Continuing our series on RDBMS migrations, this post will demo a schema migration from Oracle to CockroachDB.
CockroachDB is an Open Source, scalable, distributed RDBMS.
This post will focus on installing and configuring a CockroachDB cluster. For this demo we will run a small 3-node docker cluster.
- Install cockroachdb container:
# docker pull cockroachdb/cockroach:v20.1.4 v20.1.4: Pulling from cockroachdb/cockroach 7d2977b12acb: Pull complete 4cde57938762: Pull complete 9ac7e265a083: Pull complete aa9283d1991d: Pull complete Digest: sha256:578d1a10d3fb913c2db96c34ac4943a9bcb262babc54d0734b7f9fbfe902618 Status: Downloaded newer image for cockroachdb/cockroach:v20.1.4 docker.io/cockroachdb/cockroach:v20.1.4
- Create docker network bridge for the cluster:
# docker network create -d bridge crdbnet 47e9f669ffb87b6cbf3fd12ab4abdaabe1b72efad44e00f999ab207ba8ce1c68
- Create directories for persistant storage:
:/# mkdir crdb :/# cd crdb :/crdb# mkdir crdb1 crdb2 crdb3
- Start the 3 nodes:
:/crdb# docker run -d --name crdb1 --hostname crdb1 --net crdbnet -p 26257:26257 -p 8080:8080 -v "${PWD}/crdb1:/cockroach/cockroach-data" cockroachdb/cockroach:v20.1.4 start --insecure --join=crdb1,crdb2,crdb3
b670326cdd1f072c4c7f02834603eae57d557f73ba0835c1bffe4f2c57b5cafd
:/crdb# docker run -d --name crdb2 --hostname crdb2 --net crdbnet -v "${PWD}/crdb2:/cockroach/cockroach-data" cockroachdb/cockroach:v20.1.4 start --insecure --join=crdb1,crdb2,crdb3
5e64c7646a2ef32a365265512090c9b8ae212d752b02757911ddd4f8b6d06e51
:/crdb# docker run -d --name crdb3 --hostname crdb3 --net crdbnet -v "${PWD}/crdb3:/cockroach/cockroach-data" cockroachdb/cockroach:v20.1.4 start --insecure --join=crdb1,crdb2,crdb3
473daa83e0fc4b6b017f43b9ef2cfdb5642bbbe092153493ac01fb5760e0ee37
- Verify running containers:
:/crdb# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 473daa83e0fc cockroachdb/cockroach:v20.1.4 "/cockroach/cockroac…" 11 seconds ago Up 10 seconds 8080/tcp, 26257/tcp crdb3 5e64c7646a2e cockroachdb/cockroach:v20.1.4 "/cockroach/cockroac…" 44 seconds ago Up 43 seconds 8080/tcp, 26257/tcp crdb2 b670326cdd1f cockroachdb/cockroach:v20.1.4 "/cockroach/cockroac…" 2 minutes ago Up 2 minutes 0.0.0.0:8080->8080/tcp, 0.0.0.0:26257->26257/tcp crdb1
- Initialize the CockroachDB cluster:
:/crdb# docker exec -it crdb1 ./cockroach init --insecure Cluster successfully initialized :/crdb# grep 'node starting' /crdb/crdb1/logs/cockroach.log -A 11 CockroachDB node starting at 2020-08-21 20:06:26.978548804 +0000 UTC (took 208.7s) build: CCL v20.1.4 @ 2020/07/29 22:56:36 (go1.13.9) webui: http://crdb1:8080 sql: postgresql://root@crdb1:26257?sslmode=disable RPC client flags: /cockroach/cockroach <client cmd> --host=crdb1:26257 --insecure logs: /cockroach/cockroach-data/logs temp dir: /cockroach/cockroach-data/cockroach-temp026819416 external I/O path: /cockroach/cockroach-data/extern store[0]: path=/cockroach/cockroach-data storage engine: rocksdb status: initialized new cluster clusterID: ec306441-9c57-43b7-b35e-f0386eb052f5
- Verify access to the cluster using CRDB SQL shell:
:/crdb# docker exec -it crdb1 ./cockroach sql --insecure # # Welcome to the CockroachDB SQL shell. # All statements must be terminated by a semicolon. # To exit, type: \q. # # Server version: CockroachDB CCL v20.1.4 (x86_64-unknown-linux-gnu, built 2020/07/29 22:56:36, go1.13.9) (same version as client) # Cluster ID: ec306441-9c57-43b7-b35e-f0386eb052f5 # # Enter \? for a brief introduction. #
- We are going to migrate the example HR Schema from Oracle:
root@:26257/defaultdb> create database HR; CREATE DATABASE Time: 14.555853ms root@:26257/defaultdb> \l database_name ----------------- defaultdb hr postgres system (4 rows) Time: 1.641729ms
- Verify Admin UI is running at http://localhost:8080:
In the next post we will migrate the HR schema from Oracle to CockroachDB
