path: root/src/tools/cephfs/top/cephfs-top

#!/usr/bin/python3

import argparse
import sys
import curses
import errno
import json
import signal
import time
import math
import threading

from collections import OrderedDict
from datetime import datetime
from enum import Enum, unique

import rados


class FSTopException(Exception):
    def __init__(self, msg=''):
        self.error_msg = msg

    def get_error_msg(self):
        return self.error_msg


@unique
class MetricType(Enum):
    METRIC_TYPE_NONE = 0
    METRIC_TYPE_PERCENTAGE = 1
    METRIC_TYPE_LATENCY = 2
    METRIC_TYPE_SIZE = 3
    METRIC_TYPE_STDEV = 4


FS_TOP_PROG_STR = 'cephfs-top'
FS_TOP_ALL_FS_APP = 'ALL_FS_APP'
FS_TOP_FS_SELECTED_APP = 'SELECTED_FS_APP'

# version match b/w fstop and stats emitted by mgr/stats
FS_TOP_SUPPORTED_VER = 2

ITEMS_PAD_LEN = 3
ITEMS_PAD = " " * ITEMS_PAD_LEN
DEFAULT_REFRESH_INTERVAL = 1
# min refresh interval allowed
MIN_REFRESH_INTERVAL = 0.5

# metadata provided by mgr/stats
FS_TOP_MAIN_WINDOW_COL_CLIENT_ID = "client_id"
FS_TOP_MAIN_WINDOW_COL_MNT_ROOT = "mount_root"
FS_TOP_MAIN_WINDOW_COL_MNTPT_HOST_ADDR = "mount_point@host/addr"

MAIN_WINDOW_TOP_LINE_ITEMS_START = [ITEMS_PAD,
                                    FS_TOP_MAIN_WINDOW_COL_CLIENT_ID,
                                    FS_TOP_MAIN_WINDOW_COL_MNT_ROOT]
MAIN_WINDOW_TOP_LINE_ITEMS_END = [FS_TOP_MAIN_WINDOW_COL_MNTPT_HOST_ADDR]

MAIN_WINDOW_TOP_LINE_METRICS_LEGACY = ["READ_LATENCY",
                                       "WRITE_LATENCY",
                                       "METADATA_LATENCY"
                                       ]

# adjust this map according to stats version and maintain order
# as emitted by mgr/stast
MAIN_WINDOW_TOP_LINE_METRICS = OrderedDict([
    ("CAP_HIT", MetricType.METRIC_TYPE_PERCENTAGE),
    ("READ_LATENCY", MetricType.METRIC_TYPE_LATENCY),
    ("WRITE_LATENCY", MetricType.METRIC_TYPE_LATENCY),
    ("METADATA_LATENCY", MetricType.METRIC_TYPE_LATENCY),
    ("DENTRY_LEASE", MetricType.METRIC_TYPE_PERCENTAGE),
    ("OPENED_FILES", MetricType.METRIC_TYPE_NONE),
    ("PINNED_ICAPS", MetricType.METRIC_TYPE_NONE),
    ("OPENED_INODES", MetricType.METRIC_TYPE_NONE),
    ("READ_IO_SIZES", MetricType.METRIC_TYPE_SIZE),
    ("WRITE_IO_SIZES", MetricType.METRIC_TYPE_SIZE),
    ("AVG_READ_LATENCY", MetricType.METRIC_TYPE_LATENCY),
    ("STDEV_READ_LATENCY", MetricType.METRIC_TYPE_STDEV),
    ("AVG_WRITE_LATENCY", MetricType.METRIC_TYPE_LATENCY),
    ("STDEV_WRITE_LATENCY", MetricType.METRIC_TYPE_STDEV),
    ("AVG_METADATA_LATENCY", MetricType.METRIC_TYPE_LATENCY),
    ("STDEV_METADATA_LATENCY", MetricType.METRIC_TYPE_STDEV),
])
MGR_STATS_COUNTERS = list(MAIN_WINDOW_TOP_LINE_METRICS.keys())

FS_TOP_VERSION_HEADER_FMT = '{prog_name} - {now}'
FS_TOP_CLIENT_HEADER_FMT = 'Total Client(s): {num_clients} - '\
    '{num_mounts} FUSE, {num_kclients} kclient, {num_libs} libcephfs'
FS_TOP_NAME_TOPL_FMT = 'Filesystem: {fs_name} - {client_count} client(s)'

