apache/shardingsphere · error · DataNodeGenerateException

2

2

Error message

Can not find data source in sharding rule, invalid actual data node '%s'.

What it means

DataNodeGenerateException ('Can not find data source in sharding rule, invalid actual data node') is thrown by ShardingTable.generateDataNodes while building the actual data nodes for a sharding table rule. Each configured actual data node string is parsed into (dataSource, tableName); if the parsed data source name is not in the rule's known data source names (dataSourceNames), the node is rejected. It is a configuration-load-time validation of data node expressions.

Source

Thrown at features/sharding/core/src/main/java/org/apache/shardingsphere/sharding/rule/ShardingTable.java:202

        int index = 0;
        for (String each : dataSourceNames) {
            DataNode dataNode = new DataNode(each, (String) null, logicTable);
            result.add(dataNode);
            dataNodeIndexMap.put(dataNode, index);
            actualDataSourceNames.add(each);
            addActualTable(dataNode.getDataSourceName(), dataNode.getTableName());
            index++;
        }
        return result;
    }
    
    private List<DataNode> generateDataNodes(final Collection<String> actualDataNodes, final Collection<String> dataSourceNames) {
        List<DataNode> result = new ArrayList<>(actualDataNodes.size());
        int index = 0;
        for (String each : actualDataNodes) {
            DataNode dataNode = new DataNode(each);
            if (!dataSourceNames.contains(dataNode.getDataSourceName())) {
                throw new DataNodeGenerateException(each);
            }
            result.add(dataNode);
            dataNodeIndexMap.put(dataNode, index);
            actualDataSourceNames.add(dataNode.getDataSourceName());
            addActualTable(dataNode.getDataSourceName(), dataNode.getTableName());
            index++;
        }
        return result;
    }
    
    /**
     * Get data node groups.
     *
     * @return data node groups, key is data source name, values are data nodes belong to this data source
     */
    public Map<String, List<DataNode>> getDataNodeGroups() {
        return DataNodeUtils.getDataNodeGroups(actualDataNodes);
    }

View on GitHub (pinned to e952770a21)

Solutions

1. Register the missing data source first (REGISTER STORAGE UNIT / add to dataSources) before creating or altering the sharding rule.
2. Fix the actualDataNodes expression to reference only configured data sources (correct range or prefix).
3. After renaming/removing storage units, update every sharding rule that references them.

Example fix

-- before: ds_9 not registered
CREATE SHARDING TABLE RULE t_order (
  DATANODES("ds_9.t_order_${0..3}"), ...
);

-- after: register units, then reference them
REGISTER STORAGE UNIT ds_0 (...), ds_1 (...);
CREATE SHARDING TABLE RULE t_order (
  DATANODES("ds_${0..1}.t_order_${0..3}"), ...
);

// Before creating/altering a rule, check every data node's data source is registered
Set<String> registered = /* storage unit names from SHOW STORAGE UNITS */ Set.of("ds_0", "ds_1");
for (String node : List.of("ds_${0..1}.t_order_${0..3}".expanded())) { // expand inline expression
    String ds = node.split("\\.")[0];
    if (!registered.contains(ds)) { throw new IllegalStateException("Unregistered data source: " + ds); }
}

try {
    proxySession.executeddl("CREATE SHARDING TABLE RULE ...");
} catch (final DataNodeGenerateException ex) {
    // register the missing storage unit, then re-apply the rule
}

When it happens

Trigger: An actualDataNodes entry like ds_9.t_order_0 where ds_9 is not among the data source names available to the sharding rule (not registered in mode configuration / not in dataSourceNames), or an inline expression that expands to an unconfigured data source index.

Common situations: Typo in the data source prefix; inline expression ds_${0..4} when only ds_0..ds_2 exist; renaming a data source without updating sharding rules; adding a rule via DistSQL before registering the data source (REGISTER STORAGE UNIT).

Related errors

• 41
• 1
• 37
• 4
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AI-assisted analysis of apache/shardingsphere@e952770a21 (2026-08-14). Data as JSON: /api/errors/e141fefd742940cb. Report an issue: GitHub.