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Posted to issues@impala.apache.org by "Michael Ho (JIRA)" <ji...@apache.org> on 2018/01/12 06:48:00 UTC
[jira] [Resolved] (IMPALA-6359) Blocking in Service threads due to
tcmalloc contention due to memory allocations for RowBatch::Deserialize
[ https://issues.apache.org/jira/browse/IMPALA-6359?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Michael Ho resolved IMPALA-6359.
--------------------------------
Resolution: Duplicate
Fix Version/s: Not Applicable
The mitigation is being tracked in IMPALA-5518.
> Blocking in Service threads due to tcmalloc contention due to memory allocations for RowBatch::Deserialize
> ----------------------------------------------------------------------------------------------------------
>
> Key: IMPALA-6359
> URL: https://issues.apache.org/jira/browse/IMPALA-6359
> Project: IMPALA
> Issue Type: Sub-task
> Components: Distributed Exec
> Reporter: Mostafa Mokhtar
> Assignee: Michael Ho
> Priority: Critical
> Fix For: Not Applicable
>
>
> This is a regression compared to thrift with KRPC is enabled.
> Results are based on running 48 concurrent TPCDS queries on a 40 node cluster, regression is in the order of 2-4x (Will update the JIRA with a more accurate number soon).
> Service threads stall on memory allocation in the stack below, looking at the Service threads memory allocation/deallocation I believe they won't benefit much from the per thread cache as there is more allocations than deallocations on this threads as a result they go to the CentralFreeList for most allocations.
> {code}
> #0 0x00000000020931e7 in base::internal::SpinLockDelay(int volatile*, int, int) ()
> #1 0x00000000020dde29 in SpinLock::SlowLock() ()
> #2 0x0000000002121668 in tcmalloc::CentralFreeList::Populate() ()
> #3 0x0000000002121768 in tcmalloc::CentralFreeList::FetchFromOneSpansSafe(int, void**, void**) ()
> #4 0x00000000021217f4 in tcmalloc::CentralFreeList::RemoveRange(void**, void**, int) ()
> #5 0x000000000212ef53 in tcmalloc::ThreadCache::FetchFromCentralCache(unsigned long, unsigned long) ()
> #6 0x00000000021d37fb in tc_malloc ()
> #7 0x0000000000b27c3a in impala::MemPool::FindChunk(long, bool) ()
> #8 0x0000000000b354e6 in impala::MemPool::Allocate(long) ()
> #9 0x0000000000b34409 in impala::RowBatch::Deserialize(kudu::Slice const&, kudu::Slice const&, long, bool) ()
> #10 0x0000000000b347fb in impala::RowBatch::RowBatch(impala::RowDescriptor const*, impala::RowBatchHeaderPB const&, kudu::Slice const&, kudu::Slice const&, impala::MemTracker*) ()
> #11 0x0000000000b15d68 in impala::KrpcDataStreamRecvr::SenderQueue::AddBatchWork(long, impala::RowBatchHeaderPB const&, kudu::Slice const&, kudu::Slice const&, boost::unique_lock<impala::SpinLock>*) ()
> #12 0x0000000000b18715 in impala::KrpcDataStreamRecvr::SenderQueue::AddBatch(impala::TransmitDataRequestPB const*, kudu::rpc::RpcContext*) ()
> #13 0x0000000000b0e750 in impala::KrpcDataStreamMgr::AddData(impala::TransmitDataRequestPB const*, kudu::rpc::RpcContext*) ()
> #14 0x0000000001183305 in kudu::rpc::GeneratedServiceIf::Handle(kudu::rpc::InboundCall*) ()
> #15 0x00000000011bad7d in impala::ImpalaServicePool::RunThread() ()
> #16 0x0000000000d18a73 in impala::Thread::SuperviseThread(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::function<void ()()>, impala::Promise<long>*) ()
> {code}
> I added logging to track allocations that take a long time and found that in the extreme case some allocations take up to 10 seconds when allocating 16KB of memory.
> {code}
> MonotonicStopWatch timer;
> timer.Start();
> SCOPED_TIMER(recvr_->deserialize_row_batch_timer_);
> // At this point, the row batch will be inserted into batch_queue_. Close() will
> // handle deleting any unconsumed batches from batch_queue_. Close() cannot proceed
> // until there are no pending insertion to batch_queue_.
