Add conf enable_query_memroy_overcommit
If true, when the process does not exceed the soft mem limit, the query memory will not be limited; when the process memory exceeds the soft mem limit, the query with the largest ratio between the currently used memory and the exec_mem_limit will be canceled.
If false, cancel query when the memory used exceeds exec_mem_limit, same as before.
When the system MemAvailable is less than the warning water mark, or the memory used by the BE process exceeds the mem soft limit, run minor gc and try to release cache.
When the MemAvailable of the system is less than the low water mark, or the memory used by the BE process exceeds the mem limit, run fucc gc, try to release the cache, and start canceling from the query with the largest memory usage until the memory of mem_limit * 20% is released.
boost::stacktrace::stacktrace() has memory leak, so use glog internal func to print stacktrace.
The reason for the memory leak of boost::stacktrace is that a state is saved in the thread local of each thread but not actively released. The test found that each thread leaked about 100M after calling boost::stacktrace.
refer to:
boostorg/stacktrace#118boostorg/stacktrace#111
mem tracker can be logically divided into 4 layers: 1)process 2)type 3)query/load/compation task etc. 4)exec node etc.
type includes
enum Type {
GLOBAL = 0, // Life cycle is the same as the process, e.g. Cache and default Orphan
QUERY = 1, // Count the memory consumption of all Query tasks.
LOAD = 2, // Count the memory consumption of all Load tasks.
COMPACTION = 3, // Count the memory consumption of all Base and Cumulative tasks.
SCHEMA_CHANGE = 4, // Count the memory consumption of all SchemaChange tasks.
CLONE = 5, // Count the memory consumption of all EngineCloneTask. Note: Memory that does not contain make/release snapshots.
BATCHLOAD = 6, // Count the memory consumption of all EngineBatchLoadTask.
CONSISTENCY = 7 // Count the memory consumption of all EngineChecksumTask.
}
Object pointers are no longer saved between each layer, and the values of process and each type are periodically aggregated.
other fix:
In [fix](memtracker) Fix transmit_tracker null pointer because phamp is not thread safe #13528, I tried to separate the memory that was manually abandoned in the query from the orphan mem tracker. But in the actual test, the accuracy of this part of the memory cannot be guaranteed, so put it back to the orphan mem tracker again.
# Proposed changes
This PR fixed lots of issues when building from source on macOS with Apple M1 chip.
## ATTENTION
The job for supporting macOS with Apple M1 chip is too big and there are lots of unresolved issues during runtime:
1. Some errors with memory tracker occur when BE (RELEASE) starts.
2. Some UT cases fail.
...
Temporarily, the following changes are made on macOS to start BE successfully.
1. Disable memory tracker.
2. Use tcmalloc instead of jemalloc.
This PR kicks off the job. Guys who are interested in this job can continue to fix these runtime issues.
## Use case
```shell
./build.sh -j 8 --be --clean
cd output/be/bin
ulimit -n 60000
./start_be.sh --daemon
```
## Something else
It takes around _**10+**_ minutes to build BE (with prebuilt third-parties) on macOS with M1 chip. We will improve the development experience on macOS greatly when we finish the adaptation job.
Previously, bthread_getspecific was called every time bthread local was used. In the test at #10823, it was found that frequent calls to bthread_getspecific had performance problems.
So a cache is implemented on pthread local based on the btls key, but the btls key cannot correctly sense bthread switching.
So, based on bthread_self to get the bthread id to implement the cache.
disable page cache by default
disable chunk allocator by default
not use chunk allocator for vectorized allocator by default
add a new config memory_linear_growth_threshold = 128Mb, not allocate memory by RoundUpToPowerOf2 if the allocated size is larger than this threshold. This config is added to MemPool, ChunkAllocator, PodArray, Arena.
This config is never used online and there exist bugs if enable this config. So that I remove this config and related tests.
