[CASSANDRA-6309] Pig CqlStorage generates ERROR 1108: Duplicate schema alias

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 1.2.13, 2.0.4
• Severity: Normal
• Assignee: Alex Liu
• Reporter: Thunder Stumpges

Authors

Alex Liu

Reviewers

Brandon Williams

• Created: 06/Nov/13 23:15
• Updated: 16/Apr/19 09:32
• Resolved: 13/Dec/13 17:42

Description

In Pig after loading a simple CQL3 table from Cassandra 2.0.1, and dumping contents, I receive:
Caused by: org.apache.pig.impl.plan.PlanValidationException: ERROR 1108: Duplicate schema alias: author in "cm"

cm = load 'cql://thunder_test/cassandra_messages' USING CqlStorage;
dump cm
ERROR org.apache.pig.tools.grunt.Grunt - org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066: Unable to open iterator for alias cm
...
Caused by: org.apache.pig.impl.plan.PlanValidationException: ERROR 1108: Duplicate schema alias: author in "cm"
at org.apache.pig.newplan.logical.visitor.SchemaAliasVisitor.validate(SchemaAliasVisitor.java:75)

running 'describe cm' gives:
cm:

{message_id: chararray,author: chararray,author: chararray,body: chararray,message_id: chararray}

The original table schema in Cassandra is:
CREATE TABLE cassandra_messages (
message_id text,
author text,
body text,
PRIMARY KEY (message_id, author)
) WITH
bloom_filter_fp_chance=0.010000 AND
caching='KEYS_ONLY' AND
comment='null' AND
dclocal_read_repair_chance=0.000000 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.100000 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='NONE' AND
memtable_flush_period_in_ms=0 AND
compaction=

{'class': 'SizeTieredCompactionStrategy'}

AND
compression=

{'sstable_compression': 'LZ4Compressor'}

;

it appears that the code in CqlStorage.getColumnMetadata at ~line 478 takes the "keys" columns (in my case, message_id and author) and appends the columns from getColumnMeta (which has all three columns). Thus the keys columns are duplicated.