Support Questions
Find answers, ask questions, and share your expertise
Announcements
Alert: Welcome to the Unified Cloudera Community. Former HCC members be sure to read and learn how to activate your account here.

Data Extraction-295 million rows-Client Fetch Wait Time: 2.6h, what can we about it?

Highlighted

Data Extraction-295 million rows-Client Fetch Wait Time: 2.6h, what can we about it?

Explorer

Hello,

Greetings!

I have been working on a select query to retrieve 295 million rows, the query looks like as below

SELECT 1 as nofrecords,age as age1 , desc as desc , custid FROM DB1.table1_aggr table1_aggr_aggry. This query takes too long to respond, the Web UI indicates it has 9.9 million rows produced but it does not write any thing on the terminal, Also every time the query fails after 3 hours (10.0 million rows produced) saying one of the ImpalaD is not reachable.

 

I looked at the query profile and see it as

Query Type: QUERY

  • Query State: EXCEPTION
  • Start Time: Aug 6, 2014 10:13:41 AM
  • End Time: Aug 6, 2014 12:47:40 PM
  • Duration: 2h, 33m
  • Rows Produced: 9,992,192
  • Aggregate Peak Memory Usage: 791.6 MiB
  • Bytes Streamed: 353.2 MiB
  • Client Fetch Wait Time: 2.6h
  • Client Fetch Wait Time Percentage: 100

I do understand client Fetch Wait time is taking too much time i.e 100% time but why is it so? I am just running on a terminal and How can I fix this problem ?

 

 

 

3 REPLIES 3
Highlighted

Re: Data Extraction-295 million rows-Client Fetch Wait Time: 2.6h, what can we about it?

Explorer

Also does it make any difference if you issue the same query against a view and against a table?

Highlighted

Re: Data Extraction-295 million rows-Client Fetch Wait Time: 2.6h, what can we about it?

Rising Star

Try running the shell with the -B command-line flag to disable pretty-printing. 

Highlighted

Re: Data Extraction-295 million rows-Client Fetch Wait Time: 2.6h, what can we about it?

Explorer
Even that is done it is taking 10 hours
Don't have an account?
Coming from Hortonworks? Activate your account here