MariaDB

Connect HolmesGPT to MariaDB databases to analyze query performance, investigate slow queries, check replication status, examine database health, and read data for troubleshooting.

You can configure multiple MariaDB instances with different names (e.g., app-mariadb, cache-mariadb, staging-mariadb).

Creating a Read-Only User

-- Create user
CREATE USER 'holmes_readonly'@'%' IDENTIFIED BY 'your_secure_password';

-- Grant read-only permissions
GRANT SELECT, SHOW VIEW, PROCESS, REPLICATION CLIENT ON *.* TO 'holmes_readonly'@'%';

-- Grant access to performance and information schemas
GRANT SELECT ON performance_schema.* TO 'holmes_readonly'@'%';
GRANT SELECT ON information_schema.* TO 'holmes_readonly'@'%';

FLUSH PRIVILEGES;

Configuration

Holmes CLIHolmes Helm ChartRobusta Helm Chart

~/.holmes/config.yaml:

toolsets:
  app-mariadb:
    type: database
    config:
      connection_url: "mysql+pymysql://holmes_readonly:your_secure_password@mariadb.example.com:3306/appdb"
    llm_instructions: "Application database with user and session data"

  cache-mariadb:
    type: database
    config:
      connection_url: "mysql+pymysql://cache_user:pass@cache-mariadb.internal:3306/cache"
    llm_instructions: "Cache database for session storage"

Using environment variables:

toolsets:
  app-mariadb:
    type: database
    config:
      connection_url: "{{ env.MARIADB_URL }}"

Connection URL format:

mysql+pymysql://[username]:[password]@[host]:[port]/[database]

Note: MariaDB uses MySQL wire protocol, so use mysql+pymysql:// in the connection URL.

Step 1: Create secret with credentials

kubectl create secret generic mariadb-credentials \
  --from-literal=url='mysql+pymysql://holmes_readonly:your_secure_password@mariadb.example.com:3306/appdb' \
  -n holmes

Step 2: Configure in values.yaml

additionalEnvVars:
  - name: MARIADB_URL
    valueFrom:
      secretKeyRef:
        name: mariadb-credentials
        key: url

toolsets:
  app-mariadb:
    type: database
    config:
      connection_url: "{{ env.MARIADB_URL }}"
    llm_instructions: "Application database with user and session data"

Multiple instances:

additionalEnvVars:
  - name: APP_MARIADB_URL
    valueFrom:
      secretKeyRef:
        name: mariadb-app
        key: url
  - name: CACHE_MARIADB_URL
    valueFrom:
      secretKeyRef:
        name: mariadb-cache
        key: url

toolsets:
  app-mariadb:
    type: database
    config:
      connection_url: "{{ env.APP_MARIADB_URL }}"

  cache-mariadb:
    type: database
    config:
      connection_url: "{{ env.CACHE_MARIADB_URL }}"

Step 1: Create secret with credentials

kubectl create secret generic mariadb-credentials \
  --from-literal=url='mysql+pymysql://holmes_readonly:your_secure_password@mariadb.example.com:3306/appdb' \
  -n default

Step 2: Configure in values.yaml

holmes:
  additionalEnvVars:
    - name: MARIADB_URL
      valueFrom:
        secretKeyRef:
          name: mariadb-credentials
          key: url

  toolsets:
    app-mariadb:
      type: database
      config:
        connection_url: "{{ env.MARIADB_URL }}"
      llm_instructions: "Application database with user and session data"

Multiple instances:

holmes:
  additionalEnvVars:
    - name: APP_MARIADB_URL
      valueFrom:
        secretKeyRef:
          name: mariadb-app
          key: url
    - name: CACHE_MARIADB_URL
      valueFrom:
        secretKeyRef:
          name: mariadb-cache
          key: url

  toolsets:
    app-mariadb:
      type: database
      config:
        connection_url: "{{ env.APP_MARIADB_URL }}"

    cache-mariadb:
      type: database
      config:
        connection_url: "{{ env.CACHE_MARIADB_URL }}"

Configuration Options

• connection_url (required): MariaDB connection URL
• read_only (default: true): Only allow SELECT/SHOW/DESCRIBE/EXPLAIN/WITH statements
• verify_ssl (default: true): Verify SSL certificates
• max_rows (default: 200): Maximum rows to return (1-10000)
• llm_instructions: Context about this database

Common Use Cases

"Analyze query performance: SELECT * FROM users WHERE last_login > NOW() - INTERVAL 30 DAY"

"Show replication status and lag"

"List tables by size"

Migrating from the MariaDB MCP addon

Earlier versions shipped a separate MariaDB MCP server, enabled through mcpAddons.mariadb in the Helm chart. That addon has been removed and the chart no longer renders it, so leaving the old value in place gives you no MariaDB access at all.

To migrate, remove the mcpAddons.mariadb block from your Helm values and configure this data source with your connection URL as shown above. The MCP server's read-only mode is replaced by the read_only option, which defaults to true.