Cassandra Backup

cassandra.py

from trove.guestagent.strategies.backup import base
from eventlet.green import subprocess


class CassandraDump(base.BackupRunner):
    """ Implementation of Backup Strategy for CassandraDump """
    __strategy_name__ = 'cassandradump'

    # The '-' will redirect the output to stdout for streaming
    cmd = ('sudo tar cpfP - '
           '$(sudo find /var/lib/cassandra/data/ -type d -name %(filename)s)')
           
    
    def pre_cmd(self):
        # TODO: Need to add pre_command to base class
        # TODO: Add kwargs to base class
        pre_cmd = 'nodetool snapshot -t %(filename)s' % self.kwargs
        subprocess.check_call(pre_cmd, shell=True)
    
    def run(self):
        self.pre_cmd()
        super(CassandraDump, self).run()
        self.post_cmd()
    
    def post_cmd():
        # see https://review.openstack.org/#/c/55311/
        # TODO: Do some post processing to see if nodetool worked?
        subprocess.check_call('nodetool clearsnapshot', shell=True)
        return True
    
    def check_process():
        # check for error logs?
        pass
        
    @property
    def filename(self):
        return '%s.tar' % self.base_filename

It could work but, at check_process it would be better to use utils.execute_with_timeout, which would allow to handle output and then check if output contains "all keyspaces"

about "-h 127.0.0.1" - it is not necassery because nodetool connects cassandra by several hosts (lo, eth0 etc).

about data_dir, since data dir is configurable, it would be better to read it from config file.

this is just a rough idea, I didn't completely test it. I think the check_process should be the post_dump command I was referring to.