[Reclaiming buffer][202106] Database migrator for reclaiming buffer (#…

…1897)

This is to cherry-pick community PR #1822 to 202106.

- What I did
Db migrator support reclaiming reserved buffer for unused ports
As there is no empty slot for database version between 202106 and master (202111), this migration will be done regardless of whether database version is changed. The DB migrator should be idempotent.

- How I did it
For admin down ports, if the buffer objects configuration aligns with default configuration, set the buffer objects configuration as:
1. Dynamic model: all normal buffer objects are configured on admin down ports. Buffer manager will apply zero profiles on admin down ports.
2. Static model: zero buffer objects are configured on admin down ports.

- How to verify it
1. Unit test.
2. Manually test.

scripts/db_migrator.py

@@ -74,7 +74,7 @@ def __init__(self, namespace, socket=None):
 
         if asic_type == "mellanox":
             from mellanox_buffer_migrator import MellanoxBufferMigrator
-            self.mellanox_buffer_migrator = MellanoxBufferMigrator(self.configDB)
+            self.mellanox_buffer_migrator = MellanoxBufferMigrator(self.configDB, self.appDB, self.stateDB)
 
     def migrate_pfc_wd_table(self):
         '''
@@ -364,9 +364,9 @@ def prepare_dynamic_buffer_for_warm_reboot(self, buffer_pools=None, buffer_profi
                     self.appDB.set(self.appDB.APPL_DB, appl_db_key, field, data)
 
             if keys_copied:
-                log.log_info("The following items in table {} in CONFIG_DB have been copied to APPL_DB: {}".format(table_name, keys_copied))
+                log.log_notice("The following items in table {} in CONFIG_DB have been copied to APPL_DB: {}".format(table_name, keys_copied))
             if keys_ignored:
-                log.log_info("The following items in table {} in CONFIG_DB have been ignored: {}".format(table_name, keys_copied))
+                log.log_notice("The following items in table {} in CONFIG_DB have been ignored: {}".format(table_name, keys_copied))
 
         return True
 
@@ -582,6 +582,16 @@ def common_migration_ops(self):
 
         self.migrate_copp_table()
 
+        # To migrate buffer on Mellanox platforms
+        # For legacy branches, this is the only place it can be called because
+        #  - Putting it in version 2_0_1 causes db_migrator not able to run
+        #    when the switch is migrated from 202106-no-reclaiming-buffer whose db version is 2_0_2
+        #    to 202106-reclaiming-buffer, which causes reclaiming buffer not take effect
+        #  - Putting it in version 2_0_2 is not a solution either because
+        #    version 2_0_3 has been occupied by 202111
+        if self.asic_type == "mellanox":
+            self.mellanox_buffer_migrator.mlnx_reclaiming_unused_buffer()
+
     def migrate(self):
         version = self.get_version()
         log.log_info('Upgrading from version ' + version)

scripts/mellanox_buffer_migrator.py

@@ -79,15 +79,18 @@
        Not providing it means no buffer profile migration required.
 """
 from sonic_py_common import logger
+import re
 
 SYSLOG_IDENTIFIER = 'mellanox_buffer_migrator'
 
 # Global logger instance
 log = logger.Logger(SYSLOG_IDENTIFIER)
 
 class MellanoxBufferMigrator():
-    def __init__(self, configDB):
+    def __init__(self, configDB, appDB, stateDB):
         self.configDB = configDB
+        self.appDB = appDB
+        self.stateDB = stateDB
 
         self.platform = None
         self.sku = None
@@ -834,3 +837,259 @@ def mlnx_flush_new_buffer_configuration(self):
 
