Enforce stricter transaction limits (#9740) (#9775)

* Enforce stricter transaction limits (#9740) * changelog * make CHANGELOG entry more verbose
arangodb · Aug 21, 2019 · bd5df4d · bd5df4d
1 parent 663212b
commit bd5df4d
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Showing 8 changed files with 221 additions and 139 deletions.
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,6 +1,15 @@
 v3.5.1 (XXXX-XX-XX)
 -------------------
 
+* Changes the _idle_ timeout of stream transactions to 10 seconds and the total
+  per DB server size of stream transaction data to 128 MB. The idle timer is
+  restarted after every operation in a stream transaction, so it is not the
+  total timeout for the transaction.
+
+  These limits were documented in the manual for stream transactions since 3.5.0,
+  but are enforced only as of 3.5.1. Enforcing the limits is useful to free up
+  resources from abandoned transactions.
+
 * Consistently honor the return value of all attempts to queue tasks in the
   internal scheduler.
 

diff --git a/arangod/ClusterEngine/ClusterTransactionCollection.cpp b/arangod/ClusterEngine/ClusterTransactionCollection.cpp
@@ -35,8 +35,7 @@ ClusterTransactionCollection::ClusterTransactionCollection(TransactionState* trx
                                                            TRI_voc_cid_t cid,
                                                            AccessMode::Type accessType,
                                                            int nestingLevel)
-    : TransactionCollection(trx, cid, accessType, nestingLevel),
-      _lockType(AccessMode::Type::NONE) {}
+    : TransactionCollection(trx, cid, accessType, nestingLevel) {}
 
 ClusterTransactionCollection::~ClusterTransactionCollection() {}
 

diff --git a/arangod/ClusterEngine/ClusterTransactionCollection.h b/arangod/ClusterEngine/ClusterTransactionCollection.h
@@ -60,9 +60,6 @@ class ClusterTransactionCollection final : public TransactionCollection {
 
   /// @brief request an unlock for a collection
   int doUnlock(AccessMode::Type, int nestingLevel) override;
-
- private:
-  AccessMode::Type _lockType;  // collection lock type, used for exclusive locks
 };
 }  // namespace arangodb
 

diff --git a/arangod/RestHandler/RestTransactionHandler.cpp b/arangod/RestHandler/RestTransactionHandler.cpp
@@ -166,7 +166,7 @@ void RestTransactionHandler::executeBegin() {
 
 
   bool parseSuccess = false;
-  VPackSlice body = parseVPackBody(parseSuccess);
+  VPackSlice slice = parseVPackBody(parseSuccess);
   if (!parseSuccess) {
     // error message generated in parseVPackBody
     return;
@@ -175,7 +175,7 @@ void RestTransactionHandler::executeBegin() {
   transaction::Manager* mgr = transaction::ManagerFeature::manager();
   TRI_ASSERT(mgr != nullptr);
 
-  Result res = mgr->createManagedTrx(_vocbase, tid, body);
+  Result res = mgr->createManagedTrx(_vocbase, tid, slice);
   if (res.fail()) {
     generateError(res);
   } else {