Tracing error "object is not iterable"

Question

Cassandra writes to a table are slow(the write latency was 38ms per insertion). I was trying to find out why by turning tracing on. However I get this error, which I don't understand. Note that the inserts themselves do succeed. I am using cassandra 1.2.5

Error: 'NoneType' object is not iterable

Here is the insert:

insert into table1(col1, col2, col3,
                   col15, col6, col11,
                   col12, col13, col14,
                   col7,col8, col10,
                   col9, col4, col5)
            values (6000000, 1, 'name_1', 'name_alias_1',
                    false,false, 676, 59455,
                    'REG', 'ADM', 'CRT', 'AST', 
                    {'1000000001', '1000000002', '1000000003', '1000000004'}, 
                    '2013-06-26 19:44:36', '2013-06-26 19:44:36');

and here is the table desc:

CREATE TABLE table1 (
  col1 bigint,
  col2 bigint,
  col3 text,
  col4 timestamp,
  col5 timestamp,
  col6 boolean,
  col7 text,
  col8 text,
  col9 set<text>,
  col10 text,
  col11 boolean,
  col12 bigint,
  col13 int,
  col14 text,
  col15 text
  PRIMARY KEY (col1, col2)
) WITH
  bloom_filter_fp_chance=0.010000 AND
  caching='KEYS_ONLY' AND
  comment='' AND
  dclocal_read_repair_chance=0.000000 AND
  gc_grace_seconds=864000 AND
  read_repair_chance=0.100000 AND
  replicate_on_write='true' AND
  populate_io_cache_on_flush='false' AND
  compaction={'class': 'SizeTieredCompactionStrategy'} AND
  compression={'sstable_compression': 'SnappyCompressor'};

Answer 1

This is a bug in pre-1.2.6 Tracing (https://issues.apache.org/jira/browse/CASSANDRA-5668). The only fix is to upgrade.