     def mlnx_is_buffer_model_dynamic(self):
         return self.is_buffer_config_default and not self.is_msft_sku
+
+    def mlnx_reorganize_buffer_tables(self, buffer_table, name):
+        """
+        This is to reorganize the BUFFER_PG and BUFFER_QUEUE tables from single tier index to double tiers index.
+        Originally, the index is like <port>|<ids>. However, we need to check all the items with respect to a port,
+        which requires two tiers index, <port> and then <ids>
+        Eg.
+        Before reorganize:
+        {
+          "Ethernet0|0": {"profile" : "[BUFFER_PROFILE|ingress_lossy_profile]"},
+          "Ethernet0|3-4": {"profile": "[BUFFER_PROFILE|pg_lossless_100000_5m_profile]"},
+          "Ethernet4|0": {"profile" : "[BUFFER_PROFILE|ingress_lossy_profile]"},
+          "Ethernet4|3-4": {"profile": "[BUFFER_PROFILE|pg_lossless_50000_5m_profile]"}
+        }
+        After reorganize:
+        {
+          "Ethernet0": {
+             "0": {"profile" : "[BUFFER_PROFILE|ingress_lossy_profile]"},
+             "3-4": {"profile": "[BUFFER_PROFILE|pg_lossless_100000_5m_profile]"}
+          },
+          "Ethernet4": {
+             "0": {"profile" : "[BUFFER_PROFILE|ingress_lossy_profile]"},
+             "3-4": {"profile": "[BUFFER_PROFILE|pg_lossless_50000_5m_profile]"}
+          }
+        }
+        """
+        result = {}
+        for key, item in buffer_table.items():
+            if len(key) != 2:
+                log.log_error('Table {} contains invalid key {}, skip this item'.format(name, key))
+                continue
+            port, ids = key
+            if not port in result:
+                result[port] = {}
+            result[port][ids] = item
+
+        return result
+
+    def mlnx_reclaiming_unused_buffer(self):
+        cable_length_key = self.configDB.get_keys('CABLE_LENGTH')
+        if not cable_length_key:
+            log.log_notice("No cable length table defined, do not migrate buffer objects for reclaiming buffer")
+            return;
+
+        log.log_info("Migrate buffer objects for reclaiming buffer based on 'CABLE_LENGTH|{}'".format(cable_length_key[0]))
+
+        device_metadata = self.configDB.get_entry('DEVICE_METADATA', 'localhost')
+        is_dynamic = (device_metadata.get('buffer_model') == 'dynamic')
+
+        port_table = self.configDB.get_table('PORT')
+        buffer_pool_table = self.configDB.get_table('BUFFER_POOL')
+        buffer_profile_table = self.configDB.get_table('BUFFER_PROFILE')
+        buffer_pg_table = self.configDB.get_table('BUFFER_PG')
+        buffer_queue_table = self.configDB.get_table('BUFFER_QUEUE')
+        buffer_ingress_profile_list_table = self.configDB.get_table('BUFFER_PORT_INGRESS_PROFILE_LIST')
+        buffer_egress_profile_list_table = self.configDB.get_table('BUFFER_PORT_EGRESS_PROFILE_LIST')
+        cable_length_entries = self.configDB.get_entry('CABLE_LENGTH', cable_length_key[0])
+
+        buffer_pg_items = self.mlnx_reorganize_buffer_tables(buffer_pg_table, 'BUFFER_PG')
+        buffer_queue_items = self.mlnx_reorganize_buffer_tables(buffer_queue_table, 'BUFFER_QUEUE')
+
+        single_pool = True
+        if 'ingress_lossy_pool' in buffer_pool_table:
+            ingress_lossy_profile = buffer_profile_table.get('ingress_lossy_profile')
+            if ingress_lossy_profile:
+                if '[BUFFER_POOL|ingress_lossy_pool]' == ingress_lossy_profile.get('pool'):
+                    single_pool = False
+
+        # Construct buffer items to be applied to admin down ports
+        if is_dynamic:
+            # For dynamic model, we just need to add the default buffer objects to admin down ports
+            # Buffer manager will apply zero profiles automatically when a port is shutdown
+            lossy_pg_item = {'profile': '[BUFFER_PROFILE|ingress_lossy_profile]'} if 'ingress_lossy_profile' in buffer_profile_table else None
+            lossy_queue_item = {'profile': '[BUFFER_PROFILE|q_lossy_profile]'} if 'q_lossy_profile' in buffer_profile_table else None
+            lossless_queue_item = {'profile': '[BUFFER_PROFILE|egress_lossless_profile]'} if 'egress_lossless_profile' in buffer_profile_table else None
+
+            queue_items_to_apply = {'0-2': lossy_queue_item,
+                                    '3-4': lossless_queue_item,
+                                    '5-6': lossy_queue_item}
+
+            if single_pool:
+                if 'ingress_lossless_profile' in buffer_profile_table:
+                    ingress_profile_list_item = {'profile_list': '[BUFFER_PROFILE|ingress_lossless_profile]'}
+                else:
+                    ingress_profile_list_item = None
+            else:
+                if 'ingress_lossless_profile' in buffer_profile_table and 'ingress_lossy_profile' in buffer_profile_table:
+                    ingress_profile_list_item = {'profile_list': '[BUFFER_PROFILE|ingress_lossless_profile],[BUFFER_PROFILE|ingress_lossy_profile]'}
