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<?php

/**

 * Copyright (c) 2007-2011, Servigistics, Inc.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  - Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *  - Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *  - Neither the name of Servigistics, Inc. nor the names of

 *    its contributors may be used to endorse or promote products derived from

 *    this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 *

 * @copyright Copyright 2007-2011 Servigistics, Inc. (http://servigistics.com)

 * @license http://solr-php-client.googlecode.com/svn/trunk/COPYING New BSD

 * @version $Id: Balancer.php 54 2011-02-04 16:29:18Z donovan.jimenez $

 *

 * @package Apache

 * @subpackage Solr

 * @author Donovan Jimenez <djimenez@conduit-it.com>, Dan Wolfe

 */

// See Issue #1 (http://code.google.com/p/solr-php-client/issues/detail?id=1)

// Doesn't follow typical include path conventions, but is more convenient for users

require_once(dirname(dirname(__FILE__)) . '/Service.php');

require_once(dirname(dirname(__FILE__)) . '/NoServiceAvailableException.php');

/**

 * Reference Implementation for using multiple Solr services in a distribution. Functionality

 * includes:

 * 	routing of read / write operations

 * 	failover (on selection) for multiple read servers

 */

class Apache_Solr_Service_Balancer

{

	/**

	 * SVN Revision meta data for this class

	 */

	const SVN_REVISION = '$Revision: 54 $';

	/**

	 * SVN ID meta data for this class

	 */

	const SVN_ID = '$Id: Balancer.php 54 2011-02-04 16:29:18Z donovan.jimenez $';

	protected $_createDocuments = true;

	protected $_readableServices = array();

	protected $_writeableServices = array();

	protected $_currentReadService = null;

	protected $_currentWriteService = null;

	protected $_readPingTimeout = 2;

	protected $_writePingTimeout = 4;

	// Configuration for server selection backoff intervals

	protected $_useBackoff = false;		// Set to true to use more resillient write server selection

	protected $_backoffLimit = 600;		// 10 minute default maximum

	protected $_backoffEscalation = 2.0; 	// Rate at which to increase backoff period

	protected $_defaultBackoff = 2.0;		// Default backoff interval

	/**

	 * Escape a value for special query characters such as ':', '(', ')', '*', '?', etc.

	 *

	 * NOTE: inside a phrase fewer characters need escaped, use {@link Apache_Solr_Service::escapePhrase()} instead

	 *

	 * @param string $value

	 * @return string

	 */

	static public function escape($value)

	{

		return Apache_Solr_Service::escape($value);

	}

	/**

	 * Escape a value meant to be contained in a phrase for special query characters

	 *

	 * @param string $value

	 * @return string

	 */

	static public function escapePhrase($value)

	{

		return Apache_Solr_Service::escapePhrase($value);

	}

	/**

	 * Convenience function for creating phrase syntax from a value

	 *

	 * @param string $value

	 * @return string

	 */

	static public function phrase($value)

	{

		return Apache_Solr_Service::phrase($value);

	}

	/**

	 * Constructor. Takes arrays of read and write service instances or descriptions

	 *

	 * @param array $readableServices

	 * @param array $writeableServices

	 */

	public function __construct($readableServices = array(), $writeableServices = array())

	{

		//setup readable services

		foreach ($readableServices as $service)

		{

			$this->addReadService($service);

		}

		//setup writeable services

		foreach ($writeableServices as $service)

		{

			$this->addWriteService($service);

		}

	}

	public function setReadPingTimeout($timeout)

	{

		$this->_readPingTimeout = $timeout;

	}

	public function setWritePingTimeout($timeout)

	{

		$this->_writePingTimeout = $timeout;

	}

	public function setUseBackoff($enable)

	{

		$this->_useBackoff = $enable;

	}

	/**

	 * Generates a service ID

	 *

	 * @param string $host

	 * @param integer $port

	 * @param string $path

	 * @return string

	 */

	protected function _getServiceId($host, $port, $path)

	{

		return $host . ':' . $port . $path;

	}

	/**

	 * Adds a service instance or service descriptor (if it is already

	 * not added)

