @@ def setUp(self):
         '''
         self.dataplane = ptf.dataplane_instance
 
+    def getMedianInterval(self, masked_exp_pkt):
+        intervals = []
+        # Verify two LACP packets.
+        (rcv_device, rcv_port, rcv_pkt, last_pkt_time) = self.dataplane.poll(port_number=self.exp_iface, timeout=self.timeout, exp_pkt=masked_exp_pkt)
+        last_pkt_time = round(float(last_pkt_time), 2)
+
+        for i in range(0, self.interval_count):
+            (rcv_device, rcv_port, rcv_pkt, curr_pkt_time) = self.dataplane.poll(port_number=self.exp_iface, timeout=self.timeout, exp_pkt=masked_exp_pkt)
+
+            # Check the packet received.
+            self.assertTrue(rcv_pkt != None, "Failed to receive LACP packet\n")
+
+            # Get current packet timing
+            curr_pkt_time = round(float(curr_pkt_time), 2)
+
+            interval   = curr_pkt_time - last_pkt_time
+            intervals += [ interval ]
+
+            last_pkt_time = curr_pkt_time
+
+        # Get the median
+        intervals.sort()
+        current_pkt_timing = intervals[self.interval_count / 2]
+        return current_pkt_timing
+
+
     def runTest(self):
 
         # Get test parameters
         self.exp_iface = self.test_params['exp_iface']
         self.timeout = self.test_params['timeout']
         self.packet_timing = self.test_params['packet_timing']
         self.ether_type = self.test_params['ether_type']
+        self.interval_count = int(self.test_params['interval_count'])
+        if self.interval_count < 1:
+            self.interval_count = 3
+
+        # Make sure the interval count is odd, so that we only look at one median interval
+        if self.interval_count % 2 == 0:
+            self.interval_count += 1
 
         # Generate a packet.
         exp_pkt = simple_eth_packet(eth_type=self.ether_type)
@@ -116,17 +150,6 @@ def runTest(self):
         # Flush packets in dataplane
         self.dataplane.flush()
 
-        # Verify two LACP packets.
-        (rcv_device, rcv_port, rcv_pkt, first_pkt_time) = self.dataplane.poll(port_number=self.exp_iface, timeout=self.timeout, exp_pkt=masked_exp_pkt)
-        (rcv_device, rcv_port, rcv_pkt, last_pkt_time) = self.dataplane.poll(port_number=self.exp_iface, timeout=self.timeout, exp_pkt=masked_exp_pkt)
-
-        # Check the packet received.
-        self.assertTrue(rcv_pkt != None, "Failed to receive LACP packet\n")
-
-        # Get current packet timing
-        first_pkt_time = round(float(first_pkt_time), 2)
-        last_pkt_time = round(float(last_pkt_time), 2)
-        current_pkt_timing = last_pkt_time - first_pkt_time
-
         # Check that packet timing matches the expected value.
-        self.assertTrue(abs(current_pkt_timing - float(self.packet_timing)) < 0.1, "Bad packet timing: %.2f seconds while expected timing is %d seconds from %s" % (current_pkt_timing, self.packet_timing, self.exp_iface))
+        current_pkt_timing = self.getMedianInterval(masked_exp_pkt)
+        self.assertTrue(abs(current_pkt_timing - float(self.packet_timing)) < 0.1, "Bad packet timing: %.2f seconds while expected timing is %d seconds from port %s out of %d intervals" % (current_pkt_timing, self.packet_timing, self.exp_iface, self.interval_count))

ansible/roles/test/tasks/lag_2.yml

@@ -57,6 +57,10 @@
   include_vars: vars/topo_t0.yml
   when: testbed_type == 't0'
 
+- name: Include testbed topology configuration (to get LAG IP and PTF docker interfaces, that are behind LAG VMs).
+  include_vars: vars/topo_t0-116.yml
+  when: testbed_type == 't0-116'
+
 - set_fact:
     dut_mac: "{{ ansible_Ethernet0['macaddress'] }}"
 

ansible/roles/test/tasks/lag_lacp_timing_test.yml

@@ -7,6 +7,10 @@
 # @ params: iface_behind_lag_member_0   -   PTF docker iface, that receives all the packets that VM LAG member does.
 # @ params: iface_behind_lag_member_1   -   PTF docker iface, that receives all the packets that VM LAG member does.
 # @ params: vm_name     -       VM hostname that will be printed before running test.
+# @ params: interval_count              -   specifying how many packet internvals to test.
+#                                           When internval count is n, n+1 packets will be
+#                                           received to get n internvals, the test will
+#                                           then check the median internval.
 # 
 # Originally in lagall.yml, and lag_2.yml should cover it 
 #--------------------------------------------------------
@@ -16,17 +20,23 @@
     packet_timing: "{{ lacp_timer }}"
     packet_timeout: 35
 
+- set_fact:
+    interval_count: 3
+  when: interval_count is not defined
+
+- debug: msg="Finding median of {{ interval_count }} packet intervals"
+
 - name: Check LACP timing on eth{{ iface_behind_lag_member[0] }} (interface behind {{ vm_name }}).
   include: lag_run_ptf.yml
   vars:
     lag_ptf_test_name: LacpTimingTest
-    params: "exp_iface={{ iface_behind_lag_member[0] }}; timeout={{ packet_timeout }}; packet_timing={{ packet_timing }}; ether_type={{ lacp_ether_type }}"
+    params: "exp_iface={{ iface_behind_lag_member[0] }}; timeout={{ packet_timeout }}; packet_timing={{ packet_timing }}; ether_type={{ lacp_ether_type }}; interval_count={{ interval_count }}"
     change_dir: /tmp
 
 - name: Check LACP timing on eth{{ iface_behind_lag_member[1] }} (interface behind {{ vm_name }}).
   include: lag_run_ptf.yml
   vars:
     lag_ptf_test_name: LacpTimingTest
-    params: "exp_iface={{ iface_behind_lag_member[1] }}; timeout={{ packet_timeout }}; packet_timing={{ packet_timing }}; ether_type={{ lacp_ether_type }}"
+    params: "exp_iface={{ iface_behind_lag_member[1] }}; timeout={{ packet_timeout }}; packet_timing={{ packet_timing }}; ether_type={{ lacp_ether_type }}; interval_count={{ interval_count }}"
     change_dir: /tmp
   when: iface_behind_lag_member[1] is defined

ansible/roles/test/tasks/single_lag_test.yml

@@ -81,6 +81,7 @@
   vars: 
     vm_name: "{{ peer_device }}"
     lacp_timer: 1
+    interval_count: 3
 
 # make sure portchannel peer rate is set to slow
 - name: make sure all lag members on VM are set to slow
@@ -98,3 +99,4 @@
   vars: 
     vm_name: "{{ peer_device }}"
     lacp_timer: 30
+    interval_count: 3