[hbase] branch branch-2.4 updated: HBASE-26590 Hbase-client Meta lookup performance regression between hbase-1 and hbase-2 (#4008) (#4012)

[huaxiangsun]

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huaxiangsun pushed a commit to branch branch-2.4
in repository https://gitbox.apache.org/repos/asf/hbase.git


The following commit(s) were added to refs/heads/branch-2.4 by this push:
     new f3639bc  HBASE-26590 Hbase-client Meta lookup performance regression 
between hbase-1 and hbase-2 (#4008) (#4012)
f3639bc is described below

commit f3639bc80c7aac9cbcf31f6566df9b929613f018
Author: huaxiangsun <huaxiang...@apache.org>
AuthorDate: Thu Jan 6 11:55:51 2022 -0800

    HBASE-26590 Hbase-client Meta lookup performance regression between hbase-1 
and hbase-2 (#4008) (#4012)
    
    Change scan caching back to 1 to avoid extra work at Region Server side. 
For most cases, the extra 4 results
    fetched are wasted at the client side.
    
    Signed-off-by: Duo Zhang <zhang...@apache.org>
---
 .../java/org/apache/hadoop/hbase/client/ConnectionImplementation.java   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git 
a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
 
b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
index cfbc19c..145dc91 100644
--- 
a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
+++ 
b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
@@ -888,7 +888,7 @@ class ConnectionImplementation implements 
ClusterConnection, Closeable {
     byte[] metaStopKey =
       RegionInfo.createRegionName(tableName, HConstants.EMPTY_START_ROW, "", 
false);
     Scan s = new Scan().withStartRow(metaStartKey).withStopRow(metaStopKey, 
true)
-      .addFamily(HConstants.CATALOG_FAMILY).setReversed(true).setCaching(5)
+      .addFamily(HConstants.CATALOG_FAMILY).setReversed(true).setCaching(1)
       .setReadType(ReadType.PREAD);
 
     switch (this.metaReplicaMode) {