DNM: Coordinator nodes (an addition to read-only nodes)

cmapi/cmapi_server/constants.py

@@ -4,6 +4,7 @@
 """
 import os
 from typing import NamedTuple
+from enum import Enum
 
 
 # default MARIADB ColumnStore config path
@@ -60,6 +61,15 @@
     CMAPI_INSTALL_PATH, 'cmapi_server/SingleNode.xml'
 )
 
+class MCSProgs(Enum):
+    STORAGE_MANAGER = 'StorageManager'
+    WORKER_NODE = 'workernode'
+    CONTROLLER_NODE = 'controllernode'
+    PRIM_PROC = 'PrimProc'
+    WRITE_ENGINE_SERVER = 'WriteEngineServer'
+    DML_PROC = 'DMLProc'
+    DDL_PROC = 'DDLProc'
+
 # constants for dispatchers
 class ProgInfo(NamedTuple):
     """NamedTuple for some additional info about handling mcs processes."""
@@ -73,17 +83,16 @@ class ProgInfo(NamedTuple):
 # on top level of process handling
 # mcs-storagemanager starts conditionally inside mcs-loadbrm, but should be
 # stopped using cmapi
-ALL_MCS_PROGS = {
+ALL_MCS_PROGS: dict[MCSProgs, ProgInfo] = {
     # workernode starts on primary and non primary node with 1 or 2 added
     # to subcommand (DBRM_Worker1 - on primary, DBRM_Worker2 - non primary)
-    'StorageManager': ProgInfo(15, 'mcs-storagemanager', '', False, 1),
-    'workernode': ProgInfo(13, 'mcs-workernode', 'DBRM_Worker{}', False, 1),
-    'controllernode': ProgInfo(11, 'mcs-controllernode', 'fg', True),
-    'PrimProc': ProgInfo(5, 'mcs-primproc', '', False, 1),
-    'ExeMgr': ProgInfo(9, 'mcs-exemgr', '', False, 1),
-    'WriteEngineServer': ProgInfo(7, 'mcs-writeengineserver', '', False, 3),
-    'DMLProc': ProgInfo(3, 'mcs-dmlproc', '', False),
-    'DDLProc': ProgInfo(1, 'mcs-ddlproc', '', False),
+    MCSProgs.STORAGE_MANAGER: ProgInfo(15, 'mcs-storagemanager', '', False, 1),
+    MCSProgs.WORKER_NODE: ProgInfo(13, 'mcs-workernode', 'DBRM_Worker{}', False, 1),
+    MCSProgs.CONTROLLER_NODE: ProgInfo(11, 'mcs-controllernode', 'fg', True),
+    MCSProgs.PRIM_PROC: ProgInfo(5, 'mcs-primproc', '', False, 1),
+    MCSProgs.WRITE_ENGINE_SERVER: ProgInfo(7, 'mcs-writeengineserver', '', False, 3),
+    MCSProgs.DML_PROC: ProgInfo(3, 'mcs-dmlproc', '', False),
+    MCSProgs.DDL_PROC: ProgInfo(1, 'mcs-ddlproc', '', False),
 }
 
 # constants for docker container dispatcher

cmapi/cmapi_server/controllers/api_clients.py

@@ -68,6 +68,7 @@ def add_node(
         :param node_info: Information about the node to add.
         :return: The response from the API.
         """
+        #TODO: fix interface as in remove_node used or think about universal
         return self._request('PUT', 'node', {**node_info, **extra})
 
