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Posted to commits@cassandra.apache.org by mc...@apache.org on 2021/11/09 09:16:21 UTC
[cassandra-website] branch trunk updated: Build and test
documentation improvements
This is an automated email from the ASF dual-hosted git repository.
mck pushed a commit to branch trunk
in repository https://gitbox.apache.org/repos/asf/cassandra-website.git
The following commit(s) were added to refs/heads/trunk by this push:
new b954b93 Build and test documentation improvements
b954b93 is described below
commit b954b931684e544ab50370269427f4c4ed9ae675
Author: Jacek Lewandowski <le...@gmail.com>
AuthorDate: Fri Oct 22 14:34:34 2021 +0200
Build and test documentation improvements
Patch by Jacek Lewandowski, reviewed by Michael Semb Wever and Lorina Poland, for CASSANDRA-15691
Co-authored-by: mck <mc...@apache.org>
Co-authored-by: polandll <lo...@datastax.com>
---
.../source/modules/ROOT/pages/development/ide.adoc | 122 ++-
.../modules/ROOT/pages/development/index.adoc | 2 +-
.../modules/ROOT/pages/development/patches.adoc | 13 +-
.../modules/ROOT/pages/development/testing.adoc | 1115 +++++++++++++++++++-
4 files changed, 1171 insertions(+), 81 deletions(-)
diff --git a/site-content/source/modules/ROOT/pages/development/ide.adoc b/site-content/source/modules/ROOT/pages/development/ide.adoc
index b533a6d..1f4dced 100644
--- a/site-content/source/modules/ROOT/pages/development/ide.adoc
+++ b/site-content/source/modules/ROOT/pages/development/ide.adoc
@@ -2,53 +2,73 @@
== Building and IDE Integration
-=== Building From Source
+=== Prerequisites
-Building Cassandra from source is the first important step in contributing
-to the Apache Cassandra project.
-You'll need to install http://www.oracle.com/technetwork/java/javase/downloads/index.html[Java 8], https://git-scm.com/[Git], and http://ant.apache.org/[Ant] first.
+Building Cassandra from source is the first important step in contributing to the Apache Cassandra project.
+You will need to install Java (JDK 8 or 11, depending on which version
+you want to build Cassandra against, best is to install both and then
+switch between them when needed), Git, and Ant (including ant-optional).
+
+=== Getting the source code
The source code for Cassandra is shared on the central Apache Git
repository and organized by branch, one branch for each major version.
-You can access the code for the current development branch using:
-
-// 01.15.21 - polandll - should this step be a fork rather than a clone?
-
-[source, plaintext]
-----
-git clone https://gitbox.apache.org/repos/asf/cassandra.git cassandra-trunk
-----
-
-Other branches will point to different versions of Cassandra. Switching
-to a different branch requires checking out the branch.
-For example, to checkout the latest version of Cassandra 3.0, use:
-
-[source, plaintext]
-----
-git checkout cassandra-3.0
-----
-
-You can get a list of available branches with `git branch`.
+You can access the code for the current development branch at
+https://gitbox.apache.org/repos/asf/cassandra.git (the primary location)
+or at https://github.com/apache/cassandra (a mirror location).
-Build Cassandra using ant:
+However, to develop a patch or a new feature, you should fork the Cassandra
+project first and then clone it from your own fork:
-[source, plaintext]
+[source,plaintext]
----
-ant
+git clone https://github.com/<your_git_name>/cassandra.git cassandra
----
-This may take a significant amount of time depending on artifacts that have to
-be downloaded or the number of classes that need to be compiled.
+=== Building Cassandra
+
+Cassandra is a Java project which is built using Ant.
+The build file, `build.xml` located in the root of the project content,
+has various tasks defined (you can list all of them with some short
+descriptions by running `ant -p`).
+
+The build uses the Java compiler which is currently set up in your
+shell. By default, the build uses Java 8. If you want to build
+with Java 11, you need to either add a build property `-Duse.jdk11=true`
+to your Ant build command or export the environment variable
+`CASSANDRA_USE_JDK11=true`. Otherwise, if you run the build using
+Java 11, the build script complains.
+
+Now you can build Cassandra with the default task - just execute
+`ant` or `ant jar`. This may take a significant amount of time depending
+on artifacts that have to be downloaded or the number of classes that
+need to be compiled. When the build completes, you can find a JAR file
+in the build directory, and the database service can be started with
+the `bin/cassandra` script.
