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Helix Quickstart

Posted by Kylin Soong on Dec 30, 2016 categorized as architecture

Overview
Set up ZooKeeper
- Download and install
Install Helix
Define the Cluster

Overview

This article contain the steps and scripts to run Helix Quickstart which referred in Helix Document. we’ll do the following:

Define a cluster
Add two nodes to the cluster
Add a 6-partition resource with 1 master and 2 slave replicas per partition
Verify that the cluster is healthy and inspect the Helix view
Expand the cluster: add a few nodes and rebalance the partitions
Failover: stop a node and verify the mastership transfer

Set up ZooKeeper

In this section will will set up Zookeeper ensemble with 3 nodes run one localhost.

Download and install

wget http://apache.claz.org/zookeeper/zookeeper-3.4.9/zookeeper-3.4.9.tar.gz
tar -xvf zookeeper-3.4.9.tar.gz
cp -r zookeeper-3.4.9 zookeeper-1
cp -r zookeeper-3.4.9 zookeeper-2
cp -r zookeeper-3.4.9 zookeeper-3

Setup zookeeper 1

Create zoo.cfg under zookeeper-1/conf/

cd zookeeper-1/conf/
cp zoo_sample.cfg zoo.cfg

Edit zoo.cfg, make sure dataDir, clientPort, ensemble definition as below

dataDir=/tmp/zookeeper-1
clientPort=2181
server.1=localhost:2888:3888
server.2=localhost:2889:3889
server.3=localhost:2890:3890

Create dataDir, assign a node ID

mkdir -p /tmp/zookeeper-1
echo "1" > /tmp/zookeeper-1/myid

Change into zookeeper home start Zookeeper

./bin/zkServer.sh start

NOTE: A zookeeper.out file generate which contain zookeeper log.

Setup zookeeper 2

Create zoo.cfg under zookeeper-2/conf/

cd zookeeper-2/conf/
cp zoo_sample.cfg zoo.cfg

Edit zoo.cfg, make sure dataDir, clientPort, ensemble definition as below

dataDir=/tmp/zookeeper-2
clientPort=2182
server.1=localhost:2888:3888
server.2=localhost:2889:3889
server.3=localhost:2890:3890

Create dataDir, assign a node ID

mkdir -p /tmp/zookeeper-2
echo "2" > /tmp/zookeeper-2/myid

Change into zookeeper home start Zookeeper

./bin/zkServer.sh start

Setup zookeeper 3

Create zoo.cfg under zookeeper-3/conf/

cd zookeeper-3/conf/
cp zoo_sample.cfg zoo.cfg

Edit zoo.cfg, make sure dataDir, clientPort, ensemble definition as below

dataDir=/tmp/zookeeper-3
clientPort=2183
server.1=localhost:2888:3888
server.2=localhost:2889:3889
server.3=localhost:2890:3890

Create dataDir, assign a node ID

mkdir -p /tmp/zookeeper-3
echo "3" > /tmp/zookeeper-3/myid

Change into zookeeper home start Zookeeper

./bin/zkServer.sh start

Monitor the zookeeper ensemble

$ jps -l
12275 org.apache.zookeeper.server.quorum.QuorumPeerMain
12005 org.apache.zookeeper.server.quorum.QuorumPeerMain
11741 org.apache.zookeeper.server.quorum.QuorumPeerMain

$ netstat -antulop | grep 11741
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
tcp6       0      0 :::2181                 :::*                    LISTEN      11741/java           off (0.00/0/0)
tcp6       0      0 127.0.0.1:3888          :::*                    LISTEN      11741/java           off (0.00/0/0)
tcp6       0      0 :::60540                :::*                    LISTEN      11741/java           off (0.00/0/0)
tcp6       0      0 127.0.0.1:53849         127.0.0.1:2889          ESTABLISHED 11741/java           off (0.00/0/0)
tcp6       0      0 127.0.0.1:3888          127.0.0.1:60408         ESTABLISHED 11741/java           off (0.00/0/0)
tcp6       0      0 127.0.0.1:3888          127.0.0.1:60393         ESTABLISHED 11741/java           off (0.00/0/0)

Install Helix

Download helix-core-0.6.6-pkg.tar from http://helix.apache.org/0.6.6-docs/download.cgi
Extract helix-core-0.6.6-pkg.tar to install

tar -xvf helix-core-0.6.6-pkg.tar

Define the Cluster

In this section we’ll set up a cluster helix-quickstart-cluster cluster with these attributes:

3 instances running on localhost at ports 12913,12914,12915
One database named myDB with 6 partitions
Each partition will have 3 replicas with 1 master, 2 slaves

Create the Cluster helix-quickstart-cluster

cd helix-core-0.6.6/
./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addCluster helix-quickstart-cluster

Add Nodes to the Cluster

./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addNode helix-quickstart-cluster localhost:12913
./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addNode helix-quickstart-cluster localhost:12914
./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addNode helix-quickstart-cluster localhost:12915

Define the Resource and Partitioning

In this example, the resource is a database, partitioned 6 ways.

