hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Joydeep Sen Sarma (JIRA)" <>
Subject [jira] Commented: (HIVE-1408) add option to let hive automatically run in local mode based on tunable heuristics
Date Wed, 16 Jun 2010 17:40:23 GMT


Joydeep Sen Sarma commented on HIVE-1408:

this is somewhat more complicated than i had bargained for:

- we choose local/hdfs files at query compile time based on local mode setting. however we
won't choose local mode until query compilation is complete
- we choose whether to submit job via child jvm before the point at which the pre-hook is
called. we (currently) have to submit job via child jvm for local mode
- hooks don't have access to map-reduce plans and whether there are any script operators (for

so it's not possible to implement this via hooks. (and the changes required are somewhat invasive)

> add option to let hive automatically run in local mode based on tunable heuristics
> ----------------------------------------------------------------------------------
>                 Key: HIVE-1408
>                 URL:
>             Project: Hadoop Hive
>          Issue Type: New Feature
>          Components: Query Processor
>            Reporter: Joydeep Sen Sarma
>            Assignee: Joydeep Sen Sarma
> as a followup to HIVE-543 - we should have a simple option (enabled by default) to let
hive run in local mode if possible.
> two levels of options are desirable:
> 1. // control whether local mode is automatically
> 2. Options to control different heuristics, some naiive examples:
> // don't choose local mode if data >
> // choose if local mode is enabled
for queries with user scripts
> this can be implemented as a pre/post execution hook. It makes sense to provide this
as a standard hook in the hive codebase since it's likely to improve response time for many
users (especially for test queries).
> the initial proposal is to choose this at a query level and not at per hive-task (ie.
hadoop job) level. per job-level requires more changes to compilation (to not pre-commit to
hdfs or local scratch directories at compile time).

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message