5f8d91257b
If an load task has a relatively short timeout, then we need to ensure that
each RPC of this task does not get blocked for a long time.
And an RPC is usually blocked for two reasons.
1. handling "memory exceeds limit" in the RPC
If the system finds that the memory occupied by the load exceeds the threshold,
it will select the load channel that occupies the most memory and flush the memtable in it.
this operation is done in the RPC, which may be more time consuming.
2. close the load channel
When the load channel receives the last batch, it will end the task.
It will wait for all memtables flushes to finish synchronously. This process is also time consuming.
Therefore, this PR solves this problem by.
1. Use timeout to determine whether it is a high-priority load task
If the timeout of an load task is relatively short, then we mark it as a high-priority task.
2. not processing "memory exceeds limit" for high priority tasks
3. use a separate flush thread to flush memtable for high priority tasks.
Apache Doris (incubating)
Doris is an MPP-based interactive SQL data warehousing for reporting and analysis. Its original name was Palo, developed in Baidu. After donated to Apache Software Foundation, it was renamed Doris.
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Doris provides high concurrent low latency point query performance, as well as high throughput queries of ad-hoc analysis.
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Doris provides batch data loading and real-time mini-batch data loading.
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Doris provides high availability, reliability, fault tolerance, and scalability.
The main advantages of Doris are the simplicity (of developing, deploying and using) and meeting many data serving requirements in a single system. For details, refer to Overview.
Official website: https://doris.apache.org/
License
Note
Some licenses of the third-party dependencies are not compatible with Apache 2.0 License. So you need to disable some Doris features to be complied with Apache 2.0 License. For details, refer to thethirdparty/LICENSE.txt
Technology
Doris mainly integrates the technology of Google Mesa and Apache Impala, and it is based on a column-oriented storage engine and can communicate by MySQL client.
Compile and install
See Compilation for details.
Report issues or submit pull request
If you find any bugs, feel free to file a GitHub issue or fix it by submitting a pull request.
Contact Us
Contact us through the following mailing list.
| Name | Scope | |||
|---|---|---|---|---|
| dev@doris.apache.org | Development-related discussions | Subscribe | Unsubscribe | Archives |
Links
- Doris official site - http://doris.incubator.apache.org
- User Manual (GitHub Wiki) - https://github.com/apache/incubator-doris/wiki
- Developer Mailing list - dev@doris.apache.org. Mail to dev-subscribe@doris.apache.org, follow the reply to subscribe the mail list.
- Gitter channel - https://gitter.im/apache-doris/Lobby - Online chat room with Doris developers.
- Overview - https://github.com/apache/incubator-doris/wiki/Doris-Overview
- Compile and install - https://github.com/apache/incubator-doris/wiki/Doris-Install
- Getting start - https://github.com/apache/incubator-doris/wiki/Getting-start
- Deploy and Upgrade - https://github.com/apache/incubator-doris/wiki/Doris-Deploy-%26-Upgrade
- User Manual - https://github.com/apache/incubator-doris/wiki/Doris-Create%2C-Load-and-Delete
- FAQs - https://github.com/apache/incubator-doris/wiki/Doris-FAQ