	 *

	 * @param mixed $service

	 *

	 * @throws Apache_Solr_InvalidArgumentException If service descriptor is not valid

	 */

	public function addReadService($service)

	{

		if ($service instanceof Apache_Solr_Service)

		{

			$id = $this->_getServiceId($service->getHost(), $service->getPort(), $service->getPath());

			$this->_readableServices[$id] = $service;

		}

		else if (is_array($service))

		{

			if (isset($service['host']) && isset($service['port']) && isset($service['path']))

			{

				$id = $this->_getServiceId((string)$service['host'], (int)$service['port'], (string)$service['path']);

				$this->_readableServices[$id] = $service;

			}

			else

			{

				throw new Apache_Solr_InvalidArgumentException('A Readable Service description array does not have all required elements of host, port, and path');

			}

		}

	}

	/**

	 * Removes a service instance or descriptor from the available services

	 *

	 * @param mixed $service

	 *

	 * @throws Apache_Solr_InvalidArgumentException If service descriptor is not valid

	 */

	public function removeReadService($service)

	{

		$id = '';

		if ($service instanceof Apache_Solr_Service)

		{

			$id = $this->_getServiceId($service->getHost(), $service->getPort(), $service->getPath());

		}

		else if (is_array($service))

		{

			if (isset($service['host']) && isset($service['port']) && isset($service['path']))

			{

				$id = $this->_getServiceId((string)$service['host'], (int)$service['port'], (string)$service['path']);

			}

			else

			{

				throw new Apache_Solr_InvalidArgumentException('A Readable Service description array does not have all required elements of host, port, and path');

			}

		}

		else if (is_string($service))

		{

			$id = $service;

		}

		if ($id && isset($this->_readableServices[$id]))

		{

			unset($this->_readableServices[$id]);

		}

	}

	/**

	 * Adds a service instance or service descriptor (if it is already

	 * not added)

	 *

	 * @param mixed $service

	 *

	 * @throws Apache_Solr_InvalidArgumentException If service descriptor is not valid

	 */

	public function addWriteService($service)

	{

		if ($service instanceof Apache_Solr_Service)

		{

			$id = $this->_getServiceId($service->getHost(), $service->getPort(), $service->getPath());

			$this->_writeableServices[$id] = $service;

		}

		else if (is_array($service))

		{

			if (isset($service['host']) && isset($service['port']) && isset($service['path']))

			{

				$id = $this->_getServiceId((string)$service['host'], (int)$service['port'], (string)$service['path']);

				$this->_writeableServices[$id] = $service;

			}

			else

			{

				throw new Apache_Solr_InvalidArgumentException('A Writeable Service description array does not have all required elements of host, port, and path');

			}

		}

	}

	/**

	 * Removes a service instance or descriptor from the available services

	 *

	 * @param mixed $service

	 *

	 * @throws Apache_Solr_InvalidArgumentException If service descriptor is not valid

	 */

	public function removeWriteService($service)

	{

		$id = '';

		if ($service instanceof Apache_Solr_Service)

		{

			$id = $this->_getServiceId($service->getHost(), $service->getPort(), $service->getPath());

		}

		else if (is_array($service))

		{

			if (isset($service['host']) && isset($service['port']) && isset($service['path']))

			{

				$id = $this->_getServiceId((string)$service['host'], (int)$service['port'], (string)$service['path']);

			}

			else

			{

				throw new Apache_Solr_InvalidArgumentException('A Readable Service description array does not have all required elements of host, port, and path');

			}

		}

		else if (is_string($service))

		{

			$id = $service;

		}

		if ($id && isset($this->_writeableServices[$id]))

		{

			unset($this->_writeableServices[$id]);

		}

	}

	/**

	 * Iterate through available read services and select the first with a ping

	 * that satisfies configured timeout restrictions (or the default)

	 *

	 * @return Apache_Solr_Service

	 *

	 * @throws Apache_Solr_NoServiceAvailableException If there are no read services that meet requirements

	 */

	protected function _selectReadService($forceSelect = false)

	{

		if (!$this->_currentReadService || !isset($this->_readableServices[$this->_currentReadService]) || $forceSelect)

