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Hive LLAP cache issue.

Hive LLAP cache issue.

HDP version - 2.6.2.14

I have enable the HIVE LLAP and configured successfully. I have enable the cache also with following property

hive.llap.io.memory.mode=cache

But still cache is not in use .

Please help to resolve the issue.

83492-cache.png

3 REPLIES 3

Re: Hive LLAP cache issue.

Cloudera Employee

@Ashnee Sharma based on little info shared by you, below is my guess-

The cache will only come into picture when similar data is being used by queries being run. If there is no overlap of any data in executing queries. Cache has no impact at all (as cache is empty when first query is run), the cache data will keep changing for every new (and data exclusive) query, base son cache size.

If, the above is not the case, then pleas share hive-interective server logs to further debug it.

Re: Hive LLAP cache issue.

@nkumar

We are not overlapping the data. And log files are very huge not able to attach here.

Re: Hive LLAP cache issue.

Explorer

Can you check value of hive.llap.io.enabled?  It should be checked.  hive.llap.io.enabled and hive.llap.io.memory.mode are the only two that will determine if cache is used or not.  If both of these are set, you should make sure that the queries that you are running are hitting actually data and pruning isn't skipping everything (e.g. if queryset is select col from tbl where date="2019-01-01" and there isn't any data in 2019-01-01 then you wont ever get anything in your cache).

 

James