CLIENT_METADATA_KEY = "client_metadata"
CLIENT_METADATA_MOUNT_POINT_KEY = "mount_point"
CLIENT_METADATA_MOUNT_ROOT_KEY = "root"
CLIENT_METADATA_IP_KEY = "IP"
CLIENT_METADATA_HOSTNAME_KEY = "hostname"
CLIENT_METADATA_VALID_METRICS_KEY = "valid_metrics"

GLOBAL_METRICS_KEY = "global_metrics"
GLOBAL_COUNTERS_KEY = "global_counters"

last_time = time.time()
last_read_size = {}
last_write_size = {}

fs_list = []


def calc_perc(c):
    if c[0] == 0 and c[1] == 0:
        return 0.0
    return round((c[0] / (c[0] + c[1])) * 100, 2)


def calc_lat(c):
    return round(c[0] * 1000 + c[1] / 1000000, 2)


def calc_stdev(c):
    stdev = 0.0
    if c[1] > 1:
        stdev = math.sqrt(c[0] / (c[1] - 1)) / 1000000
    return round(stdev, 2)


# in MB
def calc_size(c):
    return round(c[1] / (1024 * 1024), 2)


# in MB
def calc_avg_size(c):
    if c[0] == 0:
        return 0.0
    return round(c[1] / (c[0] * 1024 * 1024), 2)


# in MB/s
def calc_speed(size, duration):
    if duration == 0:
        return 0.0
    return round(size / (duration * 1024 * 1024), 2)


def wrap(s, sl):
    """return a '+' suffixed wrapped string"""
    if len(s) < sl:
        return s
    return f'{s[0:sl-1]}+'


class FSTop(object):
    def __init__(self, args):
        self.rados = None
        self.stdscr = None  # curses instance
        self.current_screen = ""
        self.client_name = args.id
        self.cluster_name = args.cluster
        self.conffile = args.conffile
        self.refresh_interval_secs = args.delay
        self.PAD_HEIGHT = 10000  # height of the fstop_pad
        self.PAD_WIDTH = 300  # width of the fstop_pad
        self.exit_ev = threading.Event()

    def handle_signal(self, signum, _):
        self.exit_ev.set()

    def init(self):
        try:
            if self.conffile:
                r_rados = rados.Rados(rados_id=self.client_name,
                                      clustername=self.cluster_name,
                                      conffile=self.conffile)
            else:
                r_rados = rados.Rados(rados_id=self.client_name,
                                      clustername=self.cluster_name)
            r_rados.conf_read_file()
            r_rados.connect()
            self.rados = r_rados
        except rados.Error as e:
            if e.errno == errno.ENOENT:
                raise FSTopException(f'cluster {self.cluster_name}'
                                     ' does not exist')
            else:
                raise FSTopException(f'error connecting to cluster: {e}')
        self.verify_perf_stats_support()
        signal.signal(signal.SIGTERM, self.handle_signal)
        signal.signal(signal.SIGINT, self.handle_signal)

    def fini(self):
        if self.rados:
            self.rados.shutdown()
            self.rados = None

    def selftest(self):
        stats_json = self.perf_stats_query()
        if not stats_json['version'] == FS_TOP_SUPPORTED_VER:
            raise FSTopException('perf stats version mismatch!')
        missing = [m for m in stats_json["global_counters"]
                   if m.upper() not in MGR_STATS_COUNTERS]
        if missing:
            raise FSTopException('Cannot handle unknown metrics from'
                                 f'\'ceph fs perf stats\': {missing}')

    def get_fs_names(self):
        mon_cmd = {'prefix': 'fs ls', 'format': 'json'}
        try:
            ret, buf, out = self.rados.mon_command(json.dumps(mon_cmd), b'')
        except Exception as e:
            raise FSTopException(f'Error in fs ls: {e}')
        fs_map = json.loads(buf.decode('utf-8'))
        global fs_list
        fs_list.clear()
        for filesystem in fs_map:
            fs = filesystem['name']
            fs_list.append(fs)
        return fs_list

    def setup_curses(self, win):
        self.stdscr = win
        self.stdscr.keypad(True)
        curses.use_default_colors()
        curses.start_color()
        try:
            curses.curs_set(0)
        except curses.error:
            # If the terminal do not support the visibility
            # requested it will raise an exception
            pass
        self.fstop_pad = curses.newpad(self.PAD_HEIGHT, self.PAD_WIDTH)
        self.run_all_display()

