使用CentOS 6.4构建Cassandra 1.2.6

1 年 ago

宇, 华

5 minutes

首先

我們在 CentOS 6.4 環境下使用 tarball 安裝 Cassandra 1.2.6，以下是安裝步驟備忘錄。在確保基本運作後，我們會先使用五台物理伺服器（10.0.0。[1-5]）並進行 CentOS 6.4 的乾淨安裝。

★ Kernel を確認する
$ uname -a
Linux localhost 2.6.32-358.11.1.el6.x86_64 #1 SMP Wed Jun 12 03:34:52 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

★ ディストリビューションを確認する
$ cat /etc/redhat-release
CentOS release 6.4 (Final)

安装

安装Cassandra所需的Java。在本次安装的Cassandra 1.2.6版本中，发现使用OpenJDK-1.6.0_0在启动时会出现段错误的情况，因此使用由Oracle提供的SunJDK 1.6.0_45。

★ SunJDK をインストールする
$ chmod +x ./jdk-6u45-linux-x64-rpm.bin && sudo ./jdk-6u45-linux-x64-rpm.bin
Unpacking...
Checksumming...
Extracting...
UnZipSFX 5.50 of 17 February 2002, by Info-ZIP (Zip-Bugs@lists.wku.edu).
  inflating: jdk-6u45-linux-amd64.rpm
  inflating: sun-javadb-common-10.6.2-1.1.i386.rpm
  inflating: sun-javadb-core-10.6.2-1.1.i386.rpm
  inflating: sun-javadb-client-10.6.2-1.1.i386.rpm
  inflating: sun-javadb-demo-10.6.2-1.1.i386.rpm
  inflating: sun-javadb-docs-10.6.2-1.1.i386.rpm
  inflating: sun-javadb-javadoc-10.6.2-1.1.i386.rpm
準備中...                ########################################### [100%]
   1:jdk                    ########################################### [100%]
Unpacking JAR files...
        rt.jar...
        jsse.jar...
        charsets.jar...
        tools.jar...
        localedata.jar...
        plugin.jar...
        javaws.jar...
        deploy.jar...
Installing JavaDB
準備中...                ########################################### [100%]
   1:sun-javadb-common      ########################################### [ 17%]
   2:sun-javadb-core        ########################################### [ 33%]
   3:sun-javadb-client      ########################################### [ 50%]
   4:sun-javadb-demo        ########################################### [ 67%]
   5:sun-javadb-docs        ########################################### [ 83%]
   6:sun-javadb-javadoc     ########################################### [100%]
Done.

★ バージョンを確認する
$ java -version
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed mode)

可以安装Cassandra。安装可以使用DataStax提供的RPM，但是由于Cassandra经常需要单独应用补丁，所以最好避免，本次安装将从tarball安装到/opt/cassandra目录下。

★ tarball をダウンロードする
$ wget http://www.fightrice.com/mirrors/apache/cassandra/1.2.6/apache-cassandra-1.2.6-bin.tar.gz

★ 展開後に /opt/cassandra 以下に移動する
$ tar xvzf apache-cassandra-1.2.6-bin.tar.gz && sudo mv ./apache-cassandra-1.2.6 /opt/ && sudo ln -s /opt/apache-cassandra-1.2.6 /opt/cassandra

★ ログとデータディレクトリを作成する
$ sudo mkdir -p /var/log/cassandra && sudo mkdir -p /var/lib/cassandra

设定

配置Cassandra。为了暂时使其工作，需要更改三个位置的 “seeds”、”listen_address” 和 “rpc_address”。本次设置中，将使用四台物理服务器中的三台作为种子节点。此外，”listen_address”需要指定能够互相连接的IP地址。

★ 設定を変更する (サーバ 10.0.0.1 の場合の設定例)
$ sudo vim /opt/cassandra/conf/cassandra.yaml
... (snip) ...
# any class that implements the SeedProvider interface and has a
# constructor that takes a Map<String, String> of parameters will do.
seed_provider:
    # Addresses of hosts that are deemed contact points.
    # Cassandra nodes use this list of hosts to find each other and learn
    # the topology of the ring.  You must change this if you are running
    # multiple nodes!
    - class_name: org.apache.cassandra.locator.SimpleSeedProvider
      parameters:
          # seeds is actually a comma-delimited list of addresses.
          # Ex: "<ip1>,<ip2>,<ip3>"
          - seeds: "10.0.0.1, 10.0.0.2, 10.0.0.3"
... (snip) ...
# Address to bind to and tell other Cassandra nodes to connect to. You
# _must_ change this if you want multiple nodes to be able to
# communicate!
#
# Leaving it blank leaves it up to InetAddress.getLocalHost(). This
# will always do the Right Thing _if_ the node is properly configured
# (hostname, name resolution, etc), and the Right Thing is to use the
# address associated with the hostname (it might not be).
#
# Setting this to 0.0.0.0 is always wrong.
listen_address: 10.0.0.1
... (snip) ...
# The address to bind the Thrift RPC service to -- clients connect
# here. Unlike ListenAddress above, you _can_ specify 0.0.0.0 here if
# you want Thrift to listen on all interfaces.
#
# Leaving this blank has the same effect it does for ListenAddress,
# (i.e. it will be based on the configured hostname of the node).
rpc_address: 0.0.0.0
... (snip) ...

