Hard exit when loosing leadership

src/lavinmq/config.cr

@@ -115,7 +115,7 @@ module LavinMQ
         p.on("--raise-gc-warn", "Raise on GC warnings") { @raise_gc_warn = true }
         p.on("--no-data-dir-lock", "Don't put a file lock in the data directory (default true)") { @data_dir_lock = false }
         p.on("-d", "--debug", "Verbose logging") { @log_level = ::Log::Severity::Debug }
-        p.on("-h", "--help", "Show this help") { puts p; exit 1 }
+        p.on("-h", "--help", "Show this help") { puts p; exit 0 }
         p.on("-v", "--version", "Show version") { puts LavinMQ::VERSION; exit 0 }
         p.on("--build-info", "Show build information") { puts LavinMQ::BUILD_INFO; exit 0 }
         p.on("--guest-only-loopback=BOOL", "Limit guest user to only connect from loopback address") do |v|

src/lavinmq/data_dir_lock.cr

@@ -11,6 +11,7 @@ module LavinMQ
       @lock.read_buffering = false
     end
 
+    # See `man 2 flock`
     def acquire
       begin
         @lock.flock_exclusive(blocking: false)
@@ -21,7 +22,7 @@ module LavinMQ
         Log.info { "Lock acquired" }
       end
       @lock.truncate
-      @lock.print System.hostname
+      @lock.print "PID #{Process.pid} @ #{System.hostname}"
       @lock.fsync
     end
 
@@ -31,7 +32,7 @@ module LavinMQ
       @lock.flock_unlock
     end
 
-    # Read from the lock file to detect lost lock
+    # Read from the lock file to detect lost lock on networked filesystems (NFS/SMB)
     # See "Lost locks" in `man 2 fcntl`
     def poll
       @lock.read_at(0, 1, &.read_byte) || raise IO::EOFError.new

src/lavinmq/launcher.cr

@@ -44,9 +44,8 @@ module LavinMQ
       loop do
         if leadership = @leadership
           if leadership.wait(30.seconds)
-            Log.warn { "Lost leadership" }
-            stop
-            exit 1
+            Log.fatal { "Lost cluster leadership" }
+            exit 3 # 3rd character in the alphabet is C(lustering)
           else
             @data_dir_lock.try &.poll
             GC.collect

src/lavinmqperf.cr

@@ -17,7 +17,7 @@ class Perf
     @parser = OptionParser.new
     @banner = "Usage: #{PROGRAM_NAME} [throughput | bind-churn | queue-churn | connection-churn | connection-count] [arguments]"
     @parser.banner = @banner
-    @parser.on("-h", "--help", "Show this help") { puts @parser; exit 1 }
+    @parser.on("-h", "--help", "Show this help") { puts @parser; exit 0 }
     @parser.on("-v", "--version", "Show version") { puts LavinMQ::VERSION; exit 0 }
     @parser.on("--build-info", "Show build information") { puts LavinMQ::BUILD_INFO; exit 0 }
     @parser.invalid_option { |arg| abort "Invalid argument: #{arg}" }