    def display_fs_menu(self, stdscr, selected_row_idx):
        stdscr.clear()
        h, w = stdscr.getmaxyx()
        global fs_list
        if not fs_list:
            title = ['No filesystem available',
                     'Press "q" to go back to home (All Filesystem Info) screen']
            pos_x1 = w // 2 - len(title[0]) // 2
            pos_x2 = w // 2 - len(title[1]) // 2
            stdscr.addstr(1, pos_x1, title[0], curses.A_STANDOUT | curses.A_BOLD)
            stdscr.addstr(3, pos_x2, title[1])
        else:
            title = ['Filesystems', 'Press "q" to go back to home (All Filesystem Info) screen']
            pos_x1 = w // 2 - len(title[0]) // 2
            pos_x2 = w // 2 - len(title[1]) // 2
            stdscr.addstr(1, pos_x1, title[0], curses.A_STANDOUT | curses.A_BOLD)
            stdscr.addstr(3, pos_x2, title[1])
            for index, name in enumerate(fs_list):
                x = w // 2 - len(name) // 2
                y = h // 2 - len(fs_list) // 2 + index
                if index == selected_row_idx:
                    stdscr.attron(curses.color_pair(1))
                    stdscr.addstr(y, x, name)
                    stdscr.attroff(curses.color_pair(1))
                else:
                    stdscr.addstr(y, x, name)
        stdscr.refresh()

    def set_key(self, stdscr):
        curses.curs_set(0)
        curses.init_pair(1, curses.COLOR_BLACK, curses.COLOR_WHITE)
        curr_row = 0
        key = 0
        endmenu = False
        while not endmenu:
            global fs_list
            fs_list = self.get_fs_names()

            if key == curses.KEY_UP and curr_row > 0:
                curr_row -= 1
            elif key == curses.KEY_DOWN and curr_row < len(fs_list) - 1:
                curr_row += 1
            elif (key in [curses.KEY_ENTER, 10, 13]) and fs_list:
                self.stdscr.erase()
                self.run_display(fs_list[curr_row])
                endmenu = True
            elif key == ord('q'):
                self.stdscr.erase()
                self.run_all_display()
                endmenu = True

            try:
                self.display_fs_menu(stdscr, curr_row)
            except curses.error:
                pass
            curses.halfdelay(self.refresh_interval_secs)
            key = stdscr.getch()

    def set_option(self, opt):
        if opt == ord('m'):
            curses.wrapper(self.set_key)
        elif opt == ord('q'):
            if self.current_screen == FS_TOP_ALL_FS_APP:
                quit()
            else:
                self.run_all_display()

    def verify_perf_stats_support(self):
        mon_cmd = {'prefix': 'mgr module ls', 'format': 'json'}
        try:
            ret, buf, out = self.rados.mon_command(json.dumps(mon_cmd), b'')
        except Exception as e:
            raise FSTopException(f'error checking \'stats\' module: {e}')
        if ret != 0:
            raise FSTopException(f'error checking \'stats\' module: {out}')
        if 'stats' not in json.loads(buf.decode('utf-8'))['enabled_modules']:
            raise FSTopException('\'stats\' module not enabled. Use'
                                 '\'ceph mgr module enable stats\' to enable')

    def perf_stats_query(self):
        mgr_cmd = {'prefix': 'fs perf stats', 'format': 'json'}
        try:
            ret, buf, out = self.rados.mgr_command(json.dumps(mgr_cmd), b'')
        except Exception as e:
            raise FSTopException(f'error in \'perf stats\' query: {e}')
        if ret != 0:
            raise FSTopException(f'error in \'perf stats\' query: {out}')
        return json.loads(buf.decode('utf-8'))

    def items(self, item):
        if item == "CAP_HIT":
            return "chit"
        if item == "READ_LATENCY":
            return "rlat"
        if item == "WRITE_LATENCY":
            return "wlat"
        if item == "METADATA_LATENCY":
            return "mlat"
        if item == "DENTRY_LEASE":
            return "dlease"
        if item == "OPENED_FILES":
            return "ofiles"
        if item == "PINNED_ICAPS":
            return "oicaps"
        if item == "OPENED_INODES":
            return "oinodes"
        if item == "READ_IO_SIZES":
            return "rtio"
        if item == "WRITE_IO_SIZES":
            return "wtio"
        if item == 'AVG_READ_LATENCY':
            return 'rlatavg'
        if item == 'STDEV_READ_LATENCY':
            return 'rlatsd'
        if item == 'AVG_WRITE_LATENCY':
            return 'wlatavg'
        if item == 'STDEV_WRITE_LATENCY':
            return 'wlatsd'
        if item == 'AVG_METADATA_LATENCY':
            return 'mlatavg'
        if item == 'STDEV_METADATA_LATENCY':
            return 'mlatsd'
        else:
            # return empty string for none type
            return ''

