Enhanced crash_gen tool to run clusters, with a new README file

tests/pytest/crash_gen/README.md

@@ -0,0 +1,130 @@
+<center><h1>User's Guide to the Crash_Gen Tool</h1></center>
+
+# Introduction
+
+To effectively test and debug our TDengine product, we have developed a simple tool to 
+exercise various functions of the system in a randomized fashion, hoping to expose 
+maximum number of problems, hopefully without a pre-determined scenario.
+
+# Preparation
+
+To run this tool, please ensure the followed preparation work is done first.
+
+1. Fetch a copy of the TDengine source code, and build it successfully in the `build/` 
+    directory
+1. Ensure that the system has Python3.8 or above properly installed. We use 
+    Ubuntu 20.04LTS as our own development environment, and suggest you also use such
+    an environment if possible.
+
+# Simple Execution
+
+To run the tool with the simplest method, follow the steps below:
+
+1. Open a terminal window, start the `taosd` service in the `build/` directory 
+    (or however you prefer to start the `taosd` service)
+1. Open another terminal window, go into the `tests/pytest/` directory, and
+    run `./crash_gen.sh -p -t 3 -s 10` (change the two parameters here as you wish)
+1. Watch the output to the end and see if you get a `SUCCESS` or `FAILURE`
+
+That's it!
+
+# Running Clusters
+
+This tool also makes it easy to test/verify the clustering capabilities of TDengine. You
+can start a cluster quite easily with the following command:
+
+```
+$ cd tests/pytest/
+$ ./crash_gen.sh -e -o 3
+```
+
+The `-e` option above tells the tool to start the service, and do not run any tests, while 
+the `-o 3` option tells the tool to start 3 DNodes and join them together in a cluster. 
+Obviously you can adjust the the number here.
+
+## Behind the Scenes
+
+When the tool runs a cluster, it users a number of directories, each holding the information
+for a single DNode, see:
+
+```
+$ ls build/cluster*
+build/cluster_dnode_0:
+cfg  data  log
+
+build/cluster_dnode_1:
+cfg  data  log
+
+build/cluster_dnode_2:
+cfg  data  log
+```
+
+Therefore, when something goes wrong and you want to reset everything with the cluster, simple
+erase all the files:
+
+```
+$ rm -rf build/cluster_dnode_*
+```
+
+## Addresses and Ports
+
+The DNodes in the cluster all binds the the `127.0.0.1` IP address (for now anyway), and
+uses port 6030 for the first DNode, and 6130 for the 2nd one, and so on.
+
+## Testing Against a Cluster
+
+In a separate terminal window, you can invoke the tool in client mode and test against
+a cluster, such as:
+
+```
+$ ./crash_gen.sh -p -t 10 -s 100 -i 3
+```
+
+Here the `-i` option tells the tool to always create tables with 3 replicas, and run 
+all tests against such tables.
+
+# Additional Features
+
+The exhaustive features of the tool is available through the `-h` option:
+
+```
+$ ./crash_gen.sh -h
+usage: crash_gen_bootstrap.py [-h] [-a] [-b MAX_DBS] [-c CONNECTOR_TYPE] [-d] [-e] [-g IGNORE_ERRORS] [-i MAX_REPLICAS] [-l] [-n] [-o NUM_DNODES] [-p] [-r]
+                              [-s MAX_STEPS] [-t NUM_THREADS] [-v] [-x]
+
+TDengine Auto Crash Generator (PLEASE NOTICE the Prerequisites Below)
+---------------------------------------------------------------------
+1. You build TDengine in the top level ./build directory, as described in offical docs
+2. You run the server there before this script: ./build/bin/taosd -c test/cfg
+
+optional arguments:
+  -h, --help            show this help message and exit
+  -a, --auto-start-service
+                        Automatically start/stop the TDengine service (default: false)
+  -b MAX_DBS, --max-dbs MAX_DBS
+                        Maximum number of DBs to keep, set to disable dropping DB. (default: 0)
+  -c CONNECTOR_TYPE, --connector-type CONNECTOR_TYPE
+                        Connector type to use: native, rest, or mixed (default: 10)
+  -d, --debug           Turn on DEBUG mode for more logging (default: false)
+  -e, --run-tdengine    Run TDengine service in foreground (default: false)
+  -g IGNORE_ERRORS, --ignore-errors IGNORE_ERRORS
+                        Ignore error codes, comma separated, 0x supported (default: None)
+  -i MAX_REPLICAS, --max-replicas MAX_REPLICAS
+                        Maximum number of replicas to use, when testing against clusters. (default: 1)
+  -l, --larger-data     Write larger amount of data during write operations (default: false)
+  -n, --dynamic-db-table-names
+                        Use non-fixed names for dbs/tables, useful for multi-instance executions (default: false)
+  -o NUM_DNODES, --num-dnodes NUM_DNODES
+                        Number of Dnodes to initialize, used with -e option. (default: 1)
+  -p, --per-thread-db-connection
+                        Use a single shared db connection (default: false)
+  -r, --record-ops      Use a pair of always-fsynced fils to record operations performing + performed, for power-off tests (default: false)
+  -s MAX_STEPS, --max-steps MAX_STEPS
+                        Maximum number of steps to run (default: 100)
+  -t NUM_THREADS, --num-threads NUM_THREADS
+                        Number of threads to run (default: 10)
+  -v, --verify-data     Verify data written in a number of places by reading back (default: false)
+  -x, --continue-on-exception
+                        Continue execution after encountering unexpected/disallowed errors/exceptions (default: false)
+```
+

