Add a garbage collector daemon

Summary:
Phabricator generates a bunch of data that we don't need to keep around forever,
add a GC daemon to get rid of it with some basic configuration options.

This needs a couple more diffs to get some of the details but I think this is a
reasonable start.

I also fixed a couple of UI things related to this, e.g. the daemon logs page
going crazy when a daemon gets stuck in a loop and dumps tons of data to stdout.

Test Plan:
  - Ran gc daemon in 'phd debug' mode and saw it delete stuff, then sleep once
it had cleaned everything up.
  - Mucked around with TTLs and verified they work correctly.
  - Viewed gc'd transcripts in the web interface and made sure they displayed
okay.
  - Viewed daemon logs before/after garbage collection.
  - Running some run-at / run-for tests now, I'll update if the daemon doesn't
shut off in ~10-15 minutes. :P

Reviewed By: tuomaspelkonen
Reviewers: jungejason, tuomaspelkonen, aran
CC: aran, tuomaspelkonen, epriestley
Differential Revision: 583

conf/default.conf.php

@@ -375,6 +375,37 @@ return array(
   // silly (but sort of awesome).
   'remarkup.enable-embedded-youtube' => false,
 
+
+// -- Garbage Collection ---------------------------------------------------- //
+
+  // Phabricator generates various logs and caches in the database which can
+  // be garbage collected after a while to make the total data size more
+  // manageable. To run garbage collection, launch a
+  // PhabricatorGarbageCollector daemon.
+
+  // Since the GC daemon can issue large writes and table scans, you may want to
+  // run it only during off hours or make sure it is scheduled so it doesn't
+  // overlap with backups. This determines when the daemon can start running
+  // each day.
+  'gcdaemon.run-at'    => '12 AM',
+
+  // How many seconds after 'gcdaemon.run-at' the daemon may collect garbage
+  // for. By default it runs continuously, but you can set it to run for a
+  // limited period of time. For instance, if you do backups at 3 AM, you might
+  // run garbage collection for an hour beforehand. This is not a high-precision
+  // limit so you may want to leave some room for the GC to actually stop, and
+  // if you set it to something like 3 seconds you're on your own.
+  'gcdaemon.run-for'   => 24 * 60 * 60,
+
+  // These 'ttl' keys configure how much old data the GC daemon keeps around.
+  // Objects older than the ttl will be collected. Set any value to 0 to store
+  // data indefinitely.
+
+  'gcdaemon.ttl.herald-transcripts'         => 30 * (24 * 60 * 60),
+  'gcdaemon.ttl.daemon-logs'                =>  7 * (24 * 60 * 60),
+  'gcdaemon.ttl.differential-render-cache'  =>  7 * (24 * 60 * 60),
+
+
 // -- Customization --------------------------------------------------------- //
 
   // Paths to additional phutil libraries to load.

scripts/install/update_phabricator.sh

@@ -58,5 +58,6 @@ sudo /etc/init.d/httpd start
 
 # $ROOT/phabricator/bin/phd repository-launch-master
 # $ROOT/phabricator/bin/phd launch metamta
+# $ROOT/phabricator/bin/phd launch garbagecollector
 # $ROOT/phabricator/bin/phd launch 4 taskmaster
 # $ROOT/phabricator/bin/phd launch ircbot /config/bot.json

src/__phutil_library_map__.php

@@ -352,6 +352,7 @@ phutil_register_library_map(array(
     'PhabricatorFileURI' => 'applications/files/uri',
     'PhabricatorFileUploadController' => 'applications/files/controller/upload',
     'PhabricatorFileViewController' => 'applications/files/controller/view',
+    'PhabricatorGarbageCollectorDaemon' => 'infrastructure/daemon/garbagecollector',
     'PhabricatorGoodForNothingWorker' => 'infrastructure/daemon/workers/worker/goodfornothing',
     'PhabricatorHandleObjectSelectorDataView' => 'applications/phid/handle/view/selector',
     'PhabricatorHelpController' => 'applications/help/controller/base',
@@ -844,6 +845,7 @@ phutil_register_library_map(array(
     'PhabricatorFileTransformController' => 'PhabricatorFileController',
     'PhabricatorFileUploadController' => 'PhabricatorFileController',
     'PhabricatorFileViewController' => 'PhabricatorFileController',
+    'PhabricatorGarbageCollectorDaemon' => 'PhabricatorDaemon',
     'PhabricatorGoodForNothingWorker' => 'PhabricatorWorker',
     'PhabricatorHelpController' => 'PhabricatorController',
     'PhabricatorHelpKeyboardShortcutController' => 'PhabricatorHelpController',

src/applications/daemon/view/daemonlogevents/PhabricatorDaemonLogEventsView.php

@@ -43,11 +43,46 @@ final class PhabricatorDaemonLogEventsView extends AphrontView {
     }
 