    def mtype(self, typ):
        if typ == MetricType.METRIC_TYPE_PERCENTAGE:
            return "(%)"
        elif typ == MetricType.METRIC_TYPE_LATENCY:
            return "(ms)"
        elif typ == MetricType.METRIC_TYPE_SIZE:
            return "(MB)"
        elif typ == MetricType.METRIC_TYPE_STDEV:
            return "(ms)"
        else:
            # return empty string for none type
            return ''

    def avg_items(self, item):
        if item == "READ_IO_SIZES":
            return "raio"
        if item == "WRITE_IO_SIZES":
            return "waio"
        else:
            # return empty string for none type
            return ''

    def speed_items(self, item):
        if item == "READ_IO_SIZES":
            return "rsp"
        if item == "WRITE_IO_SIZES":
            return "wsp"
        else:
            # return empty string for none type
            return ''

    def speed_mtype(self, typ):
        if typ == MetricType.METRIC_TYPE_SIZE:
            return "(MB/s)"
        else:
            # return empty string for none type
            return ''

    @staticmethod
    def has_metric(metadata, metrics_key):
        return metrics_key in metadata

    @staticmethod
    def has_metrics(metadata, metrics_keys):
        for key in metrics_keys:
            if not FSTop.has_metric(metadata, key):
                return False
        return True

    def create_top_line_and_build_coord(self):
        xp = 0
        x_coord_map = {}

        heading = []
        for item in MAIN_WINDOW_TOP_LINE_ITEMS_START:
            heading.append(item)
            nlen = len(item) + len(ITEMS_PAD)
            x_coord_map[item] = (xp, nlen)
            xp += nlen

        for item, typ in MAIN_WINDOW_TOP_LINE_METRICS.items():
            if item in MAIN_WINDOW_TOP_LINE_METRICS_LEGACY:
                continue
            it = f'{self.items(item)}{self.mtype(typ)}'
            heading.append(it)
            nlen = len(it) + len(ITEMS_PAD)
            x_coord_map[item] = (xp, nlen)
            xp += nlen

            if item == "READ_IO_SIZES" or item == "WRITE_IO_SIZES":
                # average io sizes
                it = f'{self.avg_items(item)}{self.mtype(typ)}'
                heading.append(it)
                nlen = len(it) + len(ITEMS_PAD)
                if item == "READ_IO_SIZES":
                    x_coord_map["READ_IO_AVG"] = (xp, nlen)
                if item == "WRITE_IO_SIZES":
                    x_coord_map["WRITE_IO_AVG"] = (xp, nlen)
                xp += nlen

                # io speeds
                it = f'{self.speed_items(item)}{self.speed_mtype(typ)}'
                heading.append(it)
                nlen = len(it) + len(ITEMS_PAD)
                if item == "READ_IO_SIZES":
                    x_coord_map["READ_IO_SPEED"] = (xp, nlen)
                if item == "WRITE_IO_SIZES":
                    x_coord_map["WRITE_IO_SPEED"] = (xp, nlen)
                xp += nlen

        for item in MAIN_WINDOW_TOP_LINE_ITEMS_END:
            heading.append(item)
            nlen = len(item) + len(ITEMS_PAD)
            x_coord_map[item] = (xp, nlen)
            xp += nlen
        title = ITEMS_PAD.join(heading)
        self.fsstats.addstr(self.tablehead_y, 0, title, curses.A_STANDOUT | curses.A_BOLD)
        return x_coord_map

    def create_client(self, client_id, metrics, counters,
                      client_meta, x_coord_map, y_coord):
        global last_time
        size = 0
        cur_time = time.time()
        duration = cur_time - last_time
        last_time = cur_time
        for item in MAIN_WINDOW_TOP_LINE_ITEMS_START:
            coord = x_coord_map[item]
            hlen = coord[1] - 1
            if item == FS_TOP_MAIN_WINDOW_COL_CLIENT_ID:
                self.fsstats.addstr(y_coord, coord[0],
                                    wrap(client_id.split('.')[1], hlen), curses.A_DIM)
            elif item == FS_TOP_MAIN_WINDOW_COL_MNT_ROOT:
                if FSTop.has_metric(client_meta,
                                    CLIENT_METADATA_MOUNT_ROOT_KEY):
                    self.fsstats.addstr(
                        y_coord, coord[0],
                        wrap(client_meta[CLIENT_METADATA_MOUNT_ROOT_KEY], hlen), curses.A_DIM)
                else:
                    self.fsstats.addstr(y_coord, coord[0], "N/A", curses.A_DIM)

