[vpp-dev] anomaly in deleting tcp idle session in vpp

[emma sdi]

---------- Forwarded message ----------
From: khers <s3m2e1.6s...@gmail.com>
Date: Sat, Jun 2, 2018 at 1:09 PM
Subject: Re: [vpp-dev] anomaly in deleting tcp idle session in vpp
To: Andrew Yourtchenko <ayour...@gmail.com>


Dear Andrew,

I have observed a contradiction. In my test case, after being session table
full, vpp start to delete idle sessions.
trex command : ./t-rex-64 -c 3 --active-flows 10000  -f
/cap2/concurrent_connection_test.yaml  --nc -m 1000 --no-key
yaml file and pcap file and patch file is attached to this email.

I changed vpp 18.04 version to log session timeout type before removing
them. Accordingly, I observed sessions with timeout type 1 ( 1 is used for
idle session timeout) in my log.

set acl-plugin session timeout udp idle 60
set acl-plugin session timeout tcp idle 3600
set acl-plugin session timeout tcp transient 30




On Wed, May 30, 2018 at 7:59 PM, Andrew Yourtchenko <ayour...@gmail.com>
wrote:

> If the table is full it should fifo-reuse the tcp transient sessions, not
> the established ones.
>
> --a
>
> On 30 May 2018, at 14:00, emma sdi <s3m2e1.6s...@gmail.com> wrote:
>
> Dear Folks,
> I have a problem with vpp stateful mode. I observed that vpp start to
> delete tcp idle sessions when session table is full. my question is this
> behavior is implemented and indeed it is normal routine? or is this an
> anomaly? because this behavior is not normal generally (for example in
> conntrack) and an established session have to exist till its timeout will
> be zero. I expect vpp holds all old tcp idle sessions instead of creating
> new sessions when session table doesn't have any empty entry.
> Best Regards,
> 
>
>

concurrent_connection_test.yaml
Description: application/yaml

concurrent_connection_test_pcap.pcap
Description: application/vnd.tcpdump.pcap

diff --git a/src/plugins/acl/fa_node.c b/src/plugins/acl/fa_node.c
index a36a5815..bb965bb2 100644
--- a/src/plugins/acl/fa_node.c
+++ b/src/plugins/acl/fa_node.c
@@ -388,6 +388,9 @@ acl_fa_conn_list_delete_session (acl_main_t *am, fa_full_session_id_t sess_id)
     return 0;
   }
   fa_session_t *sess = get_session_ptr(am, sess_id.thread_index, sess_id.session_index);
+  u32 res = -1;  
+  if(sess)
+     res = fa_session_get_timeout_type (am, sess);  
   /* we should never try to delete the session with another thread index */
   ASSERT(sess->thread_index == thread_index);
   if (~0 != sess->link_prev_idx) {
@@ -408,6 +411,8 @@ acl_fa_conn_list_delete_session (acl_main_t *am, fa_full_session_id_t sess_id)
   if (pw->fa_conn_list_tail[sess->link_list_id] == sess_id.session_index) {
     pw->fa_conn_list_tail[sess->link_list_id] = sess->link_prev_idx;
   }
+
+  printf("acl_fa_conn_list_delete_session: the session timeout type is %d \n  ", res);
   return 1;
 }
 
@@ -449,6 +454,9 @@ acl_fa_delete_session (acl_main_t * am, u32 sw_if_index, fa_full_session_id_t se
   void *oldheap = clib_mem_set_heap(am->acl_mheap);
   fa_session_t *sess = get_session_ptr(am, sess_id.thread_index, sess_id.session_index);
   ASSERT(sess->thread_index == os_get_thread_index ());
+  u32 res = -1;
+  if(sess)   
+     res = fa_session_get_timeout_type (am, sess);
   BV (clib_bihash_add_del) (&am->fa_sessions_hash,
 			    &sess->info.kv, 0);
   acl_fa_per_worker_data_t *pw = &am->per_worker_data[sess_id.thread_index];
@@ -459,6 +467,8 @@ acl_fa_delete_session (acl_main_t * am, u32 sw_if_index, fa_full_session_id_t se
   clib_mem_set_heap (oldheap);
   pw->fa_session_dels_by_sw_if_index[sw_if_index]++;
   clib_smp_atomic_add(&am->fa_session_total_dels, 1);
+  printf("acl_delete_session_function:the session timeout type is %d \n", res);
+
 }
 
 static int