/**
 * SMB Witness Protocol client implementation as defined in MS-SWN specification.
 * Manages witness registrations, notifications, and heartbeats for cluster failover support.
 */
public class WitnessClient implements AutoCloseable {
    private static final Logger log = LoggerFactory.getLogger(WitnessClient.class);

    // Polling and backoff constants (in ms)

    protected boolean forceExtendedSecurity = false;
    /** Whether to negotiate only SMB2 or higher protocols */
    protected boolean smb2OnlyNegotiation = false;
    /** Whether to failover to port 139 if port 445 fails */
    protected boolean port139FailoverEnabled = false;
    /** Whether to use NT SMB operations */
    protected boolean useNTSmbs = true;

     * @return whether to enforce the use of secure negotiation.
     */
    boolean isRequireSecureNegotiate();

    /**
     * Enable port 139 failover
     *
     * Property {@code jcifs.smb.client.port139.enabled} (boolean, default false)
     *
     * @return whether to failover to legacy transport on port 139
     */
    boolean isPort139FailoverEnabled();

    /**
     *

        poolSpy.logon(ctx, address);

        // Then: Should connect to IPC$ share
        verify(tree).connectLogon(ctx);
    }

    @Test
    @DisplayName("Should sort addresses by fail count and failover")
    void testFailoverWithFailCounts() throws Exception {
        // Given: Multiple addresses with different fail counts
        Address addr1 = mock(Address.class);

                setSessionSetup(response);

                // Initialize multi-channel after successful session setup
                initializeMultiChannel();

                // Initialize witness support for fast failover
                initializeWitnessSupport();

                if (ex != null) {
                    throw ex;
                }
                return (T) (response != null ? response.getNextResponse() : null);

        /** Round-robin distribution */
        ROUND_ROBIN,
        /** Least connections */
        LEAST_CONNECTIONS,
        /** Random selection */
        RANDOM,
        /** Failover only (use primary until failure) */
        FAILOVER_ONLY
    }

    /**
     * Represents a group of channels for a single session.
     */
    public static class ChannelGroup {

requires a setting in the replication configuration called [replica modification sync](https://aws.amazon.com/about-aws/whats-new/2020/12/amazon-s3-replication-adds-support-two-way-replication/).

For active-active replication, automatic failover occurs on `GET/HEAD` operations if object or object version requested qualifies for replication and is missing on one site, but present on the other. This allows the applications to take full advantage of two-way replication even before the two sites...

        assertFalse(secureNegotiate, "Should delegate secure negotiate requirement");
        assertTrue(ntlmTargetName, "Should delegate NTLM target name setting");
        assertFalse(port139Failover, "Should delegate port 139 failover setting");
        assertTrue(dfsStrictView, "Should delegate DFS strict view setting");

        verify(mockDelegate).isUseSMB2OnlyNegotiation();
        verify(mockDelegate).isRequireSecureNegotiate();

## 1. Overview

Persistent handles (also known as durable handles) allow SMB3 connections to survive network disconnections, server reboots, and client reconnections. This feature is critical for enterprise reliability and seamless failover scenarios.

## 2. Protocol Specification Reference

- **MS-SMB2 Section 2.2.13.2.3**: SMB2_CREATE_DURABLE_HANDLE_REQUEST
- **MS-SMB2 Section 2.2.13.2.4**: SMB2_CREATE_DURABLE_HANDLE_REQUEST_V2

* Upgrade to etcd client 3.3.17 to fix bug where etcd client does not parse IPv6 addresses correctly when members are joining, and to fix bug where failover on multi-member etcd cluster fails certificate check on DNS mismatch ([#83801](https://github.com/kubernetes/kubernetes/pull/83801), [@jpbetz](https://github.com/jpbetz))