[ https://issues.apache.org/jira/browse/HBASE-15248?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15753974#comment-15753974 ]
Anoop Sam John commented on HBASE-15248: ---------------------------------------- BC is having diff sized buckets and slots in it. This sizes as per the possible HFile block sizes. By def we consider 4K, 8K... 512K.. But we give an additional +1KB size for each of the bucket size and so to a slot.. So a 4K is actually becoming 5K. And ya extra bytes are taken off by this cur header and next block header. So right now u have removed the eager fetch of next block header right? [~saint....@gmail.com].. Still the cur block, header we will need? Am trying to solve issues under the parent so that I can make HBASE-17204 to happen. > BLOCKSIZE 4k should result in 4096 bytes on disk; i.e. fit inside a > BucketCache 'block' of 4k > --------------------------------------------------------------------------------------------- > > Key: HBASE-15248 > URL: https://issues.apache.org/jira/browse/HBASE-15248 > Project: HBase > Issue Type: Sub-task > Components: BucketCache > Reporter: stack > > Chatting w/ a gentleman named Daniel Pol who is messing w/ bucketcache, he > wants blocks to be the size specified in the configuration and no bigger. His > hardware set ups fetches pages of 4k and so a block that has 4k of payload > but has then a header and the header of the next block (which helps figure > whats next when scanning) ends up being 4203 bytes or something, and this > then then translates into two seeks per block fetch. > This issue is about what it would take to stay inside our configured size > boundary writing out blocks. > If not possible, give back better signal on what to do so you could fit > inside a particular constraint. -- This message was sent by Atlassian JIRA (v6.3.4#6332)