tests/pytest/crash_gen/crash_gen.py

@@ -18,6 +18,7 @@ from __future__ import annotations
 from typing import Set
 from typing import Dict
 from typing import List
+from typing import Optional # Type hinting, ref: https://stackoverflow.com/questions/19202633/python-3-type-hinting-for-none
 
 import textwrap
 import time
@@ -62,9 +63,10 @@ gContainer: Container
 
 
 class WorkerThread:
-    def __init__(self, pool: ThreadPool, tid, tc: ThreadCoordinator,
+    def __init__(self, pool: ThreadPool, tid, tc: ThreadCoordinator):
-                 # te: TaskExecutor,
+        """
-                 ):  # note: main thread context!
+            Note: this runs in the main thread context
+        """                 
         # self._curStep = -1
         self._pool = pool
         self._tid = tid
@@ -1007,6 +1009,8 @@ class Database:
         possibly in a cluster environment.
 
         For now we use it to manage state transitions in that database
+
+        TODO: consider moving, but keep in mind it contains "StateMachine"
     '''
     _clsLock = threading.Lock() # class wide lock
     _lastInt = 101  # next one is initial integer
@@ -1182,7 +1186,7 @@ class Task():
 
     def __init__(self, execStats: ExecutionStats, db: Database):
         self._workerThread = None
-        self._err = None # type: Exception
+        self._err: Optional[Exception] = None
         self._aborted = False
         self._curStep = None
         self._numRows = None  # Number of rows affected
@@ -1318,10 +1322,11 @@ class Task():
             self._aborted = True
             traceback.print_exc()
         except BaseException: # TODO: what is this again??!!
-            self.logDebug(
+            raise RuntimeError("Punt")
-                "[=] Unexpected exception, SQL: {}".format(
+            # self.logDebug(
-                    wt.getDbConn().getLastSql()))
+            #     "[=] Unexpected exception, SQL: {}".format(
-            raise
+            #         wt.getDbConn().getLastSql()))
+            # raise
         self._execStats.endTaskType(self.__class__.__name__, self.isSuccess())
 
         self.logDebug("[X] task execution completed, {}, status: {}".format(
@@ -1498,7 +1503,8 @@ class TaskCreateDb(StateTransitionTask):
         # was: self.execWtSql(wt, "create database db")
         repStr = ""
         if gConfig.max_replicas != 1:
-            numReplica = Dice.throw(gConfig.max_replicas) + 1 # 1,2 ... N
+            # numReplica = Dice.throw(gConfig.max_replicas) + 1 # 1,2 ... N
+            numReplica = gConfig.max_replicas # fixed, always
             repStr = "replica {}".format(numReplica)
         self.execWtSql(wt, "create database {} {}"
             .format(self._db.getName(), repStr) )
@@ -2050,7 +2056,7 @@ class ClientManager:
 class MainExec:
     def __init__(self):        
         self._clientMgr = None
-        self._svcMgr = None
+        self._svcMgr = None # type: ServiceManager
 
         signal.signal(signal.SIGTERM, self.sigIntHandler)
         signal.signal(signal.SIGINT,  self.sigIntHandler)
@@ -2063,17 +2069,16 @@ class MainExec:
             self._svcMgr.sigUsrHandler(signalNumber, frame)
         
     def sigIntHandler(self, signalNumber, frame):
-        if self._svcMgr:
+        if  self._svcMgr:
             self._svcMgr.sigIntHandler(signalNumber, frame)
-        if self._clientMgr:
+        if  self._clientMgr:
             self._clientMgr.sigIntHandler(signalNumber, frame)
 
     def runClient(self):
         global gSvcMgr
         if gConfig.auto_start_service:
-            self._svcMgr = ServiceManager()
+            gSvcMgr = self._svcMgr = ServiceManager() # hack alert
-            gSvcMgr = self._svcMgr # hack alert
+            gSvcMgr.startTaosService() # we start, don't run
-            self._svcMgr.startTaosService() # we start, don't run
         
         self._clientMgr = ClientManager()
         ret = None
@@ -2086,12 +2091,10 @@ class MainExec:
 
     def runService(self):
         global gSvcMgr
-        self._svcMgr = ServiceManager()
+        gSvcMgr = self._svcMgr = ServiceManager(gConfig.num_dnodes) # save it in a global variable TODO: hack alert
-        gSvcMgr = self._svcMgr # save it in a global variable TODO: hack alert
 
