hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Rupinder Singh <rsi...@care.com>
Subject Very poor read performance with composite keys in hbase
Date Tue, 30 Apr 2013 17:48:32 GMT

I have an hbase cluster where I have a table with a composite key. I map this table to a Hive
external table using which I insert/select data into/from this table:
CREATE EXTERNAL TABLE event(key struct<name:string,dateCreated:string,uid:string>, {more
columns here})
STORED BY 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'
WITH SERDEPROPERTIES ("hbase.columns.mapping" = ":key, other columns ")
TBLPROPERTIES ("hbase.table.name" = "event");

The table has about 10 million rows. When I do a select * using all 3 components of the key,
essentially selecting just 1 row, the response time is almost 700 sec, which seems pretty

For comparison purpose, I created another table with a simple string key, and the rest of
the columns etc same. The key is a string UUID. Table has same number of column families and
same number of rows.
CREATE EXTERNAL TABLE test_event(key string, blah blah.....
TBLPROPERTIES ("hbase.table.name" = "test_event");

When I select a single row from this table by doing select * where key='something', the response
time is 35 sec.

This seems to indicate that in case of composite keys, there is a full table scan happening.
 This seems weird.

What am I missing here? Is there something special I need to do to get good read performance
if I am using composite keys ?
Insert performance in both cases is comparable and is as per expectation.

Any help is appreciated.
Here is the env spec:

Amazon EMR
Hbase Cluster- 3 core nodes with 7.5 GB RAM each, 2 CPUs of 2.2 GHz each. Master 7.5 GB RAM,
2 CPUs of 2.2 GHz each
Hive Cluster - 3 core nodes 3.75 GB RAM each, 1 CPU of 1.8 GHz. Master 3.75 GB RAM, 1 CPU
of 1.8 GHz


This email is intended for the person(s) to whom it is addressed and may contain information
that is PRIVILEGED or CONFIDENTIAL. Any unauthorized use, distribution, copying, or disclosure
by any person other than the addressee(s) is strictly prohibited. If you have received this
email in error, please notify the sender immediately by return email and delete the message
and any attachments from your system.
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message