     foreach ($this->events as $event) {
+
+      // Limit display log size. If a daemon gets stuck in an output loop this
+      // page can be like >100MB if we don't truncate stuff. Try to do cheap
+      // line-based truncation first, and fall back to expensive UTF-8 character
+      // truncation if that doesn't get things short enough.
+
+      $message = $event->getMessage();
+
+      $more_lines = null;
+      $more_chars = null;
+      $line_limit = 12;
+      if (substr_count($message, "\n") > $line_limit) {
+        $message = explode("\n", $message);
+        $more_lines = count($message) - $line_limit;
+        $message = array_slice($message, 0, $line_limit);
+        $message = implode("\n", $message);
+      }
+
+      $char_limit = 8192;
+      if (strlen($message) > $char_limit) {
+        $message = phutil_utf8v($message);
+        $more_chars = count($message) - $char_limit;
+        $message = array_slice($message, 0, $char_limit);
+        $message = implode('', $message);
+      }
+
+      $more = null;
+      if ($more_chars) {
+        $more = number_format($more_chars);
+        $more = "\n<... {$more} more characters ...>";
+      } else if ($more_lines) {
+        $more = number_format($more_lines);
+        $more = "\n<... {$more} more lines ...>";
+      }
+
       $row = array(
         phutil_escape_html($event->getLogType()),
         phabricator_date($event->getEpoch(), $this->user),
         phabricator_time($event->getEpoch(), $this->user),
-        str_replace("\n", '<br />', phutil_escape_html($event->getMessage())),
+        str_replace("\n", '<br />', phutil_escape_html($message.$more)),
       );
 
       if ($this->combinedLog) {

src/applications/daemon/view/daemonlogevents/__init__.php

@@ -11,6 +11,7 @@ phutil_require_module('phabricator', 'view/control/table');
 phutil_require_module('phabricator', 'view/utils');
 
 phutil_require_module('phutil', 'markup');
+phutil_require_module('phutil', 'utils');
 
 
 phutil_require_source('PhabricatorDaemonLogEventsView.php');

src/applications/herald/controller/transcript/HeraldTranscriptController.php

@@ -42,12 +42,19 @@ class HeraldTranscriptController extends HeraldController {
       throw new Exception('Uknown transcript!');
     }
 
-    $field_names = HeraldFieldConfig::getFieldMap();
-    $condition_names = HeraldConditionConfig::getConditionMap();
-    $action_names = HeraldActionConfig::getActionMap();
-
     require_celerity_resource('herald-test-css');
 
+    $nav = $this->buildSideNav();
+
+    $object_xscript = $xscript->getObjectTranscript();
+    if (!$object_xscript) {
+      $notice = id(new AphrontErrorView())
+        ->setSeverity(AphrontErrorView::SEVERITY_NOTICE)
+        ->setTitle('Old Transcript')
+        ->appendChild(
+          '<p>Details of this transcript have been garbage collected.</p>');
+      $nav->appendChild($notice);
+    } else {
       $filter = $this->getFilterPHIDs();
       $this->filterTranscript($xscript, $filter);
       $phids = array_merge($filter, $this->getTranscriptPHIDs($xscript));
@@ -58,10 +65,6 @@ class HeraldTranscriptController extends HeraldController {
         ->loadHandles();
       $this->handles = $handles;
 
-    $object_xscript = $xscript->getObjectTranscript();
-
-    $nav = $this->buildSideNav();
-
       $apply_xscript_panel = $this->buildApplyTranscriptPanel(
         $xscript);
       $nav->appendChild($apply_xscript_panel);
@@ -73,9 +76,11 @@ class HeraldTranscriptController extends HeraldController {
       $object_xscript_panel = $this->buildObjectTranscriptPanel(
         $xscript);
       $nav->appendChild($object_xscript_panel);
+    }
 
 /*
 
+  TODO
 
     $notice = null;
     if ($xscript->getDryRun()) {
@@ -84,30 +89,6 @@ class HeraldTranscriptController extends HeraldController {
           This was a dry run to test Herald rules, no actions were executed.
         </tools:notice>;
     }
-
-    if (!$object_xscript) {
-      $notice =
-        <x:frag>
-          <tools:notice title="Old Transcript">
-            Details of this transcript have been discarded. Full transcripts
-            are retained for 30 days.
-          </tools:notice>
-          {$notice}
-        </x:frag>;
-    }
-
-
-    return
-      <herald:standard-page title="Transcript">
-        <div style="padding: 1em;">
-          <tools:side-nav items={$this->renderNavItems()}>
-            {$notice}
-            {$apply_xscript_markup}
-            {$rule_table}
-            {$object_xscript_table}
-          </tools:side-nav>
-        </div>
-      </herald:standard-page>;
 */
 
     return $this->buildStandardPageResponse(
@@ -264,7 +245,7 @@ class HeraldTranscriptController extends HeraldController {
     foreach ($xscript->getApplyTranscripts() as $id => $apply_xscript) {
       $rule_id = $apply_xscript->getRuleID();
       if ($filter_owned) {
-        if (!$rule_xscripts[$rule_id]) {
+        if (empty($rule_xscripts[$rule_id])) {
           // No associated rule so you can't own this effect.
           continue;
         }

src/applications/herald/controller/transcript/__init__.php

@@ -14,6 +14,7 @@ phutil_require_module('phabricator', 'applications/herald/storage/transcript/bas
 phutil_require_module('phabricator', 'applications/phid/handle/data');
 phutil_require_module('phabricator', 'infrastructure/celerity/api');
 phutil_require_module('phabricator', 'view/control/table');
+phutil_require_module('phabricator', 'view/form/error');
 phutil_require_module('phabricator', 'view/layout/panel');
 phutil_require_module('phabricator', 'view/layout/sidenav');
 

src/docs/configuration/managing_daemons.diviner

@@ -70,3 +70,4 @@ You can get a list of launchable daemons with **phd list**:
   - **PhabricatorTaskmasterDaemon** runs a generic task queue; and
   - **PhabricatorRepository** daemons track repositories, descriptions are
     available in the @{article:Diffusion User Guide}.
+  - **PhabricatorGarbageCollectorDaemon** cleans up old logs and caches.

