|author||mynameborat <firstname.lastname@example.org>||Fri Apr 02 17:17:06 2021 -0700|
|committer||GitHub <email@example.com>||Fri Apr 02 17:17:06 2021 -0700|
SAMZA-2633: Rolling upgrades cause downtime to upgraded processors for the entire deployment window (#1484) Description: During rolling upgrades, the current debounce timer gets extended every time when there is a quorum change notification. As a result, processors that were upgraded earlier in the deployment window remain unavailable waiting for work assignment. In some scenarios, this cause processors to be unavailable for 20 minutes or so depending on the size of the quorum and the debounce time configuration. Refer to SAMZA-2633 for more information. Changes: Optimize the leader workflow to skip rebalance if there is no changes to work assignment Make processors start with most recent agreed job model on startup Leader persists the active job model version in ZK to enable change  Introduce config for applications to opt-in for the optimization Usage Instructions: Set job.coordinator.zk.enable-startup-with-active-job-model to true as part of the application configuration to enable processor use the recent active job model during startup and also enable leader to skip rebalances if the work assignment remains the same.
Apache Samza is a distributed stream processing framework. It uses Apache Kafka for messaging, and Apache Hadoop YARN to provide fault tolerance, processor isolation, security, and resource management.
Samza's key features include:
To build Samza from a git checkout, run:
./gradlew clean build
To build Samza from a source release, it is first necessary to download the gradle wrapper script above. This bootstrapping process requires Gradle to be installed on the source machine. Gradle is available through most package managers or directly from its website. To bootstrap the wrapper, run:
gradle -b bootstrap.gradle
After the bootstrap script has completed, the regular gradlew instructions below are available.
./gradlew -PscalaSuffix=2.11 clean build
To run all tests:
./gradlew clean test
To run a single test:
./gradlew clean :samza-test:test -Dtest.single=TestStatefulTask
To run key-value performance tests:
./gradlew samza-shell:kvPerformanceTest -PconfigPath=file://$PWD/samza-test/src/main/config/perf/kv-perf.properties
To run yarn integration tests:
./bin/integration-tests.sh <dir> yarn-integration-tests
To run standalone integration tests:
./bin/integration-tests.sh <dir> standalone-integration-tests
./gradlew checkstyleMain checkstyleTest
To run a job (defined in a properties file):
./gradlew samza-shell:runJob -PconfigPath=/path/to/job/config.properties
To inspect a job's latest checkpoint:
./gradlew samza-shell:checkpointTool -PconfigPath=/path/to/job/config.properties
To modify a job's checkpoint (assumes that the job is not currently running), give it a file with the new offset for each partition, in the format
./gradlew samza-shell:checkpointTool -PconfigPath=/path/to/job/config.properties \ -PnewOffsets=file:///path/to/new/offsets.properties
To get Eclipse projects, run:
For IntelliJ, run:
Apache Samza is a top level project of the Apache Software Foundation.