hmc/php/orchestrator/HMC.php - ambari - Git at Google

 <?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.
  */

 include_once '../util/Logger.php';
 include_once '../conf/Config.inc';
 include_once "../util/lock.php";
 include_once '../db/HMCDBAccessor.php';
 include_once "../util/HMCTxnUtils.php";

 /**
  * Interface between UI and install framework layer.
  */
 class HMC {

   private $dbHandle;

   private $dbPath;

   private $logger;

   private $clusterName;

   private $command;

   function __construct($dbPath, $clusterName) {
     $this->dbPath = $dbPath;
     $this->clusterName = $clusterName;
     $this->logger = new HMCLogger("HMC");
     $this->dbHandle = new HMCDBAccessor($dbPath);

     if (!isset($GLOBALS["PHP_EXEC_PATH"])) {
       $GLOBALS["PHP_EXEC_PATH"] = "/usr/bin/php";
     }
     // TODO
     if (!isset($GLOBALS["CLUSTERMAIN_PATH"])) {
       $GLOBALS["CLUSTERMAIN_PATH"] = "ClusterMain.php";
     }

     $this->command = $GLOBALS["PHP_EXEC_PATH"]
         . " " . $GLOBALS["CLUSTERMAIN_PATH"];
   }

   /**
    * Function to deploy and start HDP across the whole cluster
    * Runs in the background
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function deployHDP() {
     $action = "deployHDP";
     $msg = "Deploying cluster";
     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath
         . " -a deploy ";
     return $this->internalTrigger($action, $msg, $args);
   }

   /**
    * Function to deploy all the required rpms and start all required
    * services on a given node
    * Runs in the background
    * @param array $nodes Hostnames of the nodes to be deployed
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function deployNodes($nodes) {
     $action = "deployNodes";
     $nodeList = implode(",", $nodes);
     $msg = "Deploying on nodes, list=" . $nodeList;
     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath
         . " -a deployNode ";
     foreach ($nodes as $node) {
       $args .= " -n " . $node;
     }
     return $this->internalTrigger($action, $msg, $args);
   }


   /**
    * Function to start all the services in order.
    * Runs in the background.
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function startAllServices() {
     $action = "startAllServices";
     $msg = "Starting all services";
     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath
         . " -a startAll ";

     return $this->internalTrigger($action, $msg, $args);
   }

   /**
    * Function to stop all the services in order.
    * Runs in the background.
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function stopAllServices() {
     $action = "stopAllServices";
     $msg = "Stopping all services";
     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath
         . " -a stopAll ";

     return $this->internalTrigger($action, $msg, $args);
   }

   /**
    * NOT SUPPORTED
    * Function to start given services.
    * Runs in the background.
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function startServices($services) {
     $action = "startServices";
     $svcList = implode(",", $services);
     $msg = "Starting services, list=".$svcList;
     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath
         . " -a start ";
     foreach ($services as $svc) {
       $args .= " -s " . $svc;
     }
     return $this->internalTrigger($action, $msg, $args);
   }

   /**
    * NOT SUPPORTED
    * Function to stop given services.
    * Runs in the background.
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function stopServices($services) {
     $action = "stopServices";
     $svcList = implode(",", $services);
     $msg = "Stopping services, list=".$svcList;
     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath
         . " -a stop ";
     foreach ($services as $svc) {
       $args .= " -s " . $svc;
     }
     return $this->internalTrigger($action, $msg, $args);
   }

   /**
    * NOT SUPPORTED
    * Function to start a given service and all the services it depends upon to
    * start successfully in the required order.
    * Runs in the background.
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function startDependentServices($service) {
     // generate a txn id which is returned back to the UI for progress
     // monitoring

     // use popen/pclose to start a background process
     // background script:
     // generate site.pp to start service and dependent services in required order
     // update progress, make logs accessible
     error_log("Start dependent services is not supported");
     exit (1);
   }

   /**
    * NOT SUPPORTED
    * Function to stop a given service and all the services that depend upon it
    * in the required order.
    * Runs in the background.
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function stopDependentServices($service) {
     // generate a txn id which is returned back to the UI for progress
     // monitoring

     // use popen/pclose to start a background process
     // background script:
     // generate site.pp to stop service and dependent services in required order
     // update progress, make logs accessible
     error_log("Stop dependent services is not supported");
     exit (1);
   }

