MediaWiki  1.23.0
PoolCounterRedis.php
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1 <?php
55  protected $ring;
57  protected $pool;
59  protected $serversByLabel;
61  protected $keySha1;
63  protected $lockTTL;
64 
66  protected $conn;
68  protected $slot;
70  protected $onRelease;
72  protected $session;
74  protected $slotTime;
75 
76  const AWAKE_ONE = 1; // wake-up if when a slot can be taken from an existing process
77  const AWAKE_ALL = 2; // wake-up if an existing process finishes and wake up such others
78 
80  protected static $active = null;
81 
82  function __construct( $conf, $type, $key ) {
83  parent::__construct( $conf, $type, $key );
84 
85  $this->serversByLabel = $conf['servers'];
86  $this->ring = new HashRing( array_fill_keys( array_keys( $conf['servers'] ), 100 ) );
87 
88  $conf['redisConfig']['serializer'] = 'none'; // for use with Lua
89  $this->pool = RedisConnectionPool::singleton( $conf['redisConfig'] );
90 
91  $this->keySha1 = sha1( $this->key );
92  $met = ini_get( 'max_execution_time' ); // usually 0 in CLI mode
93  $this->lockTTL = $met ? 2*$met : 3600;
94 
95  if ( self::$active === null ) {
96  self::$active = array();
97  register_shutdown_function( array( __CLASS__, 'releaseAll' ) );
98  }
99  }
100 
104  protected function getConnection() {
105  if ( !isset( $this->conn ) ) {
106  $conn = false;
107  $servers = $this->ring->getLocations( $this->key, 3 );
108  ArrayUtils::consistentHashSort( $servers, $this->key );
109  foreach ( $servers as $server ) {
110  $conn = $this->pool->getConnection( $this->serversByLabel[$server] );
111  if ( $conn ) {
112  break;
113  }
114  }
115  if ( !$conn ) {
116  return Status::newFatal( 'pool-servererror', implode( ', ', $servers ) );
117  }
118  $this->conn = $conn;
119  }
120  return Status::newGood( $this->conn );
121  }
122 
123  function acquireForMe() {
124  $section = new ProfileSection( __METHOD__ );
125 
126  return $this->waitForSlotOrNotif( self::AWAKE_ONE );
127  }
128 
129  function acquireForAnyone() {
130  $section = new ProfileSection( __METHOD__ );
131 
132  return $this->waitForSlotOrNotif( self::AWAKE_ALL );
133  }
134 
135  function release() {
136  $section = new ProfileSection( __METHOD__ );
137 
138  if ( $this->slot === null ) {
139  return Status::newGood( PoolCounter::NOT_LOCKED ); // not locked
140  }
141 
142  $status = $this->getConnection();
143  if ( !$status->isOK() ) {
144  return $status;
145  }
146  $conn = $status->value;
147 
148  static $script =
149 <<<LUA
150  local kSlots,kSlotsNextRelease,kWakeup,kWaiting = unpack(KEYS)
151  local rMaxWorkers,rExpiry,rSlot,rSlotTime,rAwakeAll,rTime = unpack(ARGV)
152  -- Add the slots back to the list (if rSlot is "w" then it is not a slot).
153  -- Treat the list as expired if the "next release" time sorted-set is missing.
154  if rSlot ~= 'w' and redis.call('exists',kSlotsNextRelease) == 1 then
155  if 1*redis.call('zScore',kSlotsNextRelease,rSlot) ~= (rSlotTime + rExpiry) then
156  -- Slot lock expired and was released already
157  elseif redis.call('lLen',kSlots) >= (1*rMaxWorkers - 1) then
158  -- Clear list to save space; it will re-init as needed
159  redis.call('del',kSlots,kSlotsNextRelease)
160  else
161  -- Add slot back to pool and update the "next release" time
162  redis.call('rPush',kSlots,rSlot)
163  redis.call('zAdd',kSlotsNextRelease,rTime + 30,rSlot)
164  -- Always keep renewing the expiry on use
165  redis.call('expireAt',kSlots,math.ceil(rTime + rExpiry))
166  redis.call('expireAt',kSlotsNextRelease,math.ceil(rTime + rExpiry))
167  end
168  end
169  -- Update an ephemeral list to wake up other clients that can
170  -- reuse any cached work from this process. Only do this if no
171  -- slots are currently free (e.g. clients could be waiting).
