Start building proper cleanup if instanciation throws in between.

arangod/Aql/ExecutionEngine.cpp

@@ -419,7 +419,7 @@ struct CoordinatorInstanciator : public WalkerWorker<ExecutionNode> {
      // this is relevant to decide whether or not the engine there is a main
      // query or a dependent one.
   std::unordered_map<std::string, std::string> queryIds;
-     // map from itoa(ID of RemoteNode in original plan) + shardId
+     // map from itoa(ID of RemoteNode in original plan) + "_" + shardId
      //     to   queryId on DBserver
      // this is built up when we instanciate the various engines on the
      // DBservers and used when we instanciate the one using them on the
@@ -588,7 +588,7 @@ struct CoordinatorInstanciator : public WalkerWorker<ExecutionNode> {
           // std::cout << "DB SERVER ANSWERED WITHOUT ERROR: " << res->answer->body() << ", REMOTENODEID: " << info.idOfRemoteNode << " SHARDID:"  << res->shardID << ", QUERYID: " << queryId << "\n";
           std::string theID
             = triagens::basics::StringUtils::itoa(info.idOfRemoteNode)
-            + res->shardID;
+            + "_" + res->shardID;
           queryIds.emplace(std::make_pair(theID, queryId));
         }
         else {
@@ -706,7 +706,7 @@ struct CoordinatorInstanciator : public WalkerWorker<ExecutionNode> {
         for (auto const& shardId : shardIds) {
           std::string theId 
             = triagens::basics::StringUtils::itoa(remoteNode->id())
-            + shardId;
+            + "_" + shardId;
           auto it = queryIds.find(theId);
           if (it == queryIds.end()) {
             THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, "could not find query id in list");
@@ -764,6 +764,8 @@ struct CoordinatorInstanciator : public WalkerWorker<ExecutionNode> {
           id = TRI_NewTickServer();
 
           queryRegistry->insert(id, engine->getQuery(), 3600.0);
+          // TODO: put an entry into queryIds such that we can delete
+          // this one here if things go wrong during instanciation.
         }
       }
       else {
@@ -836,16 +838,6 @@ struct CoordinatorInstanciator : public WalkerWorker<ExecutionNode> {
 // --SECTION--                                                  public functions
 // -----------------------------------------------------------------------------
 
-////////////////////////////////////////////////////////////////////////////////
-/// @brief add a block to the engine
-////////////////////////////////////////////////////////////////////////////////
-
-void ExecutionEngine::addBlock (ExecutionBlock* block) {
-  TRI_ASSERT(block != nullptr);
-
-  _blocks.push_back(block);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief create an execution engine from a plan
 ////////////////////////////////////////////////////////////////////////////////
@@ -884,9 +876,36 @@ ExecutionEngine* ExecutionEngine::instanciateFromPlan (QueryRegistry* queryRegis
       }
 #endif
 
+      try {
         engine = inst.get()->buildEngines(); 
         root = engine->root();
       }
+      catch (...) {
+        // We need to destroy all queries that we have built and stuffed
+        // into the QueryRegistry as well as those that we have pushed to
+        // the DBservers via HTTP:
+        // TODOTODOTODO
+#if 0
+        for (auto& q : queryIds) {
+          std::string theId = q.first;
+          std::string queryId = q.second;
+          auto pos = theId.find('_');
+          TRI_ASSERT(pos != std::string::npos);
+          size_t engineId = triagens::basics::uint64(theId.substr(0,pos));
+          std::string shardId = theId.substr(pos+1);
+          if (engines[engineId].location == COORDINATOR) {
+            // Remove query from registry:
+
+          } 
+          else {
+            // Remove query from DBserver:
+
+          }
+        }
+#endif
+        throw;
+      }
+    }
     else {
       // instanciate the engine on a local server
       engine = new ExecutionEngine(query);
@@ -908,6 +927,16 @@ ExecutionEngine* ExecutionEngine::instanciateFromPlan (QueryRegistry* queryRegis
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief add a block to the engine
+////////////////////////////////////////////////////////////////////////////////
+
+void ExecutionEngine::addBlock (ExecutionBlock* block) {
+  TRI_ASSERT(block != nullptr);
+
+  _blocks.push_back(block);
+}
+
 
 // -----------------------------------------------------------------------------
 // --SECTION--                                                       END-OF-FILE