From 8bc723477b60ce1ed0a71081630459621cb0f284 Mon Sep 17 00:00:00 2001 From: Michael Stack Date: Wed, 4 Apr 2018 11:25:25 -0700 Subject: [PATCH] HBASE-20337 Update the doc on how to setup shortcircuit reads; its stale; ADDENDUM --- src/main/asciidoc/_chapters/schema_design.adoc | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/main/asciidoc/_chapters/schema_design.adoc b/src/main/asciidoc/_chapters/schema_design.adoc index 12d449b9107..a25b85e1a0d 100644 --- a/src/main/asciidoc/_chapters/schema_design.adoc +++ b/src/main/asciidoc/_chapters/schema_design.adoc @@ -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