apolloconfig/apollo · error · BadRequestException

value too long. length limit:%s

Error message

value too long. length limit:%s

What it means

A BadRequestException (HTTP 400) thrown from ItemService.checkItemValueLength() when an item's value exceeds the configured length limit. The limit is determined by getItemValueLengthLimit(): per-namespace override > per-appId override > global default (DEFAULT_ITEM_VALUE_LENGTH = 20000). For gray-release namespaces (cluster name matching pattern [0-9]{14}-[a-zA-Z0-9]{16}), the limit may be raised to the parent namespace's limit if it is larger.

Source

Thrown at apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/ItemService.java:234

    auditService.audit(Item.class.getSimpleName(), managedItem.getId(), Audit.OP.UPDATE,
        managedItem.getDataChangeLastModifiedBy());

    return managedItem;
  }

  private boolean checkItemValueLength(long namespaceId, String value) {
    Namespace currentNamespace = namespaceService.findOne(namespaceId);
    int limit = getItemValueLengthLimit(currentNamespace);
    if (currentNamespace != null) {
      Matcher m = clusterPattern.matcher(currentNamespace.getClusterName());
      boolean isGray = m.matches();
      if (isGray) {
        limit = getGrayNamespaceItemValueLengthLimit(currentNamespace, limit);
      }
    }
    if (!StringUtils.isEmpty(value) && value.length() > limit) {
      throw new BadRequestException("value too long. length limit:" + limit);
    }
    return true;
  }

  private int getGrayNamespaceItemValueLengthLimit(Namespace grayNamespace,
      int grayNamespaceLimit) {
    Namespace parentNamespace = namespaceService.findParentNamespace(grayNamespace);
    if (parentNamespace != null) {
      int parentLimit = getItemValueLengthLimit(parentNamespace);
      if (parentLimit > grayNamespaceLimit) {
        return parentLimit;
      }
    }
    return grayNamespaceLimit;
  }

  private boolean checkItemKeyLength(String key) {
    if (!StringUtils.isEmpty(key) && key.length() > bizConfig.itemKeyLengthLimit()) {

View on GitHub (pinned to d95fc18d11)

Solutions

1. Shorten the value to be within the limit, or store large data externally and reference it by URL/key in Apollo.
2. Increase the limit via biz config key 'item.value.length.limit' (minimum 5).
3. Set a per-appId override via 'appid.value.length.limit.override' (JSON: {"appId": limit}) or per-namespace via 'namespace.value.length.limit.override' (JSON: {"namespaceId": limit}).
4. For gray namespaces, ensure the parent namespace has a sufficiently large limit so the gray limit inherits it.

Example fix

// before: storing a huge value directly
item.setValue(hugeCertificatePem); // > 20000 chars -> rejected

// after option 1: reference externally
item.setValue("s3://config-bucket/cert.pem");

// after option 2: increase limit in biz config
// System Settings: item.value.length.limit = 50000

// Check value length against the configured limit before saving
int limit = bizConfig.itemValueLengthLimit(); // default 20000
if (!StringUtils.isEmpty(value) && value.length() > limit) {
    // truncate, externalize, or increase limit before proceeding
    throw new IllegalArgumentException("Value exceeds limit of " + limit);
}
item.setValue(value);
itemService.save(item);

When it happens

Trigger: ItemService.save() or update() is called with a value whose length exceeds the resolved limit. The check fires for non-empty values only. Config keys involved: item.value.length.limit (default 20000), appid.value.length.limit.override (JSON map), namespace.value.length.limit.override (JSON map).

Common situations: Storing a large blob, certificate, or long JSON string as a config value that exceeds 20000 characters; the global limit was lowered via config after large values were already present; a migration importing values that exceed the limit.

Related errors

• key too long. length limit:%s
• The maximum number of items (%s) for this namespace has been
• type is invalid. type should be in [0, 3].
• Comment item's key or value should be blank.
• Comment item's comment should not be blank.

AI-assisted analysis of apolloconfig/apollo@d95fc18d11 (2026-08-14). Data as JSON: /api/errors/838aa8282be33c60. Report an issue: GitHub.