[
https://issues.apache.org/jira/browse/IMPALA-6843?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16702168#comment-16702168
]
Tim Armstrong commented on IMPALA-6843:
---------------------------------------
[~alexmc_bp] the general metadata concurrency issue definitely hasn't been
forgotten about and has people actively working on it. As far as I know the
people working on metadata think this idea is flawed or not the right approach
(I'm not an expert on this area) - there's a parallel effort to solve a lot of
metadata problems more comprehensively. Generally we prioritise high-impact
bugs and try to fix them promptly but this one requires some more substantial
design changes.
There's unfortunately a lot of issues in this bug tracker that are stale or
half-baked, especially in the product backlog so I appreciate it can be
confusing figuring out what is actually relevant and up-to-date.
> Responses to prioritizedLoad() requests should be returned directly and not
> via the statestore
> ----------------------------------------------------------------------------------------------
>
> Key: IMPALA-6843
> URL: https://issues.apache.org/jira/browse/IMPALA-6843
> Project: IMPALA
> Issue Type: Improvement
> Components: Catalog
> Affects Versions: Impala 2.11.0
> Reporter: Dimitris Tsirogiannis
> Priority: Major
> Labels: catalog, frontend, latency, perfomance
>
> Currently, when a statement (e.g. SELECT) needs to access some unloaded
> tables, it issues a prioritizedLoad() request to the catalog. The catalog
> loads the table metadata but does not respond directly to the coordinator
> that issued the request. Instead, the metadata for the newly loaded tables
> are broadcast via the statestore. The problem with this approach is that the
> latency of the response may vary significantly and may depend on the
> latencies of other unrelated metadata operations (e.g. REFRESH) that happen
> to be in the same topic update.
> The response to a prioritizedLoad() request should come directly to the
> issuing coordinator. Other coordinators will receive the metadata of the
> newly loaded table via the statestore.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