-        self._svcMgr.run() # run to some end state
+        gSvcMgr.run() # run to some end state
-        self._svcMgr = None 
+        gSvcMgr = self._svcMgr = None 
-        gSvcMgr = None        
 
     def init(self): # TODO: refactor
         global gContainer
@@ -2165,6 +2168,13 @@ class MainExec:
             '--dynamic-db-table-names',
             action='store_true',
             help='Use non-fixed names for dbs/tables, useful for multi-instance executions (default: false)')        
+        parser.add_argument(
+            '-o',
+            '--num-dnodes',
+            action='store',
+            default=1,
+            type=int,
+            help='Number of Dnodes to initialize, used with -e option. (default: 1)')
         parser.add_argument(
             '-p',
             '--per-thread-db-connection',
@@ -2209,7 +2219,12 @@ class MainExec:
 
     def run(self):
         if gConfig.run_tdengine:  # run server
-            self.runService()
+            try:
+                self.runService()
+                return 0 # success
+            except ConnectionError as err:
+                Logging.error("Failed to make DB connection, please check DB instance manually")
+            return -1 # failure
         else:
             return self.runClient()
 

tests/pytest/crash_gen/db.py

@@ -12,7 +12,9 @@ from util.cases import *
 from util.dnodes import *
 from util.log import *
 
-from .misc import Logging, CrashGenError, Helper
+from .misc import Logging, CrashGenError, Helper, Dice
+import os
+import datetime
 # from .service_manager import TdeInstance
 
 class DbConn:
@@ -44,6 +46,9 @@ class DbConn:
         self._lastSql = None
         self._dbTarget = dbTarget
 
+    def __repr__(self):
+        return "[DbConn: type={}, target={}]".format(self._type, self._dbTarget)
+
     def getLastSql(self):
         return self._lastSql
 
@@ -54,7 +59,7 @@ class DbConn:
         # below implemented by child classes
         self.openByType()
 
-        Logging.debug("[DB] data connection opened, type = {}".format(self._type))
+        Logging.debug("[DB] data connection opened: {}".format(self))
         self.isOpen = True
 
     def close(self):
@@ -277,15 +282,18 @@ class DbTarget:
         self.cfgPath  = cfgPath
         self.hostAddr = hostAddr
         self.port     = port
-
+    
     def __repr__(self):
         return "[DbTarget: cfgPath={}, host={}:{}]".format(
-            self.cfgPath, self.hostAddr, self.port)
+            Helper.getFriendlyPath(self.cfgPath), self.hostAddr, self.port)
+
+    def getEp(self):
+        return "{}:{}".format(self.hostAddr, self.port)
 
 class DbConnNative(DbConn):
     # Class variables
     _lock = threading.Lock()
-    _connInfoDisplayed = False
+    # _connInfoDisplayed = False # TODO: find another way to display this
     totalConnections = 0 # Not private
 
     def __init__(self, dbTarget):
@@ -304,9 +312,9 @@ class DbConnNative(DbConn):
         cls = self.__class__ # Get the class, to access class variables
         with cls._lock: # force single threading for opening DB connections. # TODO: whaaat??!!!
             dbTarget = self._dbTarget
-            if not cls._connInfoDisplayed:
+            # if not cls._connInfoDisplayed:
-                cls._connInfoDisplayed = True # updating CLASS variable
+            #     cls._connInfoDisplayed = True # updating CLASS variable
-                Logging.info("Initiating TAOS native connection to {}".format(dbTarget))                    
+            Logging.debug("Initiating TAOS native connection to {}".format(dbTarget))                    
             # Make the connection         
             # self._conn = taos.connect(host=hostAddr, config=cfgPath)  # TODO: make configurable
             # self._cursor = self._conn.cursor()
@@ -424,3 +432,4 @@ class DbManager():
 
     def cleanUp(self):
         self._dbConn.close()
+

tests/pytest/crash_gen/misc.py

@@ -1,6 +1,7 @@
 import threading
 import random
 import logging
+import os
 
 
 class CrashGenError(Exception):
@@ -26,7 +27,7 @@ class LoggingFilter(logging.Filter):
 
 class MyLoggingAdapter(logging.LoggerAdapter):
     def process(self, msg, kwargs):
-        return "[{}]{}".format(threading.get_ident() % 10000, msg), kwargs
+        return "[{}] {}".format(threading.get_ident() % 10000, msg), kwargs
         # return '[%s] %s' % (self.extra['connid'], msg), kwargs
 
 
@@ -71,12 +72,44 @@ class Logging:
     def warning(cls, msg):
         cls.logger.warning(msg)
 
+    @classmethod
+    def error(cls, msg):
+        cls.logger.error(msg)
+
 class Status:
     STATUS_STARTING = 1
     STATUS_RUNNING  = 2
     STATUS_STOPPING = 3
     STATUS_STOPPED  = 4
 