   /**
    * NOT SUPPORTED
    * Function to reconfigure a cluster by first stopping the whole cluster,
    * re-pushing new configs to all nodes and restarting all services.
    * Runs in the background.
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function reconfigureHDP() {
     // generate a txn id which is returned back to the UI for progress
     // monitoring

     // use popen/pclose to start a background process
     // background script:
     // generate site.pp to stop all services in required order
     // update progress, make logs accessible
     // generate site.pp with new configs
     // update progress, make logs accessible
     // generate site.pp to start all services in required order
     // update progress, make logs accessible
     error_log("Re-configuring is not supported");
     exit (1);

   }

   /**
    * Function to reconfigure services by first stopping the services and the
    * required dependencies, re-pushing new configs to required nodes and
    * restarting all the required services.
    * Runs in the background.
    * @param array services to re-configure
    * @return mixed
    *  txn_id: transaction id to refer to to get progress updates and logs
    *  array ( "txn_id" => $txn_id );
    */
   public function reconfigureServices($services) {
     $action = "reconfigureServices";
     $svcList = implode(",", $services);
     $msg = "Reconfiguring services, list=".$svcList;

     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath
         . " -a reconfigure ";

     foreach ($services as $svc) {
       $args .= " -s " . $svc;
     }

     return $this->internalTrigger($action, $msg, $args);
   }

   /**
    * Get progress update for a given transaction.
    * @param txnId Transaction Id
    * @return mixed
    *   array ( "txn_id" => $txn_id,
    *           "result" => 0,
    *           "processRunning" => bool,
    *           "subTxns" => array (
    *              array (
    *                "subTxnId" =>
    *                "parentSubTxnId" =>
    *                "state" =>
    *                "description" =>
    *              )
    *           )
    *        )
    */
   public function getProgress($txnId) {
     // given the txn id generated for one of the supported actions, provide
     // the current progress update
     // this could also be a trigger to update the current state if needed
     $response = array ( "result" => 0, "error" => "");
     $txnInfo = $this->dbHandle->getTransactionStatusInfo($this->clusterName,
         $txnId);

     if ($txnInfo === FALSE || $txnInfo["result"] != 0) {
       return $txnInfo;
     }

     $pidInfo = json_decode($txnInfo["pidInfo"], true);
     $procRunning = HMCTxnUtils::checkTxnProcessStatus($pidInfo);

     $response["processRunning"] = $procRunning;

     $subTxnInfo = $this->dbHandle->getAllSubTransactionsInfo($this->clusterName,
         $txnId);
     if ($subTxnInfo === FALSE || $subTxnInfo["result"] != 0) {
       return $subTxnInfo;
     }

     $orderedSubTxns = $this->orderSubTxns($subTxnInfo["subTxns"]);

     $response["txnId"] = $txnId;
     $response["subTxns"] = array();
     foreach($orderedSubTxns as $sTxnId => $sTxn) {
       if (isset($sTxn["opStatus"])) {
         $sTxn["opStatus"] = json_decode($sTxn["opStatus"], true);
       } else {
         $sTxn["opStatus"] = array();
       }
       array_push($response["subTxns"], $sTxn);
     }

     return $response;
   }

   public function orderSubTxns($subTxns) {
     $subTxnCount = count($subTxns);

     $parentIndexedSubTxns = array();
     $allSubTxns = array();

     foreach ($subTxns as $subTxn) {
       $allSubTxns[$subTxn["subTxnId"]] = $subTxn;
     }

     foreach ($subTxns as $subTxn) {
       if (!isset($parentIndexedSubTxns[$subTxn["parentSubTxnId"]])) {
         $parentIndexedSubTxns[$subTxn["parentSubTxnId"]] = array();
       }
       $parentIndexedSubTxns[$subTxn["parentSubTxnId"]][$subTxn["subTxnId"]] = $subTxn;
     }

     $rankedSubTxns = array();
     $currentRank = 0;
     $rankedIndexes = array();

     $this->_orderSubTxns($rankedSubTxns, $rankedIndexes,
        $currentRank, $allSubTxns, $parentIndexedSubTxns, $subTxns);


     assert(count($rankedSubTxns) == $subTxnCount);
     return $rankedSubTxns;
   }

   private function _orderSubTxns(&$rankedSubTxns, &$rankedIndexes,
       &$currentRank, &$allSubTxns, $parentIndexedSubTxns, $subTxnsToOrder) {

