From: Trond Norbye <trond.norbye@sun.com>
Date: Mon, 12 Oct 2009 21:31:25 +0000 (+0200)
Subject: Simplify wrong_failure_counter_test to only test the changed code
X-Git-Tag: 0.34~3^2
X-Git-Url: https://git.m6w6.name/?a=commitdiff_plain;h=dd50ba14e3e23af4660ce5894863d8fabe95afba;p=m6w6%2Flibmemcached

Simplify wrong_failure_counter_test to only test the changed code

The original version of wrong_failure_counter_test didn't work on gaz because
the server_failure_counter was already set when entering the test case. The
purpose of the test was to ensure that memcached_quit didn't increment the
server_failure_counter, and to do so it tried to set different behavior flags.
Some of these would cause a really low retry timeout, which in turn could
cause "problems" on a slow server.

There was another problem in memcached_quit_server on some platforms caused
by the draining of the input pipe from from the server. This function could
get a read error, resulting in memcached_quit_server being called
recursively but this time signaling an IO error causing the counter to be
increased. We should ignore these errors, because they are triggered
while we are draining the stream from the server.
---

diff --git a/libmemcached/memcached_quit.c b/libmemcached/memcached_quit.c
index 860ee126..8ac76d48 100644
--- a/libmemcached/memcached_quit.c
+++ b/libmemcached/memcached_quit.c
@@ -39,6 +39,15 @@ void memcached_quit_server(memcached_server_st *ptr, uint8_t io_death)
       ssize_t nread;
       while (memcached_io_read(ptr, buffer, sizeof(buffer)/sizeof(*buffer),
                                &nread) == MEMCACHED_SUCCESS);
+
+      /*
+       * memcached_io_read may call memcached_quit_server with io_death if
+       * it encounters problems, but we don't care about those occurences.
+       * The intention of that loop is to drain the data sent from the
+       * server to ensure that the server processed all of the data we
+       * sent to the server.
+       */
+      ptr->server_failure_counter= 0;
     }
     memcached_io_close(ptr);
 
diff --git a/tests/function.c b/tests/function.c
index cfdccb28..8e33968e 100644
--- a/tests/function.c
+++ b/tests/function.c
@@ -4784,8 +4784,8 @@ static test_return_t  test_get_last_disconnect(memcached_st *memc)
 }
 
 /*
- * This tests ensures expected disconnections (for some behavior changes
- * for instance) do not wrongly increase failure counter
+ * This test ensures that the failure counter isn't incremented during
+ * normal termination of the memcached instance.
  */
 static test_return_t wrong_failure_counter_test(memcached_st *memc)
 {
@@ -4794,34 +4794,38 @@ static test_return_t wrong_failure_counter_test(memcached_st *memc)
   /* Set value to force connection to the server */
   const char *key= "marmotte";
   const char *value= "milka";
-  char *string = NULL;
-  size_t string_length;
-  uint32_t flags;
 
+  /*
+   * Please note that I'm abusing the internal structures in libmemcached
+   * in a non-portable way and you shouldn't be doing this. I'm only
+   * doing this in order to verify that the library works the way it should
+   */
+  uint32_t number_of_hosts= memc->number_of_hosts;
+  memc->number_of_hosts= 1;
+
+  /* Ensure that we are connected to the server by setting a value */
   rc= memcached_set(memc, key, strlen(key),
                     value, strlen(value),
                     (time_t)0, (uint32_t)0);
   assert(rc == MEMCACHED_SUCCESS || rc == MEMCACHED_BUFFERED);
 
 
-  /* put failure limit to 1 */
-  rc= memcached_behavior_set(memc, MEMCACHED_BEHAVIOR_SERVER_FAILURE_LIMIT, 1);
-  assert(rc == MEMCACHED_SUCCESS);
-  /* Put a retry timeout to effectively activate failure_limit effect */
-  rc= memcached_behavior_set(memc, MEMCACHED_BEHAVIOR_RETRY_TIMEOUT, 1);
-  assert(rc == MEMCACHED_SUCCESS);
-  /* change behavior that triggers memcached_quit()*/
-  rc= memcached_behavior_set(memc, MEMCACHED_BEHAVIOR_TCP_NODELAY, 1);
-  assert(rc == MEMCACHED_SUCCESS);
+  /* The test is to see that the memcached_quit doesn't increase the
+   * the server failure conter, so let's ensure that it is zero
+   * before sending quit
+   */
+  memc->hosts[0].server_failure_counter= 0;
 
+  memcached_quit(memc);
 
-  /* Check if we still are connected */
-  string= memcached_get(memc, key, strlen(key),
-                        &string_length, &flags, &rc);
+  /* Verify that it memcached_quit didn't increment the failure counter
+   * Please note that this isn't bullet proof, because an error could
+   * occur...
+   */
+  assert(memc->hosts[0].server_failure_counter == 0);
 
-  assert(rc == MEMCACHED_SUCCESS);
-  assert(string);
-  free(string);
+  /* restore the instance */
+  memc->number_of_hosts= number_of_hosts;
 
   return TEST_SUCCESS;
 }