Question

I am trying out some basic queries with Cassandra CounterColumnFamily from the cli. I basically have a column family ‘page_view_counts’ with Row Key as url. Each row has 3 counts (impressions, conversions and revenue) associated with it. I have indexed one of the counts as I want to retrieve rows with conversion > 10 etc.

This is output for describe page_view_counts:

  ColumnFamily: page_view_counts
  Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
  Default column value validator: org.apache.cassandra.db.marshal.CounterColumnType
  Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
  GC grace seconds: 864000
  Compaction min/max thresholds: 4/32
  Read repair chance: 0.1
  DC Local Read repair chance: 0.0
  Replicate on write: true
  Caching: KEYS_ONLY
  Bloom Filter FP chance: default
  Column Metadata:
    Column Name: conversion
      Validation Class: org.apache.cassandra.db.marshal.CounterColumnType
      Index Name: page_view_counts_conversion_idx
      Index Type: KEYS
  Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy
  Compression Options:
    sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor

some sample data in my column family:

RowKey: row27
=> (counter=conversion, value=27000)
=> (counter=impression, value=54000)
=> (counter=revenue, value=81000)
------------------- 
RowKey: row29
=> (counter=conversion, value=29000)
=> (counter=impression, value=58000)
=> (counter=revenue, value=87000)
------------------- 
RowKey: row81
=> (counter=conversion, value=81000)
=> (counter=impression, value=162000)
=> (counter=revenue, value=243000)

But I am getting these errors when I do the following queries :

[default@hector] get page_view_counts where conversion>23;
invalid operation for commutative columnfamily page_view_counts
[default@hector] get page_view_counts where conversion=long('1000');
invalid operation for commutative columnfamily page_view_counts
[default@hector] get page_view_counts where conversion=1000;
invalid operation for commutative columnfamily page_view_counts
[default@hector] get page_view_counts where KEY='row81';
java.lang.NumberFormatException: An hex string representing bytes must have an even length
[default@hector] get page_view_counts where KEY=bytes('row81');
java.lang.RuntimeException: java.lang.RuntimeException: org.apache.cassandra.db.marshal.MarshalException: cannot parse 'row81' as hex bytes
[default@hector] get page_view_counts where KEY=utf8('row81');
invalid operation for commutative columnfamily page_view_counts

Can someone please help me with this?

Thanks.

Answer 1

Try this:

assume page_view_counts keys as UTF8Type;
get page_view_counts['row81'];