1. Fix LoadTask, ChunkAllocator, TabletMeta, Brpc, the accuracy of memory track.
2. Modified some MemTracker names, deleted some unnecessary trackers, and improved readability.
3. More powerful MemTracker debugging capabilities.
4. Avoid creating TabletColumn temporary objects and improve BE startup time by 8%.
5. Fix some other details.
Currently, there are 2 status code in BE, one is common/Status.h,
and the other is olap/olap_define.h called OLAPStatus.
OLAPStatus is just an enum type, it is very simple and could not save many informations,
I will unify these code to common/Status.
Early Design Documentation: https://shimo.im/docs/DT6JXDRkdTvdyV3G
Implement a new way of memory statistics based on TCMalloc New/Delete Hook,
MemTracker and TLS, and it is expected that all memory new/delete/malloc/free
of the BE process can be counted.
Modify the implementation of MemTracker:
1. Simplify a lot of useless logic;
2. Added MemTrackerTaskPool, as the ancestor of all query and import trackers, This is used to track the local memory usage of all tasks executing;
3. Add cosume/release cache, trigger a cosume/release when the memory accumulation exceeds the parameter mem_tracker_consume_min_size_bytes;
4. Add a new memory leak detection mode (Experimental feature), throw an exception when the remaining statistical value is greater than the specified range when the MemTracker is destructed, and print the accurate statistical value in HTTP, the parameter memory_leak_detection
5. Added Virtual MemTracker, cosume/release will not sync to parent. It will be used when introducing TCMalloc Hook to record memory later, to record the specified memory independently;
6. Modify the GC logic, register the buffer cached in DiskIoMgr as a GC function, and add other GC functions later;
7. Change the global root node from Root MemTracker to Process MemTracker, and remove Process MemTracker in exec_env;
8. Modify the macro that detects whether the memory has reached the upper limit, modify the parameters and default behavior of creating MemTracker, modify the error message format in mem_limit_exceeded, extend and apply transfer_to, remove Metric in MemTracker, etc.;
Modify where MemTracker is used:
1. MemPool adds a constructor to create a temporary tracker to avoid a lot of redundant code;
2. Added trackers for global objects such as ChunkAllocator and StorageEngine;
3. Added more fine-grained trackers such as ExprContext;
4. RuntimeState removes FragmentMemTracker, that is, PlanFragmentExecutor mem_tracker, which was previously used for independent statistical scan process memory, and replaces it with _scanner_mem_tracker in OlapScanNode;
5. MemTracker is no longer recorded in ReservationTracker, and ReservationTracker will be removed later;
1. Consider the responsibility of Reader, Rename Reader to TabletReader, I think the new name TabletReader can represent its function exactly, it is more suitable and meaningful
2. add virtual keyword for the destructor of OlapScanner, because VOlapScanner is derived from it
3. refactor struct ReaderParams and KeysParam as TabletReader's inner struct，guard by TabletReader name scope, it's also more reasonable
4. reduce OlapScanner's member data amount, just use _parent->member_data is simpler
5. bugfix: TupleReader has the same memeber data _collect_iter to its parent class Reader, this usage is dangerous, the writer may make some mistake, so i delete TupleReader::_collect_iter to fix it.
6. call set_tablet_reader() in OlapScanner::prepare() to setup _tablet_reader, VOlapScanner should override set_tablet_reader to new BlockReader instead, use this way to avoid new Reader twice by reset unique_ptr _tablet_reader
7. if the member data is a inseparable part of a class, i suggest using normal variable while not pointer variable, because pointer bring a indirect lay and must handle coping and destructing carefully, it's not necessary
8. some other small changes for readability or design
1. replace all boost::shared_ptr to std::shared_ptr
2. replace all boost::scopted_ptr to std::unique_ptr
3. replace all boost::scoped_array to std::unique<T[]>
4. replace all boost:thread to std::thread
At present, the application of vlog in the code is quite confusing.
It is inherited from impala VLOG_XX format, and there is also VLOG(number) format.
VLOG(number) format does not have a unified specification, so this pr standardizes the use of VLOG
We make all MemTrackers shared, in order to show MemTracker real-time consumptions on the web.
As follows:
1. nearly all MemTracker raw ptr -> shared_ptr
2. Use CreateTracker() to create new MemTracker(in order to add itself to its parent)
3. RowBatch & MemPool still use raw ptrs of MemTracker, it's easy to ensure RowBatch & MemPool destructor exec
before MemTracker's destructor. So we don't change these code.
4. MemTracker can use RuntimeProfile's counter to calc consumption. So RuntimeProfile's counter need to be shared
too. We add a shared counter pool to store the shared counter, don't change other counters of RuntimeProfile.
Note that, this PR doesn't change the MemTracker tree structure. So there still have some orphan trackers, e.g. RowBlockV2's MemTracker. If you find some shared MemTrackers are little memory consumption & too time-consuming, you could make them be the orphan, then it's fine to use the raw ptr.
1. the table include key column of double/float type
2. when run checksum task, will use all of key columns to compare
3. schema.column(idx) of double/float type is NULL
#3735
Currently, we have Field and ColumnSchema to access column data in a
row. These two classes are mostly the same. So we should unify these to
one class. Now, Field has offset information, which is an row attribute,
so we remove offset in Field.
RowCursor now has some logic which belong to Schema, so in this patch I
add Schema attribute to RowCursor to make RowCursor simple. After this
change, only Schema will handle Field/ColumnSchema.
I extract some logic from RowCursor to be/src/olap/row.h, then we can
use same logic to handle different types of row. Each type of row has
same function that to get Cell of this row. A cell represent a column
content with a null indicator.
NOTE: This patch would modify all Backend's data.
And this will cause a very long time to restart be.
So if you want to interferer your product environment,
you should upgrade backend one by one.
1. Refactoring be is to clarify the structure the codes.
2. Use unique id to indicate a rowset.
Nameing rowset with tablet_id and version will lead to
many conflicts among compaction, clone, restore.
3. Extract an rowset interface to encapsulate rowsets
with different format.