		{

			if ($this->_currentReadService && isset($this->_readableServices[$this->_currentReadService]) && $forceSelect)

			{

				// we probably had a communication error, ping the current read service, remove it if it times out

				if ($this->_readableServices[$this->_currentReadService]->ping($this->_readPingTimeout) === false)

				{

					$this->removeReadService($this->_currentReadService);

				}

			}

			if (count($this->_readableServices))

			{

				// select one of the read services at random

				$ids = array_keys($this->_readableServices);

				$id = $ids[rand(0, count($ids) - 1)];

				$service = $this->_readableServices[$id];

				if (is_array($service))

				{

					//convert the array definition to a client object

					$service = new Apache_Solr_Service($service['host'], $service['port'], $service['path']);

					$this->_readableServices[$id] = $service;

				}

				$service->setCreateDocuments($this->_createDocuments);

				$this->_currentReadService = $id;

			}

			else

			{

				throw new Apache_Solr_NoServiceAvailableException('No read services were available');

			}

		}

		return $this->_readableServices[$this->_currentReadService];

	}

	/**

	 * Iterate through available write services and select the first with a ping

	 * that satisfies configured timeout restrictions (or the default)

	 *

	 * @return Apache_Solr_Service

	 *

	 * @throws Apache_Solr_NoServiceAvailableException If there are no write services that meet requirements

	 */

	protected function _selectWriteService($forceSelect = false)

	{

		if($this->_useBackoff)

		{

			return $this->_selectWriteServiceSafe($forceSelect);

		}

		if (!$this->_currentWriteService || !isset($this->_writeableServices[$this->_currentWriteService]) || $forceSelect)

		{

			if ($this->_currentWriteService && isset($this->_writeableServices[$this->_currentWriteService]) && $forceSelect)

			{

				// we probably had a communication error, ping the current read service, remove it if it times out

				if ($this->_writeableServices[$this->_currentWriteService]->ping($this->_writePingTimeout) === false)

				{

					$this->removeWriteService($this->_currentWriteService);

				}

			}

			if (count($this->_writeableServices))

			{

				// select one of the read services at random

				$ids = array_keys($this->_writeableServices);

				$id = $ids[rand(0, count($ids) - 1)];

				$service = $this->_writeableServices[$id];

				if (is_array($service))

				{

					//convert the array definition to a client object

					$service = new Apache_Solr_Service($service['host'], $service['port'], $service['path']);

					$this->_writeableServices[$id] = $service;

				}

				$this->_currentWriteService = $id;

			}

			else

			{

				throw new Apache_Solr_NoServiceAvailableException('No write services were available');

			}

		}

		return $this->_writeableServices[$this->_currentWriteService];

	}

	/**

	 * Iterate through available write services and select the first with a ping

	 * that satisfies configured timeout restrictions (or the default).  The

	 * timeout period will increase until a connection is made or the limit is

	 * reached.   This will allow for increased reliability with heavily loaded

	 * server(s).

	 *

	 * @return Apache_Solr_Service

	 *

	 * @throws Apache_Solr_NoServiceAvailableException If there are no write services that meet requirements

	 */

	protected function _selectWriteServiceSafe($forceSelect = false)

	{

		if (!$this->_currentWriteService || !isset($this->_writeableServices[$this->_currentWriteService]) || $forceSelect)

		{

			if (count($this->_writeableServices))

			{

				$backoff = $this->_defaultBackoff;

				do {

					// select one of the read services at random

					$ids = array_keys($this->_writeableServices);

					$id = $ids[rand(0, count($ids) - 1)];

					$service = $this->_writeableServices[$id];

					if (is_array($service))

					{

						//convert the array definition to a client object

						$service = new Apache_Solr_Service($service['host'], $service['port'], $service['path']);

						$this->_writeableServices[$id] = $service;

					}

					$this->_currentWriteService = $id;

					$backoff *= $this->_backoffEscalation;

					if($backoff > $this->_backoffLimit)

					{

						throw new Apache_Solr_NoServiceAvailableException('No write services were available.  All timeouts exceeded.');

					}

				} while($this->_writeableServices[$this->_currentWriteService]->ping($backoff) === false);

			}

			else

			{

				throw new Apache_Solr_NoServiceAvailableException('No write services were available');

			}

		}

		return $this->_writeableServices[$this->_currentWriteService];

	}

	/**

	 * Set the create documents flag. This determines whether {@link Apache_Solr_Response} objects will

	 * parse the response and create {@link Apache_Solr_Document} instances in place.