172  if 1*rAwakeAll == 1 then
173  local count = redis.call('zCard',kWaiting)
174  for i = 1,count do
175  redis.call('rPush',kWakeup,'w')
176  end
177  redis.call('pexpire',kWakeup,1)
178  end
179  return 1
180 LUA;
181  try {
182  $res = $conn->luaEval( $script,
183  array(
184  $this->getSlotListKey(),
185  $this->getSlotRTimeSetKey(),
186  $this->getWakeupListKey(),
187  $this->getWaitSetKey(),
188  $this->workers,
189  $this->lockTTL,
190  $this->slot,
191  $this->slotTime, // used for CAS-style sanity check
192  ( $this->onRelease === self::AWAKE_ALL ) ? 1 : 0,
193  microtime( true )
194  ),
195  4 # number of first argument(s) that are keys
196  );
197  } catch ( RedisException $e ) {
198  return Status::newFatal( 'pool-error-unknown', $e->getMessage() );
199  }
200 
201  $this->slot = null;
202  $this->slotTime = null;
203  $this->onRelease = null;
204  unset( self::$active[$this->session] );
205 
207  }
208 
213  protected function waitForSlotOrNotif( $doWakeup ) {
214  if ( $this->slot !== null ) {
215  return Status::newGood( PoolCounter::LOCK_HELD ); // already acquired
216  }
217 
218  $status = $this->getConnection();
219  if ( !$status->isOK() ) {
220  return $status;
221  }
222  $conn = $status->value;
223 
224  $now = microtime( true );
225  try {
226  $slot = $this->initAndPopPoolSlotList( $conn, $now );
227  if ( ctype_digit( $slot ) ) {
228  // Pool slot acquired by this process
229  $slotTime = $now;
230  } elseif ( $slot === 'QUEUE_FULL' ) {
231  // Too many processes are waiting for pooled processes to finish
233  } elseif ( $slot === 'QUEUE_WAIT' ) {
234  // This process is now registered as waiting
235  $keys = ( $doWakeup == self::AWAKE_ALL )
236  // Wait for an open slot or wake-up signal (preferring the later)
237  ? array( $this->getWakeupListKey(), $this->getSlotListKey() )
238  // Just wait for an actual pool slot
239  : array( $this->getSlotListKey() );
240 
241  $res = $conn->blPop( $keys, $this->timeout );
242  if ( $res === array() ) {
243  $conn->zRem( $this->getWaitSetKey(), $this->session ); // no longer waiting
245  }
246 
247  $slot = $res[1]; // pool slot or "w" for wake-up notifications
248  $slotTime = microtime( true ); // last microtime() was a few RTTs ago
249  // Unregister this process as waiting and bump slot "next release" time
251  } else {
252  return Status::newFatal( 'pool-error-unknown', "Server gave slot '$slot'." );
253  }
254  } catch ( RedisException $e ) {
255  return Status::newFatal( 'pool-error-unknown', $e->getMessage() );
256  }
257 
258  if ( $slot !== 'w' ) {
259  $this->slot = $slot;
260  $this->slotTime = $slotTime;
261  $this->onRelease = $doWakeup;
262  self::$active[$this->session] = $this;
263  }
264 
266  }
267 
273  protected function initAndPopPoolSlotList( RedisConnRef $conn, $now ) {
274  static $script =
275 <<<LUA
276  local kSlots,kSlotsNextRelease,kSlotWaits = unpack(KEYS)
277  local rMaxWorkers,rMaxQueue,rTimeout,rExpiry,rSess,rTime = unpack(ARGV)
278  -- Initialize if the "next release" time sorted-set is empty. The slot key
279  -- itself is empty if all slots are busy or when nothing is initialized.
280  -- If the list is empty but the set is not, then it is the later case.
281  -- For sanity, if the list exists but not the set, then reset everything.
