add_column_family not documented about cassandra

[ryanking]

The cassandra 0.7 support is still experimental. You're going to have to just read the code for now.

[sdruon-spotuse]

The code says that the method takes "cf_def" as argument:
add_column_family(cf_def)
What is cf_def then?

Thanks a lot in advance

Sébastien Druon

[kyptin]

I figured out a few things about cf_def should be. I'm posting it here in case it's helpful to someone.

I'm able to get the cf_def for a keyspace that I added through the cassandra-cli tool. First of all, here are the commands that I used to create the keyspace:

create keyspace testing;
use testing;
create column family ServerData with column_type=Standard and comparator=LongType;

Then, here's how I access the cf_def object from within Ruby code (or irb):

require 'cassandra/0.7'
connection = Cassandra.new('testing', '127.0.0.1:9160')
keyspaces = connection.send('client').describe_keyspaces
keyspace_def = keyspaces.find{|ks| ks.name=='testing'}
cf_def = keyspace_def.cf_defs.first

Then, puts cf_def.inspect prints:

<CassandraThrift::CfDef keyspace:"testing", name:"ServerData", column_type:"Standard", comparator_type:"org.apache.cassandra.db.marshal.LongType", comment:"", row_cache_size:0.0, key_cache_size:200000.0, read_repair_chance:1.0, column_metadata:[], gc_grace_seconds:864000, default_validation_class:"org.apache.cassandra.db.marshal.BytesType", id:1035, min_compaction_threshold:4, max_compaction_threshold:32, row_cache_save_period_in_seconds:0, key_cache_save_period_in_seconds:14400, memtable_flush_after_mins:1440, memtable_throughput_in_mb:364, memtable_operations_in_millions:1.70625>

I still haven't figured out how to create a CassandraThrift::CfDef instance, but at least that's a start.