	 *

	 * @param boolean $createDocuments

	 */

	public function setCreateDocuments($createDocuments)

	{

		$this->_createDocuments = (bool) $createDocuments;

		// set on current read service

		if ($this->_currentReadService)

		{

			$service = $this->_selectReadService();

			$service->setCreateDocuments($createDocuments);

		}

	}

	/**

	 * Get the current state of teh create documents flag.

	 *

	 * @return boolean

	 */

	public function getCreateDocuments()

	{

		return $this->_createDocuments;

	}

	/**

	 * Raw Add Method. Takes a raw post body and sends it to the update service.  Post body

	 * should be a complete and well formed "add" xml document.

	 *

	 * @param string $rawPost

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function add($rawPost)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->add($rawPost);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Add a Solr Document to the index

	 *

	 * @param Apache_Solr_Document $document

	 * @param boolean $allowDups

	 * @param boolean $overwritePending

	 * @param boolean $overwriteCommitted

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function addDocument(Apache_Solr_Document $document, $allowDups = false, $overwritePending = true, $overwriteCommitted = true)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->addDocument($document, $allowDups, $overwritePending, $overwriteCommitted);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Add an array of Solr Documents to the index all at once

	 *

	 * @param array $documents Should be an array of Apache_Solr_Document instances

	 * @param boolean $allowDups

	 * @param boolean $overwritePending

	 * @param boolean $overwriteCommitted

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function addDocuments($documents, $allowDups = false, $overwritePending = true, $overwriteCommitted = true)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->addDocuments($documents, $allowDups, $overwritePending, $overwriteCommitted);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Send a commit command.  Will be synchronous unless both wait parameters are set

	 * to false.

	 *

	 * @param boolean $waitFlush

	 * @param boolean $waitSearcher

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function commit($optimize = true, $waitFlush = true, $waitSearcher = true, $timeout = 3600)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->commit($optimize, $waitFlush, $waitSearcher, $timeout);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Raw Delete Method. Takes a raw post body and sends it to the update service. Body should be

	 * a complete and well formed "delete" xml document

	 *

	 * @param string $rawPost

	 * @param float $timeout Maximum expected duration of the delete operation on the server (otherwise, will throw a communication exception)

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function delete($rawPost, $timeout = 3600)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->delete($rawPost, $timeout);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Create a delete document based on document ID

	 *

	 * @param string $id

	 * @param boolean $fromPending

	 * @param boolean $fromCommitted

	 * @param float $timeout Maximum expected duration of the delete operation on the server (otherwise, will throw a communication exception)

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function deleteById($id, $fromPending = true, $fromCommitted = true, $timeout = 3600)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->deleteById($id, $fromPending, $fromCommitted, $timeout);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Create and post a delete document based on multiple document IDs.

	 *

	 * @param array $ids Expected to be utf-8 encoded strings

	 * @param boolean $fromPending

	 * @param boolean $fromCommitted

	 * @param float $timeout Maximum expected duration of the delete operation on the server (otherwise, will throw a communication exception)

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function deleteByMultipleIds($ids, $fromPending = true, $fromCommitted = true, $timeout = 3600)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->deleteByMultipleId($ids, $fromPending, $fromCommitted, $timeout);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Create a delete document based on a query and submit it

	 *

	 * @param string $rawQuery

	 * @param boolean $fromPending

	 * @param boolean $fromCommitted

	 * @param float $timeout Maximum expected duration of the delete operation on the server (otherwise, will throw a communication exception)

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function deleteByQuery($rawQuery, $fromPending = true, $fromCommitted = true, $timeout = 3600)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->deleteByQuery($rawQuery, $fromPending, $fromCommitted, $timeout);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Use Solr Cell to extract document contents. See {@link http://wiki.apache.org/solr/ExtractingRequestHandler} for information on how

	 * to use Solr Cell and what parameters are available.

