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New Contributor
Posts: 1
Registered: ‎10-17-2018

Kudu table consistency on tablet servers using impala JDBC

Hello,

 

I've an issue with updating an impala kudu table by cloudera impala JDBC driver version: 2.5.43

 

The case:

1. Application updates some kudu table by setting new value to some column.

2. Immediately after updating the application invokes sql request that query this table along with others

3. This application suppose that this table is updated however sometimes the query returns an old data.

  

The replication factor is 3 so I think that updating has happened on one tablet server but query has gone to other tablet server. The application works right if it waits for a couple of seconds between point 1 and 2.

 

Is it possible somehow to avoid such kind of inconsistency?

 

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Cloudera Employee
Posts: 16
Registered: ‎11-12-2013

Re: Kudu table consistency on tablet servers using impala JDBC

Impala doesn't provide "read your writes" consistency by default. In order to enable it, you need to reconfigure your Impala daemons with --kudu_read_mode=READ_AT_SNAPSHOT.

See https://community.cloudera.com/t5/Interactive-Short-cycle-SQL/KUDU-Does-impala-scan-READ-LATEST-mode... for more information.
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