alibaba/DataX · error · IllegalArgumentException

label length over limit(${maxLabelLength})

Error message

label length over limit(${maxLabelLength})

What it means

GdbElement.setLabel enforces MapperConfig.getMaxLabelLength() (typically 256) on element labels. A label resolved from the record longer than the limit throws IllegalArgumentException at mapping time. For edges with null id, label is checked after UUID generation — so label length applies equally to vertices and edges.

Source

Thrown at gdbwriter/src/main/java/com/alibaba/datax/plugin/writer/gdbwriter/model/GdbElement.java:40

        return this.id;
    }

    public void setId(final String id) {
        final int maxIdLength = MapperConfig.getInstance().getMaxIdLength();
        if (id.length() > maxIdLength) {
            throw new IllegalArgumentException("id length over limit(" + maxIdLength + ")");
        }
        this.id = id;
    }

    public String getLabel() {
        return this.label;
    }

    public void setLabel(final String label) {
        final int maxLabelLength = MapperConfig.getInstance().getMaxLabelLength();
        if (label.length() > maxLabelLength) {
            throw new IllegalArgumentException("label length over limit(" + maxLabelLength + ")");
        }
        this.label = label;
    }

    public List<GdbProperty> getProperties() {
        return this.properties;
    }

    public void addProperty(final String propKey, final Object propValue, final PropertyType card) {
        if (propKey == null || propValue == null) {
            return;
        }

        final int maxPropKeyLength = MapperConfig.getInstance().getMaxPropKeyLength();
        if (propKey.length() > maxPropKeyLength) {
            throw new IllegalArgumentException("property key length over limit(" + maxPropKeyLength + ")");
        }
        if (propValue instanceof String) {

View on GitHub (pinned to 80ec23d5c5)

Solutions

1. Use a short, sanitized label vocabulary (enum-like) instead of free-text labels
2. Truncate/normalize long label values deterministically in the reader transform or SQL
3. Pre-check max label length in the source before the migration job

Example fix

-- before
SELECT concat('event_', event_name) AS label ...
-- after
SELECT concat('event_', md5(event_name)) AS label ...  -- bounded length

static String safeLabel(String raw) {
    int max = MapperConfig.getInstance().getMaxLabelLength();
    return raw.length() <= max ? raw : raw.substring(0, max - 8) + "_" + DigestUtils.md5Hex(raw).substring(0, 7);
}

static boolean isValidGdbLabel(String s) {
    return s != null && !s.isEmpty() && s.length() <= MapperConfig.getInstance().getMaxLabelLength();
}

catch (IllegalArgumentException e) {
    if (e.getMessage() != null && e.getMessage().startsWith("label length over limit")) {
        // normalize label source to a short controlled vocabulary
    }
}

When it happens

Trigger: Label column values exceeding the limit: dynamic labels like 'event_' + timestamp, long descriptive names from a source table's type/department column, or a mapping rule that concatenates fields into the label.

Common situations: Label generated from data instead of a fixed constant (e.g. per-category vertex labels from a category description column); denormalized sources where the type column is free text; no label at all is also invalid but fails the earlier 'id or label missed' check instead.

Related errors

• from length over limit(${maxIdLength})
• to length over limit(${maxIdLength})
• id length over limit(${maxIdLength})
• property key length over limit(${maxPropKeyLength})
• to or from missed in edge

AI-assisted analysis of alibaba/DataX@80ec23d5c5 (2026-08-14). Data as JSON: /api/errors/fc7f6c84d12794cf. Report an issue: GitHub.