        cidx = 0
        for item in counters:
            if item in MAIN_WINDOW_TOP_LINE_METRICS_LEGACY:
                cidx += 1
                continue
            coord = x_coord_map[item]
            m = metrics[cidx]
            key = MGR_STATS_COUNTERS[cidx]
            typ = MAIN_WINDOW_TOP_LINE_METRICS[key]
            if item.lower() in client_meta.get(
                    CLIENT_METADATA_VALID_METRICS_KEY, []):
                if typ == MetricType.METRIC_TYPE_PERCENTAGE:
                    self.fsstats.addstr(y_coord, coord[0],
                                        f'{calc_perc(m)}', curses.A_DIM)
                elif typ == MetricType.METRIC_TYPE_LATENCY:
                    self.fsstats.addstr(y_coord, coord[0],
                                        f'{calc_lat(m)}', curses.A_DIM)
                elif typ == MetricType.METRIC_TYPE_STDEV:
                    self.fsstats.addstr(y_coord, coord[0],
                                        f'{calc_stdev(m)}', curses.A_DIM)
                elif typ == MetricType.METRIC_TYPE_SIZE:
                    self.fsstats.addstr(y_coord, coord[0],
                                        f'{calc_size(m)}', curses.A_DIM)

                    # average io sizes
                    if key == "READ_IO_SIZES":
                        coord = x_coord_map["READ_IO_AVG"]
                    elif key == "WRITE_IO_SIZES":
                        coord = x_coord_map["WRITE_IO_AVG"]
                    self.fsstats.addstr(y_coord, coord[0],
                                        f'{calc_avg_size(m)}', curses.A_DIM)

                    # io speeds
                    if key == "READ_IO_SIZES":
                        coord = x_coord_map["READ_IO_SPEED"]
                    elif key == "WRITE_IO_SIZES":
                        coord = x_coord_map["WRITE_IO_SPEED"]
                    size = 0
                    if key == "READ_IO_SIZES":
                        if m[1] > 0:
                            global last_read_size
                            last_size = last_read_size.get(client_id, 0)
                            size = m[1] - last_size
                            last_read_size[client_id] = m[1]
                    if key == "WRITE_IO_SIZES":
                        if m[1] > 0:
                            global last_write_size
                            last_size = last_write_size.get(client_id, 0)
                            size = m[1] - last_size
                            last_write_size[client_id] = m[1]
                    self.fsstats.addstr(y_coord, coord[0],
                                        f'{calc_speed(abs(size), duration)}', curses.A_DIM)
                else:
                    # display 0th element from metric tuple
                    self.fsstats.addstr(y_coord, coord[0], f'{m[0]}', curses.A_DIM)
            else:
                self.fsstats.addstr(y_coord, coord[0], "N/A", curses.A_DIM)
            cidx += 1

        for item in MAIN_WINDOW_TOP_LINE_ITEMS_END:
            coord = x_coord_map[item]
            wrapLen = self.PAD_WIDTH - coord[0]
            # always place the FS_TOP_MAIN_WINDOW_COL_MNTPT_HOST_ADDR in the
            # last, it will be a very long string to display
            if item == FS_TOP_MAIN_WINDOW_COL_MNTPT_HOST_ADDR:
                if FSTop.has_metrics(client_meta,
                                     [CLIENT_METADATA_MOUNT_POINT_KEY,
                                      CLIENT_METADATA_HOSTNAME_KEY,
                                      CLIENT_METADATA_IP_KEY]):
                    mount_point = f'{client_meta[CLIENT_METADATA_MOUNT_POINT_KEY]}@'\
                        f'{client_meta[CLIENT_METADATA_HOSTNAME_KEY]}/'\
                        f'{client_meta[CLIENT_METADATA_IP_KEY]}'
                    self.fsstats.addstr(
                        y_coord, coord[0],
                        wrap(mount_point, wrapLen), curses.A_DIM)
                else:
                    self.fsstats.addstr(y_coord, coord[0], "N/A", curses.A_DIM)

    def create_clients(self, x_coord_map, stats_json, fs_name):
        counters = [m.upper() for m in stats_json[GLOBAL_COUNTERS_KEY]]
        self.tablehead_y += 2
        res = stats_json[CLIENT_METADATA_KEY].get(fs_name, {})
        client_cnt = len(res)
        self.fsstats.addstr(self.tablehead_y, 0, FS_TOP_NAME_TOPL_FMT.format(
            fs_name=fs_name, client_count=client_cnt), curses.A_BOLD | curses.A_ITALIC)
        self.tablehead_y += 2
        if client_cnt:
            for client_id, metrics in \
                    stats_json[GLOBAL_METRICS_KEY][fs_name].items():
                self.create_client(
                    client_id, metrics, counters, res[client_id],
                    x_coord_map, self.tablehead_y)
                self.tablehead_y += 1

