Apache
/
hbase
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

HBASE-20337 Update the doc on how to setup shortcircuit reads; its stale; ADDENDUM

This commit is contained in:
Michael Stack 2018-04-04 11:25:25 -07:00
parent d60decd959
commit 8bc723477b
1 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
src/main/asciidoc/_chapters/schema_design.adoc
View File

@ -1173,6 +1173,11 @@ Otherwise, shortcircuit read operates quietly in background. It does not provide
no optics on how effective it is but read latencies should show a marked improvement, especially if
good data locality, lots of random reads, and dataset is larger than available cache.
Other advanced configurations that you might play with, especially if shortcircuit functionality
is complaining in the logs, include `dfs.client.read.shortcircuit.streams.cache.size` and
`dfs.client.socketcache.capacity`. Documentation is sparse on these options. You'll have to
read source code.
For more on short-circuit reads, see Colin's old blog on rollout,
link:http://blog.cloudera.com/blog/2013/08/how-improved-short-circuit-local-reads-bring-better-performance-and-security-to-hadoop/[How Improved Short-Circuit Local Reads Bring Better Performance and Security to Hadoop].
The link:https://issues.apache.org/jira/browse/HDFS-347[HDFS-347] issue also makes for an