MyCATApache/Mycat-Server · error · ConfigException

new config for migrate read fail!please check newSchema.xml…

Error message

 new config for migrate read fail!please check newSchema.xml or  newRule.xml  {e}

What it means

ConfigComparer.loadNewConfig loads the post-migration target configuration from NEW_SCHEMA/newSchema.xml and NEW_RULE/newRule.xml via XMLSchemaLoader. Any exception is wrapped as ConfigException(' new config for migrate read fail!please check newSchema.xml or newRule.xml <cause>').

Solutions

Confirm newSchema.xml and newRule.xml exist in the migration working directory with exactly those names
Validate the new XML files parse cleanly (xmllint) and match Mycat's schema DTD
Fix the underlying error reported in the wrapped cause (missing file vs. semantic reference error)
Regenerate newSchema.xml/newRule.xml with the migration tooling or copy verified templates from a working cluster

Example fix

// before
java ... ConfigComparer // newSchema.xml absent in workdir
// after
cp newSchema.xml newRule.xml /path/to/migrator/workdir && rerun

Defensive patterns

Strategy: validation

Validate before calling

static boolean newConfigPresent(String dir){
    return new java.io.File(dir, "newSchema.xml").canRead()
        && new java.io.File(dir, "newRule.xml").canRead();
}

Try / catch

try { comparer.loadNewConfig(); }
catch (ConfigException e) { LOG.error("newSchema.xml/newRule.xml unreadable: " + e.getMessage(), e); throw e; }

Prevention

Generate newSchema.xml/newRule.xml with the migration tooling before running
Validate the new XML parses and all dataHost/dataNode references resolve
Use exact file names expected by the migrator (newSchema.xml, newRule.xml)
Smoke-test the new config in a staging Mycat instance before migration

When it happens

Trigger: Running the dataMigrator export/compare when newSchema.xml or newRule.xml is absent from the working directory, malformed, or internally inconsistent (dangling dataNode/rule references).

Common situations: User forgot to generate or copy newSchema.xml/newRule.xml before running migration; template configs edited with syntax errors; new config referencing dataHosts that do not exist in the new cluster.

Related errors

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/029ce5edaf0a5507. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/util/dataMigrator/ConfigComparer.java:95

		try{
			oldLoader = new XMLSchemaLoader();
			oldDataHosts = oldLoader.getDataHosts();
			oldDataNodes = oldLoader.getDataNodes();
			oldSchemas = oldLoader.getSchemas();
		}catch(Exception e){
			throw new ConfigException(" old config for migrate read fail!please check schema.xml or  rule.xml  "+e);
		}
		
	}
	
	private void loadNewConfig(){
		try{
			newLoader = new XMLSchemaLoader(NEW_SCHEMA, NEW_RULE);
			newDataHosts = newLoader.getDataHosts();
			newDataNodes = newLoader.getDataNodes();
			newSchemas = newLoader.getSchemas();
		}catch(Exception e){
			throw new ConfigException(" new config for migrate read fail!please check newSchema.xml or  newRule.xml  "+e);
		}
		
	}
	
	
	private void loadTablesFile() throws Exception{
		Properties pro = new Properties();
		if(!isAwaysUseMaster){
			dnIndexProps = loadDnIndexProps();
		}
		try{
			pro.load(ConfigComparer.class.getResourceAsStream(TABLES_FILE));
		}catch(Exception e){
			throw new ConfigException("tablesFile.properties read fail!");
		}
		Iterator<Entry<Object, Object>> it = pro.entrySet().iterator();
		while(it.hasNext()){
			Entry<Object, Object> entry  = it.next();

View on GitHub (pinned to 65f8d8beb7)