MediaWiki
REL1_23
|
00001 <?php 00053 class PoolCounterRedis extends PoolCounter { 00055 protected $ring; 00057 protected $pool; 00059 protected $serversByLabel; 00061 protected $keySha1; 00063 protected $lockTTL; 00064 00066 protected $conn; 00068 protected $slot; 00070 protected $onRelease; 00072 protected $session; 00074 protected $slotTime; 00075 00076 const AWAKE_ONE = 1; // wake-up if when a slot can be taken from an existing process 00077 const AWAKE_ALL = 2; // wake-up if an existing process finishes and wake up such others 00078 00080 protected static $active = null; 00081 00082 function __construct( $conf, $type, $key ) { 00083 parent::__construct( $conf, $type, $key ); 00084 00085 $this->serversByLabel = $conf['servers']; 00086 $this->ring = new HashRing( array_fill_keys( array_keys( $conf['servers'] ), 100 ) ); 00087 00088 $conf['redisConfig']['serializer'] = 'none'; // for use with Lua 00089 $this->pool = RedisConnectionPool::singleton( $conf['redisConfig'] ); 00090 00091 $this->keySha1 = sha1( $this->key ); 00092 $met = ini_get( 'max_execution_time' ); // usually 0 in CLI mode 00093 $this->lockTTL = $met ? 2*$met : 3600; 00094 00095 if ( self::$active === null ) { 00096 self::$active = array(); 00097 register_shutdown_function( array( __CLASS__, 'releaseAll' ) ); 00098 } 00099 } 00100 00104 protected function getConnection() { 00105 if ( !isset( $this->conn ) ) { 00106 $conn = false; 00107 $servers = $this->ring->getLocations( $this->key, 3 ); 00108 ArrayUtils::consistentHashSort( $servers, $this->key ); 00109 foreach ( $servers as $server ) { 00110 $conn = $this->pool->getConnection( $this->serversByLabel[$server] ); 00111 if ( $conn ) { 00112 break; 00113 } 00114 } 00115 if ( !$conn ) { 00116 return Status::newFatal( 'pool-servererror', implode( ', ', $servers ) ); 00117 } 00118 $this->conn = $conn; 00119 } 00120 return Status::newGood( $this->conn ); 00121 } 00122 00123 function acquireForMe() { 00124 $section = new ProfileSection( __METHOD__ ); 00125 00126 return $this->waitForSlotOrNotif( self::AWAKE_ONE ); 00127 } 00128 00129 function acquireForAnyone() { 00130 $section = new ProfileSection( __METHOD__ ); 00131 00132 return $this->waitForSlotOrNotif( self::AWAKE_ALL ); 00133 } 00134 00135 function release() { 00136 $section = new ProfileSection( __METHOD__ ); 00137 00138 if ( $this->slot === null ) { 00139 return Status::newGood( PoolCounter::NOT_LOCKED ); // not locked 00140 } 00141 00142 $status = $this->getConnection(); 00143 if ( !$status->isOK() ) { 00144 return $status; 00145 } 00146 $conn = $status->value; 00147 00148 static $script = 00149 <<<LUA 00150 local kSlots,kSlotsNextRelease,kWakeup,kWaiting = unpack(KEYS) 00151 local rMaxWorkers,rExpiry,rSlot,rSlotTime,rAwakeAll,rTime = unpack(ARGV) 00152 -- Add the slots back to the list (if rSlot is "w" then it is not a slot). 00153 -- Treat the list as expired if the "next release" time sorted-set is missing. 00154 if rSlot ~= 'w' and redis.call('exists',kSlotsNextRelease) == 1 then 00155 if 1*redis.call('zScore',kSlotsNextRelease,rSlot) ~= (rSlotTime + rExpiry) then 00156 -- Slot lock expired and was released already 00157 elseif redis.call('lLen',kSlots) >= (1*rMaxWorkers - 1) then 00158 -- Clear list to save space; it will re-init as needed 00159 redis.call('del',kSlots,kSlotsNextRelease) 00160 else 00161 -- Add slot back to pool and update the "next release" time 00162 redis.call('rPush',kSlots,rSlot) 00163 redis.call('zAdd',kSlotsNextRelease,rTime + 30,rSlot) 00164 -- Always keep renewing the expiry on use 00165 redis.call('expireAt',kSlots,math.ceil(rTime + rExpiry)) 00166 redis.call('expireAt',kSlotsNextRelease,math.ceil(rTime + rExpiry)) 00167 end 00168 end 00169 -- Update an ephemeral list to wake up other clients that can 00170 -- reuse any cached work from this process. Only do this if no 00171 -- slots are currently free (e.g. clients could be waiting). 