| 460 | } |
| 461 | |
| 462 | void _authenticate(Duration currentMinTimeout, Duration currentMaxTimeout) |
| 463 | { |
| 464 | if (!running.load()) { |
| 465 | VLOG(1) << "Ignoring _authenticate because the driver is not running!"; |
| 466 | return; |
| 467 | } |
| 468 | |
| 469 | delete CHECK_NOTNULL(authenticatee); |
| 470 | authenticatee = nullptr; |
| 471 | |
| 472 | CHECK_SOME(authenticating); |
| 473 | const Future<bool>& future = authenticating.get(); |
| 474 | |
| 475 | if (master.isNone()) { |
| 476 | LOG(INFO) << "Ignoring _authenticate because the master is lost"; |
| 477 | authenticating = None(); |
| 478 | // Set it to false because we do not want further retries until |
| 479 | // a new master is detected. |
| 480 | // We obviously do not need to reauthenticate either even if |
| 481 | // 'reauthenticate' is currently true because the master is |
| 482 | // lost. |
| 483 | reauthenticate = false; |
| 484 | return; |
| 485 | } |
| 486 | |
| 487 | if (reauthenticate || !future.isReady()) { |
| 488 | LOG(INFO) |
| 489 | << "Failed to authenticate with master " << master->pid() << ": " |
| 490 | << (reauthenticate ? "master changed" : |
| 491 | (future.isFailed() ? future.failure() : "future discarded")); |
| 492 | |
| 493 | authenticating = None(); |
| 494 | reauthenticate = false; |
| 495 | |
| 496 | // TODO(vinod): Add a limit on number of retries. |
| 497 | |
| 498 | // Grow the timeout range using exponential backoff: |
| 499 | // |
| 500 | // [min, min + factor * 2^0] |
| 501 | // [min, min + factor * 2^1] |
| 502 | // ... |
| 503 | // [min, min + factor * 2^N] |
| 504 | // ... |
| 505 | // [min, max] // Stop at max. |
| 506 | Duration maxTimeout = |
| 507 | currentMinTimeout + (currentMaxTimeout - currentMinTimeout) * 2; |
| 508 | |
| 509 | authenticate( |
| 510 | currentMinTimeout, |
| 511 | std::min(maxTimeout, flags.authentication_timeout_max)); |
| 512 | |
| 513 | return; |
| 514 | } |
| 515 | |
| 516 | if (!future.get()) { |
| 517 | LOG(ERROR) << "Master " << master->pid() << " refused authentication"; |
| 518 | error("Master refused authentication"); |
| 519 | return; |