     def remove_node(

cmapi/cmapi_server/controllers/endpoints.py

@@ -434,7 +434,7 @@ def put_config(self):
                 MCSProcessManager.stop_node(
                     is_primary=node_config.is_primary_node(),
                     use_sudo=use_sudo,
-                    timeout=request_timeout
+                    timeout=request_timeout,
                 )
             except CMAPIBasicError as err:
                 raise_422_error(
@@ -463,6 +463,7 @@ def put_config(self):
                     MCSProcessManager.start_node(
                         is_primary=node_config.is_primary_node(),
                         use_sudo=use_sudo,
+                        is_read_only=node_config.is_read_only(),
                     )
                 except CMAPIBasicError as err:
                     raise_422_error(
@@ -666,7 +667,8 @@ def put_start(self):
         try:
             MCSProcessManager.start_node(
                 is_primary=node_config.is_primary_node(),
-                use_sudo=use_sudo
+                use_sudo=use_sudo,
+                is_read_only=node_config.is_read_only(),
             )
         except CMAPIBasicError as err:
             raise_422_error(
@@ -701,7 +703,7 @@ def put_shutdown(self):
             MCSProcessManager.stop_node(
                 is_primary=node_config.is_primary_node(),
                 use_sudo=use_sudo,
-                timeout=timeout
+                timeout=timeout,
             )
         except CMAPIBasicError as err:
             raise_422_error(
@@ -910,16 +912,21 @@ def put_add_node(self):
         node = request_body.get('node', None)
         config = request_body.get('config', DEFAULT_MCS_CONF_PATH)
         in_transaction = request_body.get('in_transaction', False)
+        read_only = request_body.get('read_only', False)
+        add_other_nodes_dbroots = request_body.get('add_other_nodes_dbroots', True)
 
         if node is None:
             raise_422_error(module_logger, func_name, 'missing node argument')
 
+        if not read_only and ('add_other_nodes_dbroots' in request_body):
+            raise_422_error(module_logger, func_name, 'add_other_nodes_dbroots is only valid when read_only is true')
+
         try:
             if not in_transaction:
                 with TransactionManager(extra_nodes=[node]):
-                    response = ClusterHandler.add_node(node, config)
+                    response = ClusterHandler.add_node(node, config, read_only, add_other_nodes_dbroots)
             else:
-                response = ClusterHandler.add_node(node, config)
+                response = ClusterHandler.add_node(node, config, read_only, add_other_nodes_dbroots)
         except CMAPIBasicError as err:
             raise_422_error(module_logger, func_name, err.message)
 

cmapi/cmapi_server/handlers/cluster.py

@@ -15,7 +15,7 @@
     get_current_key, get_version, update_revision_and_manager,
 )
 from cmapi_server.node_manipulation import (
-    add_node, add_dbroot, remove_node, switch_node_maintenance,
+    add_node, add_dbroot, remove_node, switch_node_maintenance, update_dbroots_of_readonly_nodes,
 )
 from mcs_node_control.models.misc import get_dbrm_master
 from mcs_node_control.models.node_config import NodeConfig
@@ -50,7 +50,7 @@ def toggle_cluster_state(
     broadcast_new_config(config, distribute_secrets=True)
 
 
-class ClusterHandler():
+class ClusterHandler:
     """Class for handling MCS Cluster operations."""
 
     @staticmethod
@@ -140,14 +140,22 @@ def shutdown(
         return {'timestamp': operation_start_time}
 
     @staticmethod
-    def add_node(node: str, config: str = DEFAULT_MCS_CONF_PATH) -> dict:
+    def add_node(
+        node: str, config: str = DEFAULT_MCS_CONF_PATH,
+        read_only: bool = False,
+        add_other_nodes_dbroots: bool = True,
+    ) -> dict:
         """Method to add node to MCS CLuster.
 
         :param node: node IP or name or FQDN
         :type node: str
         :param config: columnstore xml config file path,
                        defaults to DEFAULT_MCS_CONF_PATH
         :type config: str, optional
+        :param read_only: add node in read-only mode (not starting write engine), defaults to False
+        :type read_only: bool, optional
+        :param add_other_nodes_dbroots: for read-only nodes, whether to add dbroots of other nodes
+        :type add_other_nodes_dbroots: bool, optional
         :raises CMAPIBasicError: on exception while starting transaction
         :raises CMAPIBasicError: if transaction start isn't successful
         :raises CMAPIBasicError: on exception while adding node
@@ -158,20 +166,29 @@ def add_node(node: str, config: str = DEFAULT_MCS_CONF_PATH) -> dict:
         :rtype: dict
         """
         logger: logging.Logger = logging.getLogger('cmapi_server')
-        logger.debug(f'Cluster add node command called. Adding node {node}.')
+        logger.debug(
+            f'Cluster add node command called. Adding node {node} in '
+            f'{"read-only" if read_only else "read-write"} mode.'
+        )
 
