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Diffstat (limited to '')
-rw-r--r-- | src/jaegertracing/thrift/lib/php/lib/Transport/TSocketPool.php | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/src/jaegertracing/thrift/lib/php/lib/Transport/TSocketPool.php b/src/jaegertracing/thrift/lib/php/lib/Transport/TSocketPool.php new file mode 100644 index 000000000..cb9e8ddfa --- /dev/null +++ b/src/jaegertracing/thrift/lib/php/lib/Transport/TSocketPool.php @@ -0,0 +1,310 @@ +<?php +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + * + * @package thrift.transport + */ + +namespace Thrift\Transport; + +use Thrift\Exception\TException; + +/** + * This library makes use of APC cache to make hosts as down in a web + * environment. If you are running from the CLI or on a system without APC + * installed, then these null functions will step in and act like cache + * misses. + */ +if (!function_exists('apc_fetch')) { + function apc_fetch($key) + { + return false; + } + + function apc_store($key, $var, $ttl = 0) + { + return false; + } +} + +/** + * Sockets implementation of the TTransport interface that allows connection + * to a pool of servers. + * + * @package thrift.transport + */ +class TSocketPool extends TSocket +{ + /** + * Remote servers. Array of associative arrays with 'host' and 'port' keys + */ + private $servers_ = array(); + + /** + * How many times to retry each host in connect + * + * @var int + */ + private $numRetries_ = 1; + + /** + * Retry interval in seconds, how long to not try a host if it has been + * marked as down. + * + * @var int + */ + private $retryInterval_ = 60; + + /** + * Max consecutive failures before marking a host down. + * + * @var int + */ + private $maxConsecutiveFailures_ = 1; + + /** + * Try hosts in order? or Randomized? + * + * @var bool + */ + private $randomize_ = true; + + /** + * Always try last host, even if marked down? + * + * @var bool + */ + private $alwaysTryLast_ = true; + + /** + * Socket pool constructor + * + * @param array $hosts List of remote hostnames + * @param mixed $ports Array of remote ports, or a single common port + * @param bool $persist Whether to use a persistent socket + * @param mixed $debugHandler Function for error logging + */ + public function __construct( + $hosts = array('localhost'), + $ports = array(9090), + $persist = false, + $debugHandler = null + ) { + parent::__construct(null, 0, $persist, $debugHandler); + + if (!is_array($ports)) { + $port = $ports; + $ports = array(); + foreach ($hosts as $key => $val) { + $ports[$key] = $port; + } + } + + foreach ($hosts as $key => $host) { + $this->servers_ [] = array('host' => $host, + 'port' => $ports[$key]); + } + } + + /** + * Add a server to the pool + * + * This function does not prevent you from adding a duplicate server entry. + * + * @param string $host hostname or IP + * @param int $port port + */ + public function addServer($host, $port) + { + $this->servers_[] = array('host' => $host, 'port' => $port); + } + + /** + * Sets how many time to keep retrying a host in the connect function. + * + * @param int $numRetries + */ + public function setNumRetries($numRetries) + { + $this->numRetries_ = $numRetries; + } + + /** + * Sets how long to wait until retrying a host if it was marked down + * + * @param int $numRetries + */ + public function setRetryInterval($retryInterval) + { + $this->retryInterval_ = $retryInterval; + } + + /** + * Sets how many time to keep retrying a host before marking it as down. + * + * @param int $numRetries + */ + public function setMaxConsecutiveFailures($maxConsecutiveFailures) + { + $this->maxConsecutiveFailures_ = $maxConsecutiveFailures; + } + + /** + * Turns randomization in connect order on or off. + * + * @param bool $randomize + */ + public function setRandomize($randomize) + { + $this->randomize_ = $randomize; + } + + /** + * Whether to always try the last server. + * + * @param bool $alwaysTryLast + */ + public function setAlwaysTryLast($alwaysTryLast) + { + $this->alwaysTryLast_ = $alwaysTryLast; + } + + /** + * Connects the socket by iterating through all the servers in the pool + * and trying to find one that works. + */ + public function open() + { + // Check if we want order randomization + if ($this->randomize_) { + shuffle($this->servers_); + } + + // Count servers to identify the "last" one + $numServers = count($this->servers_); + + for ($i = 0; $i < $numServers; ++$i) { + // This extracts the $host and $port variables + extract($this->servers_[$i]); + + // Check APC cache for a record of this server being down + $failtimeKey = 'thrift_failtime:' . $host . ':' . $port . '~'; + + // Cache miss? Assume it's OK + $lastFailtime = apc_fetch($failtimeKey); + if ($lastFailtime === false) { + $lastFailtime = 0; + } + + $retryIntervalPassed = false; + + // Cache hit...make sure enough the retry interval has elapsed + if ($lastFailtime > 0) { + $elapsed = time() - $lastFailtime; + if ($elapsed > $this->retryInterval_) { + $retryIntervalPassed = true; + if ($this->debug_) { + call_user_func( + $this->debugHandler_, + 'TSocketPool: retryInterval ' . + '(' . $this->retryInterval_ . ') ' . + 'has passed for host ' . $host . ':' . $port + ); + } + } + } + + // Only connect if not in the middle of a fail interval, OR if this + // is the LAST server we are trying, just hammer away on it + $isLastServer = false; + if ($this->alwaysTryLast_) { + $isLastServer = ($i == ($numServers - 1)); + } + + if (($lastFailtime === 0) || + ($isLastServer) || + ($lastFailtime > 0 && $retryIntervalPassed)) { + // Set underlying TSocket params to this one + $this->host_ = $host; + $this->port_ = $port; + + // Try up to numRetries_ connections per server + for ($attempt = 0; $attempt < $this->numRetries_; $attempt++) { + try { + // Use the underlying TSocket open function + parent::open(); + + // Only clear the failure counts if required to do so + if ($lastFailtime > 0) { + apc_store($failtimeKey, 0); + } + + // Successful connection, return now + return; + } catch (TException $tx) { + // Connection failed + } + } + + // Mark failure of this host in the cache + $consecfailsKey = 'thrift_consecfails:' . $host . ':' . $port . '~'; + + // Ignore cache misses + $consecfails = apc_fetch($consecfailsKey); + if ($consecfails === false) { + $consecfails = 0; + } + + // Increment by one + $consecfails++; + + // Log and cache this failure + if ($consecfails >= $this->maxConsecutiveFailures_) { + if ($this->debug_) { + call_user_func( + $this->debugHandler_, + 'TSocketPool: marking ' . $host . ':' . $port . + ' as down for ' . $this->retryInterval_ . ' secs ' . + 'after ' . $consecfails . ' failed attempts.' + ); + } + // Store the failure time + apc_store($failtimeKey, time()); + + // Clear the count of consecutive failures + apc_store($consecfailsKey, 0); + } else { + apc_store($consecfailsKey, $consecfails); + } + } + } + + // Oh no; we failed them all. The system is totally ill! + $error = 'TSocketPool: All hosts in pool are down. '; + $hosts = array(); + foreach ($this->servers_ as $server) { + $hosts [] = $server['host'] . ':' . $server['port']; + } + $hostlist = implode(',', $hosts); + $error .= '(' . $hostlist . ')'; + if ($this->debug_) { + call_user_func($this->debugHandler_, $error); + } + throw new TException($error); + } +} |