    def create_header(self, stats_json, help, screen_title="", color_id=0):
        num_clients, num_mounts, num_kclients, num_libs = 0, 0, 0, 0
        if not stats_json['version'] == FS_TOP_SUPPORTED_VER:
            self.header.addstr(0, 0, 'perf stats version mismatch!', curses.A_BOLD)
            return False
        global fs_list
        for fs_name in fs_list:
            client_metadata = stats_json[CLIENT_METADATA_KEY].get(fs_name, {})
            client_cnt = len(client_metadata)
            if client_cnt:
                num_clients = num_clients + client_cnt
                num_mounts = num_mounts + len(
                    [client for client, metadata in client_metadata.items() if
                     CLIENT_METADATA_MOUNT_POINT_KEY in metadata
                     and metadata[CLIENT_METADATA_MOUNT_POINT_KEY] != 'N/A'])
                num_kclients = num_kclients + len(
                    [client for client, metadata in client_metadata.items() if
                     "kernel_version" in metadata])
                num_libs = num_clients - (num_mounts + num_kclients)
        now = datetime.now().ctime()
        self.header.addstr(0, 0, FS_TOP_VERSION_HEADER_FMT.format(prog_name=FS_TOP_PROG_STR,
                                                                  now=now), curses.A_BOLD)
        self.header.addstr(2, 0, screen_title, curses.color_pair(color_id) | curses.A_BOLD)
        self.header.addstr(3, 0, FS_TOP_CLIENT_HEADER_FMT.format(num_clients=num_clients,
                                                                 num_mounts=num_mounts,
                                                                 num_kclients=num_kclients,
                                                                 num_libs=num_libs), curses.A_DIM)
        self.header.addstr(4, 0, help, curses.A_DIM)
        return True

    def run_display(self, fs):
        # clear the pads to have a smooth refresh
        self.header.erase()
        self.fsstats.erase()

        self.current_screen = FS_TOP_FS_SELECTED_APP
        screen_title = "Selected Filesystem Info"
        help_commands = "Press 'q' to go back to home (All Filesystem Info) screen"\
            " | Press 'm' to select another filesystem"
        curses.init_pair(3, curses.COLOR_MAGENTA, -1)

        top, left = 0, 0  # where to place pad
        vscrollOffset, hscrollOffset = 0, 0  # scroll offsets

        # calculate the initial viewport height and width
        windowsize = self.stdscr.getmaxyx()
        self.viewportHeight, self.viewportWidth = windowsize[0] - 1, windowsize[1] - 1

        # create header subpad
        self.header_height = 7
        self.header = self.fstop_pad.subwin(self.header_height, self.viewportWidth, 0, 0)

        # create fsstats subpad
        fsstats_begin_y = self.header_height
        fsstats_height = self.PAD_HEIGHT - self.header_height
        self.fsstats = self.fstop_pad.subwin(fsstats_height, self.PAD_WIDTH, fsstats_begin_y, 0)

        curses.halfdelay(1)
        cmd = self.stdscr.getch()
        while not self.exit_ev.is_set():
            if cmd in [ord('m'), ord('q')]:
                self.set_option(cmd)
                self.exit_ev.set()

            # header display
            global fs_list
            fs_list = self.get_fs_names()
            stats_json = self.perf_stats_query()
            vscrollEnd = 0
            if fs not in fs_list:
                help = "Error: The selected filesystem is not available now. " + help_commands
                self.header.erase()  # erase previous text
                self.create_header(stats_json, help, screen_title, 3)
            else:
                self.tablehead_y = 0
                help = "HELP: " + help_commands
                self.fsstats.erase()  # erase previous text

                vscrollEnd = len(stats_json[CLIENT_METADATA_KEY].get(fs, {}))
                if self.create_header(stats_json, help, screen_title, 3):
                    x_coord_map = self.create_top_line_and_build_coord()
                    self.create_clients(x_coord_map, stats_json, fs)