+                else:
+                    ingress_profile_list_item = None
+
+            if 'egress_lossless_profile' in buffer_profile_table and 'egress_lossy_profile' in buffer_profile_table:
+                egress_profile_list_item = {'profile_list': '[BUFFER_PROFILE|egress_lossless_profile],[BUFFER_PROFILE|egress_lossy_profile]'}
+            else:
+                egress_profile_list_item = None
+
+            pools_to_insert = None
+            profiles_to_insert = None
+
+        else:
+            # For static model, we need more.
+            # Define zero buffer pools and profiles
+            ingress_zero_pool = {'size': '0', 'mode': 'static', 'type': 'ingress'}
+            ingress_lossy_pg_zero_profile = {
+                "pool":"[BUFFER_POOL|ingress_zero_pool]",
+                "size":"0",
+                "static_th":"0"
+            }
+            lossy_pg_item = {'profile': '[BUFFER_PROFILE|ingress_lossy_pg_zero_profile]'}
+
+            ingress_lossless_zero_profile = {
+                "pool":"[BUFFER_POOL|ingress_lossless_pool]",
+                "size":"0",
+                "dynamic_th":"-8"
+            }
+
+            if single_pool:
+                ingress_profile_list_item = {'profile_list': '[BUFFER_PROFILE|ingress_lossless_zero_profile]'}
+            else:
+                ingress_lossy_zero_profile = {
+                    "pool":"[BUFFER_POOL|ingress_lossy_pool]",
+                    "size":"0",
+                    "dynamic_th":"-8"
+                }
+                ingress_profile_list_item = {'profile_list': '[BUFFER_PROFILE|ingress_lossless_zero_profile],[BUFFER_PROFILE|ingress_lossy_zero_profile]'}
+
+            egress_lossless_zero_profile = {
+                "pool":"[BUFFER_POOL|egress_lossless_pool]",
+                "size":"0",
+                "dynamic_th":"-8"
+            }
+            lossless_queue_item = {'profile': '[BUFFER_PROFILE|egress_lossless_zero_profile]'}
+
+            egress_lossy_zero_profile = {
+                "pool":"[BUFFER_POOL|egress_lossy_pool]",
+                "size":"0",
+                "dynamic_th":"-8"
+            }
+            lossy_queue_item = {'profile': '[BUFFER_PROFILE|egress_lossy_zero_profile]'}
+            egress_profile_list_item = {'profile_list': '[BUFFER_PROFILE|egress_lossless_zero_profile],[BUFFER_PROFILE|egress_lossy_zero_profile]'}
+
+            queue_items_to_apply = {'0-2': lossy_queue_item,
+                                    '3-4': lossless_queue_item,
+                                    '5-6': lossy_queue_item}
+
+            pools_to_insert = {'ingress_zero_pool': ingress_zero_pool}
+            profiles_to_insert = {'ingress_lossy_pg_zero_profile': ingress_lossy_pg_zero_profile,
+                                  'ingress_lossless_zero_profile': ingress_lossless_zero_profile,
+                                  'egress_lossless_zero_profile': egress_lossless_zero_profile,
+                                  'egress_lossy_zero_profile': egress_lossy_zero_profile}
+            if not single_pool:
+                profiles_to_insert['ingress_lossy_zero_profile'] = ingress_lossy_zero_profile
+
+        lossless_profile_pattern = '\[BUFFER_PROFILE\|pg_lossless_([1-9][0-9]*000)_([1-9][0-9]*m)_profile\]'
+        zero_item_count = 0
+        reclaimed_ports = set()
+        for port_name, port_info in port_table.items():
+            if port_info.get('admin_status') == 'up':
+                # Handles admin down ports only
+                continue
+
+            # If items to be applied to admin down port of BUFFER_PG table have been generated,
+            # Check whether the BUFFER_PG items with respect to the port align with the default one,
+            # and insert the items to BUFFER_PG
+            # The same logic for BUFFER_QUEUE, BUFFER_PORT_INGRESS_PROFILE_LIST and BUFFER_PORT_EGRESS_PROFILE_LIST
+            if lossy_pg_item:
+                port_pgs = buffer_pg_items.get(port_name)
+                is_default = False
+                if not port_pgs:
+                    is_default = True
+                else:
+                    if set(port_pgs.keys()) == set(['3-4']):
+                        if is_dynamic:
+                            reclaimed_ports.add(port_name)
+                            if port_pgs['3-4']['profile'] == 'NULL':
+                                is_default = True
+                        else:
+                            match = re.search(lossless_profile_pattern, port_pgs['3-4']['profile'])
+                            if match:
+                                speed = match.group(1)
+                                cable_length = match.group(2)
+                                if speed == port_info.get('speed') and cable_length == cable_length_entries.get(port_name):
+                                    is_default = True