> batch.reset(new RowBatch(recvr_->row_desc(), header, tuple_offsets, tuple_data,
> recvr_->mem_tracker()));
> timer.Stop();
> if (timer.ElapsedTime() > 1000000) {
> LOG(INFO) << "TTT RowBatch allocation size:" << header.uncompressed_size() << " allocation time " << timer.ElapsedTime();
> }
> {code}
> Call stacks from other threads that release RowBatch memory which also are affected by the tcmalloc contention
> {code}
> #0 0x000000000212c1f4 in tcmalloc::PageHeap::MayMergeSpans(tcmalloc::Span*, tcmalloc::Span*) ()
> #1 0x000000000212c54d in tcmalloc::PageHeap::MergeIntoFreeList(tcmalloc::Span*) ()
> #2 0x000000000212c874 in tcmalloc::PageHeap::Delete(tcmalloc::Span*) ()
> #3 0x0000000002121090 in tcmalloc::CentralFreeList::ReleaseToSpans(void*) ()
> #4 0x000000000212111b in tcmalloc::CentralFreeList::ReleaseListToSpans(void*) ()
> #5 0x000000000212138c in tcmalloc::CentralFreeList::InsertRange(void*, void*, int) ()
> #6 0x000000000212f0f4 in tcmalloc::ThreadCache::ReleaseToCentralCache(tcmalloc::ThreadCache::FreeList*, unsigned long, int) ()
> #7 0x000000000212f1bc in tcmalloc::ThreadCache::ListTooLong(tcmalloc::ThreadCache::FreeList*, unsigned long) ()
> #8 0x00000000021d3d10 in tc_free ()
> #9 0x0000000000b26af8 in impala::MemPool::FreeAll() ()
> #10 0x0000000000b339b1 in impala::RowBatch::Reset() ()
> #11 0x0000000000fea7b1 in impala::PartitionedAggregationNode::Open(impala::RuntimeState*) ()
> #12 0x0000000000b77dfd in impala::FragmentInstanceState::Open() ()
> #13 0x0000000000b7943b in impala::FragmentInstanceState::Exec() ()
> #14 0x0000000000b68a0a in impala::QueryState::ExecFInstance(impala::FragmentInstanceState*) ()
> {code}
> {code}
> Thread 682 (Thread 0x7f61ebec4700 (LWP 28762)):
> #0 0x00000000020931e7 in base::internal::SpinLockDelay(int volatile*, int, int) ()
> #1 0x00000000020dde29 in SpinLock::SlowLock() ()
> #2 0x000000000212140f in tcmalloc::CentralFreeList::InsertRange(void*, void*, int) ()
> #3 0x000000000212f0f4 in tcmalloc::ThreadCache::ReleaseToCentralCache(tcmalloc::ThreadCache::FreeList*, unsigned long, int) ()
> #4 0x000000000212f1bc in tcmalloc::ThreadCache::ListTooLong(tcmalloc::ThreadCache::FreeList*, unsigned long) ()
> #5 0x00000000021d3d10 in tc_free ()
> #6 0x0000000000b338b1 in impala::RowBatch::~RowBatch() ()
> #7 0x0000000000d8d1e3 in impala::HdfsScanNode::GetNextInternal(impala::RuntimeState*, impala::RowBatch*, bool*) ()
> #8 0x0000000000d8ebf2 in impala::HdfsScanNode::GetNext(impala::RuntimeState*, impala::RowBatch*, bool*) ()
> #9 0x0000000000fee76e in impala::PartitionedHashJoinNode::NextProbeRowBatch(impala::RuntimeState*, impala::RowBatch*) ()
> #10 0x0000000000ff43b1 in impala::PartitionedHashJoinNode::GetNext(impala::RuntimeState*, impala::RowBatch*, bool*) ()
> #11 0x0000000000fee76e in impala::PartitionedHashJoinNode::NextProbeRowBatch(impala::RuntimeState*, impala::RowBatch*) ()
> #12 0x0000000000ff43b1 in impala::PartitionedHashJoinNode::GetNext(impala::RuntimeState*, impala::RowBatch*, bool*) ()
> #13 0x0000000000fee76e in impala::PartitionedHashJoinNode::NextProbeRowBatch(impala::RuntimeState*, impala::RowBatch*) ()
> #14 0x0000000000ff43b1 in impala::PartitionedHashJoinNode::GetNext(impala::RuntimeState*, impala::RowBatch*, bool*) ()
> #15 0x0000000000fea54d in impala::PartitionedAggregationNode::Open(impala::RuntimeState*) ()
> #16 0x0000000000b77dfd in impala::FragmentInstanceState::Open() ()
> #17 0x0000000000b7943b in impala::FragmentInstanceState::Exec() ()
> #18 0x0000000000b68a0a in impala::QueryState::ExecFInstance(impala::FragmentInstanceState*) ()
> #19 0x0000000000d18a73 in impala::Thread::SuperviseThread(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::function<void ()()>, impala::Promise<long>*) ()
> #20 0x0000000000d19204 in boost::detail::thread_data<boost::_bi::bind_t<void, void (*)(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::function<void ()()>, impala::Promise<long>*), boost::_bi::list4<boost::_bi::value<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::_bi::value<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::_bi::value<boost::function<void ()()> >, boost::_bi::value<impala::Promise<long>*> > > >::run() ()
> #21 0x000000000129bf5a in thread_proxy ()
> #22 0x000000326c607aa1 in start_thread () from /lib64/libpthread.so.0
> #23 0x000000326c2e893d in clone () from /lib64/libc.so.6
> {code}
> This regression was observed with the tcmalloc options below
> {code}
> TCMALLOC_MAX_TOTAL_THREAD_CACHE_BYTES=2147483648
> TCMALLOC_TRANSFER_NUM_OBJ=40
> {code}
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