Classify named AMQP recovery errors

Both connections were already named at newConnection() -- 'fleetd-reply-inbox' and
'fleetd-lead-mailbox' -- and neither name ever reached the log: 0 occurrences in
fleetd.out, and both connections logged under the same thread name
'[AMQP Connection 10.10.20.13:5672]'. So when one of the two died and never came
back, the log could not say which.

AmqpConnectionFailureLogger extends DefaultExceptionHandler and overrides only the
protected log(String, Throwable) sink that every handle* method calls virtually, so
the identity is added without changing any handler action.

My brief caused a defect here and the correction is the interesting part. I told the
worker the client 'currently uses ForgivingExceptionHandler', read off the log line
c.r.c.i.ForgivingExceptionHandler -- which names where the LOGGER FIELD is declared,
not the instance's class. javap on the jar shows ConnectionFactory's constructor does
'new DefaultExceptionHandler', and DefaultExceptionHandler extends StrictExceptionHandler
extends ForgivingExceptionHandler. The first version therefore extended the base and
silently dropped strict channel-closing on four listener/consumer paths. Now pinned by
a type assertion on both factories plus a behavioural test that handleConsumerException
still closes the channel once.

Verified on merge with a mutation the worker did not run: it mutated the parent class,
so I mutated the copied private-static isSocketClosedOrConnectionReset in the DANGEROUS
direction (always true => every failure logs at WARN and vanishes from the redeploy
gate's ERROR count). Caught: 'inbox failure line ==> expected: <ERROR> but was: <WARN>'.

Merged main in first; the auto-merge compiled. 1379 green, unpiped.

fleetd/src/main/java/dev/ltms/fleet/msg/AmqpReplyInbox.java

@@ -8,6 +8,7 @@ import com.rabbitmq.client.DeliverCallback;
 import com.rabbitmq.client.Recoverable;
 import com.rabbitmq.client.RecoveryListener;
 import com.rabbitmq.client.Return;
+import com.rabbitmq.client.impl.DefaultExceptionHandler;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -153,17 +154,22 @@ public final class AmqpReplyInbox implements ReplyInbox, AutoCloseable {
     /** As {@link #open(String)}, with an explicit consumer prefetch (CB-527: caps the held backlog per target). */
     public static AmqpReplyInbox open(String uri, int prefetch) {
         try {
-            ConnectionFactory factory = new ConnectionFactory();
-            factory.setUri(uri);
-            // Self-heal transient blips; topology recovery re-declares queues and re-attaches consumers.
-            factory.setAutomaticRecoveryEnabled(true);
-            factory.setTopologyRecoveryEnabled(true);
-            return new AmqpReplyInbox(factory.newConnection("fleetd-reply-inbox"), prefetch);
+            return new AmqpReplyInbox(connectionFactory(uri).newConnection(AmqpConnectionFailureLogger.REPLY_INBOX), prefetch);
         } catch (Exception e) {
             throw new IllegalStateException("cannot connect to AMQP broker at " + uri, e);
         }
     }
 
