alibaba/arthas · warning · ObjectTooLargeException

Object size exceeds size limit: {}

Error message

Object size exceeds size limit: {}

What it means

ObjectView.appendStringBuilder() throws ObjectTooLargeException (a private checked Exception) when the accumulated rendering buffer would exceed maxObjectLength. This is a safety valve to prevent Arthas from rendering and serializing arbitrarily large objects (e.g. deeply nested or huge collections) which could exhaust memory. maxObjectLength defaults to GlobalOptions.objectSizeLimit or ArthasConstants.MAX_HTTP_CONTENT_LENGTH.

Source

Thrown at core/src/main/java/com/taobao/arthas/core/view/ObjectView.java:689

     * 是否展开当前深度的节点
     *
     * @param deep   当前节点的深度
     * @param expand 展开极限
     * @return true:当前节点需要展开 / false:当前节点不需要展开
     */
    private static boolean isExpand(int deep, int expand) {
        return deep < expand;
    }

    /**
     * append string to a string builder, with upper limit check
     * @param buf the StringBuilder buffer
     * @param data the data to be appended
     * @throws ObjectTooLargeException if the size has exceeded the upper limit
     */
    private void appendStringBuilder(StringBuilder buf, String data) throws ObjectTooLargeException {
        if (buf.length() + data.length() > maxObjectLength) {
            throw new ObjectTooLargeException("Object size exceeds size limit: " + maxObjectLength);
        }
        buf.append(data);
    }

    private static class ObjectTooLargeException extends Exception {

        public ObjectTooLargeException(String message) {
            super(message);
        }
    }

    public static int normalizeMaxObjectLength(Integer limit) {
        if (limit != null && limit > 0) {
            return limit;
        }
        int globalLimit = GlobalOptions.objectSizeLimit;
        if (globalLimit > 0) {
            return globalLimit;

View on GitHub (pinned to 21cf2e9ba5)

Solutions

  1. Increase the size limit via the global option: options objectSizeLimit <larger-value> (e.g. 10485760 for ~10MB).
  2. Narrow the inspection target — use a more specific OGNL expression to extract only the needed field instead of dumping the whole object.
  3. Reduce the expand depth to avoid rendering deeply nested sub-objects.
  4. If the limit is intentionally low for memory protection, filter or paginate the data at the source before inspection.

Example fix

// before: default limit too small for large object
ognl '@com.example.BigCache@instance' // throws ObjectTooLargeException

// after: raise limit then inspect
options objectSizeLimit 10485760
ognl '@com.example.BigCache@instance'
// or narrow scope:
ognl '@com.example.BigCache@instance.smallField'
Defensive patterns

Strategy: validation

Validate before calling

// Raise the limit before inspecting large objects (Arthas CLI)
// options objectSizeLimit 10485760
// Or programmatically ensure maxObjectLength is sufficient
int estimated = estimateRenderedSize(target);
if (estimated > maxObjectLength) {
    // narrow the inspection target instead of dumping the whole object
}

Try / catch

// ObjectTooLargeException is private; callers see a truncated/empty render instead.
// Prevent by tuning objectSizeLimit or narrowing OGNL expressions.
// No external try-catch needed — handle by adjusting options.

Prevention

When it happens

Trigger: Inspecting an object (via ognl/watch/etc.) whose string representation, when rendered with indentation and nesting, pushes the StringBuilder past the configured maxObjectLength threshold.

Common situations: Running 'ognl' or 'watch' on a large collection or deeply-nested POJO; the global option objectSizeLimit is set low; inspecting an object that contains a very long string or byte[] rendered as text.

Related errors

AI-assisted analysis of alibaba/arthas@21cf2e9ba5 (2026-08-14). Data as JSON: /api/errors/40b9c68888d292ef. Report an issue: GitHub.