As far as I can tell the cache on write settings are more global than just the 
table in question.
https://hbase.apache.org/book/config.files.html

Is there a table-level option or API level option I’m not aware of?
-Carlos


From: [email protected] [mailto:[email protected]] On Behalf Of Stack
Sent: Monday, March 31, 2014 2:59 PM
To: Rendon, Carlos (KBB)
Cc: Hbase-User
Subject: Re: Blockcache Eviction on Write?

On Mon, Mar 31, 2014 at 10:37 AM, Rendon, Carlos (KBB) 
<[email protected]<mailto:[email protected]>> wrote:
Table does not exist yet. I'm expecting random access across the rowkey 
namespace. I also expect bursts of access to a given row, all of which will 
change its contents and also read it.

My question is from reading here: 
https://hbase.apache.org/book/regionserver.arch.html#block.cache
that blockcache wastes memory/CPU/GCs if there aren't many hits to it or if you 
have random writes that you typically don't read. So I was wondering if writing 
on every read had the same effect.

After reading the recent thread "Cache invalidation in Blockcache" I can see 
that during bursts the reads would be coming from the memstore and also that 
reads still need to be made to the underlying HFiles because data from both 
sources are merged together to produce a result.

In the scenario I have, it sounds like it is useful to have the HFile blocks 
cached in the blockcache, even if the data ultimately is returned from the 
memstore due to a recent write.


And enable cache on write if you are frequently going to be just reading back 
what you wrote?

St.Ack

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