+    static ConnectionFactory connectionFactory(String uri) throws Exception {
+        ConnectionFactory factory = new ConnectionFactory();
+        factory.setUri(uri);
+        // Self-heal transient blips; topology recovery re-declares queues and re-attaches consumers.
+        factory.setAutomaticRecoveryEnabled(true);
+        factory.setTopologyRecoveryEnabled(true);
+        factory.setExceptionHandler(new AmqpConnectionFailureLogger(AmqpConnectionFailureLogger.REPLY_INBOX, log));
+        return factory;
+    }
+
     /** Wrap an already-open connection with {@link #DEFAULT_PREFETCH} (injection seam for the contract test). */
     AmqpReplyInbox(Connection connection) {
         this(connection, DEFAULT_PREFETCH);
@@ -571,3 +577,44 @@ public final class AmqpReplyInbox implements ReplyInbox, AutoCloseable {
         }
     }
 }
+
+/**
+ * Keeps RabbitMQ's forgiving exception behaviour while adding the connection identity that its
+ * default logger drops. Package-private so both AMQP connections use the same two names.
+ */
+final class AmqpConnectionFailureLogger extends DefaultExceptionHandler {
+
+    static final String REPLY_INBOX = "fleetd-reply-inbox";
+    static final String LEAD_MAILBOX = "fleetd-lead-mailbox";
+
+    private final String connectionName;
+    private final Logger logger;
+
+    AmqpConnectionFailureLogger(String connectionName, Logger logger) {
+        this.connectionName = connectionName;
+        this.logger = logger;
+    }
+
+    String connectionName() {
+        return connectionName;
+    }
+
+    @Override
+    protected void log(String message, Throwable cause) {
+        if (isSocketClosedOrConnectionReset(cause)) {
+            logger.warn("AMQP connection {}: {} (Exception message: {})", connectionName, message, cause.getMessage());
+        } else {
+            logger.error("AMQP connection {}: {}", connectionName, message, cause);
+        }
+    }
+
+    private static boolean isSocketClosedOrConnectionReset(Throwable cause) {
+        // Deliberate copy of ForgivingExceptionHandler's private static helper; check it on amqp-client upgrades.
+        if (!(cause instanceof IOException)) {
+            return false;
+        }
+        return "Connection reset".equals(cause.getMessage())
+                || "Socket closed".equals(cause.getMessage())
+                || "Connection reset by peer".equals(cause.getMessage());
+    }
+}

fleetd/src/main/java/dev/ltms/fleet/msg/LeadMailbox.java

@@ -122,17 +122,22 @@ public final class LeadMailbox implements LeadChannel, AutoCloseable {
     /** As {@link #open(String, String)}, with an explicit consumer prefetch. */
     public static LeadMailbox open(String uri, String selfCoordId, int prefetch) {
         try {
-            ConnectionFactory factory = new ConnectionFactory();
-            factory.setUri(uri);
-            // Self-heal transient blips; topology recovery re-declares the queue and re-attaches the consumer.
-            factory.setAutomaticRecoveryEnabled(true);
-            factory.setTopologyRecoveryEnabled(true);
-            return new LeadMailbox(factory.newConnection("fleetd-lead-mailbox"), selfCoordId, prefetch);
+            return new LeadMailbox(connectionFactory(uri).newConnection(AmqpConnectionFailureLogger.LEAD_MAILBOX), selfCoordId, prefetch);
         } catch (Exception e) {
             throw new IllegalStateException("cannot connect to AMQP coordination broker at " + uri, e);
         }
     }
 
+    static ConnectionFactory connectionFactory(String uri) throws Exception {
+        ConnectionFactory factory = new ConnectionFactory();
+        factory.setUri(uri);
+        // Self-heal transient blips; topology recovery re-declares queues and re-attaches consumers.
+        factory.setAutomaticRecoveryEnabled(true);
+        factory.setTopologyRecoveryEnabled(true);
+        factory.setExceptionHandler(new AmqpConnectionFailureLogger(AmqpConnectionFailureLogger.LEAD_MAILBOX, log));
+        return factory;
+    }
+
     /** Wrap an already-open connection with {@link #DEFAULT_PREFETCH} (injection seam for tests). */
     LeadMailbox(Connection connection, String selfCoordId) {
         this(connection, selfCoordId, DEFAULT_PREFETCH);

