[CASSANDRA-13549] Cqlsh throws and error when querying a duration data type

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.11.0, 4.0-alpha1, 4.0
• Component/s: Legacy/CQL

Environment

Cassandra 3.10 dev environment running on a MacOS Sierra

• Severity: Normal
• Assignee: Akhil Mehra
• Reporter: Akhil Mehra

Authors

Akhil Mehra

Reviewers

Benjamin Lerer

• Created: 23/May/17 23:00
• Updated: 15/May/20 08:05
• Resolved: 29/May/17 15:46

Description

Overview

Querying duration related data from the cqlsh prompt results in an error.

Consider the following create table and insert statement.

Table and insert statement with duration data type

CREATE TABLE duration_test (
  primary_key text,
  col20 duration,
  PRIMARY KEY (primary_key)
);
INSERT INTO duration_test (primary_key, col20) VALUES ('primary_key_example', 1y5mo89h4m48s);

On executing a select query on col20 in cqlsh I get an error "Failed to format value '"\x00\xfe\x02GS\xfc\xa5\xc0\x00' : 'ascii' codec can't decode byte 0xfe in position 2: ordinal not in range(128)"

Duration Query

Select  col20 from duration_test;

Investigation

On investigating this further I found that the current python Cassandra driver used found in lib/cassandra-driver-internal-only-3.7.0.post0-2481531.zip does not seem to support duration data type. This was added in Jan this year https://github.com/datastax/python-driver/pull/689.

So I downloaded the latest driver release https://github.com/datastax/python-driver/releases/tag/3.9.0. I embedded the latest driver into cassandra-driver-internal-only-3.7.0.post0-2481531.zip. This fixed the driver related issue but there was still a formatting issue.

I then went on to modify the format_value_duration methos in the pylib/cqlshlib/formatting.py. Diff posted below

 @formatter_for('Duration')
 def format_value_duration(val, colormap, **_):
-    buf = six.iterbytes(val)
-    months = decode_vint(buf)
-    days = decode_vint(buf)
-    nanoseconds = decode_vint(buf)
-    return format_python_formatted_type(duration_as_str(months, days, nanoseconds), colormap, 'duration')
+    return format_python_formatted_type(duration_as_str(val.months, val.days, val.nanoseconds), colormap, 'duration')

This resulted in fixing the issue and duration types are now correctly displayed.

Happy to fix the issue if I can get some guidance on:

1. If this is a valid issue. Tried searching JIRA but did not find anything reported.
2. If my assumptions are correct i.e. this is actually a bug
3. how to package the new driver into the source code.