trove upgrade 用于将数据库从一个版本更新到另一个版本，如：将mysql5.5更换到mysql5.6
trove/taskmanager/manager.py 368行
def upgrade(self, context, instance_id, datastore_version_id):
instance_tasks = models.BuiltInstanceTasks.load(context, instance_id)
datastore_version = DatastoreVersion.load_by_uuid(datastore_version_id)
with EndNotification(context):
instance_tasks.upgrade(datastore_version)instance_tasks.upgrade(datastore_version)调用
trove/taskmanager/models.py 1501行
def upgrade(self, datastore_version):
...
try:
upgrade_info = self.guest.pre_upgrade()
...
self.server.rebuild(datastore_version.p_w_picpath_id,
files=injected_files)
...
if volume:
upgrade_info['device'] = volume_device
self.guest.post_upgrade(upgrade_info)
self.reset_task_status()
...upgrade instance 主要是以下几步完成：
self.guest.pre_upgrade：更新前的一些操作，主要是将mysql的配置文件保存在cinder volume中
self.server.rebuild：用新的数据库基础镜像重建trove的nova实例
self.guest.post_upgrade：重建nova instance後的一些操作，主要操作是从cinder volume中恢复mysql配置文件，启动mysql
self.guest.pre_upgrade，self.guest.post_upgrade 通过rcp方式调用运行在nova instance上的trove-guestagent的中对应方法
trove/guestagent/datastore/mysql/_common/manager.py 245行
def pre_upgrade(self, context):
app = self.mysql_app(self.mysql_app_status.get())
data_dir = app.get_data_dir()
mount_point, _data = os.path.split(data_dir)
save_dir = "%s/etc_mysql" % mount_point
save_etc_dir = "%s/etc" % mount_point
home_save = "%s/trove_user" % mount_point
app.status.begin_restart()
app.stop_db()
if operating_system.exists("/etc/my.cnf", as_root=True):
operating_system.create_directory(save_etc_dir, as_root=True)
operating_system.copy("/etc/my.cnf", save_etc_dir,
preserve=True, as_root=True)
operating_system.copy("/etc/mysql/.", save_dir,
preserve=True, as_root=True)
operating_system.copy("%s/." % os.path.expanduser('~'), home_save,
preserve=True, as_root=True)
self.unmount_volume(context, mount_point=data_dir)
return {
'mount_point': mount_point,
'save_dir': save_dir,
'save_etc_dir': save_etc_dir,
'home_save': home_save
}pre_upgrade备份数据库的配置文件、guestagent位于trove home 目录下的配置信息，返回包含备份信息的一个字典
trove/guestagent/datastore/mysql/_common/manager.py 275行
def post_upgrade(self, context, upgrade_info):
app = self.mysql_app(self.mysql_app_status.get())
app.stop_db()
if 'device' in upgrade_info:
self.mount_volume(context, mount_point=upgrade_info['mount_point'],
device_path=upgrade_info['device'],
write_to_fstab=True)
if operating_system.exists(upgrade_info['save_etc_dir'],
is_directory=True, as_root=True):
operating_system.copy("%s/." % upgrade_info['save_etc_dir'],
"/etc", preserve=True, as_root=True)
operating_system.copy("%s/." % upgrade_info['save_dir'], "/etc/mysql",
preserve=True, as_root=True)
operating_system.copy("%s/." % upgrade_info['home_save'],
os.path.expanduser('~'),
preserve=True, as_root=True)
self.configuration_manager.refresh_cache()
app.start_mysql()post_upgrade恢复备份中的配置文件，不对老数据库的任何文件作修改，直接使用老数据库的配置文件与数据文件启动数据库