+
+                if is_default:
+                    lossy_pg_key = '{}|0'.format(port_name)
+                    lossless_pg_key = '{}|3-4'.format(port_name)
+                    self.configDB.set_entry('BUFFER_PG', lossy_pg_key, lossy_pg_item)
+                    if is_dynamic:
+                        self.configDB.set_entry('BUFFER_PG', lossless_pg_key, {'profile': 'NULL'})
+                        # For traditional model, we must NOT remove the default lossless PG
+                        # because it has been popagated to APPL_DB during db_migrator
+                        # Leaving it untouched in CONFIG_DB enables traditional buffer manager to
+                        # remove it from CONFIG_DB as well as APPL_DB
+                        # However, removing it from CONFIG_DB causes it left in APPL_DB
+                    zero_item_count += 1
+
+            if lossy_queue_item and lossless_queue_item:
+                port_queues = buffer_queue_items.get(port_name)
+                if not port_queues:
+                    for ids, item in queue_items_to_apply.items():
+                        self.configDB.set_entry('BUFFER_QUEUE', port_name + '|' + ids, item)
+                    zero_item_count += 1
+
+            if ingress_profile_list_item:
+                port_ingress_profile_list = buffer_ingress_profile_list_table.get(port_name)
+                if not port_ingress_profile_list:
+                    self.configDB.set_entry('BUFFER_PORT_INGRESS_PROFILE_LIST', port_name, ingress_profile_list_item)
+                    zero_item_count += 1
+
+            if egress_profile_list_item:
+                port_egress_profile_list = buffer_egress_profile_list_table.get(port_name)
+                if not port_egress_profile_list:
+                    self.configDB.set_entry('BUFFER_PORT_EGRESS_PROFILE_LIST', port_name, egress_profile_list_item)
+                    zero_item_count += 1
+
+        if zero_item_count > 0:
+            if pools_to_insert:
+                for name, pool in pools_to_insert.items():
+                    self.configDB.set_entry('BUFFER_POOL', name, pool)
+
+            if profiles_to_insert:
+                for name, profile in profiles_to_insert.items():
+                    self.configDB.set_entry('BUFFER_PROFILE', name, profile)
+
+        # We need to remove BUFFER_PG table items for admin down ports from APPL_DB
+        # and then remove the buffer profiles which are no longer referenced
+        # We do it here because
+        #  - The buffer profiles were copied from CONFIG_DB by db_migrator when the database was being migrated from 1.0.6 to 2.0.0
+        #  - In this migrator the buffer priority-groups have been removed from CONFIG_DB.BUFFER_PG table
+        #  - The dynamic buffer manager will not generate buffer profile by those buffer PG items
+        #    In case a buffer profile was referenced by an admin down port only, the dynamic buffer manager won't create it after starting
+        #    This kind of buffer profiles will be left in APPL_DB and can not be removed.
+        if not is_dynamic:
+            return
+
+        warmreboot_state = self.stateDB.get(self.stateDB.STATE_DB, 'WARM_RESTART_ENABLE_TABLE|system', 'enable')
+        if warmreboot_state == 'true':
+            referenced_profiles = set()
+            keys = self.appDB.keys(self.appDB.APPL_DB, "BUFFER_PG_TABLE:*")
+            if keys is None:
+                return
+            for buffer_pg_key in keys:
+                port, pg = buffer_pg_key.split(':')[1:]
+                if port in reclaimed_ports:
+                    self.appDB.delete(self.appDB.APPL_DB, buffer_pg_key)
+                else:
+                    buffer_pg_items = self.appDB.get_all(self.appDB.APPL_DB, buffer_pg_key)
+                    profile = buffer_pg_items.get('profile')
+                    if profile:
+                        referenced_profiles.add(profile[22:-1])
+            keys = self.appDB.keys(self.appDB.APPL_DB, "BUFFER_PROFILE_TABLE:*")
+            for buffer_profile_key in keys:
+                profile = buffer_profile_key.split(':')[1]
+                if profile[:12] == 'pg_lossless_' and profile not in referenced_profiles and profile not in buffer_profile_table.keys():
+                    self.appDB.delete(self.appDB.APPL_DB, buffer_profile_key)

tests/db_migrator_input/appl_db/acs-msn4700-t1-version_2_0_0.json

@@ -712,13 +712,6 @@
         "pool": "[BUFFER_POOL_TABLE:ingress_lossless_pool]",
         "size": "124928"
     },
-    "BUFFER_PROFILE_TABLE:pg_lossless_400000_300m_profile": {
-        "xon": "37888",
-        "dynamic_th": "0",
-        "xoff": "373760",
-        "pool": "[BUFFER_POOL_TABLE:ingress_lossless_pool]",
-        "size": "420864"
-    },
     "BUFFER_PROFILE_TABLE:q_lossy_profile": {
         "dynamic_th": "3",
         "pool": "[BUFFER_POOL_TABLE:egress_lossy_pool]",