创建一个启动脚本来启动Cassandra。实际上只需要调用 /opt/cassandra/bin/cassandra shell，但是由于一些繁琐的操作，我们可以先简单地创建一个脚本。通过文件管理Cassandra的PID，并将标准输出和标准错误输出重定向到日志文件中。

★ 起動スクリプトを作成する
$ sudo cat << 'EOS' > /etc/init.d/cassandra && sudo chmod +x /etc/init.d/cassandra
#!/bin/sh
CASSANDRA_ROOT_DIR=/opt/cassandra
CASSANDRA_BIN_DIR=${CASSANDRA_ROOT_DIR}/bin
CASSANDRA_LOG_DIR=/var/log/cassandra
CASSANDRA_RUN_DIR=/var/run/cassandra
case "$1" in
  start)
    if [ ! -d ${CASSANDRA_LOG_DIR} ]; then
      mkdir ${CASSANDRA_LOG_DIR}
    fi
    if [ ! -d ${CASSANDRA_RUN_DIR} ]; then
      mkdir ${CASSANDRA_RUN_DIR}
    fi
    if [ -e ${CASSANDRA_RUN_DIR}/cassandra.pid ]; then
      if [ 1 -ne $(ps $(cat ${CASSANDRA_RUN_DIR}/cassandra.pid) | wc -l) ]; then
        echo "NG: already running (pid=$(cat ${CASSANDRA_RUN_DIR}/cassandra.pid))"
        exit 1
      fi
    fi
    ${CASSANDRA_BIN_DIR}/cassandra -p ${CASSANDRA_RUN_DIR}/cassandra.pid >> ${CASSANDRA_LOG_DIR}/cassandra.log 2>&1
    echo "OK: running cassandra (pid=$(cat ${CASSANDRA_RUN_DIR}/cassandra.pid))"
    ;;
  stop)
    kill $(cat ${CASSANDRA_RUN_DIR}/cassandra.pid)
    echo "OK: stopped cassandra"
    ;;
  restart)
    $0 stop
    sleep 2
    $0 start
    ;;
  *)
    echo "Usage: `basename $0` start|stop|restart"
esac
exit 0
EOS

确认动作

启动Cassandra节点。首先要启动的节点必须是通过seeds参数设置的任何一个节点。只要集群中有任何一个节点被设置为seeds节点，接下来要启动的节点可以是任意一个。最后可以使用附带的nodetool命令获取集群的信息。

★ ノードを起動する (同様に他のサーバでも行なう)
$ sudo /etc/init.d/cassandra start
OK: running cassandra (pid=24225)

★ 接続されているノードのステータスを表示する
$ /opt/cassandra/bin/nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address        Load       Owns (effective)  Host ID                               Token                            Rack
UN  10.0.0.1      76.43 KB   35.2%             52bdee4a-d815-4bf5-9795-9cb4c489a6f7  6225635841253981655               rack1
UN  10.0.0.2      68.81 KB    8.5%             1d9329f3-3632-4697-bb2c-a96a3d306d0d  -263408352895507995               rack1
UN  10.0.0.3       50.6 KB    4.2%             a46cc725-9a32-42a8-9290-e9c721769221  -2605039640550962807              rack1
UN  10.0.0.4      62.12 KB   47.9%             b6fd7064-6da8-436e-ae53-1190f18ebcf9  -3385583403102781077              rack1
UN  10.0.0.5      78.88 KB    4.2%             cb379e54-a0ec-42ce-a77e-98271502f4eb  -1824495877999144536              rack1

★ 接続されているノードのリングを表示する
$ /opt/cassandra/bin/nodetool ring
Datacenter: datacenter1
==========
Replicas: 1

Address        Rack        Status State   Load            Owns                Token
                                                                              -1824495877999144536
10.0.0.1       rack1       Up     Normal  76.43 KB        35.18%              6225635841253981655
10.0.0.2       rack1       Up     Normal  68.81 KB        8.46%               -263408352895507995
10.0.0.3       rack1       Up     Normal  50.6 KB         4.23%               -2605039640550962807
10.0.0.4       rack1       Up     Normal  62.12 KB        47.90%              -3385583403102781077
10.0.0.5       rack1       Up     Normal  78.88 KB        4.23%               -1824495877999144536

★ 接続されているノードの情報を表示する
$ /opt/cassandra/bin/nodetool info
Token            : 6225635841253981655
ID               : 52bdee4a-d815-4bf5-9795-9cb4c489a6f7
Gossip active    : true
Thrift active    : true
Load             : 76.43 KB
Generation No    : 1373623266
Uptime (seconds) : 1331
Heap Memory (MB) : 123.28 / 3696.00
Data Center      : datacenter1
Rack             : rack1
Exceptions       : 0
Key Cache        : size 824 (bytes), capacity 104857600 (bytes), 24 hits, 34 requests, 0.706 recent hit rate, 14400 save period in seconds
Row Cache        : size 0 (bytes), capacity 0 (bytes), 0 hits, 0 requests, NaN recent hit rate, 0 save period in seconds

最后

暂时先在CentOS 6.4上成功安装了Cassandra 1.2.6。接下来我会调查Cassandra 1.2系列的功能，还有在节点故障时的行为。一旦有一定的结果，我会考虑在另一篇文章中发布。

参考文献等

Cassandra の自動起動 Shellscript