+    def __init__(self, status):
+        self.set(status)
+
+    def __repr__(self):
+        return "[Status: v={}]".format(self._status)
+
+    def set(self, status):
+        self._status = status
+
+    def get(self):
+        return self._status
+
+    def isStarting(self):
+        return self._status == Status.STATUS_STARTING
+
+    def isRunning(self):
+        # return self._thread and self._thread.is_alive()
+        return self._status == Status.STATUS_RUNNING
+
+    def isStopping(self):
+        return self._status == Status.STATUS_STOPPING
+
+    def isStopped(self):
+        return self._status == Status.STATUS_STOPPED
+
+    def isStable(self):
+        return self.isRunning() or self.isStopped()
+
 # Deterministic random number generator
 class Dice():
     seeded = False  # static, uninitialized
@@ -118,14 +151,23 @@ class Helper:
     def convertErrno(cls, errno):
         return errno if (errno > 0) else 0x80000000 + errno
 
+    @classmethod
+    def getFriendlyPath(cls, path): # returns .../xxx/yyy
+        ht1 = os.path.split(path)
+        ht2 = os.path.split(ht1[0])
+        return ".../" + ht2[1] + '/' + ht1[1]
+
+
 class Progress:
     STEP_BOUNDARY = 0
     BEGIN_THREAD_STEP = 1
     END_THREAD_STEP   = 2
+    SERVICE_HEART_BEAT= 3
     tokens = {
         STEP_BOUNDARY:      '.',
         BEGIN_THREAD_STEP:  '[',
-        END_THREAD_STEP:    '] '
+        END_THREAD_STEP:    '] ',
+        SERVICE_HEART_BEAT: '.Y.'
     }
 
     @classmethod

tests/pytest/crash_gen/service_manager.py

@@ -7,7 +7,7 @@ import logging
 import time
 import subprocess
 
-from typing import IO
+from typing import IO, List
 
 try:
     import psutil
@@ -17,7 +17,7 @@ except:
 
 from queue import Queue, Empty
 
-from .misc import Logging, Status, CrashGenError, Dice
+from .misc import Logging, Status, CrashGenError, Dice, Helper, Progress
 from .db import DbConn, DbTarget
 
 class TdeInstance():
@@ -47,12 +47,15 @@ class TdeInstance():
                 .format(selfPath, projPath))
         return buildPath
 
-    def __init__(self, subdir='test', port=6030, fepPort=6030):
+    def __init__(self, subdir='test', tInstNum=0, port=6030, fepPort=6030):
         self._buildDir  = self._getBuildPath()
         self._subdir    = '/' + subdir # TODO: tolerate "/"
         self._port      = port # TODO: support different IP address too
         self._fepPort   = fepPort
 
+        self._tInstNum    = tInstNum
+        self._smThread    = ServiceManagerThread()
+
     def getDbTarget(self):
         return DbTarget(self.getCfgDir(), self.getHostAddr(), self._port)
 
@@ -60,7 +63,8 @@ class TdeInstance():
         return self._port
 
     def __repr__(self):
-        return "[TdeInstance: {}, subdir={}]".format(self._buildDir, self._subdir)
+        return "[TdeInstance: {}, subdir={}]".format(
+            self._buildDir, Helper.getFriendlyPath(self._subdir))
     
     def generateCfgFile(self):       
         # print("Logger = {}".format(logger))
@@ -146,8 +150,52 @@ walLevel 1
     def getHostAddr(self):
         return "127.0.0.1"
 
-    def getServiceCommand(self): # to start the instance
+    def getServiceCmdLine(self): # to start the instance
         return [self.getExecFile(), '-c', self.getCfgDir()] # used in subproce.Popen()
+    
+    def _getDnodes(self, dbc):
+        dbc.query("show dnodes")
+        cols = dbc.getQueryResult() #  id,end_point,vnodes,cores,status,role,create_time,offline reason
+        return {c[1]:c[4] for c in cols} # {'xxx:6030':'ready', 'xxx:6130':'ready'}
+
+    def createDnode(self, dbt: DbTarget):
+        """
+        With a connection to the "first" EP, let's create a dnode for someone else who
+        wants to join.
+        """
+        dbc = DbConn.createNative(self.getDbTarget())
+        dbc.open()
+
+        if dbt.getEp() in self._getDnodes(dbc):
+            Logging.info("Skipping DNode creation for: {}".format(dbt))
+            dbc.close()
+            return
+
+        sql = "CREATE DNODE \"{}\"".format(dbt.getEp())
+        dbc.execute(sql)
+        dbc.close()
+
+    def getStatus(self):
+        return self._smThread.getStatus()
+
+    def getSmThread(self):
+        return self._smThread
+
+    def start(self):
+        if not self.getStatus().isStopped():
+            raise CrashGenError("Cannot start instance from status: {}".format(self.getStatus()))
+
+        Logging.info("Starting TDengine instance: {}".format(self))
+        self.generateCfgFile() # service side generates config file, client does not
+        self.rotateLogs()
+
+        self._smThread.start(self.getServiceCmdLine())
+
+    def stop(self):
+        self._smThread.stop()
+
+    def isFirst(self):
+        return self._tInstNum == 0
 
 
 class TdeSubProcess:
@@ -159,11 +207,15 @@ class TdeSubProcess:
     "a sub process runs an instance".
     """
 