00172 if 1*rAwakeAll == 1 then 00173 local count = redis.call('zCard',kWaiting) 00174 for i = 1,count do 00175 redis.call('rPush',kWakeup,'w') 00176 end 00177 redis.call('pexpire',kWakeup,1) 00178 end 00179 return 1 00180 LUA; 00181 try { 00182 $res = $conn->luaEval( $script, 00183 array( 00184 $this->getSlotListKey(), 00185 $this->getSlotRTimeSetKey(), 00186 $this->getWakeupListKey(), 00187 $this->getWaitSetKey(), 00188 $this->workers, 00189 $this->lockTTL, 00190 $this->slot, 00191 $this->slotTime, // used for CAS-style sanity check 00192 ( $this->onRelease === self::AWAKE_ALL ) ? 1 : 0, 00193 microtime( true ) 00194 ), 00195 4 # number of first argument(s) that are keys 00196 ); 00197 } catch ( RedisException $e ) { 00198 return Status::newFatal( 'pool-error-unknown', $e->getMessage() ); 00199 } 00200 00201 $this->slot = null; 00202 $this->slotTime = null; 00203 $this->onRelease = null; 00204 unset( self::$active[$this->session] ); 00205 00206 return Status::newGood( PoolCounter::RELEASED ); 00207 } 00208 00213 protected function waitForSlotOrNotif( $doWakeup ) { 00214 if ( $this->slot !== null ) { 00215 return Status::newGood( PoolCounter::LOCK_HELD ); // already acquired 00216 } 00217 00218 $status = $this->getConnection(); 00219 if ( !$status->isOK() ) { 00220 return $status; 00221 } 00222 $conn = $status->value; 00223 00224 $now = microtime( true ); 00225 try { 00226 $slot = $this->initAndPopPoolSlotList( $conn, $now ); 00227 if ( ctype_digit( $slot ) ) { 00228 // Pool slot acquired by this process 00229 $slotTime = $now; 00230 } elseif ( $slot === 'QUEUE_FULL' ) { 00231 // Too many processes are waiting for pooled processes to finish 00232 return Status::newGood( PoolCounter::QUEUE_FULL ); 00233 } elseif ( $slot === 'QUEUE_WAIT' ) { 00234 // This process is now registered as waiting 00235 $keys = ( $doWakeup == self::AWAKE_ALL ) 00236 // Wait for an open slot or wake-up signal (preferring the later) 00237 ? array( $this->getWakeupListKey(), $this->getSlotListKey() ) 00238 // Just wait for an actual pool slot 00239 : array( $this->getSlotListKey() ); 00240 00241 $res = $conn->blPop( $keys, $this->timeout ); 00242 if ( $res === array() ) { 00243 $conn->zRem( $this->getWaitSetKey(), $this->session ); // no longer waiting 00244 return Status::newGood( PoolCounter::TIMEOUT ); 00245 } 00246 00247 $slot = $res[1]; // pool slot or "w" for wake-up notifications 00248 $slotTime = microtime( true ); // last microtime() was a few RTTs ago 00249 // Unregister this process as waiting and bump slot "next release" time 00250 $this->registerAcquisitionTime( $conn, $slot, $slotTime ); 00251 } else { 00252 return Status::newFatal( 'pool-error-unknown', "Server gave slot '$slot'." ); 00253 } 00254 } catch ( RedisException $e ) { 00255 return Status::newFatal( 'pool-error-unknown', $e->getMessage() ); 00256 } 00257 00258 if ( $slot !== 'w' ) { 00259 $this->slot = $slot; 00260 $this->slotTime = $slotTime; 00261 $this->onRelease = $doWakeup; 00262 self::$active[$this->session] = $this; 00263 } 00264 00265 return Status::newGood( $slot === 'w' ? PoolCounter::DONE : PoolCounter::LOCKED ); 00266 } 00267 00273 protected function initAndPopPoolSlotList( RedisConnRef $conn, $now ) { 00274 static $script = 00275 <<<LUA 00276 local kSlots,kSlotsNextRelease,kSlotWaits = unpack(KEYS) 00277 local rMaxWorkers,rMaxQueue,rTimeout,rExpiry,rSess,rTime = unpack(ARGV) 00278 -- Initialize if the "next release" time sorted-set is empty. The slot key 00279 -- itself is empty if all slots are busy or when nothing is initialized. 00280 -- If the list is empty but the set is not, then it is the later case. 00281 -- For sanity, if the list exists but not the set, then reset everything. 