282  if redis.call('exists',kSlotsNextRelease) == 0 then
283  redis.call('del',kSlots)
284  for i = 1,1*rMaxWorkers do
285  redis.call('rPush',kSlots,i)
286  redis.call('zAdd',kSlotsNextRelease,-1,i)
287  end
288  -- Otherwise do maintenance to clean up after network partitions
289  else
290  -- Find stale slot locks and add free them (avoid duplicates for sanity)
291  local staleLocks = redis.call('zRangeByScore',kSlotsNextRelease,0,rTime)
292  for k,slot in ipairs(staleLocks) do
293  redis.call('lRem',kSlots,0,slot)
294  redis.call('rPush',kSlots,slot)
295  redis.call('zAdd',kSlotsNextRelease,rTime + 30,slot)
296  end
297  -- Find stale wait slot entries and remove them
298  redis.call('zRemRangeByScore',kSlotWaits,0,rTime - 2*rTimeout)
299  end
300  local slot
301  -- Try to acquire a slot if possible now
302  if redis.call('lLen',kSlots) > 0 then
303  slot = redis.call('lPop',kSlots)
304  -- Update the slot "next release" time
305  redis.call('zAdd',kSlotsNextRelease,rTime + rExpiry,slot)
306  elseif redis.call('zCard',kSlotWaits) >= 1*rMaxQueue then
307  slot = 'QUEUE_FULL'
308  else
309  slot = 'QUEUE_WAIT'
310  -- Register this process as waiting
311  redis.call('zAdd',kSlotWaits,rTime,rSess)
312  redis.call('expireAt',kSlotWaits,math.ceil(rTime + 2*rTimeout))
313  end
314  -- Always keep renewing the expiry on use
315  redis.call('expireAt',kSlots,math.ceil(rTime + rExpiry))
316  redis.call('expireAt',kSlotsNextRelease,math.ceil(rTime + rExpiry))
317  return slot
318 LUA;
319  return $conn->luaEval( $script,
320  array(
321  $this->getSlotListKey(),
322  $this->getSlotRTimeSetKey(),
323  $this->getWaitSetKey(),
324  $this->workers,
325  $this->maxqueue,
326  $this->timeout,
327  $this->lockTTL,
328  $this->session,
329  $now
330  ),
331  3 # number of first argument(s) that are keys
332  );
333  }
334 
341  protected function registerAcquisitionTime( RedisConnRef $conn, $slot, $now ) {
342  static $script =
343 <<<LUA
344  local kSlots,kSlotsNextRelease,kSlotWaits = unpack(KEYS)
345  local rSlot,rExpiry,rSess,rTime = unpack(ARGV)
346  -- If rSlot is 'w' then the client was told to wake up but got no slot
347  if rSlot ~= 'w' then
348  -- Update the slot "next release" time
349  redis.call('zAdd',kSlotsNextRelease,rTime + rExpiry,rSlot)
350  -- Always keep renewing the expiry on use
351  redis.call('expireAt',kSlots,math.ceil(rTime + rExpiry))
352  redis.call('expireAt',kSlotsNextRelease,math.ceil(rTime + rExpiry))
353  end
354  -- Unregister this process as waiting
355  redis.call('zRem',kSlotWaits,rSess)
356  return 1
357 LUA;
358  return $conn->luaEval( $script,
359  array(
360  $this->getSlotListKey(),
361  $this->getSlotRTimeSetKey(),
362  $this->getWaitSetKey(),
363  $slot,
364  $this->lockTTL,
365  $this->session,
366  $now
367  ),
368  3 # number of first argument(s) that are keys
369  );
370  }
371 
375  protected function getSlotListKey() {
376  return "poolcounter:l-slots-{$this->keySha1}-{$this->workers}";
377  }
378 
382  protected function getSlotRTimeSetKey() {
383  return "poolcounter:z-renewtime-{$this->keySha1}-{$this->workers}";
384  }
385 
389  protected function getWaitSetKey() {
390  return "poolcounter:z-wait-{$this->keySha1}-{$this->workers}";
391  }
392 
396  protected function getWakeupListKey() {
397  return "poolcounter:l-wakeup-{$this->keySha1}-{$this->workers}";
398  }
399 
403  public static function releaseAll() {
404  foreach ( self::$active as $poolCounter ) {
405  try {
406  if ( $poolCounter->slot !== null ) {
407  $poolCounter->release();
408  }
409  } catch ( Exception $e ) {}
410  }
411  }
412 }
PoolCounterRedis\$lockTTL
integer $lockTTL
TTL for locks to expire (work should finish in this time) *.
Definition: PoolCounterRedis.php:58
PoolCounterRedis\AWAKE_ONE
const AWAKE_ONE
Definition: PoolCounterRedis.php:66
save
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a save
Definition: deferred.txt:4
PoolCounterRedis\$active
static $active
Definition: PoolCounterRedis.php:70
ArrayUtils\consistentHashSort
static consistentHashSort(&$array, $key, $separator="\000")
Sort the given array in a pseudo-random order which depends only on the given key and each element va...
Definition: ArrayUtils.php:49
of
globals txt Globals are evil The original MediaWiki code relied on globals for processing context far too often MediaWiki development since then has been a story of slowly moving context out of global variables and into objects Storing processing context in object member variables allows those objects to be reused in a much more flexible way Consider the elegance of
Definition: globals.txt:10
RedisConnectionPool\singleton
static singleton(array $options)
Definition: RedisConnectionPool.php:115
PoolCounterRedis\getWakeupListKey
getWakeupListKey()
Definition: PoolCounterRedis.php:386
PoolCounterRedis\acquireForMe
acquireForMe()
I want to do this task and I need to do it myself.
Definition: PoolCounterRedis.php:113
php
skin txt MediaWiki includes four core it has been set as the default in MediaWiki since the replacing Monobook it had been been the default skin since before being replaced by Vector largely rewritten in while keeping its appearance Several legacy skins were removed in the as the burden of supporting them became too heavy to bear Those in etc for skin dependent CSS etc for skin dependent JavaScript These can also be customised on a per user by etc This feature has led to a wide variety of user styles becoming that gallery is a good place to ending in php
Definition: skin.txt:62
PoolCounterRedis\$conn
RedisConnRef $conn
Definition: PoolCounterRedis.php:60
PoolCounterRedis\getConnection
getConnection()
Definition: PoolCounterRedis.php:94
PoolCounterRedis\$slot
string $slot
Pool slot value *.
Definition: PoolCounterRedis.php:61
PoolCounter\LOCK_HELD
const LOCK_HELD
Definition: PoolCounter.php:52
is
We use the convention $dbr for read and $dbw for write to help you keep track of whether the database object is a the world will explode Or to be a subsequent write query which succeeded on the master may fail when replicated to the slave due to a unique key collision Replication on the slave will stop and it may take hours to repair the database and get it back online Setting read_only in my cnf on the slave will avoid this but given the dire we prefer to have as many checks as possible We provide a but the wrapper functions like please read the documentation for except in special pages derived from QueryPage It s a common pitfall for new developers to submit code containing SQL queries which examine huge numbers of rows Remember that COUNT * is(N), counting rows in atable is like counting beans in a bucket.------------------------------------------------------------------------ Replication------------------------------------------------------------------------The largest installation of MediaWiki, Wikimedia, uses a large set ofslave MySQL servers replicating writes made to a master MySQL server. Itis important to understand the issues associated with this setup if youwant to write code destined for Wikipedia.It 's often the case that the best algorithm to use for a given taskdepends on whether or not replication is in use. Due to our unabashedWikipedia-centrism, we often just use the replication-friendly version, but if you like, you can use wfGetLB() ->getServerCount() > 1 tocheck to see if replication is in use.===Lag===Lag primarily occurs when large write queries are sent to the master.Writes on the master are executed in parallel, but they are executed inserial when they are replicated to the slaves. The master writes thequery to the binlog when the transaction is committed. The slaves pollthe binlog and start executing the query as soon as it appears. They canservice reads while they are performing a write query, but will not readanything more from the binlog and thus will perform no more writes. Thismeans that if the write query runs for a long time, the slaves will lagbehind the master for the time it takes for the write query to complete.Lag can be exacerbated by high read load. MediaWiki 's load balancer willstop sending reads to a slave when it is lagged by more than 30 seconds.If the load ratios are set incorrectly, or if there is too much loadgenerally, this may lead to a slave permanently hovering around 30seconds lag.If all slaves are lagged by more than 30 seconds, MediaWiki will stopwriting to the database. All edits and other write operations will berefused, with an error returned to the user. This gives the slaves achance to catch up. Before we had this