apache/cassandra · error · EOFException

EOF after " + (limit - bytesRead) + " bytes out of " + size

Error message

EOF after " + (limit - bytesRead) + " bytes out of " + size

What it means

TrackedDataInputPlus wraps another input with a read limit. checkCanRead throws EOFException when a read of `size` bytes would exceed the remaining limit, after skipping to the limit boundary. It signals truncated data: fewer bytes were available than the reader requested.

Solutions

1. Verify the upstream data source is complete and not truncated (check file size / frame length)
2. Validate embedded length prefixes against the available limit before reading
3. Check that writer and reader use compatible serialization versions
4. Catch EOFException and treat the payload as corrupt, logging the bytes read vs expected

Example fix

// before
input.readFully(buffer, 0, declaredLength); // may throw EOFException
// after
if (declaredLength > availableBytes()) throw new CorruptPayloadException(...);
input.readFully(buffer, 0, declaredLength);

if (limit >= 0 && needed > limit - bytesRead) throw new EOFException("truncated"); // mirror the check before reading

boolean canRead(TrackedDataInputPlus in, int n) { return in.available() >= n; }

try { in.readFully(buf, 0, n); } catch (EOFException e) { handleTruncated(e); }

When it happens

Trigger: Any of readBoolean/readByte/readChar/readDouble/readFloat/readFully (and other size-checking reads) requesting more bytes than remain before the configured limit; e.g. reading a length-prefixed field that claims more bytes than the stream contains.

Common situations: Deserializing truncated messages or files; corrupt payloads whose embedded lengths exceed the actual frame size; protocol mismatches between writer and reader versions.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• EOF after " + copied + " bytes out of " + len
• EOF after " + read + " bytes out of " + len
• Cannot deserialize index summary from
• Clustering block upper bits (those not associated with…
• Corrupt clustering value length

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/1d25f4b225f5dfaa. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/io/util/TrackedDataInputPlus.java:204

        int i = source.readUnsignedShort();
        bytesRead += TypeSizes.SHORT_SIZE;
        return i;
    }

    public int skipBytes(int n) throws IOException
    {
        int skipped = source.skipBytes(limit < 0 ? n : (int) Math.min(limit - bytesRead, n));
        bytesRead += skipped;
        return skipped;
    }

    @Inline
    private void checkCanRead(int size) throws IOException
    {
        if (limit >= 0 && bytesRead + size > limit)
        {
            skipBytes((int) (limit - bytesRead));
            throw new EOFException("EOF after " + (limit - bytesRead) + " bytes out of " + size);
        }
    }
}

View on GitHub (pinned to 88fd0f6a0e)