* [improvement](scanner_schedule) reduce memory consumption of scanner
1. limit scanner by memory consumptin rather than blocks.
2. scheduler run correcty instread of at lest 1.
Optimization "select count(*) from table" stmtement , push down "count" type to BE.
support file type : parquet ，orc in hive .
1. 4kfiles , 60kwline num
before: 1 min 37.70 sec
after: 50.18 sec
2. 50files , 60kwline num
before: 1.12 sec
after: 0.82 sec
After the last time to call scan_task.scan_func()，the should be ended, this means PipelineFragmentContext could be released.
Then after PipelineFragmentContext is released, visiting its field such as query_ctx or _state may cause core dump.
But it can only explain core 2
void ScannerScheduler::_task_group_scanner_scan(ScannerScheduler* scheduler,
taskgroup::ScanTaskTaskGroupQueue* scan_queue) {
while (!_is_closed) {
taskgroup::ScanTask scan_task;
auto success = scan_queue->take(&scan_task);
if (success) {
int64_t time_spent = 0;
{
SCOPED_RAW_TIMER(&time_spent);
scan_task.scan_func();
}
scan_queue->update_statistics(scan_task, time_spent);
}
}
}
1. Fix create catalog with resource replay bug.
If user create catalog using `create catalog hive with resource xxx`, when replaying edit log,
there is a bug that resource may be dropped, causing NPE and FE will fail to start.
In this PR, I add a new FE config `disallow_create_catalog_with_resource`, default is true.
So that `with resource` will not be allowed, and it will be deprecated later.
And also fix the replay bug to avoid NPE.
2. Fix issue when creating 2 hive catalogs to connect with and without kerberos authentication.
When user create 2 hive catalogs, one use simple auth, the other use kerberos auth.
The query may fail with error like: `Server asks us to fall back to SIMPLE auth, but this client is configured to only allow secure connections.`
So I add a default property for hive catalog: `"ipc.client.fallback-to-simple-auth-allowed" = "true"`.
Which means this property will be added automatically when user creating hive catalog, to avoid such problem.
3. Fix calling `hdfsExists()` issue
When calling `hdfsExists()` with non-zero return code, should check if it encounters error or is file not found.
3. Some code refactor
Avoid import `org.apache.parquet.Strings`
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.
1. introduce a new type `VARIANT` to encapsulate dynamic generated columns for hidding the detail of types and names of newly generated columns
2. introduce a new expression `SchemaChangeExpr` for doing schema change for extensibility
There are 2 kinds for scanner thread pool, local and remote.
Local is for local file read, specially for olap scanner.
Remote is for other external data source, such as file scanner, jdbc scanner.
This PR mainly changes:
For olap scanner, use cold or hot rowset to decide whether to use local or remote pool.
For other scanner, user remote pool by default.
Add a new BE config doris_max_remote_scanner_thread_pool_thread_num, default is 512,
indicate the max thread number of the remote scanner thread pool
This will alleviate the problem of interaction between olap queries with load job and external queries.
* [improvement](block exception safe) make block queue exception safe
This is part of exception safe: #16366.
---------
Co-authored-by: yiguolei <yiguolei@gmail.com>
Issue Number: close#16351
Dynamic schema table is a special type of table, it's schema change with loading procedure.Now we implemented this feature mainly for semi-structure data such as JSON, since JSON is schema self-described we could extract schema info from the original documents and inference the final type infomation.This speical table could reduce manual schema change operation and easily import semi-structure data and extends it's schema automatically.
make rows_read correct so that the scheduler could using this correctly.
use single scanner if has limit clause. Move it from fragment context to scannode.
---------
Co-authored-by: yiguolei <yiguolei@gmail.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
The origin scan pools are in exec_env.
But after enable new_load_scan_node by default, the scan pool in exec_env is no longer used.
All scan task will be submitted to the scan pool in scanner_scheduler.
BTW, reorganize the scan pool into 3 kinds:
local scan pool
For olap scan node
remote scan pool
For file scan node
limited scan pool
For query which set cpu resource limit or with small limit clause
TODO:
Use bthread to unify all IO task.
Some trivial issues:
fix bug that the memtable flush size printed in log is not right
Add RuntimeProfile param in VScanner
FE file path cache for external table may out of date. In this case, BE may fail to find the not exist file from FE cache.
This pr is to handle this case: instead of throw an error message to the user, we return empty result set to the user.
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.
When select large number of data from a table, the profile will show that:
- ScannerCtxSchedCount: 2.82664M(2826640)
But there is only 8 times of ScannerSchedCount, most of them are busy running.
After improvement, the ScannerCtxSchedCount will be reduced to only 10.