mechanism, the slaves wouldregularly lag by several minutes, making review of recent editsdifficult.In addition to this, MediaWiki attempts to ensure that the user seesevents occurring on the wiki in chronological order. A few seconds of lagcan be tolerated, as long as the user sees a consistent picture fromsubsequent requests. This is done by saving the master binlog positionin the session, and then at the start of each request, waiting for theslave to catch up to that position before doing any reads from it. Ifthis wait times out, reads are allowed anyway, but the request isconsidered to be in "lagged slave mode". Lagged slave mode can bechecked by calling wfGetLB() ->getLaggedSlaveMode(). The onlypractical consequence at present is a warning displayed in the pagefooter.===Lag avoidance===To avoid excessive lag, queries which write large numbers of rows shouldbe split up, generally to write one row at a time. Multi-row INSERT ...SELECT queries are the worst offenders should be avoided altogether.Instead do the select first and then the insert.===Working with lag===Despite our best efforts, it 's not practical to guarantee a low-lagenvironment. Lag will usually be less than one second, but mayoccasionally be up to 30 seconds. For scalability, it 's very importantto keep load on the master low, so simply sending all your queries tothe master is not the answer. So when you have a genuine need forup-to-date data, the following approach is advised:1) Do a quick query to the master for a sequence number or timestamp 2) Run the full query on the slave and check if it matches the data you gotfrom the master 3) If it doesn 't, run the full query on the masterTo avoid swamping the master every time the slaves lag, use of thisapproach should be kept to a minimum. In most cases you should just readfrom the slave and let the user deal with the delay.------------------------------------------------------------------------ Lock contention------------------------------------------------------------------------Due to the high write rate on Wikipedia(and some other wikis), MediaWiki developers need to be very careful to structure their writesto avoid long-lasting locks. By default, MediaWiki opens a transactionat the first query, and commits it before the output is sent. Locks willbe held from the time when the query is done until the commit. So youcan reduce lock time by doing as much processing as possible before youdo your write queries.Often this approach is not good enough, and it becomes necessary toenclose small groups of queries in their own transaction. Use thefollowing syntax:$dbw=wfGetDB(DB_MASTER
PoolCounterRedis\$pool
RedisConnectionPool $pool
Definition: PoolCounterRedis.php:55
PoolCounter\NOT_LOCKED
const NOT_LOCKED
Definition: PoolCounter.php:49
Status\newGood
static newGood( $value=null)
Factory function for good results.
Definition: Status.php:77
PoolCounter\LOCKED
const LOCKED
Definition: PoolCounter.php:44
e
in this case you re responsible for computing and outputting the entire conflict i e
Definition: hooks.txt:1038
PoolCounterRedis\waitForSlotOrNotif
waitForSlotOrNotif( $doWakeup)
Definition: PoolCounterRedis.php:203
PoolCounterRedis\AWAKE_ALL
const AWAKE_ALL
Definition: PoolCounterRedis.php:67
PoolCounterRedis\$session
string $session
Unique string to identify this process *.
Definition: PoolCounterRedis.php:63
PoolCounterRedis\initAndPopPoolSlotList
initAndPopPoolSlotList(RedisConnRef $conn, $now)
Definition: PoolCounterRedis.php:263
later
If you want to remove the page from your watchlist later
Definition: All_system_messages.txt:361
PoolCounter
When you have many workers (threads/servers) giving service, and a cached item expensive to produce e...
Definition: PoolCounter.php:42
key
design txt This is a brief overview of the new design More thorough and up to date information is available on the documentation wiki at etc Handles the details of getting and saving to the user table of the and dealing with sessions and cookies OutputPage Encapsulates the entire HTML page that will be sent in response to any server request It is used by calling its functions to add in any and then calling but I prefer the flexibility This should also do the output encoding The system allocates a global one in $wgOut Title Represents the title of an and does all the work of translating among various forms such as plain database key
Definition: design.txt:25
ProfileSection
Class for handling function-scope profiling.
Definition: Profiler.php:60
PoolCounterRedis\$slotTime
integer $slotTime
UNIX timestamp *.
Definition: PoolCounterRedis.php:64
PoolCounterRedis\$serversByLabel
array $serversByLabel
(server label => host) map *
Definition: PoolCounterRedis.php:56
PoolCounterRedis\acquireForAnyone
acquireForAnyone()
I want to do this task, but if anyone else does it instead, it's also fine for me.
