fix a race condition

This commit is contained in:
Alexander Tokmakov 2022-04-07 18:17:43 +02:00
parent 7f54e7b422
commit 2e2e2b9190
3 changed files with 23 additions and 9 deletions

View File

@ -248,6 +248,24 @@ bool MergeTreeTransaction::rollback() noexcept
for (const auto & table_and_mutation : mutations_to_kill)
table_and_mutation.first->killMutation(table_and_mutation.second);
/// Discard changes in active parts set
/// Remove parts that were created, restore parts that were removed (except parts that were created by this transaction too)
for (const auto & part : parts_to_remove)
{
if (part->version.isRemovalTIDLocked())
{
/// Don't need to remove part from working set if it was created and removed by this transaction
assert(part->version.removal_tid_lock == tid.getHash());
continue;
}
/// FIXME do not lock removal_tid when rolling back part creation, it's ugly
const_cast<MergeTreeData &>(part->storage).removePartsFromWorkingSet(NO_TRANSACTION_RAW, {part}, true);
}
for (const auto & part : parts_to_activate)
if (part->version.getCreationTID() != tid)
const_cast<MergeTreeData &>(part->storage).restoreAndActivatePart(part);
/// Kind of optimization: cleanup thread can remove these parts immediately
for (const auto & part : parts_to_remove)
{
@ -264,14 +282,6 @@ bool MergeTreeTransaction::rollback() noexcept
part->version.unlockRemovalTID(tid, TransactionInfoContext{part->storage.getStorageID(), part->name});
}
/// Discard changes in active parts set
/// Remove parts that were created, restore parts that were removed (except parts that were created by this transaction too)
for (const auto & part : parts_to_remove)
const_cast<MergeTreeData &>(part->storage).removePartsFromWorkingSet(NO_TRANSACTION_RAW, {part}, true);
for (const auto & part : parts_to_activate)
if (part->version.getCreationTID() != tid)
const_cast<MergeTreeData &>(part->storage).restoreAndActivatePart(part);
assert([&]()
{

View File

@ -16,6 +16,9 @@ class IMergeTreeDataPart;
using DataPartPtr = std::shared_ptr<const IMergeTreeDataPart>;
using DataPartsVector = std::vector<DataPartPtr>;
/// This object is responsible for tracking all changes that some transaction is making in MergeTree tables.
/// It collects all changes that queries of current transaction made in data part sets of all MergeTree tables
/// to ether make them visible when transaction commits or undo when transaction rolls back.
class MergeTreeTransaction : public std::enable_shared_from_this<MergeTreeTransaction>, private boost::noncopyable
{
friend class TransactionLog;

View File

@ -6,7 +6,7 @@
3 all_1_1_0 0
3 all_3_3_0 1
4 all_1_1_0 1 (0,0,'00000000-0000-0000-0000-000000000000') 0
4 all_2_2_0 18446744073709551615 (0,0,'00000000-0000-0000-0000-000000000000') 0
4 all_2_2_0 18446744073709551615 (1,1,'00000000-0000-0000-0000-000000000000') 0
4 all_3_3_0 0 (0,0,'00000000-0000-0000-0000-000000000000') 0
5 1
6 all_1_1_0 0
@ -19,6 +19,7 @@
1 1 AddPart 1 1 1 1 all_1_1_0
2 1 Begin 1 1 1 1
2 1 AddPart 1 1 1 1 all_2_2_0
1 1 LockPart 1 1 1 1 all_2_2_0
2 1 Rollback 1 1 1 1
3 1 Begin 1 1 1 1
3 1 AddPart 1 1 1 1 all_3_3_0