You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@kudu.apache.org by "Todd Lipcon (JIRA)" <ji...@apache.org> on 2017/03/20 02:56:41 UTC
[jira] [Updated] (KUDU-1802) Deserializing scan tokens should avoid
round-trip to master
[ https://issues.apache.org/jira/browse/KUDU-1802?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Todd Lipcon updated KUDU-1802:
------------------------------
Labels: ramp-up (was: )
> Deserializing scan tokens should avoid round-trip to master
> -----------------------------------------------------------
>
> Key: KUDU-1802
> URL: https://issues.apache.org/jira/browse/KUDU-1802
> Project: Kudu
> Issue Type: Improvement
> Components: client, perf
> Affects Versions: 1.2.0
> Reporter: Todd Lipcon
> Labels: ramp-up
>
> Currently, KuduScanToken::DeserializeIntoScanner calls KuduClient::OpenTable() which makes a GetTableSchema call to the master. This round trip is a bit expensive because it's always a "thundering herd" for an Impala query or Spark job -- every host deserializes a bunch of scan tokens at the same time and ends up having to back off.
> We should consider some ways to avoid this.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)