src/infrastructure/daemon/garbagecollector/PhabricatorGarbageCollectorDaemon.php

@@ -0,0 +1,139 @@
+<?php
+
+/*
+ * Copyright 2011 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Collects old logs and caches to reduce the amount of data stored in the
+ * database.
+ *
+ * @group daemon
+ */
+class PhabricatorGarbageCollectorDaemon extends PhabricatorDaemon {
+
+  public function run() {
+
+    // Keep track of when we start and stop the GC so we can emit useful log
+    // messages.
+    $just_ran = false;
+
+    do {
+      $run_at   = PhabricatorEnv::getEnvConfig('gcdaemon.run-at');
+      $run_for  = PhabricatorEnv::getEnvConfig('gcdaemon.run-for');
+
+      // Just use the default timezone, we don't need to get fancy and try
+      // to localize this.
+      $start = strtotime($run_at);
+      if ($start === false) {
+        throw new Exception(
+          "Configuration 'gcdaemon.run-at' could not be parsed: '{$run_at}'.");
+      }
+
+      $now = time();
+
+      if ($now < $start || $now > ($start + $run_for)) {
+        if ($just_ran) {
+          echo "Stopped garbage collector.\n";
+          $just_ran = false;
+        }
+        // The configuration says we can't collect garbage right now, so
+        // just sleep until we can.
+        $this->sleep(300);
+        continue;
+      }
+
+      if (!$just_ran) {
+        echo "Started garbage collector.\n";
+        $just_ran = true;
+      }
+
+      $n_herald = $this->collectHeraldTranscripts();
+      $n_daemon = $this->collectDaemonLogs();
+      $n_render = $this->collectRenderCaches();
+
+      $collected = array(
+        'Herald Transcript'  => $n_herald,
+        'Daemon Log'         => $n_daemon,
+        'Render Cache'       => $n_render,
+      );
+      $collected = array_filter($collected);
+
+      foreach ($collected as $thing => $count) {
+        $count = number_format($count);
+        echo "Garbage collected {$count} '{$thing}' objects.\n";
+      }
+
+      $total = array_sum($collected);
+      if ($total < 100) {
+        // We didn't max out any of the GCs so we're basically caught up. Ease
+        // off the GC loop so we don't keep doing table scans just to delete
+        // a handful of rows.
+        $this->sleep(300);
+      } else {
+        $this->stillWorking();
+      }
+    } while (true);
+
+  }
+
+  private function collectHeraldTranscripts() {
+    $ttl = PhabricatorEnv::getEnvConfig('gcdaemon.ttl.herald-transcripts');
+    if ($ttl <= 0) {
+      return 0;
+    }
+
+    $table = new HeraldTranscript();
+    $conn_w = $table->establishConnection('w');
+
+    queryfx(
+      $conn_w,
+      'UPDATE %T SET
+          objectTranscript     = "",
+          ruleTranscripts      = "",
+          conditionTranscripts = "",
+          applyTranscripts     = ""
+        WHERE `time` < %d AND objectTranscript != ""
+        LIMIT 100',
+      $table->getTableName(),
+      time() - $ttl);
+
+    return $conn_w->getAffectedRows();
+  }
+
+  private function collectDaemonLogs() {
+    $ttl = PhabricatorEnv::getEnvConfig('gcdaemon.ttl.daemon-logs');
+    if ($ttl <= 0) {
+      return 0;
+    }
+
+    $table = new PhabricatorDaemonLogEvent();
+    $conn_w = $table->establishConnection('w');
+
+    queryfx(
+      $conn_w,
+      'DELETE FROM %T WHERE epoch < %d LIMIT 100',
+      $table->getTableName(),
+      time() - $ttl);
+
+    return $conn_w->getAffectedRows();
+  }
+
+  private function collectRenderCaches() {
+    // TODO: Implement this, no epoch column on the table right now.
+    return 0;
+  }
+
+}

src/infrastructure/daemon/garbagecollector/__init__.php

@@ -0,0 +1,16 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/herald/storage/transcript/base');
+phutil_require_module('phabricator', 'infrastructure/daemon/base');
+phutil_require_module('phabricator', 'infrastructure/daemon/storage/event');
+phutil_require_module('phabricator', 'infrastructure/env');
+phutil_require_module('phabricator', 'storage/queryfx');
+
+
+phutil_require_source('PhabricatorGarbageCollectorDaemon.php');