Commit f91b91cf authored by unknown's avatar unknown
Browse files

Bug #22379 im_daemon_life_cycle.test fails on merge of 5.1 -> 5.1-engines 

Remove race situations that occur when removing pidfiles. Primarily each process should remove its own
pidfile, secondly it should be removed by the process that created it and _only_ if it's
certain the process is dead. Third, mysql-test-run.pl will remove the pidfile when process has been killed.
- Set state of an instance to STARTING _before_ calling instance->start()
- Check that pidfile of instance has been created before changing STARTING => STARTED
- Only remove the pidfile if IM kills an instance with SIGKILL, otherwise the instance will remove it itself


server-tools/instance-manager/guardian.cc:
  If state of an instance is STARTING, chech that the instance pidfile has been created
  before changing state to STARTED
  Set state to STARTING before calling instance->start(), it can take some time
  before it is fully started and during that time it should be in state STARTING
server-tools/instance-manager/instance.cc:
  Only remove the pid file of instance manager when a SIGKILL has 
  been performed sucessfully
server-tools/instance-manager/instance_options.cc:
  Check that fscanf returns 1 which is the number of args that should be scanned from
  the pid file
parent 14bebaa2

server-tools/instance-manager/guardian.cc

+21 −6
Original line number Diff line number Diff line
@@ -109,21 +109,36 @@ void Guardian_thread::process_instance(Instance *instance, 
  }



  if (instance->is_running())

  {

    /* The instance can be contacted  on it's port */



    /* If STARTING also check that pidfile has been created */

    if (current_node->state == STARTING &&

        current_node->instance->options.get_pid() == 0)

    {

      /* Pid file not created yet, don't go to STARTED state yet  */

    }

    else

    {

      /* clear status fields */

      log_info("guardian: instance %s is running, set state to STARTED",

               instance->options.instance_name);

      current_node->restart_counter= 0;

      current_node->crash_moment= 0;

      current_node->state= STARTED;

    }

  }

  else

  {

    switch (current_node->state) {

    case NOT_STARTED:

      instance->start();

      current_node->last_checked= current_time;

      log_info("guardian: starting instance %s",

               instance->options.instance_name);



      /* NOTE, set state to STARTING _before_ start() is called */

      current_node->state= STARTING;

      instance->start();

      current_node->last_checked= current_time;

      break;

    case STARTED:     /* fallthrough */

    case STARTING:    /* let the instance start or crash */

server-tools/instance-manager/instance.cc

+13 −12
Original line number Diff line number Diff line
@@ -571,18 +571,19 @@ void Instance::kill_instance(int signum) 
  /* if there are no pid, everything seems to be fine */

  if ((pid= options.get_pid()) != 0)            /* get pid from pidfile */

  {

    /*

      If we cannot kill mysqld, then it has propably crashed.

      Let us try to remove staled pidfile and return successfully

      as mysqld is probably stopped.

    */

    if (!kill(pid, signum))

      options.unlink_pidfile();

    else if (signum == SIGKILL)      /* really killed instance with SIGKILL */

      log_error("The instance %s is being stopped forsibly. Normally \

                it should not happed. Probably the instance has been \

                hanging. You should also check your IM setup",

    if (kill(pid, signum) == 0)

    {

      /* Kill suceeded */

      if (signum == SIGKILL)      /* really killed instance with SIGKILL */

      {

        log_error("The instance %s is being stopped forcibly. Normally" \

                  "it should not happen. Probably the instance has been" \

                  "hanging. You should also check your IM setup",

                  options.instance_name);

        /* After sucessful hard kill the pidfile need to be removed */

        options.unlink_pidfile();

      }

    }

  }

  return;

}

server-tools/instance-manager/instance_options.cc

+2 −1
Original line number Diff line number Diff line
@@ -377,7 +377,8 @@ pid_t Instance_options::get_pid() 
  {

    pid_t pid;



    fscanf(pid_file_stream, "%i", &pid);

    if (fscanf(pid_file_stream, "%i", &pid) != 1)

      pid= -1;

    my_fclose(pid_file_stream, MYF(0));

    return pid;

  }