CockroachDB

CockroachDB是一個分散式的資料庫軟體，目標是與PostgreSQL相容但可以提供橫向擴充的能力。

安裝

CockroachDB的設計是單一執行檔，沒有複雜的安裝包，所以下載複製到目錄裡即可：

cd /tmp
wget -qO- https://binaries.cockroachdb.com/cockroach-v2.1.3.linux-amd64.tgz | tar xvz
cp -i cockroach-v2.1.3.linux-amd64/cockroach /usr/local/bin

設定

設定分成兩塊，一塊是初始第一台機器：

cockroach start --background --insecure --listen-addr=0.0.0.0 --advertise-addr=$(ifconfig eth0 | grep inet | awk '{print $2}')

另外一塊是後續的機器，多了--join要設定：

cockroach start --background --insecure --listen-addr=0.0.0.0 --join=192.168.x.x --advertise-addr=$(ifconfig eth0 | grep inet | awk '{print $2}')

可以用以下指令確認機器都有連上cluster：

cockroach node ls --insecure

然後用PostgreSQL的client連上測試：

psql -h 192.168.x.x -p 26257 -U root

另外可能要修改replica的數量（預設是5），這組指令已經被標為deprecated但目前還可以用：

cockroach zone get .meta --insecure
echo "num_replicas: 3" | cockroach zone set .meta -f - --insecure
cockroach zone get .meta --insecure

測試

這邊是拿oltpbenchmark在AWS上測試，使用一台c5.2xlarge與五台r5.large架設Kubernetes後再裡面建立六個Pod測試。

Kubernetes

使用Kubernetes時的設定檔如下：

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: poc-r5
spec:
  replicas: 5
  serviceName: cockroachdb-r5
  selector:
    matchLabels:
      app: cockroachdb-r5
  template:
    metadata:
      labels:
        app: cockroachdb-r5
    spec:
      containers:
      - name: cockroachdb-r5
        image: ubuntu:18.04
        command: ["/bin/sh", "-c"]
        args:
          - export DEBIAN_FRONTEND=noninteractive;
            sed -i 's/archive.ubuntu.com/us.archive.ubuntu.com/' /etc/apt/sources.list;
            apt update;
            apt install -y iproute2 iputils-ping locales mtr-tiny net-tools tzdata vim-nox wget;
            locale-gen en_US.UTF-8;
            cd /tmp;
            wget -qO- https://binaries.cockroachdb.com/cockroach-v2.1.3.linux-amd64.tgz | tar xvz;
            cp -i cockroach-v2.1.3.linux-amd64/cockroach /usr/local/bin;
            sleep 3153600000
        resources:
          requests:
            memory: "15Gi"
        env:
        - name: LC_ALL
          value: en_US.UTF-8
      nodeSelector:
        instancetype: r5
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: poc-c5
spec:
  replicas: 1
  serviceName: cockroachdb-c5
  selector:
    matchLabels:
      app: cockroachdb-c5
  template:
    metadata:
      labels:
        app: cockroachdb-c5
    spec:
      containers:
      - name: cockroachdb-c5
        image: ubuntu:18.04
        command: ["/bin/sh", "-c"]
        args:
          - export DEBIAN_FRONTEND=noninteractive;
            sed -i 's/archive.ubuntu.com/us.archive.ubuntu.com/' /etc/apt/sources.list;
            apt update;
            apt install -y ant default-jdk git iproute2 iputils-ping locales mtr-tiny net-tools openjdk-8-jdk postgresql-client tzdata vim-nox wget;
            update-alternatives --set java /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java;
            locale-gen en_US.UTF-8;
            cd /root;
            git clone https://github.com/oltpbenchmark/oltpbench.git;
            cd oltpbench;
            sed -i -e 's/^ALTER TABLE/-- ALTER TABLE/' src/com/oltpbenchmark/benchmarks/tpcc/ddls/tpcc-postgres-ddl.sql;
            ant clean;
            ant;
            cp config/tpcc_config_postgres.xml config/tpcc.xml;
            sed -i -e 's/TRANSACTION_READ_COMMITTED/TRANSACTION_SERIALIZABLE/' config/tpcc.xml;
            sleep 3153600000
        resources:
          requests:
            cpu: "7000m"
        env:
        - name: LC_ALL
          value: en_US.UTF-8
      nodeSelector:
        instancetype: c5

外部連結

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