Create a Database with 6 Partitions using the MasterSlave State Model

./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addResource helix-quickstart-cluster myDB 6 MasterSlave

Let Helix Assign Partitions to Nodes

./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --rebalance helix-quickstart-cluster myDB 3

Start the Helix Controller

./bin/run-helix-controller.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --cluster helix-quickstart-cluster 2>&1 > ./controller.log &

Start up the Cluster to be Managed

./bin/start-helix-participant.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --cluster helix-quickstart-cluster --host localhost --port 12913 --steModelType MasterSlave 2>&1 > ./participant_12913.log &
./bin/start-helix-participant.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --cluster helix-quickstart-cluster --host localhost --port 12914 --steModelType MasterSlave 2>&1 > ./participant_12914.log &
./bin/start-helix-participant.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --cluster helix-quickstart-cluster --host localhost --port 12915 --steModelType MasterSlave 2>&1 > ./participant_12915.log &

Inspect the Cluster

list cluster

$ ./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --listClusters
Existing clusters:
helix-quickstart-cluster

Helix view of cluster

$ ./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --listClusterInfo helix-quickstart-cluster
Existing resources in cluster helix-quickstart-cluster:
myDB
Instances in cluster helix-quickstart-cluster:
localhost_12913
localhost_12914
localhost_12915

The details of an instance

$ ./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --listInstanceInfo helix-quickstart-cluster localhost_12913
InstanceConfig: {
  "id" : "localhost_12913",
  "mapFields" : {
  },
  "listFields" : {
  },
  "simpleFields" : {
    "HELIX_ENABLED" : "true",
    "HELIX_HOST" : "localhost",
    "HELIX_PORT" : "12913"
  }
}

Query Information about a Resource

$ ./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --listResourceInfo helix-quickstart-cluster myDB
IdealState for myDB:
{
  "id" : "myDB",
  "mapFields" : {
    "myDB_0" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "MASTER",
      "localhost_12915" : "SLAVE"
    },
    "myDB_1" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "MASTER"
    },
    "myDB_2" : {
      "localhost_12913" : "MASTER",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "SLAVE"
    },
    "myDB_3" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "MASTER"
    },
    "myDB_4" : {
      "localhost_12913" : "MASTER",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "SLAVE"
    },
    "myDB_5" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "MASTER",
      "localhost_12915" : "SLAVE"
    }
  },
  "listFields" : {
    "myDB_0" : [ "localhost_12914", "localhost_12915", "localhost_12913" ],
    "myDB_1" : [ "localhost_12915", "localhost_12913", "localhost_12914" ],
    "myDB_2" : [ "localhost_12913", "localhost_12914", "localhost_12915" ],
    "myDB_3" : [ "localhost_12915", "localhost_12913", "localhost_12914" ],
    "myDB_4" : [ "localhost_12913", "localhost_12914", "localhost_12915" ],
    "myDB_5" : [ "localhost_12914", "localhost_12913", "localhost_12915" ]
  },
  "simpleFields" : {
    "IDEAL_STATE_MODE" : "AUTO",
    "NUM_PARTITIONS" : "6",
    "REBALANCE_MODE" : "SEMI_AUTO",
    "REBALANCE_STRATEGY" : "DEFAULT",
    "REPLICAS" : "3",
    "STATE_MODEL_DEF_REF" : "MasterSlave",
    "STATE_MODEL_FACTORY_NAME" : "DEFAULT"
  }
}

ExternalView for myDB:
{
  "id" : "myDB",
  "mapFields" : {
    "myDB_0" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "MASTER",
      "localhost_12915" : "SLAVE"
    },
    "myDB_1" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "MASTER"
    },
    "myDB_2" : {
      "localhost_12913" : "MASTER",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "SLAVE"
    },
    "myDB_3" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "MASTER"
    },
    "myDB_4" : {
      "localhost_12913" : "MASTER",
      "localhost_12914" : "SLAVE",
      "localhost_12915" : "SLAVE"
    },
    "myDB_5" : {
      "localhost_12913" : "SLAVE",
      "localhost_12914" : "MASTER",
      "localhost_12915" : "SLAVE"
    }
  },
  "listFields" : {
  },
  "simpleFields" : {
    "BUCKET_SIZE" : "0",
    "IDEAL_STATE_MODE" : "AUTO",
    "NUM_PARTITIONS" : "6",
    "REBALANCE_MODE" : "SEMI_AUTO",
    "REBALANCE_STRATEGY" : "DEFAULT",
    "REPLICAS" : "3",
    "STATE_MODEL_DEF_REF" : "MasterSlave",
    "STATE_MODEL_FACTORY_NAME" : "DEFAULT"
  }
}

Query Information about a Resource partitions

./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --listResourceInfo helix-quickstart-cluster myDB_0

Expand the Cluster

Add more nodes

./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addNode helix-quickstart-cluster localhost:12916
./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addNode helix-quickstart-cluster localhost:12917
./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --addNode helix-quickstart-cluster localhost:12918

Start up new instances

./bin/start-helix-participant.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --cluster helix-quickstart-cluster --host localhost --port 12916 --stateModelType MasterSlave 2>&1 > ./participant_12916.log &
./bin/start-helix-participant.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --cluster helix-quickstart-cluster --host localhost --port 12917 --stateModelType MasterSlave 2>&1 > ./participant_12917.log &
./bin/start-helix-participant.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --cluster helix-quickstart-cluster --host localhost --port 12918 --stateModelType MasterSlave 2>&1 > ./participant_12918.log &

rebalance

./bin/helix-admin.sh --zkSvr localhost:2181,localhost:2182,localhost:2183 --rebalance helix-quickstart-cluster myDB 3