Deploying OceanBase 4.X as a Minimal Single‑Node Distributed Database

OceanBase 3.X required substantial hardware for a single‑zone deployment, while the 4.X release claims a lightweight single‑node distributed architecture that matches the performance of a traditional single‑machine database. The article walks through a hands‑on deployment of OceanBase 4.X on a single server.

Key configuration parameters

The OBD configuration file sets memory_limit to 4G (total memory for all tenants), system_memory to 1G (system tenant), leaving 3G for business tenants. __min_full_resource_pool_memory must be at least 1G to avoid the error "unit MEMORY_SIZE less than __min_full_resource_pool_memory not supported". cpu_count is set to 2, allocating one core to the system tenant and one to business tenants.

oceanbase-ce:
  servers:
    - name: ob1
      ip: 127.0.0.1
  global:
    syslog_level: WARN
    enable_syslog_recycle: true
    max_syslog_file_count: 1
    __min_full_resource_pool_memory: 1073741824
    memory_limit: 4G
    system_memory: 1G
    datafile_size: 20G
    log_disk_size: 24G
    devname: lo
    cpu_count: 2
    production_mode: false
    cluster_id: 1
    appname: obytt100
    mysql_port: 2881
    rpc_port: 2882
    data_dir: /ob_data/1
    redo_dir: /ob_log/1
    home_path: /home/admin/oceanbase/1
    zone: z1

Running obd cluster display obytt100 shows a single active observer (127.0.0.1:2881) that can be accessed with the standard MySQL client.

[root@ytt-pc scripts]# obclient -h127.0.0.1 -P2881 -uroot -Doceanbase

To create a MySQL‑compatible tenant, the article executes:

create resource unit ut1 max_cpu 1,memory_size '1G',max_iops 1024;
create resource pool p1 unit 'ut1',unit_num 1;
create tenant mysql resource_pool_list=('p1') set ob_tcp_invited_nodes='%';

Querying __all_unit_config confirms that the system tenant consumes 2 GB and the new tenant consumes 1 GB, reaching the configured memory_limit . Subsequent checks of gv$ob_servers show that both CPU and memory are fully allocated.

select name,max_cpu,round(memory_size/1024/1024/1024,2) 'memory_size_GB' from __all_unit_config;
select svr_ip,svr_port,zone,round((cpu_capacity_max-cpu_assigned_max),2) 'cpu_free_num',cpu_capacity_max 'cpu_total_num',round((mem_capacity-mem_assigned)/1024/1024/1024,2) 'mem_free_GB', round(memory_limit/1024/1024/1024,2) 'mem_total_GB' from gv$ob_servers;

Finally, a database and table are created using a single MySQL command, demonstrating that the single‑node OceanBase instance behaves like a regular MySQL server.

obclient -h127.0.0.1 -P2881 -uroot@mysql -Doceanbase -cA -e "create database ytt;use ytt;create table t1(id int primary key);"

If the system reports "No memory or reach tenant memory limit", the article suggests manually dumping data to free memory.