     $maxIndex = 0;
     $indexedSubTxns = array();

     foreach ($subTxnsToOrder as $subTxn) {
       if ($subTxn["subTxnId"] > $maxIndex) {
         $maxIndex = $subTxn["subTxnId"];
       }
       $indexedSubTxns[$subTxn["subTxnId"]] = $subTxn;
     }

     for ($i = 0; $i <= $maxIndex; ++$i) {
       if (!isset($indexedSubTxns[$i])) {
         continue;
       }

       $subTxn = $indexedSubTxns[$i];
       $parentSubTxnId = $subTxn["parentSubTxnId"];

       if (isset($parentIndexedSubTxns[$i])
           && is_array($parentIndexedSubTxns[$i])
           && count($parentIndexedSubTxns[$i]) > 0) {
         ksort($parentIndexedSubTxns[$i]);
         foreach ($parentIndexedSubTxns[$i] as $index => $pSubTxn) {
           $pSubTxnId = $pSubTxn["subTxnId"];
           $ppSubTxnId = $pSubTxn["parentSubTxnId"];
           if (!isset($rankedIndexes[$pSubTxnId])) {
             $this->_orderSubTxns($rankedSubTxns, $rankedIndexes,
                 $currentRank, $allSubTxns, $parentIndexedSubTxns,
                 $parentIndexedSubTxns[$ppSubTxnId]);
           }
           if (!isset($rankedIndexes[$pSubTxnId])) {
             $pSubTxn["rank"] = $currentRank;
             $rankedSubTxns[$currentRank] = $pSubTxn;
             $rankedIndexes[$pSubTxn["subTxnId"]] = TRUE;
             ++$currentRank;
           }
          }
       }
       if (!isset($rankedIndexes[$i])) {
         $subTxn["rank"] = $currentRank;
         $rankedSubTxns[$currentRank] = $subTxn;
         $rankedIndexes[$i] = TRUE;
         ++$currentRank;
       }
     }

     return $rankedSubTxns;
   }


   /**
    * Get logs for a given transaction
    * @param string $txnId Transaction Id
    */
   public function getLogs($txnId) {
     // get the logs for a given transaction triggered earlier.
     // not sure if we want to support filtering by log level for now

     $response = array ( "result" => 0, "error" => "");
     $txnInfo = $this->dbHandle->getTransactionStatusInfo($this->clusterName,
        $txnId);

     if ($txnInfo === FALSE || $txnInfo["result"] != 0) {
       return $txnInfo;
     }

     $subTxnInfo = $this->dbHandle->getAllSubTransactionsInfo($this->clusterName,
         $txnId);
     if ($subTxnInfo === FALSE || $subTxnInfo["result"] != 0) {
       return $subTxnInfo;
     }

     $puppetInvoker = new PuppetInvoker($this->dbPath);

     $response["txnId"] = $txnId;
     $response["subTxns"] = array();

     foreach ($subTxnInfo["subTxns"] as $subTxnId => $subTxn) {
       $nodes = array();
       $response["subTxns"][$subTxn["subTxnId"]] =
           array( "nodeReport" => array(),
                  "nodeLogs" => array());

       if (!isset($subTxn["opStatus"])) {
         continue;
       }

       $opStatus = json_decode($subTxn["opStatus"], true);
       if (!isset($opStatus["nodeReport"])) {
           continue;
       }

       $nodeReport = $opStatus["nodeReport"];

       $response["subTxns"][$subTxn["subTxnId"]]["nodeReport"] = $nodeReport;

       $keys = array ( "PUPPET_KICK_FAILED", "PUPPET_OPERATION_FAILED",
           "PUPPET_OPERATION_SUCCEEDED" );
       foreach ($keys as $key) {
         if (isset($nodeReport[$key])
             && is_array($nodeReport[$key])) {
           $nodes = array_merge($nodes, $nodeReport[$key]);
         }
       }

       $transaction = new Transaction($txnId, $subTxn["subTxnId"],
           $subTxn["parentSubTxnId"]);

