cbkeyinfo

#! /usr/bin/env python

# This script is in the PUBLIC DOMAIN and comes with NO WARRANTY OF ANY KIND.
# Written by Tim Smith <tim@couchbase.com> This script is unsupported. It did
# work for me at the time it was written.

# The Couchbase client library is not installed in the default python path,
# so in most cases it is necessary to tell Python where to find it. An
# example of calling this program:
#
# $ PYTHONPATH=/opt/couchbase/lib/python ./cbkeyinfo  --cluster 10.4.2.14:11211 foo bar 
# {'key_cas': '854284',
#  'key_data_age': '0',
#  'key_dirtied': '0',
#  'key_exptime': '0',
#  'key_flags': '0',
#  'key_is_dirty': '0',
#  'key_last_modification_time': '1348701870',
#  'key_name': 'foo',
#  'key_valid': 'valid'}
# {'key_name': 'bar'}
#
# Here the 'foo' key exists, and the 'bar' key does not. The stats command does
# not return an error when the key doesn't exist when going through moxi (on port
# 11211).
#
# Here is an example talking directly to memcached (on port 11210), instead:
#
# $ PYTHONPATH=/opt/couchbase/lib/python ./cbkeyinfo  --cluster 10.4.2.14:11210 foo bar 
# ERROR: key 'foo', <MemcachedError #4 ``Invalid arguments''>
# ERROR: key 'bar', <MemcachedError #1 ``Not found''>
# $ PYTHONPATH=/opt/couchbase/lib/python ./cbkeyinfo  --cluster 10.4.2.12:11210 foo bar
# {'key_cas': '854284',
#  'key_data_age': '0',
#  'key_dirtied': '0',
#  'key_exptime': '0',
#  'key_flags': '0',
#  'key_is_dirty': '0',
#  'key_last_modification_time': '1348702370',
#  'key_name': 'foo',
#  'key_valid': 'valid'}
# ERROR: key 'bar', <MemcachedError #4 ``Invalid arguments''>
#
# If you get an "Invalid Arguments" error, you asked for a key that doesn't
# live on that node. If you get "Not found", you asked the right node, but
# the key doesn't exist.

import mc_bin_client
from optparse import OptionParser
from pprint import pformat, pprint
import zlib

def vbucket_id_for_key(key, vbucket_count = 1024):
    return int((zlib.crc32(key) >> 16) & (vbucket_count - 1))

parser = OptionParser(usage = "usage: %prog [options] key1 [key2...]")
parser.add_option("-c", "--cluster", dest="cluster", default="localhost:11211", help="cluster HOST:PORT")
parser.add_option("-b", "--bucket", dest="bucket", default="default", help="bucket name")
parser.add_option("-p", "--password", dest="password", default="", help="bucket password")

(options, args) = parser.parse_args()

#pprint(options)
#pprint(args)

host, port = options.cluster.split(':')
port = int(port)

mc = mc_bin_client.MemcachedClient(host, port)
mc.sasl_auth_plain(options.bucket, options.password)

for key in args:
    try:
        vbid = vbucket_id_for_key(key)
        stats = mc.stats('vkey %s %d' % (key, vbid))
        stats['key_name'] = key
        stats['key_vbucket'] = vbid
        pprint(stats)
    except mc_bin_client.MemcachedError, e:
        print "ERROR: key '%s', %s" % (key, pformat(e))