hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Enis Söztutar <e...@apache.org>
Subject Re: maybe waste on blockCache
Date Mon, 20 Jun 2016 20:59:20 GMT
LRUBlock cache does not reserve the space for the in_memory tier. The space
is used for other tiers as well as long as there is space.

You can read the code at LRUBlockCache.evict() to learn more.

Enis

On Thu, Jun 16, 2016 at 1:21 AM, WangYQ <wangyongqiang0617@163.com> wrote:

> in hbase 0.98.10, if we use LruBlockCache, and set regionServer's max heap
> to 10G
> in default:
> the size of in_memory priority of LruBlockCache is :
> 10G * 0.4 * 0.25 = 1G
>
>
> 0.4: hfile.block.cache.size
> 0.25: hbase.lru.blockcache.memory.percentage
>
>
> if we do not set any user tables IN_MEMORY to true, then the whole hbase
> just need to cache hbase:meta data to in_memory LruBlockCache.
> hbase:meta does not split , so just need one regionServer to cache, so
> there is some waste in blockCache
>
>
> i think the regionServer open hbase:meta need to set  in_memory
> LruBlockCache to a certain size
> other regionServer set hbase.lru.blockcache.memory.percentage to 0, do not
> need to allocate  in_memory LruBlockCache.

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message