       $puppetLogs = $puppetInvoker->getReports($nodes, $transaction);
       $this->logger->log_debug("Got puppet reports for transaction=" .$transaction->toString()
           . ", nodes=" . print_r($nodes, true)
           . ", logs=" . print_r($puppetLogs, true));

       $response["subTxns"][$subTxn["subTxnId"]]["nodeLogs"] = $puppetLogs;
     }
     return $response;
   }

   private function internalTrigger($action, $msg, $args) {
     $this->logger->log_info("HMC triggering action=" . $action . ", " . $msg);
     $response = array ( "result" => 0, "error" => "");

     $statusInfo = array ("function" => "HMC::$action",
                          "action" => $msg);
     $txnId = HMCTxnUtils::createNewTransaction($this->dbHandle,
         $this->clusterName, $statusInfo);
     if ($txnId === FALSE) {
       $error = "Failed to create a new transaction, action=" . $action;
       $this->logger->log_error($error);
       return array ("result" => 1, "error" => $error);
     }
     $response["txnId"] = $txnId;
     $args .= " -x " . $txnId;

     $this->logger->log_debug("Triggering background process"
         . ", clusterName=" . $this->clusterName
         . ", txnId=" . $txnId
         . ", command=" . $this->command
         . ", args=" . $args);
     $backgroundPid = HMCTxnUtils::execBackgroundProcess($this->dbHandle,
         $this->clusterName, $txnId, $this->command, $args, "");

     if ($backgroundPid === FALSE) {
       $error = "Failed to trigger background process, action=" . $action;
       $this->logger->log_error($error);
       $response["result"] = 1;
       $response["error"] = $error;
     }
     return $response;
   }

   public function uninstallHDP($wipeoutData = FALSE) {
     $this->logger->log_info("Triggering uninstall"
          . ", clusterName=" . $this->clusterName
          );
     $action = "uninstallHDP";
     $msg = "Uninstalling cluster, wipeout=" . $wipeoutData;
     $args = " -c " . $this->clusterName
         . " -d " . $this->dbPath;
     if (!$wipeoutData) {
       $args .= " -a uninstallAll ";
     } else {
       $args .= " -a wipeout ";
     }
     return $this->internalTrigger($action, $msg, $args);
   }

 }

 ?>
	<?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.
	*/

	include_once '../util/Logger.php';
	include_once '../conf/Config.inc';
	include_once "../util/lock.php";
	include_once '../db/HMCDBAccessor.php';
	include_once "../util/HMCTxnUtils.php";

	/**
	* Interface between UI and install framework layer.
	*/
	class HMC {

	private $dbHandle;

	private $dbPath;

	private $logger;

	private $clusterName;

	private $command;

	function __construct($dbPath, $clusterName) {
	$this->dbPath = $dbPath;
	$this->clusterName = $clusterName;
	$this->logger = new HMCLogger("HMC");
	$this->dbHandle = new HMCDBAccessor($dbPath);

	if (!isset($GLOBALS["PHP_EXEC_PATH"])) {
	$GLOBALS["PHP_EXEC_PATH"] = "/usr/bin/php";
	}
	// TODO
	if (!isset($GLOBALS["CLUSTERMAIN_PATH"])) {
	$GLOBALS["CLUSTERMAIN_PATH"] = "ClusterMain.php";
	}

	$this->command = $GLOBALS["PHP_EXEC_PATH"]
	. " " . $GLOBALS["CLUSTERMAIN_PATH"];
	}

	/**
	* Function to deploy and start HDP across the whole cluster
	* Runs in the background
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function deployHDP() {
	$action = "deployHDP";
	$msg = "Deploying cluster";
	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath
	. " -a deploy ";
	return $this->internalTrigger($action, $msg, $args);
	}

	/**
	* Function to deploy all the required rpms and start all required
	* services on a given node
	* Runs in the background
	* @param array $nodes Hostnames of the nodes to be deployed
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function deployNodes($nodes) {
	$action = "deployNodes";
	$nodeList = implode(",", $nodes);
	$msg = "Deploying on nodes, list=" . $nodeList;
	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath
	. " -a deployNode ";
	foreach ($nodes as $node) {
	$args .= " -n " . $node;
	}
	return $this->internalTrigger($action, $msg, $args);
	}


