Currently, compaction is executed separately for each backend, and the reconstruction of the index during compaction leads to high CPU usage. To address this, we are introducing single replica compaction, where a specific primary replica is selected to perform compaction, and the remaining replicas fetch the compaction results from the primary replica.
The Backend (BE) requests replica information for all peers corresponding to a tablet from the Frontend (FE). This information includes the host where the replica is located and the replica_id. By calculating hash(replica_id), the replica with the smallest hash value is responsible for executing compaction, while the remaining replicas are responsible for fetching the compaction results from this replica.
The compaction task producer thread, before submitting a compaction task, checks whether the local replica should fetch from its peer. If it should, the task is then submitted to the single replica compaction thread pool.
When performing single replica compaction, the process begins by requesting rowset versions from the target replica. These rowset_versions are then compared with the local rowset versions. The first version that can be fetched is selected.
Currently, there are some useless includes in the codebase. We can use a tool named include-what-you-use to optimize these includes. By using a strict include-what-you-use policy, we can get lots of benefits from it.
Follow #17586.
This PR mainly changes:
Remove env/
Remove FileUtils/FilesystemUtils
Some methods are moved to LocalFileSystem
Remove olap/file_cache
Add s3 client cache for s3 file system
In my test, the time of open s3 file can be reduced significantly
Fix cold/hot separation bug for s3 fs.
This is the last PR of #17764.
After this, all IO operation should be in io/fs.
Except for tests in #17586, I also tested some case related to fs io:
clone
concurrency query on local/s3/hdfs
load error log create and clean
disk metrics
Support IPV6 in Apache Doris, the main changes are:
1. enable binding to IPV6 address if network priority in config file contains an IPV6 CIDR string
2. BRPC and HTTP support binding to IPV6 address
3. BRPC and HTTP support visiting IPV6 Services
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.
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
In engine_clone_task.cpp, it use tablet->tablet_schema() to create rowset, but in the method, it need a lock that already locked in engine_clone_task.cpp:514. It use cloned_tablet_meta->tablet_schema() originally, but modified in #11131. It need to revert to use cloned_tablet_meta->tablet_schema().
This PR supports rowset level data upload on the BE side, so that there can be both cold data and hot data in a tablet,
and there is no necessary to prohibit loading new data to cooled tablets.
Each rowset is bound to a `FileSystem`, so that the storage layer can read and write rowsets without
perceiving the underlying filesystem.
The abstracted `RemoteFileSystem` can try local caching strategies with different granularity,
instead of caching segment files as before.
To avoid conflicts with the code in be/src/io, we temporarily put the file system related code in the be/src/io/fs directory.
In the future, `FileReader`s and `FileWriter`s should be unified.
1. Provide a FE conf to test the reliability in single replica case when tablet scheduling are frequent.
2. According to #6063, almost apply this fix on current code.
1. Fix the memory leak. When the load task is canceled, the `IndexChannel` and `NodeChannel` mem trackers cannot be destructed in time.
2. Fix Load task being frequently canceled by oom and inaccurate `LoadChannel` mem tracker limit, and rewrite the variable name of `mem limit` in `LoadChannel`.
3. Fix core dump, when logout task mem tracker, phmap erase fails, resulting in repeated logout of the same tracker.
4. Fix the deadlock, when add_child_tracker mem limit exceeds, calling log_usage causes `_child_trackers_lock` deadlock.
5. Fix frequent log printing when thread mem tracker limit exceeds, which will affect readability and performance.
6. Optimize some details of mem tracker display.
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.
There are 3 error code types in BE: OLAPStatus AgentStatus Status.
It is very confused and sometimes conflict during write code.
I will try to unify them to Status.
1. Fix the problem of BE crash caused by destruct sequence. (close#8058)
2. Add a new BE config `compaction_task_num_per_fast_disk`
This config specify the max concurrent compaction task num on fast disk(typically .SSD).
So that for high speed disk, we can execute more compaction task at same time,
to compact the data as soon as possible
3. Avoid frequent selection of unqualified tablet to perform compaction.
4. Modify some log level to reduce the log size of BE.
5. Modify some clone logic to handle error correctly.
For the first, we need to make a parameter to discribe the data is local or remote.
At then, we need to support some basic function to support the operation for remote storage.