Definition: PoolCounterRedis.php:119
array
the array() calling protocol came about after MediaWiki 1.4rc1.
List of Api Query prop modules.
add
An extension or a will often add custom code to the function with or without a global variable For someone wanting email notification when an article is shown may add
Definition: hooks.txt:51
PoolCounter\$key
string $key
All workers with the same key share the lock *.
Definition: PoolCounter.php:54
list
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global list
Definition: deferred.txt:11
PoolCounterRedis\$ring
HashRing $ring
Definition: PoolCounterRedis.php:54
will
</td >< td > &</td >< td > t want your writing to be edited mercilessly and redistributed at will
Definition: All_system_messages.txt:914
$section
$section
Definition: Utf8Test.php:88
PoolCounterRedis\$onRelease
integer $onRelease
AWAKE_* constant *.
Definition: PoolCounterRedis.php:62
RedisConnectionPool
Helper class to manage Redis connections.
Definition: RedisConnectionPool.php:38
PoolCounter\QUEUE_FULL
const QUEUE_FULL
Definition: PoolCounter.php:50
PoolCounterRedis\registerAcquisitionTime
registerAcquisitionTime(RedisConnRef $conn, $slot, $now)
Definition: PoolCounterRedis.php:331
PoolCounterRedis\releaseAll
static releaseAll()
Try to make sure that locks get released (even with exceptions and fatals)
Definition: PoolCounterRedis.php:393
RedisConnRef\luaEval
luaEval( $script, array $params, $numKeys)
Definition: RedisConnectionPool.php:406
up
static configuration should be added through ResourceLoaderGetConfigVars instead can be used to get the real title after the basic globals have been set up
Definition: hooks.txt:1679
PoolCounterRedis\getWaitSetKey
getWaitSetKey()
Definition: PoolCounterRedis.php:379
PoolCounterRedis\__construct
__construct( $conf, $type, $key)
Definition: PoolCounterRedis.php:72
it
=Architecture==Two class hierarchies are used to provide the functionality associated with the different content models:*Content interface(and AbstractContent base class) define functionality that acts on the concrete content of a page, and *ContentHandler base class provides functionality specific to a content model, but not acting on concrete content. The most important function of ContentHandler is to act as a factory for the appropriate implementation of Content. These Content objects are to be used by MediaWiki everywhere, instead of passing page content around as text. All manipulation and analysis of page content must be done via the appropriate methods of the Content object. For each content model, a subclass of ContentHandler has to be registered with $wgContentHandlers. The ContentHandler object for a given content model can be obtained using ContentHandler::getForModelID($id). Also Title, WikiPage and Revision now have getContentHandler() methods for convenience. ContentHandler objects are singletons that provide functionality specific to the content type, but not directly acting on the content of some page. ContentHandler::makeEmptyContent() and ContentHandler::unserializeContent() can be used to create a Content object of the appropriate type. However, it is recommended to instead use WikiPage::getContent() resp. Revision::getContent() to get a page 's content as a Content object. These two methods should be the ONLY way in which page content is accessed. Another important function of ContentHandler objects is to define custom action handlers for a content model, see ContentHandler::getActionOverrides(). This is similar to what WikiPage::getActionOverrides() was already doing.==Serialization==With the ContentHandler facility, page content no longer has to be text based. Objects implementing the Content interface are used to represent and handle the content internally. For storage and data exchange, each content model supports at least one serialization format via ContentHandler::serializeContent($content). The list of supported formats for a given content model can be accessed using ContentHandler::getSupportedFormats(). Content serialization formats are identified using MIME type like strings. The following formats are built in:*text/x-wiki - wikitext *text/javascript - for js pages *text/css - for css pages *text/plain - for future use, e.g. with plain text messages. *text/html - for future use, e.g. with plain html messages. *application/vnd.php.serialized - for future use with the api and for extensions *application/json - for future use with the api, and for use by extensions *application/xml - for future use with the api, and for use by extensions In PHP, use the corresponding CONTENT_FORMAT_XXX constant. Note that when using the API to access page content, especially action=edit, action=parse and action=query &prop=revisions, the model and format of the content should always be handled explicitly. Without that information, interpretation of the provided content is not reliable. The same applies to XML dumps generated via maintenance/dumpBackup.php or Special:Export. Also note that the API will provide encapsulated, serialized content - so if the API was called with format=json, and contentformat is also json(or rather, application/json), the page content is represented as a string containing an escaped json structure. Extensions that use JSON to serialize some types of page content may provide specialized API modules that allow access to that content in a more natural form.