[real-time] ignore error from duplicate send action on socket.io socket (#23787)

GitOrigin-RevId: 992a39a5cff04bcc0814ac6a620ad350d6e1da14

services/real-time/app.js

@@ -262,7 +262,11 @@ if (Settings.shutdownDrainTimeWindow) {
           'EPIPE',
           'ECONNRESET',
           'ERR_STREAM_WRITE_AFTER_END',
-        ].includes(error.code)
+        ].includes(error.code) ||
+        // socket.io error handler sending on polling connection again.
+        (error.code === 'ERR_HTTP_HEADERS_SENT' &&
+          error.stack &&
+          error.stack.includes('Transport.error'))
       ) {
         Metrics.inc('disconnected_write', 1, { status: error.code })
         return logger.warn(