-    def __init__(self, tInst : TdeInstance):
+    # RET_ALREADY_STOPPED = -1
+    # RET_TIME_OUT = -3
+    # RET_SUCCESS = -4
+
+    def __init__(self):
         self.subProcess = None
-        if tInst is None:
+        # if tInst is None:
-            raise CrashGenError("Empty instance not allowed in TdeSubProcess")
+        #     raise CrashGenError("Empty instance not allowed in TdeSubProcess")
-        self._tInst = tInst # Default create at ServiceManagerThread
+        # self._tInst = tInst # Default create at ServiceManagerThread
 
     def getStdOut(self):
         return self.subProcess.stdout
@@ -177,38 +229,15 @@ class TdeSubProcess:
     def getPid(self):
         return self.subProcess.pid
 
-    # Repalced by TdeInstance class
+    def start(self, cmdLine):
-    # def getBuildPath(self):
-    #     selfPath = os.path.dirname(os.path.realpath(__file__))
-    #     if ("community" in selfPath):
-    #         projPath = selfPath[:selfPath.find("communit")]
-    #     else:
-    #         projPath = selfPath[:selfPath.find("tests")]
-
-    #     for root, dirs, files in os.walk(projPath):
-    #         if ("taosd" in files):
-    #             rootRealPath = os.path.dirname(os.path.realpath(root))
-    #             if ("packaging" not in rootRealPath):
-    #                 buildPath = root[:len(root) - len("/build/bin")]
-    #                 break
-    #     return buildPath
-
-    def start(self):
         ON_POSIX = 'posix' in sys.builtin_module_names
 
         # Sanity check
         if self.subProcess:  # already there
             raise RuntimeError("Corrupt process state")
-
+    
-        # global gContainer
-        # tInst = gContainer.defTdeInstance = TdeInstance('test3') # creae the instance
-        self._tInst.generateCfgFile() # service side generates config file, client does not
-
-        self._tInst.rotateLogs()
-
-        print("Starting TDengine instance: {}".format(self._tInst))
         self.subProcess = subprocess.Popen(
-            self._tInst.getServiceCommand(),
+            cmdLine,
             shell=False,
             # svcCmdSingle, shell=True, # capture core dump?
             stdout=subprocess.PIPE,
@@ -218,31 +247,50 @@ class TdeSubProcess:
             )  # had text=True, which interferred with reading EOF
 
     def stop(self):
+        """
+        Stop a sub process, and try to return a meaningful return code.
+
+        Common POSIX signal values (from man -7 signal):
+        SIGHUP           1
+        SIGINT           2 
+        SIGQUIT          3 
+        SIGILL           4
+        SIGTRAP          5
+        SIGABRT          6 
+        SIGIOT           6 
+        SIGBUS           7 
+        SIGEMT           - 
+        SIGFPE           8  
+        SIGKILL          9  
+        SIGUSR1         10 
+        SIGSEGV         11
+        SIGUSR2         12
+        """
         if not self.subProcess:
             print("Sub process already stopped")
-            return -1
+            return  # -1
 
-        retCode = self.subProcess.poll() # contains real sub process return code
+        retCode = self.subProcess.poll() # ret -N means killed with signal N, otherwise it's from exit(N)
         if retCode:  # valid return code, process ended
+            retCode = -retCode # only if valid
+            Logging.warning("TSP.stop(): process ended itself")
             self.subProcess = None
-        else:  # process still alive, let's interrupt it
+            return retCode
-            print(
-                "Sub process is running, sending SIG_INT and waiting for it to terminate...")
-            # sub process should end, then IPC queue should end, causing IO
-            # thread to end
-            self.subProcess.send_signal(signal.SIGINT)
-            try:
-                self.subProcess.wait(10)
-                retCode = self.subProcess.returncode
-            except subprocess.TimeoutExpired as err:
-                print("Time out waiting for TDengine service process to exit")
-                retCode = -3
-            else:
-                print("TDengine service process terminated successfully from SIG_INT")
-                retCode = -4
-                self.subProcess = None
-        return retCode
 
