Themis

Introduction

Themis provides cross-row/cross-table transaction on HBase based on google's Percolator.

pingcap/themis is forked from XiaoMi/themis, with some optimizations for SQL layer.

1. Batch prewrite/commit secondary rows.
2. Asynchronous clean secondary locks (commit secondary rows in background).
3. Add batch get APIs.
4. Add golang client: pingcap/go-themis

depends on hbase >= 0.98.5 with hadoop.version=2.0.0-alpha.
Tested on Oracle JDK7

Usage

Build

• Get the latest source code of Themis:

git clone https://github.com/pingcap/themis.git

• Build Themis

cd themis
mvn clean package -DskipTests

Deploy

• Copy themis coprocessor to $HBASE_ROOT/lib/

cp themis-coprocessor/target/themis-coprocessor-1.0-SNAPSHOT-jar-with-dependencies.jar $HBASE_ROOT/lib

• Add configurations for themis coprocessor in hbase-site.xml:

<property>
    <name>hbase.coprocessor.user.region.classes</name>
    <value>org.apache.hadoop.hbase.themis.cp.ThemisEndpoint,org.apache.hadoop.hbase.themis.cp.ThemisScanObserver,org.apache.hadoop.hbase.regionserver.ThemisRegionObserver</value>
</property>
<property>
    <name>hbase.coprocessor.master.classes</name>
    <value>org.apache.hadoop.hbase.master.ThemisMasterObserver</value>
</property>

• Restart HBase.
• Enjoy it.

Future Works

1. Buffer recent committed primary locks in region server for fast conflict checking.
2. SQL pushdown.