kafka/tools/assigner/models/reassignment.py
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#
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import json
import os
import re
import subprocess
import time
from tempfile import NamedTemporaryFile
from kafka.tools import log
from kafka.tools.exceptions import ReassignmentFailedException
from kafka.tools.models import BaseModel
class Reassignment(BaseModel):
equality_attrs = ['partitions']
def __init__(self, partitions, pause_time=10):
self.partitions = partitions
self.pause_time = pause_time
self.status_re = re.compile('.*Reassignment of partition.*?\s+(failed|still in progress|completed successfully)')
def __repr__(self):
return json.dumps(self.dict_for_reassignment())
def dict_for_reassignment(self):
reassignment = {'partitions': [], 'version': 1}
for partition in self.partitions:
reassignment['partitions'].append(partition.dict_for_reassignment())
return reassignment
def execute(self, num, total, zookeeper, tools_path, plugins=[], dry_run=True):
for plugin in plugins:
plugin.before_execute_batch(num)
if not dry_run:
self._execute(num, total, zookeeper, tools_path)
for plugin in plugins:
plugin.after_execute_batch(num)
def _execute(self, num, total, zookeeper, tools_path):
with NamedTemporaryFile(mode='w') as assignfile:
json.dump(self.dict_for_reassignment(), assignfile)
assignfile.flush()
FNULL = open(os.devnull, 'w')
proc = subprocess.Popen(['{0}/kafka-reassign-partitions.sh'.format(tools_path), '--execute',
'--zookeeper', zookeeper,
'--reassignment-json-file', assignfile.name],
stdout=FNULL, stderr=FNULL)
proc.wait()
# Wait until finished
while True:
remaining_partitions = self.check_completion(zookeeper, tools_path, assignfile.name)
if remaining_partitions == 0:
break
log.info('Partition reassignment {0}/{1} in progress [ {2}/{3} partitions remain ]. Sleeping {4} seconds'.format(num,
total,
remaining_partitions,
len(self.partitions),
self.pause_time))
time.sleep(self.pause_time)
def process_verify_match(self, line):
match_obj = self.status_re.match(line)
if match_obj:
if match_obj.group(1) == 'failed':
return -1
elif match_obj.group(1) == 'still in progress':
return 1
return 0
def check_completion(self, zookeeper, tools_path, assign_filename):
FNULL = open(os.devnull, 'w')
proc = subprocess.Popen(['{0}/kafka-reassign-partitions.sh'.format(tools_path), '--verify',
'--zookeeper', zookeeper,
'--reassignment-json-file', assign_filename],
stdout=subprocess.PIPE, stderr=FNULL)
lines = proc.stdout.readlines()
remaining_count = 0
for line in lines:
count = self.process_verify_match(line.decode())
if count < 0:
raise ReassignmentFailedException("The reassignment in progress failed with the following verification output:\n{0}".format(lines))
remaining_count += count
return remaining_count