[
https://issues.apache.org/jira/browse/CASSANDRA-8051?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14507414#comment-14507414
]
Tyler Hobbs commented on CASSANDRA-8051:
----------------------------------------
The patch handles setting serial consistency levels for reads, but not for
writes. This section of the python driver docs explains how
{{consistency_level}} and {{serial_consistency_level}} work in conjunction:
http://datastax.github.io/python-driver/api/cassandra/query.html#cassandra.query.Statement.serial_consistency_level.
To support setting the {{serial_consistency_level}} for writes, we probably
need a new cqlsh command: {{SERIAL CONSISTENCY}}.
> Add SERIAL and LOCAL_SERIAL consistency levels to cqlsh
> -------------------------------------------------------
>
> Key: CASSANDRA-8051
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8051
> Project: Cassandra
> Issue Type: Bug
> Components: Tools
> Reporter: Nicolas Favre-Felix
> Assignee: Carl Yeksigian
> Priority: Minor
> Labels: cqlsh
> Fix For: 2.0.15
>
> Attachments: 8051-2.0.txt
>
>
> cqlsh does not support setting the serial consistency level. The default
> CL.SERIAL does not let users safely execute LWT alongside an app that runs at
> LOCAL_SERIAL, and can prevent any LWT from running when a DC is down (e.g.
> with 2 DCs, RF=3 in each.)
> Implementing this well is a bit tricky. A user setting the serial CL will
> probably not want all of their statements to have a serial CL attached, but
> only the conditional updates. At the same time it would be useful to support
> serial reads. "WITH CONSISTENCY LEVEL" used to provide this flexibility.
> I believe that it is currently impossible to run a SELECT at SERIAL or
> LOCAL_SERIAL; the only workaround seems to be to run a conditional update
> with a predicate that always resolves to False, and to rely on the CAS
> response to read the data.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