         response = {'timestamp': str(datetime.now())}
 
+        if not read_only and add_other_nodes_dbroots is not True:
+            raise CMAPIBasicError('add_other_nodes_dbroots is only valid when read_only is true')
+
         try:
             add_node(
                 node, input_config_filename=config,
-                output_config_filename=config
+                output_config_filename=config,
+                read_only=read_only,
+                add_other_nodes_dbroots=add_other_nodes_dbroots,
             )
             if not get_dbroots(node, config):
-                add_dbroot(
-                    host=node, input_config_filename=config,
-                    output_config_filename=config
-                )
+                if not read_only:  # Read-only nodes don't own dbroots
+                    add_dbroot(
+                        host=node, input_config_filename=config,
+                        output_config_filename=config
+                    )
         except Exception as err:
             raise CMAPIBasicError('Error while adding node.') from err
 
@@ -214,12 +231,16 @@ def remove_node(node: str, config: str = DEFAULT_MCS_CONF_PATH) -> dict:
                 node, input_config_filename=config,
                 output_config_filename=config
             )
+
         except Exception as err:
             raise CMAPIBasicError('Error while removing node.') from err
 
         response['node_id'] = node
         active_nodes = get_active_nodes(config)
         if len(active_nodes) > 0:
+            with NodeConfig().modify_config(config) as root:
+                update_dbroots_of_readonly_nodes(root)
+
             update_revision_and_manager(
                 input_config_filename=config, output_config_filename=config
             )

cmapi/cmapi_server/helpers.py

@@ -11,7 +11,6 @@
 import socket
 import time
 from collections import namedtuple
-from functools import partial
 from random import random
 from shutil import copyfile
 from typing import Tuple, Optional
@@ -136,6 +135,10 @@ def start_transaction(
         # this copy will be updated if an optional node can't be reached
         real_active_nodes = set(active_nodes)
         logging.trace(f'Active nodes on start transaction {active_nodes}')
+
+        if not len(active_nodes):
+            logging.warning('No active nodes found, transaction start will not have any effect')
+
         for node in active_nodes:
             url = f'https://{node}:8640/cmapi/{version}/node/begin'
             node_success = False
@@ -379,7 +382,7 @@ async def update_config(node: str, headers: dict, body: dict) -> None:
                 ) as response:
                     resp_json =  await response.json(encoding='utf-8')
                     response.raise_for_status()
-                logging.info(f'Node {node} config put successfull.')
+                logging.info(f'Node {node} config put successful.')
             except aiohttp.ClientResponseError as err:
                 # TODO: may be better to check if resp status is 422 cause
                 #       it's like a signal that cmapi server raised it in
@@ -577,6 +580,7 @@ def get_dbroots(node, config=DEFAULT_MCS_CONF_PATH):
     dbroots = []
     smc_node = root.find('./SystemModuleConfig')
     mod_count = int(smc_node.find('./ModuleCount3').text)
+
     for i in range(1, mod_count+1):
         ip_addr = smc_node.find(f'./ModuleIPAddr{i}-1-3').text
         hostname = smc_node.find(f'./ModuleHostName{i}-1-3').text
@@ -596,6 +600,7 @@ def get_dbroots(node, config=DEFAULT_MCS_CONF_PATH):
                 dbroots.append(
                     smc_node.find(f"./ModuleDBRootID{i}-{j}-3").text
                 )
+
     return dbroots
 
 

cmapi/cmapi_server/logging_management.py

@@ -104,7 +104,8 @@ def enable_console_logging(logger: logging.Logger) -> None:
 def config_cmapi_server_logging():
     # add custom level TRACE only for develop purposes
     # could be activated using API endpoints or cli tool without relaunching
-    add_logging_level('TRACE', 5)
+    if not hasattr(logging, 'TRACE'):
+        add_logging_level('TRACE', 5)
     cherrypy._cplogging.LogManager.error = custom_cherrypy_error
     # reconfigure cherrypy.access log message format
     # Default access_log_format '{h} {l} {u} {t} "{r}" {s} {b} "{f}" "{a}"'