+        # process still alive, let's interrupt it
+        print("Terminate running process, send SIG_INT and wait...")
+        # sub process should end, then IPC queue should end, causing IO thread to end
+        self.subProcess.send_signal(signal.SIGINT)
+        self.subProcess.wait(20)
+        retCode = self.subProcess.returncode # should always be there
+        # May throw subprocess.TimeoutExpired exception above, therefore
+        # The process is guranteed to have ended by now
+        self.subProcess = None        
+        if retCode != 0: # != (- signal.SIGINT):
+            Logging.error("TSP.stop(): Failed to stop sub proc properly w/ SIG_INT, retCode={}".format(retCode))
+        else:
+            Logging.info("TSP.stop(): sub proc successfully terminated with SIG_INT")
+        return - retCode
 
 class ServiceManager:
     PAUSE_BETWEEN_IPC_CHECK = 1.2  # seconds between checks on STDOUT of sub process
@@ -259,19 +307,25 @@ class ServiceManager:
         # self._status = MainExec.STATUS_RUNNING # set inside
         # _startTaosService()
         self._runCluster = (numDnodes >= 1)
-        self.svcMgrThreads = [] # type: List[ServiceManagerThread]
+        self._tInsts : List[TdeInstance] = []
         for i in range(0, numDnodes):
-            self.svcMgrThreads.append(ServiceManagerThread(i))
+            ti = self._createTdeInstance(i) # construct tInst
+            self._tInsts.append(ti)
 
-    def _createThread(self, dnIndex):
+        # self.svcMgrThreads : List[ServiceManagerThread] = []
-        if not self._runCluster: # single instance 
+        # for i in range(0, numDnodes):
-            return ServiceManagerThread(0)
+        #     thread = self._createThread(i) # construct tInst
+        #     self.svcMgrThreads.append(thread)
+
+    def _createTdeInstance(self, dnIndex):
+        # if not self._runCluster: # single instance 
+        #     return ServiceManagerThread(0)
         # Create all threads in a cluster
         subdir = 'cluster_dnode_{}'.format(dnIndex)
         fepPort= 6030 # firstEP Port
         port   = fepPort + dnIndex * 100
-        ti = TdeInstance(subdir, port, fepPort)
+        return TdeInstance(subdir, dnIndex, port, fepPort)
-        return ServiceManagerThread(dnIndex, ti)
+        # return ServiceManagerThread(dnIndex, ti)
 
     def _doMenu(self):
         choice = ""
@@ -336,8 +390,8 @@ class ServiceManager:
         Determine if the service/cluster is active at all, i.e. at least
         one thread is not "stopped".
         """
-        for thread in self.svcMgrThreads:
+        for ti in self._tInsts:
-            if not thread.isStopped():
+            if not ti.getStatus().isStopped():
                 return True
         return False
 
@@ -356,28 +410,31 @@ class ServiceManager:
         Determine if the service/cluster is "stable", i.e. all of the
         threads are in "stable" status.
         """
-        for thread in self.svcMgrThreads:
+        for ti in self._tInsts:
-            if not thread.isStable():
+            if not ti.isStable():
                 return False
         return True
 
     def _procIpcAll(self):
         while self.isActive():
-            for thread in self.svcMgrThreads: # all thread objects should always be valid
+            Progress.emit(Progress.SERVICE_HEART_BEAT)
+            for ti in self._tInsts: # all thread objects should always be valid
             # while self.isRunning() or self.isRestarting() :  # for as long as the svc mgr thread is still here
-                if  thread.isRunning():
+                status = ti.getStatus()
-                    thread.procIpcBatch()  # regular processing,
+                if  status.isRunning():
-                    if  thread.isStopped():
+                    th = ti.getSmThread()
-                        thread.procIpcBatch() # one last time?
+                    th.procIpcBatch()  # regular processing,
+                    if  status.isStopped():
+                        th.procIpcBatch() # one last time?
                     # self._updateThreadStatus()
-                elif thread.isRetarting():
-                    print("Service restarting...")
-                # else this thread is stopped 
                     
             time.sleep(self.PAUSE_BETWEEN_IPC_CHECK)  # pause, before next round
         # raise CrashGenError("dummy")
         print("Service Manager Thread (with subprocess) ended, main thread exiting...")
 
+    def _getFirstInstance(self):
+        return self._tInsts[0]
+
     def startTaosServices(self):
         with self._lock:
             if self.isActive():
@@ -386,15 +443,19 @@ class ServiceManager:
             # Find if there's already a taosd service, and then kill it
             for proc in psutil.process_iter():
                 if proc.name() == 'taosd':
-                    print("Killing an existing TAOSD process in 2 seconds... press CTRL-C to interrupe")
+                    print("Killing an existing TAOSD process in 2 seconds... press CTRL-C to interrupt")
                     time.sleep(2.0)
                     proc.kill()
                 # print("Process: {}".format(proc.name()))
             
             # self.svcMgrThread = ServiceManagerThread()  # create the object
-            for thread in self.svcMgrThreads:
+            
-                thread.start()            
+            for ti in self._tInsts:
-                thread.procIpcBatch(trimToTarget=10, forceOutput=True)  # for printing 10 lines                         
+                ti.start()  
+                if not ti.isFirst():                                    
+                    tFirst = self._getFirstInstance()
+                    tFirst.createDnode(ti.getDbTarget())
+                ti.getSmThread().procIpcBatch(trimToTarget=10, forceOutput=True)  # for printing 10 lines                                     
 
     def stopTaosServices(self):
         with self._lock:
@@ -402,8 +463,8 @@ class ServiceManager:
                 Logging.warning("Cannot stop TAOS service(s), already not active")
                 return
 