==Compatibility==The ContentHandler facility is introduced in a way that should allow all existing code to keep functioning at least for pages that contain wikitext or other text based content. However, a number of functions and hooks have been deprecated in favor of new versions that are aware of the page 's content model, and will now generate warnings when used. Most importantly, the following functions have been deprecated:*Revisions::getText() and Revisions::getRawText() is deprecated in favor Revisions::getContent() *WikiPage::getText() is deprecated in favor WikiPage::getContent() Also, the old Article::getContent()(which returns text) is superceded by Article::getContentObject(). However, both methods should be avoided since they do not provide clean access to the page 's actual content. For instance, they may return a system message for non-existing pages. Use WikiPage::getContent() instead. Code that relies on a textual representation of the page content should eventually be rewritten. However, ContentHandler::getContentText() provides a stop-gap that can be used to get text for a page. Its behavior is controlled by $wgContentHandlerTextFallback it
Definition: contenthandler.txt:107
network
MediaWiki has optional support for a high distributed memory object caching system For general information on but for a larger site with heavy like it should help lighten the load on the database servers by caching data and objects in Ubuntu and probably other Linux distributions If you there s no package available for your you can compile it from epoll rt patch for Linux is current Memcached and libevent are under BSD style licenses The server should run on Linux and other Unix like systems you can run multiple servers on one machine or on multiple machines on a network
Definition: memcached.txt:16
PoolCounterRedis\getSlotRTimeSetKey
getSlotRTimeSetKey()
Definition: PoolCounterRedis.php:372
in
Prior to maintenance scripts were a hodgepodge of code that had no cohesion or formal method of action Beginning in
Definition: maintenance.txt:1
on
We ve cleaned up the code here by removing clumps of infrequently used code and moving them off somewhere else It s much easier for someone working with this code to see what s _really_ going on
Definition: hooks.txt:86
are
The ContentHandler facility adds support for arbitrary content types on wiki instead of relying on wikitext for everything It was introduced in MediaWiki Each kind of and so on Built in content types are
Definition: contenthandler.txt:5
then
skin txt MediaWiki includes four core it has been set as the default in MediaWiki since the replacing Monobook it had been been the default skin since then
Definition: skin.txt:10
needed
this class mediates it Skin Encapsulates a look and feel for the wiki All of the functions that render HTML and make choices about how to render it are here and are called from various other places when needed(most notably, OutputPage::addWikiText()). The StandardSkin object is a complete implementation
as
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:9
RedisConnRef
Helper class to handle automatically marking connectons as reusable (via RAII pattern)
Definition: RedisConnectionPool.php:348
$keys
$keys
Definition: testCompression.php:63
PoolCounterRedis\release
release()
I have successfully finished my task.
Definition: PoolCounterRedis.php:125
PoolCounterRedis\getSlotListKey
getSlotListKey()
Definition: PoolCounterRedis.php:365
from
Please log in again after you receive it</td >< td > s a saved copy from
Definition: All_system_messages.txt:3297
that
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global then executing the whole list after the page is displayed We don t do anything smart like collating updates to the same table or such because the list is almost always going to have just one item on if that
Definition: deferred.txt:11
$e
if( $useReadline) $e
Definition: eval.php:66
PoolCounter\RELEASED
const RELEASED
Definition: PoolCounter.php:45
PoolCounter\TIMEOUT
const TIMEOUT
Definition: PoolCounter.php:51
HashRing
Convenience class for weighted consistent hash rings.
Definition: HashRing.php:29
$res
$res
Definition: database.txt:21
PoolCounter\DONE
const DONE
Definition: PoolCounter.php:46
Status\newFatal
static newFatal( $message)
Factory function for fatal errors.
Definition: Status.php:63
PoolCounterRedis
Version of PoolCounter that uses Redis.
Definition: PoolCounterRedis.php:53
PoolCounterRedis\$keySha1
string $keySha1
SHA-1 of the key *.
Definition: PoolCounterRedis.php:57
$type
$type
Definition: testCompression.php:46