MyCATApache/Mycat-Server · error · RuntimeException

load crc32slot datafile error:dn=

Error message

load crc32slot datafile error:dn={k},value={range}

What it means

PartitionByCRC32PreSlot.convertToMap parses the crc32slot data file where each node's 'value' string lists slot ranges. A node entry with more than one element in its parsed range list (vv.size() > 1) is unexpected for this format, so a RuntimeException 'load crc32slot datafile error:dn=...,value=...' is thrown, failing rule init/reinit.

Solutions

  1. Inspect the data file line for the offending dn and fix it to the expected format: each value either 'start-end' or a single integer.
  2. Regenerate the slot data file with the mycat migration tooling (re-run the expansion/migration analysis) instead of hand-editing.
  3. Restore the file from a backup taken before the migration started.
  4. Ensure the mycat version reading the file matches the version that wrote it; upgrade both consistently and re-init.

Example fix

// before (datafile line)
0=1-100,200-300
// after
0=1-100
Defensive patterns

Strategy: validation

Validate before calling

for (String line : Files.readAllLines(dataFile)) {
    String value = line.substring(line.indexOf('=') + 1);
    boolean ok = value.matches("\\d+(-\\d+)?");
    if (!ok) throw new IllegalStateException("malformed slot line: " + line);
}

Try / catch

try {
    rule.init(cfg);
} catch (RuntimeException e) {
    if (e.getMessage().startsWith("load crc32slot datafile error")) {
        LOGGER.error("regenerate or restore crc32slot datafile");
    } else { throw e; }
}

Prevention

When it happens

Trigger: init/reInit -> convertToMap reads the slot mapping file (rule data file, e.g. rule.xml partition-by-crc32pre-slot data file) and a dn line contains multiple range tokens instead of a single start-end pair or single value.

Common situations: Data file manually edited or corrupted; file produced by a different mycat/migration tool version with a divergent format; partial write during migration crash leaving malformed lines; mixing formats from reInit with stale content.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/04c723999ff60e21. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/route/function/PartitionByCRC32PreSlot.java:140

    private Map<Integer, List<Range>> convertToMap(Properties p) {
        Map<Integer, List<Range>> map = new TreeMap<>();
        for (Object o : p.keySet()) {
            String k = (String) o;
            String v = p.getProperty(k);
            List<String> ranges = Splitter.on(",").omitEmptyStrings().trimResults().splitToList(v);
            List<Range> rangeList = new ArrayList<>();
            for (String range : ranges) {
                List<String> vv = Splitter.on("-").omitEmptyStrings().trimResults().splitToList(range);
                if (vv.size() == 2) {
                    Range ran = new Range(Integer.parseInt(vv.get(0)), Integer.parseInt(vv.get(1)));
                    rangeList.add(ran);

                } else if (vv.size() == 1) {
                    Range ran = new Range(Integer.parseInt(vv.get(0)), Integer.parseInt(vv.get(0)));
                    rangeList.add(ran);

                } else {
                    throw new RuntimeException("load crc32slot datafile error:dn=" + k + ",value=" + range);
                }
            }
            map.put(Integer.parseInt(k), rangeList);
        }

        return map;
    }

    @Override
    public void init() {

        super.init();
        if (ruleName != null) {
            Properties p = loadProps(ruleName, false);
            rangeMap = convertToMap(p);
            checkSize();
            hack();
        }

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