FS Stressing (my use case: Provoking ZFS on Linux hang bugs)

fs_stress.py

#!/usr/bin/env python

# Copyright (c) 2012 Ulrich Petri <mail@ulo.pe>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

"""
fs_stress.py

This script uses dd to generate read and write load on the path specified as
first command line argument.

WARNING: There are no checks for free space left on the device. This script
will keep going indefinitely.

Abort with Ctrl-C

Usage: ./fs_stress.py /path/to/test/directory
"""
from itertools import cycle
import os
import random
import sys
from tempfile import NamedTemporaryFile
from threading import Thread
from subprocess import call, Popen, PIPE, CalledProcessError
import time
import threading

try:
    from subprocess import check_output
except ImportError:
    def check_output(*popenargs, **kwargs):
        r"""Run command with arguments and return its output as a byte string.
        Backported from Python 2.7 as it's implemented as pure python on stdlib.
        """
        process = Popen(stdout=PIPE, *popenargs, **kwargs)
        output, unused_err = process.communicate()
        retcode = process.poll()
        if retcode:
            cmd = kwargs.get("args")
            if cmd is None:
                cmd = popenargs[0]
            error = CalledProcessError(retcode, cmd)
            error.output = output
            raise error
        return output

DD_PATH = check_output("which dd", shell=True)
if not DD_PATH:
    print "This utility needs the 'dd' command. Something seems to be wrong on your system."
    sys.exit(1)

DD_CMD_TEMPLATE = ("%s if=%%(source)s of=%%(target)s" % (DD_PATH,)).split()
DD_COUNT_PART = "count=%(count)d"

SPINNER_CHARS = "-\|/"

# check if we've got a GNU dd
if call("dd --version > /dev/null 2>&1", shell=True) > 0:
    DD_CMD_TEMPLATE.append("bs=1m")
else:
    DD_CMD_TEMPLATE.append("bs=1M")

class SourceGatherer(Thread):
    limit = 9

    def __init__(self, base_path, **kwargs):
        super(SourceGatherer, self).__init__(**kwargs)
        self.daemon = True
        self.base_path = base_path
        self.sources = []
        self.name = self.__class__.__name__

    def run(self):
        while True:
            if len(self.sources) > self.limit:
                time.sleep(.125)
                continue
            dir2 = None
            p1 = ""
            while not dir2:
                path1 = ""
                while not os.path.isdir(path1):
                    dir = None
                    while not dir:
                        dir = os.listdir(self.base_path)
                        time.sleep(.0625)
                    p1 = random.choice(dir)
                    path1 = os.path.join(self.base_path, p1)
                dir2 = os.listdir(path1)
            p2 = random.choice(dir2)
            self.sources.append(os.path.join(self.base_path, p1, p2))

    def get_source(self):
        while not len(self.sources):
            time.sleep(0.125)
        return self.sources.pop()

class StresserBase(Thread):
    count = None
    source = None
    target = None
    mode = "?"

    def __init__(self, base_path, **kwargs):
        super(StresserBase, self).__init__(**kwargs)
        self.base_path = base_path
        self.name = self.__class__.__name__

    def run(self):
        cmd = DD_CMD_TEMPLATE[:]
        if self.count:
            cmd.append(DD_COUNT_PART)
        params = dict(
            source=self.source,
            target=self.target,
            count=self.count,
            mode=self.mode
        )
        call([part % params for part in cmd], stderr=PIPE)

class WriteStresserBase(StresserBase):
    _target = None
    mode = "W"

    @property
    def target(self):
        if not self._target:
            path = os.path.join(self.base_path, "%02d" % (random.randint(1, 99),))
            if not os.path.exists(path):
                os.mkdir(path)
            tmpfile = NamedTemporaryFile(
                dir=path,
                delete=False
            )
            self._target = tmpfile.name
            tmpfile.close()
        return self._target

class ReadStresser(StresserBase):
    target = "/dev/null"
    mode = "R"

    def __init__(self, base_path, source, **kwargs):
        super(ReadStresser, self).__init__(base_path, **kwargs)
        self.source = source

class BigWriteStresser(WriteStresserBase):
    count = 1024
    source = "/dev/zero"

class SmallWriteStresser(WriteStresserBase):
    count = 32
    source = "/dev/urandom"


class Stresser(object):
    def __init__(self, cls, arg_provider=None):
        self.cls = cls
        self.arg_provider = arg_provider
        self.instance = None
        self.spinner = cycle(SPINNER_CHARS)
        self.start_time = 0
        self.mb = 0
        self.iteration = 0

    def update(self, should_exit=False):
        if not self.instance and not should_exit:
            if self.arg_provider:
                self.instance = self.cls(*self.arg_provider())
            else:
                self.instance = self.cls(sys.argv[1])
            self.start_time = time.time()
            self.iteration += 1
            self.instance.start()
        if self.instance:
            if self.instance.is_alive():
                return "[%s: %04d: %s GB] %s (%02d s) %s => %s" % (
                    self.instance.mode,
                    self.iteration,
                    "%07.2f" % (self.mb / 1024.0) if self.instance.mode == "W" else "   -   ",
                    self.spinner.next(),
                    time.time() - self.start_time,
                    self.instance.source,
                    self.instance.target
                    )
            else:
                if self.instance.mode == "W" and self.instance.count:
                    self.mb += self.instance.count
                self.instance = None
                self.start_time = 0
        return "[-: -]"


def thread_count():
    return len([t for t in threading.enumerate() if not t.daemon and t.name != "MainThread"])

def main():
    if len(sys.argv) < 2:
        print "Usage: %s BASE_PATH" % (os.path.basename(sys.argv[0]),)
        sys.exit(1)

    sg = SourceGatherer(sys.argv[1])
    sg.start()

    reader_args = lambda: (sys.argv[1], sg.get_source())
    stressers = (
        Stresser(BigWriteStresser),
        Stresser(SmallWriteStresser),
        Stresser(SmallWriteStresser),
        Stresser(SmallWriteStresser),
        Stresser(ReadStresser, reader_args),
        Stresser(ReadStresser, reader_args),
        Stresser(ReadStresser, reader_args),
        Stresser(ReadStresser, reader_args),
        Stresser(ReadStresser, reader_args),
    )
    should_exit = False
    while not should_exit or (should_exit and thread_count() != 0):
        try:
            out = []
            for stresser in stressers:
                out.append(stresser.update(should_exit))

            os.system("clear")
            print "\n".join(out)
            print "Threads running: %02d" % (thread_count(), )
            if should_exit:
                print "Ctrl-C pressed. Waiting for threads to finish...\nPress again to force quit."
            time.sleep(.0625)
        except KeyboardInterrupt:
            if should_exit:
                # force quit
                os._exit(1)
            should_exit = True

if __name__ == "__main__":
    main()