IoTDB Working Process

Main link

IoTDB official website：https://iotdb.apache.org/

Code library：https://github.com/apache/iotdb/tree/master

Get started quickly：https://iotdb.apache.org/UserGuide/latest/QuickStart/QuickStart.html

Subscribe to mailing list

The mailing list is where the Apache project conducts technical discussions and communication with users. Follow the mailing list to receive mail.

Mailing list address：dev@iotdb.apache.org

Follow method: Send an email to dev-subscribe@iotdb.apache.org with the email you want to receive the email, the subject content is not limited, after receiving the reply, send a confirmation email to the confirmation address again (the confirmation address is longer, it is recommended gmail mailbox).

Other mailing list:

  • notifications@iotdb.apache.org (for JIRA information notification.)
    • If you just want to pay attention to some issues, you do not need to subscribe this mailing list. Instead, you just need to click “start-watching this issue” on the jira issue webpage.
  • commits@iotdb.apache.org (for code changes notification. Take care because this mailing list may have many emails)
  • reviews@iotdb.apache.org (for code reviews notification on Github. Take care because this mailing list may have many emails)

New features, bug feedback, improvements and more

All features or bugs that you want IoTDB to do can be raised on Jira：https://issues.apache.org/jira/projects/IOTDB/issues

You can choose issue types: bug, improvement, new feature, etc. New issues will be automatically synchronized to the mailing list (notifications@), and subsequent discussions can be left on jira or on the mailing list. When the issue is resolved, close the issue.

Email discussion content (English)

  • Joining the mailing list for the first time can introduce youself briefly. (Hi, I'm xxx ...)

  • Before developing a new feature, you can send an e-mail to declare the task you want to do.（Hi，I'm working on issue IOTDB-XXX，My plan is ...）

Contributing documents

The content of all IoTDB official websites is in the docs of the project root directory:

  • docs/SystemDesign: System Design Document-English Version
  • docs/zh/SystemDesign: System Design Document-Chinese Version
  • docs/UserGuide: User Guide English Version
  • docs/zh/UserGuide: User Guide Chinese Version
  • docs/Community: community English Version
  • docs/zh/Community: community Chinese Version
  • docs/Development: Development Guide English Version
  • docs/zh/Development: Development Guide Chinese Version

Correspondence between versions and branches on the official website:

  • In progress -> master
  • major_version.x -> rel/major_version （eg 0.9.x -> rel/0.9）

Precautions:

Code Formatting

We use the Spotless plugin together with google-java-format to format our Java code. You can configure your IDE to automatically apply formatting on saving with these steps(Take idea as an example):

  1. Download the google-java-format plugin v1.7.0.5, it can be installed in IDEA (Preferences -> plugins -> search google-java-format), More detailed setup manual
  2. Install the plugin from disk (Plugins -> little gear icon -> “Install plugin from disk” -> Navigate to downloaded zip file)
  3. In the plugin settings, enable the plugin and keep the default Google code style (2-space indents)
  4. Remember to never update this plugin to a later version，until Spotless was upgraded to version 1.8+.
  5. Install the Save Actions plugin , and enable the plugin, along with “Optimize imports” and “Reformat file”
  6. In the “Save Actions” settings page, setup a “File Path Inclusion” for .*\.java. Otherwise you will get unintended reformatting in other files you edit.
  7. Fix the issues of reordering the import packages: in IDEA: choose: Preferences | Editor | Code Style | Java | imports. At the tail of the panel, there is “Import Layout”, change it to:
   import org.apache.iotdb.*
   <blank line>
   import all other imports
   <blank line>
   import java.*
   <blank line>
   import static all other imports

C++ formatting

  • Formatter: clang-format only
  • Version: pinned as clang.format.version in the root pom.xml (currently 17.0.6, aligned with Apache TsFile); CI installs LLVM/clang-format so the default clang-format on the runner matches that version
  • Entrypoint: Maven Spotless; the clangFormat configuration is attached under the spotless-cpp profile in the C++ modules and activates only on JDK 11+, so run spotless:check / spotless:apply for C++ with JDK 11 or newer (CI does). JDK 8 builds elsewhere in the reactor do not load that Spotless fragment.

Check only:

./mvnw -P with-cpp -pl iotdb-client/client-cpp spotless:check

./mvnw -P with-cpp -pl example/client-cpp-example spotless:check

Auto-fix:

./mvnw -P with-cpp -pl iotdb-client/client-cpp spotless:apply

./mvnw -P with-cpp -pl example/client-cpp-example spotless:apply

On Windows PowerShell, a comma inside -pl can be parsed incorrectly; use the two commands above, or quote the full -pl value, for example ./mvnw -P with-cpp "-pl=iotdb-client/client-cpp,example/client-cpp-example" spotless:check.

Temporarily skip Spotless (not recommended except emergency CI triage):

-Dspotless.skip=true

Risk: skipping formatting checks can introduce style drift between contributors and CI, and often causes follow-up format-only commits.

Contributing code

You can go to jira to pick up the existing issue or create your own issue and get it. The comment says that I can do this issue.

  • Clone the repository to your own local repository, clone to the local, and associate the apache repository as the upstream upstream repository.
  • Cut out a new branch from master. The branch name is determined by the function of this branch. It is usually called f_new_feature (such as f_storage_engine) or fix_bug (such as fix_query_cache_bug).
  • Add code style as the root java-google-style.xml in the idea
  • Modify the code and add test cases (unit test, integration test)
    • Integration test reference:server/src/test/java/org/apache/iotdb/db/integration/IoTDBTimeZoneIT
  • Use mvn spotless:check to check the code style and use mvn spotless:apply to correct the code style
  • Submit a PR, starting with [IOTDB-jira number]
  • Email to dev mailing list：(I've submitted a PR for issue IOTDB-xxx [link])
  • Make changes based on other people's reviews and continue to update until merged
  • close jira issue

IoTDB Debug Guide

Recommended use Intellij idea.

mvn clean package -DskipTests

Mark iotdb-core/antlr/target/generated-sources/antlr4 and iotdb-protocol/thrift-datanode/target/generated-sources/thrift as Source Root.

  • Server main function：iotdb-core/datanode/src/main/java/org/apache/iotdb/db/service/DataNode, can be started in debug mode.

  • Cli：iotdb-client/cli/src/main/java/org/apache/iotdb/cli/，Use Cli for linux and WinCli for windows, you can start directly with the parameter “-h 127.0.0.1 -p 6667 -u root -pw root”

  • Server rpc implementation (mainly used for cli and server communication, generally start interruption point here):iotdb-core/datanode/src/main/java/org/apache/iotdb/db/service/TSServiceImpl

  • all jdbc statements：executeStatement(TSExecuteStatementReq req)

  • jdbc query：executeQueryStatement(TSExecuteStatementReq req)

  • native Write interface：insertRecord(TSInsertRecordReq req) insertTablet(TSInsertTabletReq req)

  • Storage engineorg.apache.iotdb.db.storageengine.StorageEngine

  • Query engine org.apache.iotdb.db.queryengine

Frequent Questions When Compiling the Source Code

I could not download thrift-* tools, like Could not get content org.apache.maven.wagon.TransferFailedException: Transfer failed for https://github.com/apache/iotdb-bin-resources/blob/main/compile-tools/thrift-0.14-ubuntu

It is due to some network problems (especially in China), you can: