This doc is intended for contributors to cadence
server (hopefully that's you!)
Join our Slack channel(invite link in the home page) #development if you need help.
Note: All contributors need to fill out the Uber Contributor License Agreement before we can merge in any of your changes
Below are the instructions of how to set up a development Environment.
- Golang. Install on OS X with.
brew install go
- Make sure set PATH to include bin path of GO so that other executables like thriftrw can be found.
# check it first
echo $GOPATH
# append to PATH
PATH=$PATH:$GOPATH/bin
# to confirm, run
echo $PATH
- Download golang dependencies.
go mod download
After check out and go to the Cadence repo, compile the cadence
service and helper tools without running test:
git submodule update --init --recursive
make bins
You should be able to get all the binaries of this repo:
- cadence-server: the server binary
- cadence: the CLI binary
- cadence-cassandra-tool: the Cassandra schema tools
- cadence-sql-tool: the SQL schema tools(for now only supports MySQL and Postgres)
- cadence-canary: the canary test binary
- cadence-bench: the benchmark test binary
If running into any compiling issue
- For proto/thrift errors, run
git submodule update --init --recursive
to fix- Make sure you upgrade to the latest stable version of Golang.
- Check if this document is outdated by comparing with the building steps in Dockerfile
NOTE: you may skip this section if you have installed the dependencies in any other ways, for example, using homebrew.
Cadence's core data model can be running with different persistence storages, including Cassandra,MySQL and Postgres. Please refer to persistence documentation if you want to learn more. Cadence's visibility data model can be running with either Cassandra/MySQL/Postgres database, or ElasticSearch+Kafka. The latter provides advanced visibility feature
We recommend to use docker-compose to start those dependencies:
- If you want to start Cassandra dependency, use
./docker/dev/cassandra.yml
:
docker-compose -f ./docker/dev/cassandra.yml up
You will use CTRL+C
to stop it. Then docker-compose -f ./docker/dev/cassandra.yml down
to clean up the resources.
Or to run in the background
docker-compose -f ./docker/dev/cassandra.yml up -d
Also use docker-compose -f ./docker/dev/cassandra.yml down
to stop and clean up the resources.
- Alternatively, use
./docker/dev/mysql.yml
for MySQL dependency - Alternatively, use
./docker/dev/postgres.yml
for PostgreSQL dependency - Alternatively, use
./docker/dev/cassandra-esv7-kafka.yml
for Cassandra, ElasticSearch(v7) and Kafka/ZooKeeper dependencies - Alternatively, use
./docker/dev/mysql-esv7-kafka.yml
for MySQL, ElasticSearch(v7) and Kafka/ZooKeeper dependencies - Alternatively, use
./docker/dev/cassandra-opensearch-kafka.yml
for Cassandra, OpenSearch(compatible with ElasticSearch v7) and Kafka/ZooKeeper dependencies
Based on the above dependency setup, you also need to install the schemas.
- If you use
cassandra.yml
then runmake install-schema
to install Casandra schemas - If you use
cassandra-esv7-kafka.yml
then runmake install-schema && make install-schema-es-v7
to install Casandra & ElasticSearch schemas - If you use
cassandra-opensearch-kafka.yml
then runmake install-schema && make install-schema-opensearch
to install Casandra & ElasticSearch schemas - If you use
mysql.yml
then runinstall-schema-mysql
to install MySQL schemas - If you use
postgres.yml
then runinstall-schema-postgres
to install Postgres schemas mysql-esv7-kafka.yml
can be used for single MySQL + ElasticSearch or multiple MySQL + ElasticSearch mode- for single MySQL: run
install-schema-mysql && make install-schema-es-v7
- for multiple MySQL: run
make install-schema-multiple-mysql
which will install schemas for 4 mysql databases and ElasticSearch
- for single MySQL: run
If you use
cassandra-esv7-kafka.yml
and start server beforemake install-schema-es-v7
, ElasticSearch may create a wrong index on demand. You will have to delete the wrong index and then run themake install-schema-es-v7
again. To delete the wrong index:
curl -X DELETE "http://127.0.0.1:9200/cadence-visibility-dev"
Once you have done all above, try running the local binaries:
Then you will be able to run a basic local Cadence server for development.
- If you use
cassandra.yml
, then run./cadence-server start
, which will loadconfig/development.yaml
as config - If you use
mysql.yml
then run./cadence-server --zone mysql start
, which will loadconfig/development.yaml
+config/development_mysql.yaml
as config - If you use
postgres.yml
then run./cadence-server --zone postgres start
, which will loadconfig/development.yaml
+config/development_postgres.yaml
as config - If you use
cassandra-esv7-kafka.yml
then run./cadence-server --zone es_v7 start
, which will loadconfig/development.yaml
+config/development_es_v7.yaml
as config - If you use
cassandra-opensearch-kafka.yml
then run./cadence-server --zone es_opensearch start
, which will loadconfig/development.yaml
+config/development_es_opensearch.yaml
as config - If you use
mysql-esv7-kafka.yaml
- To run with multiple MySQL :
./cadence-server --zone multiple_mysql start
, which will loadconfig/development.yaml
+config/development_multiple_mysql.yaml
as config
- To run with multiple MySQL :
Then register a domain:
./cadence --do samples-domain domain register
Then run a helloworld from Go Client Sample or Java Client Sample
make bins
will build all the samples.
Then
./bin/helloworld -m worker &
will start a worker for helloworld workflow. You will see like:
$./bin/helloworld -m worker &
[1] 16520
2021-09-24T21:07:03.242-0700 INFO common/sample_helper.go:109 Logger created.
2021-09-24T21:07:03.243-0700 DEBUG common/factory.go:151 Creating RPC dispatcher outbound {"ServiceName": "cadence-frontend", "HostPort": "127.0.0.1:7933"}
2021-09-24T21:07:03.250-0700 INFO common/sample_helper.go:161 Domain successfully registered. {"Domain": "samples-domain"}
2021-09-24T21:07:03.291-0700 INFO internal/internal_worker.go:833 Started Workflow Worker {"Domain": "samples-domain", "TaskList": "helloWorldGroup", "WorkerID": "16520@IT-USA-25920@helloWorldGroup"}
2021-09-24T21:07:03.300-0700 INFO internal/internal_worker.go:858 Started Activity Worker {"Domain": "samples-domain", "TaskList": "helloWorldGroup", "WorkerID": "16520@IT-USA-25920@helloWorldGroup"}
Then
./bin/helloworld
to start a helloworld workflow. You will see the result like :
$./bin/helloworld
2021-09-24T21:07:06.220-0700 INFO common/sample_helper.go:109 Logger created.
2021-09-24T21:07:06.220-0700 DEBUG common/factory.go:151 Creating RPC dispatcher outbound {"ServiceName": "cadence-frontend", "HostPort": "127.0.0.1:7933"}
2021-09-24T21:07:06.226-0700 INFO common/sample_helper.go:161 Domain successfully registered. {"Domain": "samples-domain"}
2021-09-24T21:07:06.272-0700 INFO common/sample_helper.go:195 Started Workflow {"WorkflowID": "helloworld_75cf142b-c0de-407e-9115-1d33e9b7551a", "RunID": "98a229b8-8fdd-4d1f-bf41-df00fb06f441"}
2021-09-24T21:07:06.347-0700 INFO helloworld/helloworld_workflow.go:31 helloworld workflow started {"Domain": "samples-domain", "TaskList": "helloWorldGroup", "WorkerID": "16520@IT-USA-25920@helloWorldGroup", "WorkflowType": "helloWorldWorkflow", "WorkflowID": "helloworld_75cf142b-c0de-407e-9115-1d33e9b7551a", "RunID": "98a229b8-8fdd-4d1f-bf41-df00fb06f441"}
2021-09-24T21:07:06.347-0700 DEBUG internal/internal_event_handlers.go:489 ExecuteActivity {"Domain": "samples-domain", "TaskList": "helloWorldGroup", "WorkerID": "16520@IT-USA-25920@helloWorldGroup", "WorkflowType": "helloWorldWorkflow", "WorkflowID": "helloworld_75cf142b-c0de-407e-9115-1d33e9b7551a", "RunID": "98a229b8-8fdd-4d1f-bf41-df00fb06f441", "ActivityID": "0", "ActivityType": "main.helloWorldActivity"}
2021-09-24T21:07:06.437-0700 INFO helloworld/helloworld_workflow.go:62 helloworld activity started {"Domain": "samples-domain", "TaskList": "helloWorldGroup", "WorkerID": "16520@IT-USA-25920@helloWorldGroup", "ActivityID": "0", "ActivityType": "main.helloWorldActivity", "WorkflowType": "helloWorldWorkflow", "WorkflowID": "helloworld_75cf142b-c0de-407e-9115-1d33e9b7551a", "RunID": "98a229b8-8fdd-4d1f-bf41-df00fb06f441"}
2021-09-24T21:07:06.513-0700 INFO helloworld/helloworld_workflow.go:55 Workflow completed. {"Domain": "samples-domain", "TaskList": "helloWorldGroup", "WorkerID": "16520@IT-USA-25920@helloWorldGroup", "WorkflowType": "helloWorldWorkflow", "WorkflowID": "helloworld_75cf142b-c0de-407e-9115-1d33e9b7551a", "RunID": "98a229b8-8fdd-4d1f-bf41-df00fb06f441", "Result": "Hello Cadence!"}
See instructions for setting up replication(XDC).