fleetd/src/test/java/dev/ltms/fleet/msg/AmqpConnectionFailureLoggerTest.java

@@ -0,0 +1,134 @@
+package dev.ltms.fleet.msg;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.read.ListAppender;
+import com.rabbitmq.client.Channel;
+import com.rabbitmq.client.ConnectionFactory;
+import com.rabbitmq.client.impl.DefaultExceptionHandler;
+import org.junit.jupiter.api.Test;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.lang.reflect.Proxy;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class AmqpConnectionFailureLoggerTest {
+
+    @Test
+    void installedHandlersLogTheirOwnConnectionNamesAtErrorWithTheCause() throws Exception {
+        ConnectionFactory inboxFactory = AmqpReplyInbox.connectionFactory("amqp://127.0.0.1");
+        ConnectionFactory mailboxFactory = LeadMailbox.connectionFactory("amqp://127.0.0.1");
+
+        AmqpConnectionFailureLogger inboxHandler = installedStrictHandler(inboxFactory, "reply inbox");
+        AmqpConnectionFailureLogger mailboxHandler = installedStrictHandler(mailboxFactory, "lead mailbox");
+        assertEquals(AmqpConnectionFailureLogger.REPLY_INBOX, inboxHandler.connectionName());
+        assertEquals(AmqpConnectionFailureLogger.LEAD_MAILBOX, mailboxHandler.connectionName());
+
+        ListAppender<ILoggingEvent> inboxEvents = attach(AmqpReplyInbox.class);
+        ListAppender<ILoggingEvent> mailboxEvents = attach(LeadMailbox.class);
+        IllegalStateException inboxFailure = new IllegalStateException("inbox failure");
+        IllegalStateException mailboxFailure = new IllegalStateException("mailbox failure");
+        try {
+            inboxHandler.handleUnexpectedConnectionDriverException(null, inboxFailure);
+            mailboxHandler.handleConnectionRecoveryException(null, mailboxFailure);
+
+            assertError(inboxEvents, "AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred",
+                    inboxFailure, "inbox failure line");
+            assertError(mailboxEvents, "AMQP connection fleetd-lead-mailbox: Caught an exception during connection recovery!",
+                    mailboxFailure, "mailbox recovery line");
+        } finally {
+            detach(AmqpReplyInbox.class, inboxEvents);
+            detach(LeadMailbox.class, mailboxEvents);
+        }
+    }
+
+    @Test
+    void connectionResetKeepsForgivingHandlerWarningSemantics() {
+        AmqpConnectionFailureLogger handler = new AmqpConnectionFailureLogger(
+                AmqpConnectionFailureLogger.REPLY_INBOX, LoggerFactory.getLogger(AmqpReplyInbox.class));
+        ListAppender<ILoggingEvent> events = attach(AmqpReplyInbox.class);
+        try {
+            handler.handleUnexpectedConnectionDriverException(null, new IOException("Connection reset"));
+            assertEquals(1, events.list.size(), "the handler must still log a reset");
+            ILoggingEvent event = events.list.getFirst();
+            assertEquals(Level.WARN, event.getLevel(), "ForgivingExceptionHandler logs connection resets at WARN");
+            assertEquals("AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred "
+                            + "(Exception message: Connection reset)", event.getFormattedMessage());
+            assertTrue(event.getThrowableProxy() == null, "ForgivingExceptionHandler does not attach a reset stack trace");
+        } finally {
+            detach(AmqpReplyInbox.class, events);
+        }
+    }
+
+    @Test
+    void connectionNamesStayDistinct() {
+        assertNotEquals(AmqpConnectionFailureLogger.REPLY_INBOX, AmqpConnectionFailureLogger.LEAD_MAILBOX,
+                "reply-inbox and lead-mailbox failures must be distinguishable");
+    }
+
+    @Test
+    void strictConsumerExceptionStillClosesItsChannel() {
+        AtomicInteger closes = new AtomicInteger();
+        Channel channel = (Channel) Proxy.newProxyInstance(getClass().getClassLoader(), new Class<?>[] {Channel.class},
+                (_, method, _) -> switch (method.getName()) {
+                    case "close" -> {
+                        closes.incrementAndGet();
+                        yield null;
+                    }
+                    case "toString" -> "test-channel";
+                    default -> throw new UnsupportedOperationException(method.getName());
+                });
+        AmqpConnectionFailureLogger handler = new AmqpConnectionFailureLogger(
+                AmqpConnectionFailureLogger.REPLY_INBOX, LoggerFactory.getLogger(AmqpReplyInbox.class));
+
+        handler.handleConsumerException(channel, new IllegalStateException("consumer failed"), null, "tag", "handleDelivery");
+
+        assertEquals(1, closes.get(), "DefaultExceptionHandler must close a channel after a consumer exception");
+    }
+
+    @Test
+    void handlerOnlyChangesDefaultHandlerLogging() {
+        assertEquals(DefaultExceptionHandler.class,
+                AmqpConnectionFailureLogger.class.getSuperclass());
+        assertFalse(java.util.Arrays.stream(AmqpConnectionFailureLogger.class.getDeclaredMethods())
+                        .anyMatch(method -> method.getName().startsWith("handle")),
+                "all exception-handling methods must remain inherited from DefaultExceptionHandler");
+    }
+
+    private static ListAppender<ILoggingEvent> attach(Class<?> owner) {
+        Logger logger = (Logger) LoggerFactory.getLogger(owner);
+        logger.setLevel(Level.DEBUG);
+        ListAppender<ILoggingEvent> appender = new ListAppender<>();
+        appender.start();
+        logger.addAppender(appender);
+        return appender;
+    }
+
+    private static void detach(Class<?> owner, ListAppender<ILoggingEvent> appender) {
+        ((Logger) LoggerFactory.getLogger(owner)).detachAppender(appender);
+    }
+
+    private static AmqpConnectionFailureLogger installedStrictHandler(ConnectionFactory factory, String connection) {
+        assertInstanceOf(DefaultExceptionHandler.class, factory.getExceptionHandler(),
+                connection + " must keep DefaultExceptionHandler: replacing the strict handler with a forgiving one "
+                        + "changes when a channel is closed");
+        return assertInstanceOf(AmqpConnectionFailureLogger.class, factory.getExceptionHandler());
+    }
+
+    private static void assertError(ListAppender<ILoggingEvent> events, String message, Throwable cause, String name) {
+        assertEquals(1, events.list.size(), name);
+        ILoggingEvent event = events.list.getFirst();
+        assertEquals(Level.ERROR, event.getLevel(), name);
+        assertEquals(message, event.getFormattedMessage(), name);
+        assertEquals(cause.toString(), event.getThrowableProxy().getClassName() + ": "
+                + event.getThrowableProxy().getMessage(), name);
+    }
+}