	/**
	* Function to start all the services in order.
	* Runs in the background.
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function startAllServices() {
	$action = "startAllServices";
	$msg = "Starting all services";
	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath
	. " -a startAll ";

	return $this->internalTrigger($action, $msg, $args);
	}

	/**
	* Function to stop all the services in order.
	* Runs in the background.
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function stopAllServices() {
	$action = "stopAllServices";
	$msg = "Stopping all services";
	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath
	. " -a stopAll ";

	return $this->internalTrigger($action, $msg, $args);
	}

	/**
	* NOT SUPPORTED
	* Function to start given services.
	* Runs in the background.
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function startServices($services) {
	$action = "startServices";
	$svcList = implode(",", $services);
	$msg = "Starting services, list=".$svcList;
	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath
	. " -a start ";
	foreach ($services as $svc) {
	$args .= " -s " . $svc;
	}
	return $this->internalTrigger($action, $msg, $args);
	}

	/**
	* NOT SUPPORTED
	* Function to stop given services.
	* Runs in the background.
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function stopServices($services) {
	$action = "stopServices";
	$svcList = implode(",", $services);
	$msg = "Stopping services, list=".$svcList;
	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath
	. " -a stop ";
	foreach ($services as $svc) {
	$args .= " -s " . $svc;
	}
	return $this->internalTrigger($action, $msg, $args);
	}

	/**
	* NOT SUPPORTED
	* Function to start a given service and all the services it depends upon to
	* start successfully in the required order.
	* Runs in the background.
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function startDependentServices($service) {
	// generate a txn id which is returned back to the UI for progress
	// monitoring

	// use popen/pclose to start a background process
	// background script:
	// generate site.pp to start service and dependent services in required order
	// update progress, make logs accessible
	error_log("Start dependent services is not supported");
	exit (1);
	}

	/**
	* NOT SUPPORTED
	* Function to stop a given service and all the services that depend upon it
	* in the required order.
	* Runs in the background.
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function stopDependentServices($service) {
	// generate a txn id which is returned back to the UI for progress
	// monitoring

	// use popen/pclose to start a background process
	// background script:
	// generate site.pp to stop service and dependent services in required order
	// update progress, make logs accessible
	error_log("Stop dependent services is not supported");
	exit (1);
	}

	/**
	* NOT SUPPORTED
	* Function to reconfigure a cluster by first stopping the whole cluster,
	* re-pushing new configs to all nodes and restarting all services.
	* Runs in the background.
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function reconfigureHDP() {
	// generate a txn id which is returned back to the UI for progress
	// monitoring

	// use popen/pclose to start a background process
	// background script:
	// generate site.pp to stop all services in required order
	// update progress, make logs accessible
	// generate site.pp with new configs
	// update progress, make logs accessible
	// generate site.pp to start all services in required order
	// update progress, make logs accessible
	error_log("Re-configuring is not supported");
	exit (1);

	}

	/**
	* Function to reconfigure services by first stopping the services and the
	* required dependencies, re-pushing new configs to required nodes and
	* restarting all the required services.
	* Runs in the background.
	* @param array services to re-configure
	* @return mixed
	* txn_id: transaction id to refer to to get progress updates and logs
	* array ( "txn_id" => $txn_id );
	*/
	public function reconfigureServices($services) {
	$action = "reconfigureServices";
	$svcList = implode(",", $services);
	$msg = "Reconfiguring services, list=".$svcList;

	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath
	. " -a reconfigure ";

	foreach ($services as $svc) {
	$args .= " -s " . $svc;
	}

	return $this->internalTrigger($action, $msg, $args);
	}

	/**
	* Get progress update for a given transaction.
	* @param txnId Transaction Id
	* @return mixed
	* array ( "txn_id" => $txn_id,
	* "result" => 0,
	* "processRunning" => bool,
	* "subTxns" => array (
	* array (
	* "subTxnId" =>
	* "parentSubTxnId" =>
	* "state" =>
	* "description" =>
	* )
	* )
	* )
	*/
	public function getProgress($txnId) {
	// given the txn id generated for one of the supported actions, provide
	// the current progress update
	// this could also be a trigger to update the current state if needed
	$response = array ( "result" => 0, "error" => "");
	$txnInfo = $this->dbHandle->getTransactionStatusInfo($this->clusterName,
	$txnId);

	if ($txnInfo === FALSE \|\| $txnInfo["result"] != 0) {
	return $txnInfo;
	}

	$pidInfo = json_decode($txnInfo["pidInfo"], true);
	$procRunning = HMCTxnUtils::checkTxnProcessStatus($pidInfo);