Take a look at the list of issues labeled with good first issue. These issues are a great way to start contributing to Cadence.
Later when you are more familiar with Cadence, look at issues with up-for-grabs.
A Cadence server cluster is composed of four different services: Frontend, Matching, History and Worker(system). Here's what's in each top-level directory in this repository:
- canary/ : The test code that needs to run periodically to ensure Cadence is healthy
- client/ : Client wrappers to let the four different services talk to each other
- cmd/ : The main function to build binaries for servers and CLI tools
- config/ : Sample configuration files
- docker/ : Code/scripts to build docker images
- docs/ : Documentation
- host/ : End-to-end integration tests
- schema/ : Versioned persistence schema for Cassandra/MySQL/Postgres/ElasticSearch
- scripts/ : Scripts for CI build
- tools/ : CLI tools for Cadence workflows and also schema updates for persistence
- service/ : Contains four sub-folders that dedicated for each of the four services
- common/ : Basically contains all the rest of the code in Cadence server, the names of the sub folder are the topics of the packages
If looking at the Git history of the file/package, there should be some engineers focusing on each area/package/component that you are working on. You will probably get code review from them. Don't hesitate to ask for some early feedback or help on Slack.
To run all the package tests use the below command. This will run all the tests excluding end-to-end integration test in host/ package):
make test
You will see some test failures because of errors connecting to MySQL/Postgres if only Cassandra is up. This is okay if you don't write any code related to persistence layer.
To run all end-to-end integration tests in host/ package:
make test_e2e
To debug a specific test case when you see some failure, you can trigger it from an IDE, or use the command
go test -v <path> -run <TestSuite> -testify.m <TestSpercificTaskName>
# example:
go test -v github.com/uber/cadence/common/persistence/persistence-tests -run TestVisibilitySamplingSuite -testify.m TestListClosedWorkflowExecutions
After all the preparation you are about to write code and make a Pull Request for the issue.
You have a few options for choosing when to submit:
-
You can open a PR with an initial prototype with "Draft" option or with "WIP"(work in progress) in the title. This is useful when want to get some early feedback.
-
PR is supposed to be or near production ready. You should have fixed all styling, adding new tests if possible, and verified the change doesn't break any existing tests.
-
For small changes where the approach seems obvious, you can open a PR with what you believe to be production-ready or near-production-ready code. As you get more experience with how we develop code, you'll find that more PRs will begin falling into this category.
Overcommit adds some requirements to your commit messages. At Uber, we follow the Chris Beams guide to writing git commit messages. Read it, follow it, learn it, love it.
All commit messages are from the titles of your pull requests. So make sure follow the rules when titling them. Please don't use very generic titles like "bug fixes".
All PR titles should start with UPPER case.
Examples:
- Make sync activity retry multiple times before fetch history from remote
- Enable archival config per domain
The project has strict rule about Golang format. You have to run
make fmt
to re-format your code. Otherwise the CI(buildkite) test will fail.
Also, this project is Open Source Software, and requires a header at the beginning of all new source files you are adding. To verify that all files contain the header execute:
make copyright
We take code reviews very seriously at Cadence. Please don't be deterred if you feel like you've received some hefty feedback. That's completely normal and expected—and, if you're an external contributor, we very much appreciate your contribution!
In this repository in particular, merging a PR means accepting responsibility for maintaining that code for, quite possibly, the lifetime of Cadence. To take on that reponsibility, we need to ensure that meets our strict standards for production-ready code.
No one is expected to write perfect code on the first try. That's why we have code reviews in the first place!
Also, don't be embarrassed when your review points out syntax errors, stray whitespace, typos, and missing docstrings! That's why we have reviews. These properties are meant to guide you in your final scan.
If someone leaves line comments on your PR without leaving a top-level "looks good to me" (LGTM), it means they feel you should address their line comments before merging.
You should respond to all unresolved comments whenever you push a new revision or before you merge.
Also, as you gain confidence in Go, you'll find that some of the nitpicky style feedback you get does not make for obviously better code. Don't be afraid to stick to your guns and push back. Much of coding style is subjective.
External contributors: you don't need to worry about this section. We'll merge your PR as soon as you've addressed all review feedback(you will get at least one approval) and pipeline runs are all successful(meaning all tests are passing).