00282 if redis.call('exists',kSlotsNextRelease) == 0 then 00283 redis.call('del',kSlots) 00284 for i = 1,1*rMaxWorkers do 00285 redis.call('rPush',kSlots,i) 00286 redis.call('zAdd',kSlotsNextRelease,-1,i) 00287 end 00288 -- Otherwise do maintenance to clean up after network partitions 00289 else 00290 -- Find stale slot locks and add free them (avoid duplicates for sanity) 00291 local staleLocks = redis.call('zRangeByScore',kSlotsNextRelease,0,rTime) 00292 for k,slot in ipairs(staleLocks) do 00293 redis.call('lRem',kSlots,0,slot) 00294 redis.call('rPush',kSlots,slot) 00295 redis.call('zAdd',kSlotsNextRelease,rTime + 30,slot) 00296 end 00297 -- Find stale wait slot entries and remove them 00298 redis.call('zRemRangeByScore',kSlotWaits,0,rTime - 2*rTimeout) 00299 end 00300 local slot 00301 -- Try to acquire a slot if possible now 00302 if redis.call('lLen',kSlots) > 0 then 00303 slot = redis.call('lPop',kSlots) 00304 -- Update the slot "next release" time 00305 redis.call('zAdd',kSlotsNextRelease,rTime + rExpiry,slot) 00306 elseif redis.call('zCard',kSlotWaits) >= 1*rMaxQueue then 00307 slot = 'QUEUE_FULL' 00308 else 00309 slot = 'QUEUE_WAIT' 00310 -- Register this process as waiting 00311 redis.call('zAdd',kSlotWaits,rTime,rSess) 00312 redis.call('expireAt',kSlotWaits,math.ceil(rTime + 2*rTimeout)) 00313 end 00314 -- Always keep renewing the expiry on use 00315 redis.call('expireAt',kSlots,math.ceil(rTime + rExpiry)) 00316 redis.call('expireAt',kSlotsNextRelease,math.ceil(rTime + rExpiry)) 00317 return slot 00318 LUA; 00319 return $conn->luaEval( $script, 00320 array( 00321 $this->getSlotListKey(), 00322 $this->getSlotRTimeSetKey(), 00323 $this->getWaitSetKey(), 00324 $this->workers, 00325 $this->maxqueue, 00326 $this->timeout, 00327 $this->lockTTL, 00328 $this->session, 00329 $now 00330 ), 00331 3 # number of first argument(s) that are keys 00332 ); 00333 } 00334 00341 protected function registerAcquisitionTime( RedisConnRef $conn, $slot, $now ) { 00342 static $script = 00343 <<<LUA 00344 local kSlots,kSlotsNextRelease,kSlotWaits = unpack(KEYS) 00345 local rSlot,rExpiry,rSess,rTime = unpack(ARGV) 00346 -- If rSlot is 'w' then the client was told to wake up but got no slot 00347 if rSlot ~= 'w' then 00348 -- Update the slot "next release" time 00349 redis.call('zAdd',kSlotsNextRelease,rTime + rExpiry,rSlot) 00350 -- Always keep renewing the expiry on use 00351 redis.call('expireAt',kSlots,math.ceil(rTime + rExpiry)) 00352 redis.call('expireAt',kSlotsNextRelease,math.ceil(rTime + rExpiry)) 00353 end 00354 -- Unregister this process as waiting 00355 redis.call('zRem',kSlotWaits,rSess) 00356 return 1 00357 LUA; 00358 return $conn->luaEval( $script, 00359 array( 00360 $this->getSlotListKey(), 00361 $this->getSlotRTimeSetKey(), 00362 $this->getWaitSetKey(), 00363 $slot, 00364 $this->lockTTL, 00365 $this->session, 00366 $now 00367 ), 00368 3 # number of first argument(s) that are keys 00369 ); 00370 } 00371 00375 protected function getSlotListKey() { 00376 return "poolcounter:l-slots-{$this->keySha1}-{$this->workers}"; 00377 } 00378 00382 protected function getSlotRTimeSetKey() { 00383 return "poolcounter:z-renewtime-{$this->keySha1}-{$this->workers}"; 00384 } 00385 00389 protected function getWaitSetKey() { 00390 return "poolcounter:z-wait-{$this->keySha1}-{$this->workers}"; 00391 } 00392 00396 protected function getWakeupListKey() { 00397 return "poolcounter:l-wakeup-{$this->keySha1}-{$this->workers}"; 00398 } 00399 00403 public static function releaseAll() { 00404 foreach ( self::$active as $poolCounter ) { 00405 try { 00406 if ( $poolCounter->slot !== null ) { 00407 $poolCounter->release(); 00408 } 00409 } catch ( Exception $e ) {} 00410 } 00411 } 00412 }