	 *

	 * NOTE: when passing an Apache_Solr_Document instance, field names and boosts will automatically be prepended by "literal." and "boost."

	 * as appropriate. Any keys from the $params array will NOT be treated this way. Any mappings from the document will overwrite key / value

	 * pairs in the params array if they have the same name (e.g. you pass a "literal.id" key and value in your $params array but you also

	 * pass in a document isntance with an "id" field" - the document's value(s) will take precedence).

	 *

	 * @param string $file Path to file to extract data from

	 * @param array $params optional array of key value pairs that will be sent with the post (see Solr Cell documentation)

	 * @param Apache_Solr_Document $document optional document that will be used to generate post parameters (literal.* and boost.* params)

	 * @param string $mimetype optional mimetype specification (for the file being extracted)

	 *

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_InvalidArgumentException if $file, $params, or $document are invalid.

	 */

	public function extract($file, $params = array(), $document = null, $mimetype = 'application/octet-stream')

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->extract($file, $params, $document, $mimetype);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Use Solr Cell to extract document contents. See {@link http://wiki.apache.org/solr/ExtractingRequestHandler} for information on how

	 * to use Solr Cell and what parameters are available.

	 *

	 * NOTE: when passing an Apache_Solr_Document instance, field names and boosts will automatically be prepended by "literal." and "boost."

	 * as appropriate. Any keys from the $params array will NOT be treated this way. Any mappings from the document will overwrite key / value

	 * pairs in the params array if they have the same name (e.g. you pass a "literal.id" key and value in your $params array but you also

	 * pass in a document isntance with an "id" field" - the document's value(s) will take precedence).

	 *

	 * @param string $data Data that will be passed to Solr Cell

	 * @param array $params optional array of key value pairs that will be sent with the post (see Solr Cell documentation)

	 * @param Apache_Solr_Document $document optional document that will be used to generate post parameters (literal.* and boost.* params)

	 * @param string $mimetype optional mimetype specification (for the file being extracted)

	 *

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_InvalidArgumentException if $file, $params, or $document are invalid.

	 *

	 * @todo Should be using multipart/form-data to post parameter values, but I could not get my implementation to work. Needs revisisted.

	 */

	public function extractFromString($data, $params = array(), $document = null, $mimetype = 'application/octet-stream')

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->extractFromString($data, $params, $document, $mimetype);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Send an optimize command.  Will be synchronous unless both wait parameters are set

	 * to false.

	 *

	 * @param boolean $waitFlush

	 * @param boolean $waitSearcher

	 * @param float $timeout Maximum expected duration of the optimize operation on the server (otherwise, will throw a communication exception)

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function optimize($waitFlush = true, $waitSearcher = true, $timeout = 3600)

	{

		$service = $this->_selectWriteService();

		do

		{

			try

			{

				return $service->optimize($waitFlush, $waitSearcher, $timeout);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectWriteService(true);

		} while ($service);

		return false;

	}

	/**

	 * Simple Search interface

	 *

	 * @param string $query The raw query string

	 * @param int $offset The starting offset for result documents

	 * @param int $limit The maximum number of result documents to return

	 * @param array $params key / value pairs for query parameters, use arrays for multivalued parameters

	 * @param string $method The HTTP method (Apache_Solr_Service::METHOD_GET or Apache_Solr_Service::METHOD::POST)

	 * @return Apache_Solr_Response

	 *

	 * @throws Apache_Solr_HttpTransportException If an error occurs during the service call

	 */

	public function search($query, $offset = 0, $limit = 10, $params = array(), $method = Apache_Solr_Service::METHOD_GET)

	{

		$service = $this->_selectReadService();

		do

		{

			try

			{

				return $service->search($query, $offset, $limit, $params, $method);

			}

			catch (Apache_Solr_HttpTransportException $e)

			{

				if ($e->getCode() != 0) //IF NOT COMMUNICATION ERROR

				{

					throw $e;

				}

			}

			$service = $this->_selectReadService(true);

		} while ($service);

		return false;

	}

}