	$response["processRunning"] = $procRunning;

	$subTxnInfo = $this->dbHandle->getAllSubTransactionsInfo($this->clusterName,
	$txnId);
	if ($subTxnInfo === FALSE \|\| $subTxnInfo["result"] != 0) {
	return $subTxnInfo;
	}

	$orderedSubTxns = $this->orderSubTxns($subTxnInfo["subTxns"]);

	$response["txnId"] = $txnId;
	$response["subTxns"] = array();
	foreach($orderedSubTxns as $sTxnId => $sTxn) {
	if (isset($sTxn["opStatus"])) {
	$sTxn["opStatus"] = json_decode($sTxn["opStatus"], true);
	} else {
	$sTxn["opStatus"] = array();
	}
	array_push($response["subTxns"], $sTxn);
	}

	return $response;
	}

	public function orderSubTxns($subTxns) {
	$subTxnCount = count($subTxns);

	$parentIndexedSubTxns = array();
	$allSubTxns = array();

	foreach ($subTxns as $subTxn) {
	$allSubTxns[$subTxn["subTxnId"]] = $subTxn;
	}

	foreach ($subTxns as $subTxn) {
	if (!isset($parentIndexedSubTxns[$subTxn["parentSubTxnId"]])) {
	$parentIndexedSubTxns[$subTxn["parentSubTxnId"]] = array();
	}
	$parentIndexedSubTxns[$subTxn["parentSubTxnId"]][$subTxn["subTxnId"]] = $subTxn;
	}

	$rankedSubTxns = array();
	$currentRank = 0;
	$rankedIndexes = array();

	$this->_orderSubTxns($rankedSubTxns, $rankedIndexes,
	$currentRank, $allSubTxns, $parentIndexedSubTxns, $subTxns);


	assert(count($rankedSubTxns) == $subTxnCount);
	return $rankedSubTxns;
	}

	private function _orderSubTxns(&$rankedSubTxns, &$rankedIndexes,
	&$currentRank, &$allSubTxns, $parentIndexedSubTxns, $subTxnsToOrder) {

	$maxIndex = 0;
	$indexedSubTxns = array();

	foreach ($subTxnsToOrder as $subTxn) {
	if ($subTxn["subTxnId"] > $maxIndex) {
	$maxIndex = $subTxn["subTxnId"];
	}
	$indexedSubTxns[$subTxn["subTxnId"]] = $subTxn;
	}

	for ($i = 0; $i <= $maxIndex; ++$i) {
	if (!isset($indexedSubTxns[$i])) {
	continue;
	}

	$subTxn = $indexedSubTxns[$i];
	$parentSubTxnId = $subTxn["parentSubTxnId"];

	if (isset($parentIndexedSubTxns[$i])
	&& is_array($parentIndexedSubTxns[$i])
	&& count($parentIndexedSubTxns[$i]) > 0) {
	ksort($parentIndexedSubTxns[$i]);
	foreach ($parentIndexedSubTxns[$i] as $index => $pSubTxn) {
	$pSubTxnId = $pSubTxn["subTxnId"];
	$ppSubTxnId = $pSubTxn["parentSubTxnId"];
	if (!isset($rankedIndexes[$pSubTxnId])) {
	$this->_orderSubTxns($rankedSubTxns, $rankedIndexes,
	$currentRank, $allSubTxns, $parentIndexedSubTxns,
	$parentIndexedSubTxns[$ppSubTxnId]);
	}
	if (!isset($rankedIndexes[$pSubTxnId])) {
	$pSubTxn["rank"] = $currentRank;
	$rankedSubTxns[$currentRank] = $pSubTxn;
	$rankedIndexes[$pSubTxn["subTxnId"]] = TRUE;
	++$currentRank;
	}
	}
	}
	if (!isset($rankedIndexes[$i])) {
	$subTxn["rank"] = $currentRank;
	$rankedSubTxns[$currentRank] = $subTxn;
	$rankedIndexes[$i] = TRUE;
	++$currentRank;
	}
	}

	return $rankedSubTxns;
	}


	/**
	* Get logs for a given transaction
	* @param string $txnId Transaction Id
	*/
	public function getLogs($txnId) {
	// get the logs for a given transaction triggered earlier.
	// not sure if we want to support filtering by log level for now