scripts/redeploy-fleetd.sh

@@ -116,6 +116,50 @@ check_log_path_matches_plist() {
   ok "log path check: script and plist agree ($resolved_out)"
 }
 
+# Classify ERROR lines in one fresh log region. AMQP failure messages now include the connection
+# name, so a recovery can clear only errors for its own connection. A candidate with neither name
+# remains unexplained: it must never be quieted by a recovery on the other connection.
+classify_amqp_connection_errors() {
+  local log_file="$1" line pending_inbox=0 pending_lead_mailbox=0
+  REDEPLOY_ERROR_COUNT=0
+  REDEPLOY_RECOVERED_AMQP_ERRORS=0
+  REDEPLOY_UNEXPLAINED_ERRORS=0
+
+  while IFS= read -r line || [ -n "$line" ]; do
+    case "$line" in
+      *' ERROR '*|*' SEVERE '*)
+        REDEPLOY_ERROR_COUNT=$((REDEPLOY_ERROR_COUNT + 1))
+        case "$line" in
+          *'AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred'*|*'AMQP connection fleetd-reply-inbox: Caught an exception during connection recovery!'*)
+            pending_inbox=$((pending_inbox + 1))
+            ;;
+          *'AMQP connection fleetd-lead-mailbox: An unexpected connection driver error occurred'*|*'AMQP connection fleetd-lead-mailbox: Caught an exception during connection recovery!'*)
+            pending_lead_mailbox=$((pending_lead_mailbox + 1))
+            ;;
+          *'AMQP connection'*'An unexpected connection driver error occurred'*|*'AMQP connection'*'Caught an exception during connection recovery!'*)
+            REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + 1))
+            ;;
+          *) REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + 1)) ;;
+        esac
+        ;;
+      *'AMQP connection recovered; cleared held replies for fresh redelivery'*)
+        if [ "$pending_inbox" -gt 0 ]; then
+          pending_inbox=$((pending_inbox - 1))
+          REDEPLOY_RECOVERED_AMQP_ERRORS=$((REDEPLOY_RECOVERED_AMQP_ERRORS + 1))
+        fi
+        ;;
+      *'AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery'*)
+        if [ "$pending_lead_mailbox" -gt 0 ]; then
+          pending_lead_mailbox=$((pending_lead_mailbox - 1))
+          REDEPLOY_RECOVERED_AMQP_ERRORS=$((REDEPLOY_RECOVERED_AMQP_ERRORS + 1))
+        fi
+        ;;
+    esac
+  done < "$log_file"
+
+  REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + pending_inbox + pending_lead_mailbox))
+}
+
 # CB-600: sourceable for testing. When this file is SOURCED (not executed) it stops here — nothing
 # below runs — so a test harness can `source` it to call check_log_path_matches_plist (or the
 # other pure helpers above) against a throwaway plist fixture without ever reaching the mutating
@@ -361,15 +405,21 @@ tail -n "+$((RESTART_MARK + 1))" "$OUT" 2>/dev/null \
   | grep -iE 'deferred|classification:|fleet health:|coverage' | tail -8 | sed 's/^/   /' \
   || echo "   (nothing reported)"
 
