[ZOOKEEPER-4718] Removing unnecessary heap memory allocation in serialization can help reduce GC pressure.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.8.1
• Fix Version/s: 3.9.0
• Component/s: server
• Labels: pull-request-available
• Assignee: Zili Chen
• Reporter: Yan Zhao
• Created: 06/Jul/23 07:10
• Updated: 04/Aug/23 11:28
• Resolved: 07/Jul/23 01:56

Description

For each request, we will serialize it to a byte array.
In SerializeUtils#serializeRequest, before serializing the request, it always allocates 32 byte array. It's unnecessary; we can allocate the byte array in the catch code block.

    public static byte[] serializeRequest(Request request) {
        if (request == null || request.getHdr() == null) {
            return null;
        }
        byte[] data = new byte[32];
        try {
            data = Util.marshallTxnEntry(request.getHdr(), request.getTxn(), request.getTxnDigest());
        } catch (IOException e) {
            LOG.error("This really should be impossible", e);
        }
        return data;
    }

Issue Links

• links to: GitHub Pull Request #2031