diff --git a/src/vnet/session/session_debug.c b/src/vnet/session/session_debug.c
new file mode 100644
index 0000000..33d1dc5
--- /dev/null
+++ b/src/vnet/session/session_debug.c
@@ -0,0 +1,281 @@
+/*
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/session/session_debug.h>
+#include <vnet/session/session.h>
+
+#if SESSION_DEBUG > 0
+
+session_dbg_main_t session_dbg_main;
+
+static clib_error_t *
+show_session_dbg_clock_cycles_fn (vlib_main_t * vm, unformat_input_t * input,
+				  vlib_cli_command_t * cmd)
+{
+  u32 thread;
+
+  if (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    return clib_error_return (0, "unknown input `%U'", format_unformat_error,
+			      input);
+
+  for (thread = 0; thread < vec_len (session_dbg_main.wrk); thread++)
+    {
+      vlib_cli_output (vm, "Threads %u:\n", thread);
+      session_dbg_evts_t *sdm = &session_dbg_main.wrk[thread];
+
+#define _(sym, disp, type, str) 								         \
+  if(disp)								\
+    {									\
+      if (!type)							\
+	vlib_cli_output (vm, "\t %25s : %12lu ", str,                 	\
+	                 sdm->counters[SESS_Q_##sym].u64);		\
+      else								\
+	vlib_cli_output (vm, "\t %25s : %12.3f ", str,                  \
+	                 sdm->counters[SESS_Q_##sym].f64);		\
+    }
+      foreach_session_events
+#undef _
+    }
+  return 0;
+}
+
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (show_session_dbg_clock_cycles_command, static) =
+{
+  .path = "show session dbg clock_cycles",
+  .short_help = "show session dbg clock_cycles",
+  .function = show_session_dbg_clock_cycles_fn,
+};
+/* *INDENT-ON* */
+
+
+static clib_error_t *
+clear_session_dbg_clock_cycles_fn (vlib_main_t * vm, unformat_input_t * input,
+				   vlib_cli_command_t * cmd)
+{
+  session_dbg_evts_t *sde;
+  u32 thread;
+
+  if (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    return clib_error_return (0, "unknown input `%U'", format_unformat_error,
+			      input);
+
+  for (thread = 0; thread < vec_len (session_dbg_main.wrk); thread++)
+    {
+      sde = &session_dbg_main.wrk[thread];
+      clib_memset (sde, 0, sizeof (session_dbg_evts_t));
+      sde->last_time = vlib_time_now (vlib_mains[thread]);
+      sde->start_time = sde->last_time;
+    }
+
+  return 0;
+}
+
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (clear_session_clock_cycles_command, static) =
+{
+  .path = "clear session dbg clock_cycles",
+  .short_help = "clear session dbg clock_cycles",
+  .function = clear_session_dbg_clock_cycles_fn,
+};
+/* *INDENT-ON* */
+
+void
+session_debug_init (void)
+{
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
+  session_dbg_main_t *sdm = &session_dbg_main;
+  u32 num_threads, thread;
+
+  num_threads = vtm->n_vlib_mains;
+
+  vec_validate_aligned (sdm->wrk, num_threads - 1, CLIB_CACHE_LINE_BYTES);
+  for (thread = 0; thread < num_threads; thread++)
+    {
+      clib_memset (&sdm->wrk[thread], 0, sizeof (session_dbg_evts_t));
+      sdm->wrk[thread].start_time = vlib_time_now (vlib_mains[thread]);
+    }
+}
+#else
+void
+session_debug_init (void)
+{
+}
+#endif
+
+void
+dump_thread_0_event_queue (void)
+{
+  session_main_t *smm = vnet_get_session_main ();
+  vlib_main_t *vm = &vlib_global_main;
+  u32 my_thread_index = vm->thread_index;
+  session_event_t _e, *e = &_e;
+  svm_msg_q_ring_t *ring;
+  session_t *s0;
+  svm_msg_q_msg_t *msg;
+  svm_msg_q_t *mq;
+  int i, index;
+
+  mq = smm->wrk[my_thread_index].vpp_event_queue;
+  index = mq->q->head;
+
+  for (i = 0; i < mq->q->cursize; i++)
+    {