-# Errors since the restart, anchored to the marker so old noise cannot leak in.
-ERRS="$(tail -n "+$((RESTART_MARK + 1))" "$OUT" 2>/dev/null | grep -cE ' (ERROR|SEVERE) ' || true)"
+# Errors since the restart, anchored to the marker so old noise cannot leak in. Keep the fresh
+# region in a file because the classifier must preserve the order of errors and recoveries.
+FRESH_LOG="$(mktemp -t fleetd-fresh-log)"
+trap 'rm -f "$FRESH_LOG"' EXIT
+tail -n "+$((RESTART_MARK + 1))" "$OUT" > "$FRESH_LOG" 2>/dev/null || true
+classify_amqp_connection_errors "$FRESH_LOG"
 say "result"
 ok "pid $NEW_PID, jar $(jar_id)"
-if [ "${ERRS:-0}" -gt 0 ]; then
-  warn "$ERRS ERROR lines since restart:"
-  tail -n "+$((RESTART_MARK + 1))" "$OUT" | grep -E ' (ERROR|SEVERE) ' | tail -5 | sed 's/^/   /'
-else
+if [ "$REDEPLOY_ERROR_COUNT" -eq 0 ]; then
   ok "no ERROR lines since restart"
+elif [ "$REDEPLOY_UNEXPLAINED_ERRORS" -eq 0 ]; then
+  ok "$REDEPLOY_RECOVERED_AMQP_ERRORS AMQP connection reset ERROR lines recovered since restart"
+else
+  warn "$REDEPLOY_ERROR_COUNT ERROR lines since restart:"
+  grep -E ' (ERROR|SEVERE) ' "$FRESH_LOG" | tail -5 | sed 's/^/   /'
 fi
 echo
 echo "   Next: call fleet_whoami and confirm it still answers 'primary'. A lead whose tab label"

scripts/test-redeploy-fleetd.sh

@@ -0,0 +1,238 @@
+#!/usr/bin/env bash
+# Self-contained checks for the pure log classifier in redeploy-fleetd.sh.
+
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+TMP="$(mktemp -d "$ROOT/.redeploy-log-test.XXXXXX")"
+trap 'rm -rf "$TMP"' EXIT
+
+# Sourcing stops before redeploy-fleetd.sh can build, stop, or start the daemon.
+source "$ROOT/scripts/redeploy-fleetd.sh"
+
+fail() {
+  printf 'FAIL: %s\n' "$*" >&2
+  return 1
+}
+
+assert_equals() {
+  local expected="$1" actual="$2" description="$3"
+  [ "$expected" = "$actual" ] || fail "$description: expected $expected, got $actual"
+}
+
+classify_fixture() {
+  local name="$1"
+  classify_amqp_connection_errors "$TMP/$name"
+}
+
+test_no_errors() {
+  cat > "$TMP/no-errors.log" <<'LOG'
+2026-09-05 12:00:00 INFO fleetd listening
+LOG
+  classify_fixture no-errors.log
+  assert_equals 0 "$REDEPLOY_ERROR_COUNT" "no-errors total"
+  assert_equals 0 "$REDEPLOY_UNEXPLAINED_ERRORS" "no-errors unexplained"
+}
+
+test_recovery_patterns_match_source() {
+  grep -F 'AMQP connection {}: {}' "$ROOT/fleetd/src/main/java/dev/ltms/fleet/msg/AmqpReplyInbox.java" > /dev/null \
+    || fail "AMQP failure pattern no longer matches source"
+  grep -F 'AMQP connection recovered; cleared held replies for fresh redelivery' \
+    "$ROOT/fleetd/src/main/java/dev/ltms/fleet/msg/AmqpReplyInbox.java" > /dev/null \
+    || fail "reply-inbox recovery pattern no longer matches source"
+  grep -F 'AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery' \
+    "$ROOT/fleetd/src/main/java/dev/ltms/fleet/msg/LeadMailbox.java" > /dev/null \
+    || fail "lead-mailbox recovery pattern no longer matches source"
+}
+
+test_attributed_recovered_connection_error() {
+  cat > "$TMP/attributed-recovered.log" <<'LOG'
+2026-09-05 12:00:00 ERROR [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred
+2026-09-05 12:00:01 INFO [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection recovered; cleared held replies for fresh redelivery
+LOG
+  classify_fixture attributed-recovered.log
+  assert_equals 1 "$REDEPLOY_ERROR_COUNT" "attributed-recovered total"
+  assert_equals 1 "$REDEPLOY_RECOVERED_AMQP_ERRORS" "attributed-recovered errors"
+  assert_equals 0 "$REDEPLOY_UNEXPLAINED_ERRORS" "attributed-recovered unexplained"
+}
+
+test_source_derived_error_shapes_recover_by_connection() {
+  # These ERROR shapes come from AmqpConnectionFailureLogger on main. They need a live-log check
+  # after redeploy because the new code has not yet written a production line.
+  cat > "$TMP/source-derived.log" <<'LOG'
+17:37:53.537 ERROR [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred
+17:37:54.537 ERROR [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection fleetd-reply-inbox: Caught an exception during connection recovery!
+17:37:55.537 ERROR [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred
+17:37:56.537 ERROR [AMQP Connection broker:5672] d.ltms.fleet.msg.LeadMailbox - AMQP connection fleetd-lead-mailbox: An unexpected connection driver error occurred
+17:37:57.537 ERROR [AMQP Connection broker:5672] d.ltms.fleet.msg.LeadMailbox - AMQP connection fleetd-lead-mailbox: Caught an exception during connection recovery!
+17:37:58.537 ERROR [AMQP Connection broker:5672] d.ltms.fleet.msg.LeadMailbox - AMQP connection fleetd-lead-mailbox: An unexpected connection driver error occurred
+17:38:00.000 INFO  [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection recovered; cleared held replies for fresh redelivery
+17:38:01.000 INFO  [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection recovered; cleared held replies for fresh redelivery
+17:38:02.000 INFO  [AMQP Connection broker:5672] d.l.fleet.msg.AmqpReplyInbox - AMQP connection recovered; cleared held replies for fresh redelivery
+17:38:03.000 INFO  [AMQP Connection broker:5672] d.ltms.fleet.msg.LeadMailbox - AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery
+17:38:04.000 INFO  [AMQP Connection broker:5672] d.ltms.fleet.msg.LeadMailbox - AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery
