nodetool-toppartitions

#!/usr/bin/env python3

#
# Copyright (C) 2018-present ScyllaDB
#

#
# This file is part of Scylla.
#
# Scylla is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Scylla is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
#

import argparse
import os
import json
from functools import reduce
import requests

def scylla_api_get(item, params={}):
    headers = {
        'Content-Type': 'application/json',
        'Accept': 'application/json',
    }

    response = requests.get('http://127.0.0.1:10000/{}'.format(item), headers=headers, params=params)
    return response

def toppartitions(kscf, duration, list_size, capacity):
    r = scylla_api_get('column_family/toppartitions/{}'.format(kscf), {
        'duration': str(duration),
        'list_size': str(list_size),
        'capacity': str(capacity)})
    return json.loads(r.text)

def print_pks(title, map):
    print(title)
    w = reduce(lambda n, r: max(len(r['partition']), n), map, len('Partition')+3)
    print(("  %-{}s%s".format(w)) % ('Partition', 'Count'))
    for r in map:
        print(("  %-{}s%s".format(w)) % (r['partition'], r['count']))
    print()

ap = argparse.ArgumentParser(description='Samples database reads and writes and reports the most active partitions in a specified table')
ap.add_argument('-k', type=int,
    default=10, dest='list_size',
    help='The number of the top partitions to list (default: 10)')
ap.add_argument('-s', type=int,
    default=256, dest='capacity',
    help='The capacity of stream summary (default: 256)')
ap.add_argument('keyspace',
    help='Name of keyspace')
ap.add_argument('table',
    help='Name of column family')
ap.add_argument('duration', type=int,
    help='Query duration in milliseconds')

args = ap.parse_args()
res = toppartitions("{}:{}".format(args.keyspace, args.table), args.duration, args.list_size, args.capacity)
if res == {}:
    print("(nothing reported)")
    exit(1)
print_pks("READ", res["read"])
print_pks("WRITE", res["write"])
exit(0)