-            for thread in self.svcMgrThreads:
+            for ti in self._tInsts:
-                thread.stop()
+                ti.stop()
                 
     def run(self):
         self.startTaosServices()
@@ -412,7 +473,7 @@ class ServiceManager:
             self.stopTaosServices()  # should have started already
 
     def restart(self):
-        if not self.isStable():
+        if not self.getStatus().isStable():
             Logging.warning("Cannot restart service/cluster, when not stable")
             return
 
@@ -440,42 +501,27 @@ class ServiceManagerThread:
     """
     MAX_QUEUE_SIZE = 10000
 
-    def __init__(self, tInstNum = 0, tInst : TdeInstance = None):
+    def __init__(self):
         # Set the sub process
         self._tdeSubProcess = None # type: TdeSubProcess
 
         # Arrange the TDengine instance
-        self._tInstNum = tInstNum # instance serial number in cluster, ZERO based
+        # self._tInstNum = tInstNum # instance serial number in cluster, ZERO based
-        self._tInst    = tInst or TdeInstance() # Need an instance
+        # self._tInst    = tInst or TdeInstance() # Need an instance
 
         self._thread = None # The actual thread, # type: threading.Thread
-        self._status = Status.STATUS_STOPPED # The status of the underlying service, actually.
+        self._status = Status(Status.STATUS_STOPPED) # The status of the underlying service, actually.
 
     def __repr__(self):
-        return "[SvcMgrThread: tInstNum={}]".format(self._tInstNum)
+        return "[SvcMgrThread: status={}, subProc={}]".format(
+            self.getStatus(), self._tdeSubProcess)
 
     def getStatus(self):
         return self._status
 
-    def isStarting(self):
-        return self._status == Status.STATUS_STARTING
-
-    def isRunning(self):
-        # return self._thread and self._thread.is_alive()
-        return self._status == Status.STATUS_RUNNING
-
-    def isStopping(self):
-        return self._status == Status.STATUS_STOPPING
-
-    def isStopped(self):
-        return self._status == Status.STATUS_STOPPED
-
-    def isStable(self):
-        return self.isRunning() or self.isStopped()
-
     # Start the thread (with sub process), and wait for the sub service
     # to become fully operational
-    def start(self):
+    def start(self, cmdLine):
         if self._thread:
             raise RuntimeError("Unexpected _thread")
         if self._tdeSubProcess:
@@ -483,9 +529,9 @@ class ServiceManagerThread:
 
         Logging.info("Attempting to start TAOS service: {}".format(self))
 
-        self._status = Status.STATUS_STARTING
+        self._status.set(Status.STATUS_STARTING)
-        self._tdeSubProcess = TdeSubProcess(self._tInst)
+        self._tdeSubProcess = TdeSubProcess()
-        self._tdeSubProcess.start()
+        self._tdeSubProcess.start(cmdLine)
 
         self._ipcQueue = Queue()
         self._thread = threading.Thread( # First thread captures server OUTPUT
@@ -505,10 +551,11 @@ class ServiceManagerThread:
             time.sleep(1.0)
             # self.procIpcBatch() # don't pump message during start up
             print("_zz_", end="", flush=True)
-            if self._status == Status.STATUS_RUNNING:
+            if self._status.isRunning():
                 Logging.info("[] TDengine service READY to process requests")
                 Logging.info("[] TAOS service started: {}".format(self))
-                self._verifyDnode(self._tInst) # query and ensure dnode is ready
+                # self._verifyDnode(self._tInst) # query and ensure dnode is ready
+                # Logging.debug("[] TAOS Dnode verified: {}".format(self))
                 return  # now we've started
         # TODO: handle failure-to-start  better?
         self.procIpcBatch(100, True) # display output before cronking out, trim to last 20 msgs, force output
@@ -523,25 +570,27 @@ class ServiceManagerThread:
         # ret = {row[0]:row[1] for row in stCols if row[3]=='TAG'} # name:type
         isValid = False
         for col in cols:
-            print("col = {}".format(col))
+            # print("col = {}".format(col))
             ep = col[1].split(':') # 10.1.30.2:6030
-            print("ep={}".format(ep))
+            print("Found ep={}".format(ep))
             if tInst.getPort() == int(ep[1]): # That's us
-                print("Valid Dnode matched!")
+                # print("Valid Dnode matched!")
                 isValid = True # now we are valid
                 break
         if not isValid:
-            raise RuntimeError("Failed to start Dnode, port = {}, expected: {}".
+            print("Failed to start dnode, sleep for a while")
-                format(ep[1], tInst.getPort()))
+            time.sleep(600)
+            raise RuntimeError("Failed to start Dnode, expected port not found: {}".
+                format(tInst.getPort()))
         dbc.close()
 
     def stop(self):
         # can be called from both main thread or signal handler
         print("Terminating TDengine service running as the sub process...")
-        if self.isStopped():
+        if self.getStatus().isStopped():
             print("Service already stopped")
             return
-        if self.isStopping():
+        if self.getStatus().isStopping():
             print("Service is already being stopped")
             return
         # Linux will send Control-C generated SIGINT to the TDengine process
@@ -550,39 +599,42 @@ class ServiceManagerThread:
         if not self._tdeSubProcess:
             raise RuntimeError("sub process object missing")
 