	$response = array ( "result" => 0, "error" => "");
	$txnInfo = $this->dbHandle->getTransactionStatusInfo($this->clusterName,
	$txnId);

	if ($txnInfo === FALSE \|\| $txnInfo["result"] != 0) {
	return $txnInfo;
	}

	$subTxnInfo = $this->dbHandle->getAllSubTransactionsInfo($this->clusterName,
	$txnId);
	if ($subTxnInfo === FALSE \|\| $subTxnInfo["result"] != 0) {
	return $subTxnInfo;
	}

	$puppetInvoker = new PuppetInvoker($this->dbPath);

	$response["txnId"] = $txnId;
	$response["subTxns"] = array();

	foreach ($subTxnInfo["subTxns"] as $subTxnId => $subTxn) {
	$nodes = array();
	$response["subTxns"][$subTxn["subTxnId"]] =
	array( "nodeReport" => array(),
	"nodeLogs" => array());

	if (!isset($subTxn["opStatus"])) {
	continue;
	}

	$opStatus = json_decode($subTxn["opStatus"], true);
	if (!isset($opStatus["nodeReport"])) {
	continue;
	}

	$nodeReport = $opStatus["nodeReport"];

	$response["subTxns"][$subTxn["subTxnId"]]["nodeReport"] = $nodeReport;

	$keys = array ( "PUPPET_KICK_FAILED", "PUPPET_OPERATION_FAILED",
	"PUPPET_OPERATION_SUCCEEDED" );
	foreach ($keys as $key) {
	if (isset($nodeReport[$key])
	&& is_array($nodeReport[$key])) {
	$nodes = array_merge($nodes, $nodeReport[$key]);
	}
	}

	$transaction = new Transaction($txnId, $subTxn["subTxnId"],
	$subTxn["parentSubTxnId"]);

	$puppetLogs = $puppetInvoker->getReports($nodes, $transaction);
	$this->logger->log_debug("Got puppet reports for transaction=" .$transaction->toString()
	. ", nodes=" . print_r($nodes, true)
	. ", logs=" . print_r($puppetLogs, true));

	$response["subTxns"][$subTxn["subTxnId"]]["nodeLogs"] = $puppetLogs;
	}
	return $response;
	}

	private function internalTrigger($action, $msg, $args) {
	$this->logger->log_info("HMC triggering action=" . $action . ", " . $msg);
	$response = array ( "result" => 0, "error" => "");

	$statusInfo = array ("function" => "HMC::$action",
	"action" => $msg);
	$txnId = HMCTxnUtils::createNewTransaction($this->dbHandle,
	$this->clusterName, $statusInfo);
	if ($txnId === FALSE) {
	$error = "Failed to create a new transaction, action=" . $action;
	$this->logger->log_error($error);
	return array ("result" => 1, "error" => $error);
	}
	$response["txnId"] = $txnId;
	$args .= " -x " . $txnId;

	$this->logger->log_debug("Triggering background process"
	. ", clusterName=" . $this->clusterName
	. ", txnId=" . $txnId
	. ", command=" . $this->command
	. ", args=" . $args);
	$backgroundPid = HMCTxnUtils::execBackgroundProcess($this->dbHandle,
	$this->clusterName, $txnId, $this->command, $args, "");

	if ($backgroundPid === FALSE) {
	$error = "Failed to trigger background process, action=" . $action;
	$this->logger->log_error($error);
	$response["result"] = 1;
	$response["error"] = $error;
	}
	return $response;
	}

	public function uninstallHDP($wipeoutData = FALSE) {
	$this->logger->log_info("Triggering uninstall"
	. ", clusterName=" . $this->clusterName
	);
	$action = "uninstallHDP";
	$msg = "Uninstalling cluster, wipeout=" . $wipeoutData;
	$args = " -c " . $this->clusterName
	. " -d " . $this->dbPath;
	if (!$wipeoutData) {
	$args .= " -a uninstallAll ";
	} else {
	$args .= " -a wipeout ";
	}
	return $this->internalTrigger($action, $msg, $args);
	}

	}

	?>