            # scroll and refresh
            if cmd == curses.KEY_DOWN:
                if (vscrollEnd - vscrollOffset) > 1:
                    vscrollOffset += 1
                else:
                    vscrollOffset = vscrollEnd
            elif cmd == curses.KEY_UP:
                if vscrollOffset > 0:
                    vscrollOffset -= 1
            elif cmd == curses.KEY_NPAGE:
                if (vscrollEnd - vscrollOffset) / 20 > 1:
                    vscrollOffset += 20
                else:
                    vscrollOffset = vscrollEnd
            elif cmd == curses.KEY_PPAGE:
                if vscrollOffset / 20 >= 1:
                    vscrollOffset -= 20
                else:
                    vscrollOffset = 0
            elif cmd == curses.KEY_RIGHT:
                if hscrollOffset < self.PAD_WIDTH - self.viewportWidth - 1:
                    hscrollOffset += 1
            elif cmd == curses.KEY_LEFT:
                if hscrollOffset > 0:
                    hscrollOffset -= 1
            elif cmd == curses.KEY_HOME:
                hscrollOffset = 0
            elif cmd == curses.KEY_END:
                hscrollOffset = self.PAD_WIDTH - self.viewportWidth - 1
            elif cmd == curses.KEY_RESIZE:
                # terminal resize event. Update the viewport dimensions
                windowsize = self.stdscr.getmaxyx()
                self.viewportHeight, self.viewportWidth = windowsize[0] - 1, windowsize[1] - 1

            if cmd:
                try:
                    # refresh the viewport for the header portion
                    if cmd not in [curses.KEY_DOWN,
                                   curses.KEY_UP,
                                   curses.KEY_NPAGE,
                                   curses.KEY_PPAGE,
                                   curses.KEY_RIGHT,
                                   curses.KEY_LEFT]:
                        self.fstop_pad.refresh(0, 0,
                                               top, left,
                                               top + self.header_height, left + self.viewportWidth)
                    # refresh the viewport for the current table header portion in the fsstats pad
                    if cmd not in [curses.KEY_DOWN,
                                   curses.KEY_UP,
                                   curses.KEY_NPAGE,
                                   curses.KEY_PPAGE]:
                        self.fstop_pad.refresh(fsstats_begin_y, hscrollOffset,
                                               top + fsstats_begin_y, left,
                                               7, left + self.viewportWidth)
                    # refresh the viewport for the current client records portion in the fsstats pad
                    self.fstop_pad.refresh(fsstats_begin_y + 1 + vscrollOffset, hscrollOffset,
                                           top + fsstats_begin_y + 2, left,
                                           top + self.viewportHeight, left + self.viewportWidth)
                except curses.error:
                    # This happens when the user switches to a terminal of different zoom size.
                    # just retry it.
                    pass
            # End scroll and refresh

            curses.halfdelay(self.refresh_interval_secs * 10)
            cmd = self.stdscr.getch()

    def run_all_display(self):
        # clear text from the previous screen
        if self.current_screen == FS_TOP_FS_SELECTED_APP:
            self.header.erase()

        self.current_screen = FS_TOP_ALL_FS_APP
        screen_title = "All Filesystem Info"
        curses.init_pair(2, curses.COLOR_CYAN, -1)

        top, left = 0, 0  # where to place pad
        vscrollOffset, hscrollOffset = 0, 0  # scroll offsets

        # calculate the initial viewport height and width
        windowsize = self.stdscr.getmaxyx()
        self.viewportHeight, self.viewportWidth = windowsize[0] - 1, windowsize[1] - 1

        # create header subpad
        self.header_height = 7
        self.header = self.fstop_pad.subwin(self.header_height, self.viewportWidth, 0, 0)

        # create fsstats subpad
        fsstats_begin_y = self.header_height
        fsstats_height = self.PAD_HEIGHT - self.header_height
        self.fsstats = self.fstop_pad.subwin(fsstats_height, self.PAD_WIDTH, fsstats_begin_y, 0)

        curses.halfdelay(1)
        cmd = self.stdscr.getch()
        while not self.exit_ev.is_set():
            if cmd in [ord('m'), ord('q')]:
                self.set_option(cmd)
                self.exit_ev.set()

            # header display
            global fs_list
            fs_list = self.get_fs_names()
            stats_json = self.perf_stats_query()
            vscrollEnd = 0
            if not fs_list:
                help = "INFO: No filesystem is available [Press 'q' to quit]"
                self.header.erase()  # erase previous text
                self.fsstats.erase()
                self.create_header(stats_json, help, screen_title, 2)
            else:
                self.tablehead_y = 0
                help = "HELP: Press 'm' to select a filesystem | Press 'q' to quit"
                self.fsstats.erase()  # erase previous text
                for index, fs in enumerate(fs_list):
                    #  Get the vscrollEnd in advance
                    vscrollEnd += len(stats_json[CLIENT_METADATA_KEY].get(fs, {}))
                    if self.create_header(stats_json, help, screen_title, 2):
                        if not index:  # do it only for the first fs
                            x_coord_map = self.create_top_line_and_build_coord()
                        self.create_clients(x_coord_map, stats_json, fs)