+17:38:05.000 INFO  [AMQP Connection broker:5672] d.ltms.fleet.msg.LeadMailbox - AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery
+LOG
+  classify_fixture source-derived.log
+  assert_equals 6 "$REDEPLOY_ERROR_COUNT" "source-derived total"
+  assert_equals 6 "$REDEPLOY_RECOVERED_AMQP_ERRORS" "source-derived recovered"
+  assert_equals 0 "$REDEPLOY_UNEXPLAINED_ERRORS" "source-derived unexplained"
+}
+
+test_cross_connection_unattributable_errors_stay_loud() {
+  # This candidate has neither stable connection name, so LeadMailbox recovery must not consume it.
+  cat > "$TMP/cross-unattributable.log" <<'LOG'
+2026-09-05 12:00:00 ERROR [AMQP Connection broker:5672] unknown - AMQP connection: An unexpected connection driver error occurred
+2026-09-05 12:00:01 ERROR [AMQP Connection broker:5672] unknown - AMQP connection: An unexpected connection driver error occurred
+2026-09-05 12:00:02 INFO  [AMQP Connection 10.10.20.13:5672] d.ltms.fleet.msg.LeadMailbox - AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery
+2026-09-05 12:00:03 INFO  [AMQP Connection 10.10.20.13:5672] d.ltms.fleet.msg.LeadMailbox - AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery
+LOG
+  classify_fixture cross-unattributable.log
+  assert_equals 2 "$REDEPLOY_ERROR_COUNT" "cross-unattributable total"
+  assert_equals 0 "$REDEPLOY_RECOVERED_AMQP_ERRORS" "cross-unattributable recovered"
+  assert_equals 2 "$REDEPLOY_UNEXPLAINED_ERRORS" "cross-unattributable unexplained"
+}
+
+test_attributed_cross_connection_errors_stay_loud() {
+  # LeadMailbox recovery cannot heal AmqpReplyInbox errors.
+  cat > "$TMP/cross-attributed.log" <<'LOG'
+2026-09-05 12:00:00 ERROR AmqpReplyInbox - AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred
+2026-09-05 12:00:01 ERROR AmqpReplyInbox - AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred
+2026-09-05 12:00:02 INFO LeadMailbox - AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery
+2026-09-05 12:00:03 INFO LeadMailbox - AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery
+LOG
+  classify_fixture cross-attributed.log
+  assert_equals 2 "$REDEPLOY_ERROR_COUNT" "cross-attributed total"
+  assert_equals 0 "$REDEPLOY_RECOVERED_AMQP_ERRORS" "cross-attributed recovered"
+  assert_equals 2 "$REDEPLOY_UNEXPLAINED_ERRORS" "cross-attributed unexplained"
+}
+
+test_attributed_unrecovered_connection_error() {
+  cat > "$TMP/unrecovered.log" <<'LOG'
+2026-09-05 12:00:00 ERROR AmqpReplyInbox - AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred
+LOG
+  classify_fixture unrecovered.log
+  assert_equals 1 "$REDEPLOY_ERROR_COUNT" "unrecovered total"
+  assert_equals 0 "$REDEPLOY_RECOVERED_AMQP_ERRORS" "unrecovered AMQP errors"
+  assert_equals 1 "$REDEPLOY_UNEXPLAINED_ERRORS" "unrecovered unexplained"
+}
+
+test_other_error_is_unexplained() {
+  cat > "$TMP/other-error.log" <<'LOG'
+2026-09-05 12:00:00 ERROR dev.ltms.fleet.Fleetd - startup failed
+2026-09-05 12:00:01 INFO dev.ltms.fleet.msg.AmqpReplyInbox - AMQP connection recovered; cleared held replies for fresh redelivery
+LOG
+  classify_fixture other-error.log
+  assert_equals 1 "$REDEPLOY_ERROR_COUNT" "other-error total"
+  assert_equals 1 "$REDEPLOY_UNEXPLAINED_ERRORS" "other-error unexplained"
+}
+
+test_recovery_requirement_mutation_is_caught() {
+  classify_amqp_connection_errors() {
+    local log_file="$1" line
+    REDEPLOY_ERROR_COUNT=0
+    REDEPLOY_RECOVERED_AMQP_ERRORS=0
+    REDEPLOY_UNEXPLAINED_ERRORS=0
+    while IFS= read -r line || [ -n "$line" ]; do
+      case "$line" in
+        *' ERROR '*|*' SEVERE '*)
+          REDEPLOY_ERROR_COUNT=$((REDEPLOY_ERROR_COUNT + 1))
+          case "$line" in
+            *'AMQP connection fleetd-reply-inbox: An unexpected connection driver error occurred'*)
+              REDEPLOY_RECOVERED_AMQP_ERRORS=$((REDEPLOY_RECOVERED_AMQP_ERRORS + 1))
+              ;;
+            *) REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + 1)) ;;
+          esac
+          ;;
+      esac
+    done < "$log_file"
+  }
+
+  if test_attributed_unrecovered_connection_error > "$TMP/mutation-output" 2>&1; then
+    fail "mutation accepted an unrecovered connection error"
+  fi
+  grep -F 'FAIL: unrecovered AMQP errors: expected 0, got 1' "$TMP/mutation-output" > /dev/null \
+    || fail "mutation failed without the expected assertion"
+  printf 'Recovery mutation: FAIL: unrecovered AMQP errors: expected 0, got 1\n'
+}
+
+test_shared_counter_mutation_is_caught() {
+  classify_amqp_connection_errors() {
+    local log_file="$1" line pending=0
+    REDEPLOY_ERROR_COUNT=0
+    REDEPLOY_RECOVERED_AMQP_ERRORS=0
+    REDEPLOY_UNEXPLAINED_ERRORS=0
+    while IFS= read -r line || [ -n "$line" ]; do
+      case "$line" in
+        *' ERROR '*|*' SEVERE '*)
+          REDEPLOY_ERROR_COUNT=$((REDEPLOY_ERROR_COUNT + 1))
+          case "$line" in
+            *'AMQP connection'*'An unexpected connection driver error occurred'*|*'AMQP connection'*'Caught an exception during connection recovery!'*)
+              case "$line" in
+                *'fleetd-reply-inbox'*|*'fleetd-lead-mailbox'*) pending=$((pending + 1)) ;;
+                *) REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + 1)) ;;
+              esac
+              ;;
+            *) REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + 1)) ;;
+          esac
+          ;;
+        *'AMQP connection recovered; cleared held replies for fresh redelivery'*|*'AMQP lead mailbox connection recovered; cleared held messages for fresh redelivery'*)
+          if [ "$pending" -gt 0 ]; then
+            pending=$((pending - 1))
+            REDEPLOY_RECOVERED_AMQP_ERRORS=$((REDEPLOY_RECOVERED_AMQP_ERRORS + 1))
+          fi
+          ;;
+      esac
+    done < "$log_file"
+    REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + pending))
+  }
+
+  if test_attributed_cross_connection_errors_stay_loud > "$TMP/shared-mutation-output" 2>&1; then
+    fail "shared counter mutation accepted cross-connection recovery"
+  fi
+  grep -F 'FAIL: cross-attributed recovered: expected 0, got 2' "$TMP/shared-mutation-output" > /dev/null \
+    || fail "shared counter mutation failed without the expected assertion"
+  printf 'Shared-counter mutation: FAIL: cross-attributed recovered: expected 0, got 2\n'
+}
+
+test_unattributable_quiet_mutation_is_caught() {
+  classify_amqp_connection_errors() {
+    local log_file="$1" line
+    REDEPLOY_ERROR_COUNT=0
+    REDEPLOY_RECOVERED_AMQP_ERRORS=0
+    REDEPLOY_UNEXPLAINED_ERRORS=0
+    while IFS= read -r line || [ -n "$line" ]; do
+      case "$line" in
+        *' ERROR '*|*' SEVERE '*)
+          REDEPLOY_ERROR_COUNT=$((REDEPLOY_ERROR_COUNT + 1))
+          case "$line" in
+            *'AMQP connection'*'An unexpected connection driver error occurred'*|*'AMQP connection'*'Caught an exception during connection recovery!'*)
+              REDEPLOY_RECOVERED_AMQP_ERRORS=$((REDEPLOY_RECOVERED_AMQP_ERRORS + 1))
+              ;;
+            *) REDEPLOY_UNEXPLAINED_ERRORS=$((REDEPLOY_UNEXPLAINED_ERRORS + 1)) ;;
+          esac
+          ;;
+      esac
+    done < "$log_file"
+  }
+
+  if test_cross_connection_unattributable_errors_stay_loud > "$TMP/unattributable-mutation-output" 2>&1; then
+    fail "unattributable mutation accepted an unknown connection"
+  fi
+  grep -F 'FAIL: cross-unattributable recovered: expected 0, got 2' "$TMP/unattributable-mutation-output" > /dev/null \
+    || fail "unattributable mutation failed without the expected assertion"
+  printf 'Unattributable mutation: FAIL: cross-unattributable recovered: expected 0, got 2\n'
+}
+
+test_no_errors
+test_recovery_patterns_match_source
+test_attributed_recovered_connection_error
+test_source_derived_error_shapes_recover_by_connection
+test_cross_connection_unattributable_errors_stay_loud
+test_attributed_cross_connection_errors_stay_loud
+test_attributed_unrecovered_connection_error
+test_other_error_is_unexplained
+test_recovery_requirement_mutation_is_caught
+test_shared_counter_mutation_is_caught
+test_unattributable_quiet_mutation_is_caught
+printf 'PASS: redeploy log classifier\n'