Co-authored-by: yiguolei <yiguolei@gmail.com>
When the physical memory of the process reaches 90% of the mem limit, trigger the load channel mgr to brush down
The default value of be.conf mem_limit is changed from 90% to 80%, and stability is the priority.
Fix deadlock in arena_locks in BufferPool::BufferAllocator::ScavengeBuffers and _lock in DebugString
In order to avoid different mem tracker consumption values of multiple queries/loads, and the difference between the virtual memory of alloc and the physical memory actually increased by the process.
The memory alloc in PODArray and mempool will not be recorded in the query/load mem tracker immediately, but will be gradually recorded in the mem tracker during the memory usage.
But mem pool allocates memory from chunk allocator. If this chunk is used after the second time, it may have used physical memory. The above mechanism will cause the load channel memory statistics to be less than the actual value.
The mem hook record tracker cannot guarantee that the final consumption is 0, nor can it guarantee that the memory alloc and free are recorded in a one-to-one correspondence.
In the life cycle of a memtable from insert to flush, the memory free of hook is more than that of alloc, resulting in tracker consumption less than 0.
In order to avoid the cumulative error of the upper load channel tracker, the memtable tracker consumption is reset to zero on destructor.
The mem hook consumes the orphan tracker by default. If the thread does not attach other trackers, by default all consumption will be passed to the process tracker through the orphan tracker.
In real time, consumption of all other trackers + orphan tracker consumption = process tracker consumption.
Ideally, all threads are expected to attach to the specified tracker, so that "all memory has its own ownership", and the consumption of the orphan mem tracker is close to 0, but greater than 0.
After the consume mem tracker exceeds the mem limit in the mem hook, the boost stacktrace will be printed. A query/load will only be printed once, and the process tracker will only be printed once per second.
After the process memory reaches the upper limit, the boost stacktrace will be printed every second. The observed phenomena are as follows:
After query/load is canceled, the memory increases instantly;
tcmalloc profile total physical memory is less than perf process memory;
The process mem tracker is smaller than the perf process memory;
tcmalloc/jemalloc allocator cache does not participate in the mem check as part of the process physical memory.
because new/malloc will trigger mem hook when using tcmalloc/jemalloc allocator cache, but it may not actually alloc physical memory, which is not expected in mem hook fail.
in addition:
The value of tcmalloc/jemalloc allocator cache is used as a mem tracker, the parent is the process mem tracker, which is updated every 1s.
Modify the process default mem_limit to 90%. expect mem tracker to effectively limit the memory usage of the process.
In some cases, when the user executes the query for the first time, an error of the exceeded mem limit will be reported, and the query will be successful only after the second execution.
This is because when the query is executed for the first time, the memory consumed by adding the page cache and other caches is recorded in the query mem tracker, hoping to unify the behavior of multiple queries.
A temporary solution, remove the hook of scanner thread, test clickbench q13
Before removing the scanner thread hook
Enable page cache: 3G for the first query, 3G for the tracker; 900M for the second query, 900M for the tracker.
Turn off page cache: 1.9G for the first query, 1.9G for the tracker; 900M for the second query, 900M for the tracker
After removing the scanner thread hook and fix MemTrackerLimiter::cache_consume_local bug
Enable page cache: 2916M for the first query, 1147M for the tracker; 979M for the second query, 1144M for the tracker
Turn off page cache: 1809M for the first query, 1147M for the tracker; 975M for the second query, 1145M for the tracker
TODO, a better solution is to track storage-related memory separately, in the scanner thread. Otherwise, it is impossible to know where the process memory grows when querying.
Refactor TaggableLogger
Refactor status handling in agent task:
Unify log format in TaskWorkerPool
Pass Status to the top caller, and replace some OLAPInternalError with more detailed error message Status
Premature return with the opposite condition to reduce indention
Return the real process memory information when the process exceeds mem limit
Optimize the memory exceed limit log printing logic
process tracker does not participate in process memory limit.