+      msg = (svm_msg_q_msg_t *) (&mq->q->data[0] + mq->q->elsize * index);
+      ring = svm_msg_q_ring (mq, msg->ring_index);
+      clib_memcpy_fast (e, svm_msg_q_msg_data (mq, msg), ring->elsize);
+
+      switch (e->event_type)
+	{
+	case SESSION_IO_EVT_TX:
+	  s0 = session_get_if_valid (e->session_index, my_thread_index);
+	  fformat (stdout, "[%04d] TX session %d\n", i, s0->session_index);
+	  break;
+
+	case SESSION_CTRL_EVT_CLOSE:
+	  s0 = session_get_from_handle (e->session_handle);
+	  fformat (stdout, "[%04d] disconnect session %d\n", i,
+		   s0->session_index);
+	  break;
+
+	case SESSION_IO_EVT_BUILTIN_RX:
+	  s0 = session_get_if_valid (e->session_index, my_thread_index);
+	  fformat (stdout, "[%04d] builtin_rx %d\n", i, s0->session_index);
+	  break;
+
+	case SESSION_CTRL_EVT_RPC:
+	  fformat (stdout, "[%04d] RPC call %llx with %llx\n",
+		   i, (u64) (uword) (e->rpc_args.fp),
+		   (u64) (uword) (e->rpc_args.arg));
+	  break;
+
+	default:
+	  fformat (stdout, "[%04d] unhandled event type %d\n",
+		   i, e->event_type);
+	  break;
+	}
+
+      index++;
+
+      if (index == mq->q->maxsize)
+	index = 0;
+    }
+}
+
+static u8
+session_node_cmp_event (session_event_t * e, svm_fifo_t * f)
+{
+  session_t *s;
+  switch (e->event_type)
+    {
+    case SESSION_IO_EVT_RX:
+    case SESSION_IO_EVT_TX:
+    case SESSION_IO_EVT_BUILTIN_RX:
+    case SESSION_IO_EVT_BUILTIN_TX:
+    case SESSION_IO_EVT_TX_FLUSH:
+      if (e->session_index == f->master_session_index)
+	return 1;
+      break;
+    case SESSION_CTRL_EVT_CLOSE:
+      break;
+    case SESSION_CTRL_EVT_RPC:
+      s = session_get_from_handle (e->session_handle);
+      if (!s)
+	{
+	  clib_warning ("session has event but doesn't exist!");
+	  break;
+	}
+      if (s->rx_fifo == f || s->tx_fifo == f)
+	return 1;
+      break;
+    default:
+      break;
+    }
+  return 0;
+}
+
+u8
+session_node_lookup_fifo_event (svm_fifo_t * f, session_event_t * e)
+{
+  session_evt_elt_t *elt;
+  session_worker_t *wrk;
+  int i, index, found = 0;
+  svm_msg_q_msg_t *msg;
+  svm_msg_q_ring_t *ring;
+  svm_msg_q_t *mq;
+  u8 thread_index;
+
+  ASSERT (e);
+  thread_index = f->master_thread_index;
+  wrk = session_main_get_worker (thread_index);
+
+  /*
+   * Search evt queue
+   */
+  mq = wrk->vpp_event_queue;
+  index = mq->q->head;
+  for (i = 0; i < mq->q->cursize; i++)
+    {
+      msg = (svm_msg_q_msg_t *) (&mq->q->data[0] + mq->q->elsize * index);
+      ring = svm_msg_q_ring (mq, msg->ring_index);
+      clib_memcpy_fast (e, svm_msg_q_msg_data (mq, msg), ring->elsize);
+      found = session_node_cmp_event (e, f);
+      if (found)
+	return 1;
+      index = (index + 1) % mq->q->maxsize;
+    }
+  /*
+   * Search pending events vector
+   */
+
+  /* *INDENT-OFF* */
+  clib_llist_foreach (wrk->event_elts, evt_list,
+                      pool_elt_at_index (wrk->event_elts, wrk->new_head),
+                      elt, ({
+    found = session_node_cmp_event (&elt->evt, f);
+    if (found)
+      {
+	clib_memcpy_fast (e, &elt->evt, sizeof (*e));
+	goto done;
+      }
+  }));
+  /* *INDENT-ON* */
+
+  /* *INDENT-OFF* */
+  clib_llist_foreach (wrk->event_elts, evt_list,
+                      pool_elt_at_index (wrk->event_elts, wrk->old_head),
+                      elt, ({
+    found = session_node_cmp_event (&elt->evt, f);
+    if (found)
+      {
+	clib_memcpy_fast (e, &elt->evt, sizeof (*e));
+	goto done;
+      }
+  }));
+  /* *INDENT-ON* */
+
+done:
+  return found;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */