eclipse-vertx/vert.x · error · java.lang.IllegalArgumentException

maxQueries must be > 0

Error message

maxQueries must be > 0

What it means

Configuration validation in setMaxQueries: the number of DNS queries sent during a single resolution (following referrals/search domains) must be at least 1. Zero or negative values would prevent any resolution, so the setter rejects them up front.

Source

Thrown at vertx-core/src/main/java/io/vertx/core/dns/AddressResolverOptions.java:418

    return this;
  }

  /**
   * @return the maximum number of queries to be sent during a resolution
   */
  public int getMaxQueries() {
    return maxQueries;
  }

  /**
   * Set the maximum number of queries when an hostname is resolved.
   *
   * @param maxQueries the max number of queries to be sent
   * @return a reference to this, so the API can be used fluently
   */
  public AddressResolverOptions setMaxQueries(int maxQueries) {
    if (maxQueries < 1) {
      throw new IllegalArgumentException("maxQueries must be > 0");
    }
    this.maxQueries = maxQueries;
    return this;
  }

  /**
   * @return the DNS queries <i>Recursion Desired</i> flag value
   */
  public boolean getRdFlag() {
    return rdFlag;
  }

  /**
   * Set the DNS queries <i>Recursion Desired</i> flag value.
   *
   * @param rdFlag the flag value
   * @return a reference to this, so the API can be used fluently
   */

View on GitHub (pinned to fb308bd8c3)

Solutions

1. Pass a positive integer (default is 4)
2. Check configuration values deserialized from JSON before building the options

When it happens

Trigger: Thrown at vertx-core/src/main/java/io/vertx/core/dns/AddressResolverOptions.java:418 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of eclipse-vertx/vert.x@fb308bd8c3 (2026-09-06). Data as JSON: /api/errors/7c12638aa0fa001c. Report an issue: GitHub.