From b8b7e583adcea63557847c505aeafa2f81f4b7b4 Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Mon, 9 Dec 2013 13:22:22 -0800
Subject: [PATCH] Show a queue utilization statistic in the Daemon console

Summary:
This came up recently in a discussion with @lifeihuang, and then tangentally with @hach-que. Make it easier for users to get a sense of whether they might need to add more daemons. Although we've improved the transparency of daemons, it's not easy for non-experts to determine at a glance how close to overflowing the queue is.

This number is approximate, but should be good enough for determining if your queue is more like 25% or 95% full.

If this goes over, say, 80%, it's probably a good idea to think about adding a couple of daemons. If it's under that, you should generally be fine.

Test Plan: {F88331}

Reviewers: btrahan, hach-que, lifeihuang

Reviewed By: btrahan

CC: hach-que, lifeihuang, aran, chad

Differential Revision: https://secure.phabricator.com/D7747
---
 .../PhabricatorDaemonConsoleController.php    | 61 ++++++++++++++++---
 .../view/PassphraseCredentialControl.php      |  2 +-
 2 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/src/applications/daemon/controller/PhabricatorDaemonConsoleController.php b/src/applications/daemon/controller/PhabricatorDaemonConsoleController.php
index ffaaf262f0..8a130939d1 100644
--- a/src/applications/daemon/controller/PhabricatorDaemonConsoleController.php
+++ b/src/applications/daemon/controller/PhabricatorDaemonConsoleController.php
@@ -7,13 +7,23 @@ final class PhabricatorDaemonConsoleController
     $request = $this->getRequest();
     $user = $request->getUser();
 
+    $window_start = (time() - (60 * 15));
+
+    // Assume daemons spend about 250ms second in overhead per task acquiring
+    // leases and doing other bookkeeping. This is probably an over-estimation,
+    // but we'd rather show that utilization is too high than too low.
+    $lease_overhead = 0.250;
+
     $completed = id(new PhabricatorWorkerArchiveTask())->loadAllWhere(
       'dateModified > %d',
-      time() - (60 * 15));
+      $window_start);
 
     $failed = id(new PhabricatorWorkerActiveTask())->loadAllWhere(
       'failureTime > %d',
-      time() - (60 * 15));
+      $window_start);
+
+    $usage_total = 0;
+    $usage_start = PHP_INT_MAX;
 
     $completed_info = array();
     foreach ($completed as $completed_task) {
@@ -27,6 +37,11 @@ final class PhabricatorDaemonConsoleController
       $completed_info[$class]['n']++;
       $duration = $completed_task->getDuration();
       $completed_info[$class]['duration'] += $duration;
+
+      // NOTE: Duration is in microseconds, but we're just using seconds to
+      // compute utilization.
+      $usage_total += $lease_overhead + ($duration / 1000000);
+      $usage_start = min($usage_start, $completed_task->getDateModified());
     }
 
     $completed_info = isort($completed_info, 'n');
@@ -41,6 +56,13 @@ final class PhabricatorDaemonConsoleController
     }
 
     if ($failed) {
+      // Add the time it takes to restart the daemons. This includes a guess
+      // about other overhead of 2X.
+      $usage_total += PhutilDaemonOverseer::RESTART_WAIT * count($failed) * 2;
+      foreach ($failed as $failed_task) {
+        $usage_start = min($usage_start, $failed_task->getFailureTime());
+      }
+
       $rows[] = array(
         phutil_tag('em', array(), pht('Temporary Failures')),
         count($failed),
@@ -48,6 +70,36 @@ final class PhabricatorDaemonConsoleController
       );
     }
 
+    $logs = id(new PhabricatorDaemonLogQuery())
+      ->setViewer($user)
+      ->withStatus(PhabricatorDaemonLogQuery::STATUS_ALIVE)
+      ->execute();
+
+    $taskmasters = 0;
+    foreach ($logs as $log) {
+      if ($log->getDaemon() == 'PhabricatorTaskmasterDaemon') {
+        $taskmasters++;
+      }
+    }
+
+    if ($taskmasters && $usage_total) {
+      // Total number of wall-time seconds the daemons have been running since
+      // the oldest event. For very short times round up to 15s so we don't
+      // render any ridiculous numbers if you reload the page immediately after
+      // restarting the daemons.
+      $available_time = $taskmasters * max(15, (time() - $usage_start));
+
+      // Percentage of those wall-time seconds we can account for, which the
+      // daemons spent doing work:
+      $used_time = ($usage_total / $available_time);
+
+      $rows[] = array(
+        phutil_tag('em', array(), pht('Queue Utilization (Approximate)')),
+        sprintf('%.1f%%', 100 * $used_time),
+        null,
+      );
+    }
+
     $completed_table = new AphrontTableView($rows);
     $completed_table->setNoDataString(
       pht('No tasks have completed in the last 15 minutes.'));
@@ -71,11 +123,6 @@ final class PhabricatorDaemonConsoleController
     $completed_panel->appendChild($completed_table);
     $completed_panel->setNoBackground();
 
-    $logs = id(new PhabricatorDaemonLogQuery())
-      ->setViewer($user)
-      ->withStatus(PhabricatorDaemonLogQuery::STATUS_ALIVE)
-      ->execute();
-
     $daemon_header = id(new PHUIHeaderView())
       ->setHeader(pht('Active Daemons'));
 
diff --git a/src/applications/passphrase/view/PassphraseCredentialControl.php b/src/applications/passphrase/view/PassphraseCredentialControl.php
index 87f315ca59..a12cff7a57 100644
--- a/src/applications/passphrase/view/PassphraseCredentialControl.php
+++ b/src/applications/passphrase/view/PassphraseCredentialControl.php
@@ -2,7 +2,7 @@
 
 final class PassphraseCredentialControl extends AphrontFormControl {
 
-  private $options;
+  private $options = array();
   private $credentialType;
   private $defaultUsername;
   private $allowNull;