f20eb12457
Thread pool design point:
All tasks submitted directly to the thread pool enter a FIFO queue and are
dispatched to a worker thread when one becomes free. Tasks may also be
submitted via ThreadPoolTokens. The token wait() and shutdown() functions
can then be used to block on logical groups of tasks.
A token operates in one of two ExecutionModes, determined at token
construction time:
1. SERIAL: submitted tasks are run one at a time.
2. CONCURRENT: submitted tasks may be run in parallel.
This isn't unlike submitted without a token, but the logical grouping that tokens
impart can be useful when a pool is shared by many contexts (e.g. to
safely shut down one context, to derive context-specific metrics, etc.).
Tasks submitted without a token or via ExecutionMode::CONCURRENT tokens are
processed in FIFO order. On the other hand, ExecutionMode::SERIAL tokens are
processed in a round-robin fashion, one task at a time. This prevents them
from starving one another. However, tokenless (and CONCURRENT token-based)
tasks can starve SERIAL token-based tasks.
Thread design point:
1. It is a thin wrapper around pthread that can register itself with the singleton ThreadMgr
(a private class implemented in thread.cpp entirely, which tracks all live threads so
that they may be monitored via the debug webpages). This class has a limited subset of
boost::thread's API. Construction is almost the same, but clients must supply a
category and a name for each thread so that they can be identified in the debug web
UI. Otherwise, join() is the only supported method from boost::thread.
2. Each Thread object knows its operating system thread ID (TID), which can be used to
attach debuggers to specific threads, to retrieve resource-usage statistics from the
operating system, and to assign threads to resource control groups.
3. Threads are shared objects, but in a degenerate way. They may only have
up to two referents: the caller that created the thread (parent), and
the thread itself (child). Moreover, the only two methods to mutate state
(join() and the destructor) are constrained: the child may not join() on
itself, and the destructor is only run when there's one referent left.
These constraints allow us to access thread internals without any locks.
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 donating it to Apache Software Foundation, it was renamed Doris.
1. License
2. 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.
3. User cases
Doris not only provides high concurrent low latency point query performance, but also provides high throughput queries of ad-hoc analysis.
Doris not only provides batch data loading, but also provides near real-time mini-batch data loading.
Doris also provides high availability, reliability, fault tolerance, and scalability.
The simplicity (of developing, deploying and using) and meeting many data serving requirements in single system are the main features of Doris (refer to Overview).
4. Compile and install
Currently only supports Docker environment and Linux OS, such as Ubuntu and CentOS.
4.1 Compile in Docker environment (Recommended)
We offer a docker image as a Doris compilation environment. You can compile Doris from source in it and run the output binaries in other Linux environment.
Firstly, you must be install and start docker service.
And then you could build Doris as following steps:
Step1: Pull the docker image with Doris building environment
$ docker pull apachedoris/doris-dev:build-env-1.2
You can check it by listing images, for example:
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
apachedoris/doris-dev build-env-1.2 69cf7fff9d10 2 weeks ago 4.12GB
NOTE: You may have to use different images to compile from source.
image version commit id release version apachedoris/doris-dev:build-env before ff0dd0d 0.8.x, 0.9.x apachedoris/doris-dev:build-env-1.1 ff0dd0d or later 0.10.x or 0.11.x apachedoris/doris-dev:build-env-1.2 1648226 or later 0.12.x or later
Step2: Run the Docker image
You can run the image directly:
$ docker run -it apachedoris/doris-dev:build-env-1.2
Or if you want to compile the source located in your local host, you can map the local directory to the image by running:
$ docker run -it -v /your/local/path/incubator-doris-DORIS-x.x.x-release/:/root/incubator-doris-DORIS-x.x.x-release/ apachedoris/doris-dev:build-env-1.2
Step3: Download Doris source
Now you should attached in docker environment.
You can download Doris source by release package or by git clone in image.
(If you already downloaded the source in your local host and map it to the image in Step2, you can skip this step.)
$ wget https://dist.apache.org/repos/dist/dev/incubator/doris/xxx.tar.gz
or
$ git clone https://github.com/apache/incubator-doris.git
Step4: Build Doris
Enter Doris source path and build Doris.
$ sh build.sh
After successfully building, it will install binary files in the directory output/.
4.2 For Linux OS
Prerequisites
You must be install following softwares:
GCC 5.3.1+, Oracle JDK 1.8+, Python 2.7+, Apache Maven 3.5+, CMake 3.4.3+
After you installed above all, you also must be set them to environment variable PATH and set JAVA_HOME.
If your GCC version is lower than 5.3.1, you can run:
sudo yum install devtoolset-4-toolchain -y
and then, set the path of GCC (e.g /opt/rh/devtoolset-4/root/usr/bin) to the environment variable PATH.
Compile and install
Run the following script, it will compile thirdparty libraries and build whole Doris.
sh build.sh
After successfully building, it will install binary files in the directory output/.
5. License Notice
Some of the third-party dependencies' license are not compatible with Apache 2.0 License. So you may have to disable
some features of Doris to be complied with Apache 2.0 License. Details can be found in thirdparty/LICENSE.txt
6. Reporting Issues
If you find any bugs, please file a GitHub issue.
7. Links
- Doris official site - http://doris.incubator.apache.org
- User Manual (GitHub Wiki) - https://github.com/apache/incubator-doris/wiki
- Developer Mailing list - Subscribe to dev@doris.incubator.apache.org to discuss with us.
- 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