-        self._status = Status.STATUS_STOPPING
+        self._status.set(Status.STATUS_STOPPING)
-        retCode = self._tdeSubProcess.stop()
+        # retCode = self._tdeSubProcess.stop()
-        print("Attempted to stop sub process, got return code: {}".format(retCode))
+        try:
-        if (retCode==-11): # SGV
+            retCode = self._tdeSubProcess.stop()
-            Logging.error("[[--ERROR--]]: TDengine service SEGV fault (check core file!)")
+            # print("Attempted to stop sub process, got return code: {}".format(retCode))
-
+            if retCode == signal.SIGSEGV : # SGV
-        if self._tdeSubProcess.isRunning():  # still running
+                Logging.error("[[--ERROR--]]: TDengine service SEGV fault (check core file!)")
-            print("FAILED to stop sub process, it is still running... pid = {}".format(
+        except subprocess.TimeoutExpired as err:
+            print("Time out waiting for TDengine service process to exit")
+        else:    
+            if self._tdeSubProcess.isRunning():  # still running, should now never happen
+                print("FAILED to stop sub process, it is still running... pid = {}".format(
                     self._tdeSubProcess.getPid()))
-        else:
+            else:
-            self._tdeSubProcess = None  # not running any more
+                self._tdeSubProcess = None  # not running any more
-            self.join()  # stop the thread, change the status, etc.
+                self.join()  # stop the thread, change the status, etc.
 
         # Check if it's really stopped
-        outputLines = 20 # for last output
+        outputLines = 10 # for last output
-        if  self.isStopped():
+        if  self.getStatus().isStopped():
             self.procIpcBatch(outputLines)  # one last time
-            print("End of TDengine Service Output: {}".format(self))
+            Logging.debug("End of TDengine Service Output: {}".format(self))
-            print("----- TDengine Service (managed by SMT) is now terminated -----\n")
+            Logging.info("----- TDengine Service (managed by SMT) is now terminated -----\n")
         else:
             print("WARNING: SMT did not terminate as expected: {}".format(self))
 
     def join(self):
         # TODO: sanity check
-        if not self.isStopping():
+        if not self.getStatus().isStopping():
             raise RuntimeError(
-                "Unexpected status when ending svc mgr thread: {}".format(
+                "SMT.Join(): Unexpected status: {}".format(self._status))
-                    self._status))
 
         if self._thread:
             self._thread.join()
             self._thread = None
-            self._status = Status.STATUS_STOPPED
+            self._status.set(Status.STATUS_STOPPED)
             # STD ERR thread
             self._thread2.join()
             self._thread2 = None
@@ -651,25 +703,27 @@ class ServiceManagerThread:
             queue.put(line)
             self._printProgress("_i")
 
-            if self._status == Status.STATUS_STARTING:  # we are starting, let's see if we have started
+            if self._status.isStarting():  # we are starting, let's see if we have started
                 if line.find(self.TD_READY_MSG) != -1:  # found
                     Logging.info("Waiting for the service to become FULLY READY")
                     time.sleep(1.0) # wait for the server to truly start. TODO: remove this
-                    Logging.info("Service instance #{} is now FULLY READY".format(self._tInstNum))   
+                    Logging.info("Service is now FULLY READY") # TODO: more ID info here?
-                    self._status = Status.STATUS_RUNNING                 
+                    self._status.set(Status.STATUS_RUNNING)
 
             # Trim the queue if necessary: TODO: try this 1 out of 10 times
             self._trimQueue(self.MAX_QUEUE_SIZE * 9 // 10)  # trim to 90% size
 
-            if self.isStopping():  # TODO: use thread status instead
+            if self._status.isStopping():  # TODO: use thread status instead
                 # WAITING for stopping sub process to finish its outptu
                 print("_w", end="", flush=True)
 
             # queue.put(line)
         # meaning sub process must have died
-        print("\nNo more output from IO thread managing TDengine service")
+        Logging.info("\nEnd of stream detected for TDengine STDOUT: {}".format(self))
         out.close()
 
     def svcErrorReader(self, err: IO, queue):
         for line in iter(err.readline, b''):
             print("\nTDengine Service (taosd) ERROR (from stderr): {}".format(line))
+        Logging.info("\nEnd of stream detected for TDengine STDERR: {}".format(self))
+        err.close()