eclipse-vertx/vert.x · error · io.netty.handler.codec.DecoderException

Could not convert address ${data} to InetAddress.

Error message

Could not convert address ${data} to InetAddress.

What it means

Decoding error for A/AAAA DNS records: after the byte length matched, converting the record's ByteBuf content to an InetAddress failed. The message includes the raw buffer data; this indicates the server returned syntactically sized but invalid address bytes.

Source

Thrown at vertx-core/src/main/java/io/vertx/core/dns/impl/RecordDecoder.java:153

        return null;
      }
    };

    static Function<DnsRecord, String> address(DnsRecordType type, int octets) {
        return record -> {
          if (record.type() == type) {
            ByteBuf data = ((DnsRawRecord)record).content();
            int size = data.readableBytes();
            if (size != octets) {
              throw new DecoderException("Invalid content length, or reader index when decoding address [index: "
                + data.readerIndex() + ", expected length: " + octets + ", actual: " + size + "].");
            }
            byte[] address = new byte[octets];
            data.getBytes(data.readerIndex(), address);
            try {
              return InetAddress.getByAddress(address).getHostAddress();
            } catch (UnknownHostException e) {
              throw new DecoderException("Could not convert address "
                + data.toString(data.readerIndex(), size, CharsetUtil.UTF_8) + " to InetAddress.");
            }
          } else {
            return null;
          }
        };
    }

    /**
     * Retrieves a domain name given a buffer containing a DNS packet. If the
     * name contains a pointer, the position of the buffer will be set to
     * directly after the pointer's index after the name has been read.
     *
     * @param buf the byte buffer containing the DNS packet
     * @return the domain name for an entry
     */
    static String readName(ByteBuf buf) {
        int position = -1;

View on GitHub (pinned to fb308bd8c3)

Solutions

1. Retry resolution against a different DNS server
2. Capture the reported buffer content to diagnose the non-rfc compliant response

When it happens

Trigger: Thrown at vertx-core/src/main/java/io/vertx/core/dns/impl/RecordDecoder.java:153 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/d736dd9ccffc3056. Report an issue: GitHub.