            # scroll and refresh
            if cmd == curses.KEY_DOWN:
                if (vscrollEnd - vscrollOffset) > 1:
                    vscrollOffset += 1
                else:
                    vscrollOffset = vscrollEnd
            elif cmd == curses.KEY_UP:
                if vscrollOffset > 0:
                    vscrollOffset -= 1
            elif cmd == curses.KEY_NPAGE:
                if (vscrollEnd - vscrollOffset) / 20 > 1:
                    vscrollOffset += 20
                else:
                    vscrollOffset = vscrollEnd
            elif cmd == curses.KEY_PPAGE:
                if vscrollOffset / 20 >= 1:
                    vscrollOffset -= 20
                else:
                    vscrollOffset = 0
            elif cmd == curses.KEY_RIGHT:
                if hscrollOffset < self.PAD_WIDTH - self.viewportWidth - 1:
                    hscrollOffset += 1
            elif cmd == curses.KEY_LEFT:
                if hscrollOffset > 0:
                    hscrollOffset -= 1
            elif cmd == curses.KEY_HOME:
                hscrollOffset = 0
            elif cmd == curses.KEY_END:
                hscrollOffset = self.PAD_WIDTH - self.viewportWidth - 1
            elif cmd == curses.KEY_RESIZE:
                # terminal resize event. Update the viewport dimensions
                windowsize = self.stdscr.getmaxyx()
                self.viewportHeight, self.viewportWidth = windowsize[0] - 1, windowsize[1] - 1
            if cmd:
                try:
                    # refresh the viewport for the header portion
                    if cmd not in [curses.KEY_DOWN,
                                   curses.KEY_UP,
                                   curses.KEY_NPAGE,
                                   curses.KEY_PPAGE,
                                   curses.KEY_RIGHT,
                                   curses.KEY_LEFT]:
                        self.fstop_pad.refresh(0, 0,
                                               top, left,
                                               top + self.header_height, left + self.viewportWidth)
                    # refresh the viewport for the current table header portion in the fsstats pad
                    if cmd not in [curses.KEY_DOWN,
                                   curses.KEY_UP,
                                   curses.KEY_NPAGE,
                                   curses.KEY_PPAGE]:
                        self.fstop_pad.refresh(fsstats_begin_y, hscrollOffset,
                                               top + fsstats_begin_y, left,
                                               7, left + self.viewportWidth)
                    # refresh the viewport for the current client records portion in the fsstats pad
                    self.fstop_pad.refresh(fsstats_begin_y + 1 + vscrollOffset, hscrollOffset,
                                           top + fsstats_begin_y + 2, left,
                                           top + self.viewportHeight, left + self.viewportWidth)
                except curses.error:
                    # This happens when the user switches to a terminal of different zoom size.
                    # just retry it.
                    pass
            # End scroll and refresh

            curses.halfdelay(self.refresh_interval_secs * 10)
            cmd = self.stdscr.getch()
# End class FSTop


if __name__ == '__main__':
    def float_greater_than(x):
        value = float(x)
        if value < MIN_REFRESH_INTERVAL:
            raise argparse.ArgumentTypeError(
                'Refresh interval should be greater than or equal to'
                f' {MIN_REFRESH_INTERVAL}')
        return value

    parser = argparse.ArgumentParser(description='Ceph Filesystem top utility')
    parser.add_argument('--cluster', nargs='?', const='ceph', default='ceph',
                        help='Ceph cluster to connect (defualt: ceph)')
    parser.add_argument('--id', nargs='?', const='fstop', default='fstop',
                        help='Ceph user to use to connection (default: fstop)')
    parser.add_argument('--conffile', nargs='?', default=None,
                        help='Path to cluster configuration file')
    parser.add_argument('--selftest', dest='selftest', action='store_true',
                        help='Run in selftest mode')
    parser.add_argument('-d', '--delay', nargs='?',
                        default=DEFAULT_REFRESH_INTERVAL,
                        type=float_greater_than,
                        help='Refresh interval in seconds '
                        f'(default: {DEFAULT_REFRESH_INTERVAL})')

    args = parser.parse_args()
    err = False
    ft = FSTop(args)
    try:
        ft.init()
        if args.selftest:
            ft.selftest()
            sys.stdout.write("selftest ok\n")
        else:
            curses.wrapper(ft.setup_curses)
    except FSTopException as fst:
        err = True
        sys.stderr.write(f'{fst.get_error_msg()}\n')
    except Exception as e:
        err = True
        sys.stderr.write(f'exception: {e}\n')
    finally:
        ft.fini()
    sys.exit(0 if not err else -1)