pinpoint-apm/pinpoint · error · IllegalArgumentException

invalid varLong. start offset:${offset} readOffset:${offset}

Error message

invalid varLong. start offset:${offset} readOffset:${offset}

What it means

FixedBuffer.readVar64SlowPath decodes LEB128-style variable-length 64-bit integers. If it reads the maximum number of continuation bytes without hitting a terminating byte (high bit clear), the buffer content is not a valid varLong and it throws IllegalArgumentException 'invalid varLong. start offset:... readOffset:...'.

Source

Thrown at commons-buffer/src/main/java/com/navercorp/pinpoint/common/buffer/FixedBuffer.java:401

        }
        return (int) readVar64SlowPath();
    }


    /** Variant of readRawVarint64 for when uncomfortably close to the limit. */
    /* Visible for testing */
    long readVar64SlowPath() {
        int copyOffset = this.offset;
        long result = 0;
        for (int shift = 0; shift < 64; shift += 7) {
            final byte b = this.buffer[copyOffset++];
            result |= (long) (b & 0x7F) << shift;
            if ((b & 0x80) == 0) {
                this.offset = copyOffset;
                return result;
            }
        }
        throw new IllegalArgumentException("invalid varLong. start offset:" +  this.offset + " readOffset:" + offset);
    }

    @Override
    public int readSVInt() {
        return BytesUtils.zigzagToInt(readVInt());
    }

    @Override
    public short readShort() {
        final short i = ByteArrayUtils.bytesToShort(buffer, offset);
        this.offset = this.offset + ByteArrayUtils.SHORT_BYTE_LENGTH;
        return i;
    }

    public int readUnsignedShort() {
        return readShort() & 0xFFFF;
    }

View on GitHub (pinned to 744c3d3075)

Solutions

  1. Verify the byte range being decoded actually starts at a varint boundary; fix the caller's offset.
  2. Check data was written by a compatible Pinpoint version (codec/schema mismatch).
  3. Validate or re-write the corrupted row/cell in storage.
  4. Catch IllegalArgumentException around readVInt/readVLong when decoding untrusted data and log the raw bytes.

Example fix

// before
long v = buffer.readVLong();
// after
try {
    long v = buffer.readVLong();
} catch (IllegalArgumentException e) {
    logger.warn("bad varint at offset, buffer={} ", BytesUtils.toString(buffer.getBuffer()), e);
    throw new CorruptBufferException(e);
}
Defensive patterns

Strategy: validation

Validate before calling

public static boolean isLikelyVarInt(byte[] buf, int offset) {
    for (int i = 0; i < 10 && offset + i < buf.length; i++) {
        if ((buf[offset + i] & 0x80) == 0) return true; // terminator found
    }
    return false;
}

Try / catch

try {
    long value = buffer.readVLong();
} catch (IllegalArgumentException e) {
    logger.warn("malformed varint: {}", e.getMessage());
    throw new CorruptBufferException("bad varint in cell " + rowKey, e);
}

Prevention

When it happens

Trigger: readVInt() or readVLong() invoked on bytes where the varint never terminates within the allowed shifts — either the byte stream is corrupt, the read offset is misaligned, or a fixed-width value is being read as a varint.

Common situations: Deserializing a corrupted/truncated HBase cell value; reading a buffer written by a different codec version (schema mismatch); offset arithmetic errors by the caller before calling readVInt/readVLong; treating non-varint-encoded legacy data as varint.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

AI-assisted analysis of pinpoint-apm/pinpoint@744c3d3075 (2026-09-07). Data as JSON: /api/errors/98582a24611a224c. Report an issue: GitHub.