On 2014-11-17 09:56, Erik Forsberg wrote:
> On 2014-11-15 01:24, Tyler Hobbs wrote:
>> What version of cassandra did you originally create the column family
>> in? Have you made any schema changes to it through cql or
>> cassandra-cli, or has it always been exactly the same?
>
> Oh that's a tough question given that the cluster has been around since
> 2011. So CF was probably created in Cassandra 0.7 or 0.8 via thrift
> calls from pycassa, and I don't think there has been any schema changes
> to it since.
Actually, I don't think it matters. I created a minimal repeatable set
of python code (see below). Running that against a 2.0.11 server,
creating fresh keyspace and CF, then insert some data with
thrift/pycassa, then trying to extract the data that has a different
validation class, the python-driver and cqlsh bails out.
cqlsh example after running the below script:
cqlsh:badcql> select * from "Users" where column1 = 'default_account_id'
ALLOW FILTERING;
value "\xf9\x8bu}!\xe9C\xbb\xa7=\xd0\x8a\xff';\xe5" (in col 'value')
can't be deserialized as text: 'utf8' codec can't decode byte 0xf9 in
position 0: invalid start byte
cqlsh:badcql> select * from "Users" where column1 = 'date_created' ALLOW
FILTERING;
value '\x00\x00\x00\x00Ti\xe0\xbe' (in col 'value') can't be
deserialized as text: 'utf8' codec can't decode bytes in position 6-7:
unexpected end of data
So the question remains - how do I work with this data from cqlsh and /
or the python driver?
Thanks,
\EF
--repeatable example--
#!/usr/bin/env python
# Run this in virtualenv with pycassa and cassandra-driver installed via pip
import pycassa
import cassandra
import calendar
import traceback
import time
from uuid import uuid4
keyspace = "badcql"
sysmanager = pycassa.system_manager.SystemManager("localhost")
sysmanager.create_keyspace(keyspace,
strategy_options={'replication_factor':'1'})
sysmanager.create_column_family(keyspace, "Users",
key_validation_class=pycassa.system_manager.LEXICAL_UUID_TYPE,
comparator_type=pycassa.system_manager.ASCII_TYPE,
default_validation_class=pycassa.system_manager.UTF8_TYPE)
sysmanager.create_index(keyspace, "Users", "username",
pycassa.system_manager.UTF8_TYPE)
sysmanager.create_index(keyspace, "Users", "email",
pycassa.system_manager.UTF8_TYPE)
sysmanager.alter_column(keyspace, "Users", "default_account_id",
pycassa.system_manager.LEXICAL_UUID_TYPE)
sysmanager.create_index(keyspace, "Users", "active",
pycassa.system_manager.INT_TYPE)
sysmanager.alter_column(keyspace, "Users", "date_created",
pycassa.system_manager.LONG_TYPE)
pool = pycassa.pool.ConnectionPool(keyspace, ['localhost:9160'])
cf = pycassa.ColumnFamily(pool, "Users")
user_uuid = uuid4()
cf.insert(user_uuid, {'username':'test_username', 'auth_method':'ldap',
'email':'t...@example.com', 'active':1,
'date_created':long(calendar.timegm(time.gmtime())),
'default_account_id':uuid4()})
from cassandra.cluster import Cluster
cassandra_cluster = Cluster(["localhost"])
cassandra_session = cassandra_cluster.connect(keyspace)
print "username", cassandra_session.execute('SELECT value from "Users"
where key = %s and column1 = %s', (user_uuid, 'username',))
print "email", cassandra_session.execute('SELECT value from "Users"
where key = %s and column1 = %s', (user_uuid, 'email',))
try:
print "default_account_id", cassandra_session.execute('SELECT value
from "Users" where key = %s and column1 = %s', (user_uuid,
'default_account_id',))
except Exception as e:
print "Exception trying to get default_account_id",
traceback.format_exc()
cassandra_session = cassandra_cluster.connect(keyspace)
try:
print "active", cassandra_session.execute('SELECT value from "Users"
where key = %s and column1 = %s', (user_uuid, 'active',))
except Exception as e:
print "Exception trying to get active", traceback.format_exc()
cassandra_session = cassandra_cluster.connect(keyspace)
try:
print "date_created", cassandra_session.execute('SELECT value from
"Users" where key = %s and column1 = %s', (user_uuid, 'date_created',))
except Exception as e:
print "Exception trying to get date_created", traceback.format_exc()
-- end of example --