+
+=== Building a distribution
+
+Some tasks you might be interested in are:
+
+* `build` - compile the production code without producing any JARs
+* `build-test` - compile the test code without producing any JARs
+* `artifacts` - generate Cassandra distribution in `build/dist`
+directory and package it to `tar.gz` (with and without sources)
+* `mvn-install` - generate `cassandra-all` JAR artifact along with
+sources and JavaDoc, and install it in the local Maven repository
+* `realclean` - clean the project from any build products, as well as
+from any dependencies (in fact that means removing `build` and `lib`
+directories)
[TIP]
.Hint
====
-You can setup multiple working trees for different Cassandra versions
-from the same repository using
-https://git-scm.com/docs/git-worktree[git-worktree].
+Remember to clean the project after switching branches as build artifacts
+are versioned.
====
-Now you can get started with Cassandra using IntelliJ IDEA or Eclipse.
+There are other tasks related to testing, and they are covered in
+link:testing.adoc[Testing] section.
=== Setting up Cassandra in IntelliJ IDEA
@@ -56,14 +76,10 @@ https://www.jetbrains.com/idea/[IntelliJ IDEA] by JetBrains is one of
the most popular IDEs for Cassandra and Java development in general.
The Community Edition can be freely downloaded with all features needed to get started developing Cassandra.
-Use the following procedure for Cassandra 2.1.5+.
-If you wish to work with older Cassandra versions, see our https://cwiki.apache.org/confluence/display/CASSANDRA2/RunningCassandraInIDEA[wiki] for instructions.
-
-First, clone and build Cassandra.
-Then execute the following steps to use IntelliJ IDEA.
+Use the following procedure for Cassandra 2.1.5+:
[arabic]
-. Generate the IDEA files using ant:
+. Generate project files by executing the following target from Ant build:
[source, plaintext]
----
@@ -76,6 +92,16 @@ ant generate-idea-files
The project generated by `ant generate-idea-files` contains
nearly everything you need to debug Cassandra and execute unit tests.
+
+[TIP]
+.Hint
+====
+Although you do not need to build the project with `ant jar` to import
+it some tests run tools as external processes and need the regular
+artifacts to be created. Such tests may require you to rebuild the
+project using Ant before each run even when you run the test in IDEA.
+====
+
You should be able to:
* Run/debug defaults for JUnit
@@ -84,9 +110,15 @@ You should be able to:
* Study Cassandra code style
* Inspections
+[TIP]
+.Hint
+====
+If you wish to work with older Cassandra versions, see our https://cwiki.apache.org/confluence/display/CASSANDRA2/RunningCassandraInIDEA[wiki] for instructions.
+====
+
=== Opening Cassandra in Apache NetBeans
-https://netbeans.apache.org/[Apache NetBeans] is an older open source Java IDE,
+https://netbeans.apache.org/[Apache NetBeans] is the elder of the open sourced java IDEs,
and can be used for Cassandra development.
There is no project setup or generation required to open Cassandra in NetBeans.
Use the following procedure for Cassandra 4.0+.
@@ -226,3 +258,15 @@ image::eclipse_debug6.png[image]
. Confirm `Debug` and you should see the output of Cassandra start up in the Eclipse console.
You can now set breakpoints and start debugging!
+
+=== General notes
+
+You may sometimes encounter some odd build failures when running the `ant` commands above. If you do, start `ant` with the `realclean` option:
+
+[source,plaintext]
+----
+ant realclean
+----
+
+Remember that all the tasks mentioned above may depend on building source files. If there are actual compilation errors in the code, you may not be able to generate project files for IntelliJ Idea, Netbeans, or Eclipse.
+It is especially important that you have imported the project adequately into IDE before doing merges or rebases. Otherwise, if there are conflicts, the project cannot be opened in IDE, and you will be unable to use any fancy conflict resolution tools offered by those IDEs.
diff --git a/site-content/source/modules/ROOT/pages/development/index.adoc b/site-content/source/modules/ROOT/pages/development/index.adoc
index baecaeb..defa012 100644
--- a/site-content/source/modules/ROOT/pages/development/index.adoc
+++ b/site-content/source/modules/ROOT/pages/development/index.adoc
@@ -2,7 +2,7 @@
:page-layout: basic
* xref:development/gettingstarted.adoc[Getting started]
-* xref:development/ide.adoc[IDE]
+* xref:development/ide.adoc[Building and IDE integration]
* xref:development/testing.adoc[Testing]
* xref:development/code_style.adoc[Code style]
* xref:development/how_to_commit.adoc[How to commit]
diff --git a/site-content/source/modules/ROOT/pages/development/patches.adoc b/site-content/source/modules/ROOT/pages/development/patches.adoc
index 53f9cec..944893f 100644
--- a/site-content/source/modules/ROOT/pages/development/patches.adoc
+++ b/site-content/source/modules/ROOT/pages/development/patches.adoc
@@ -128,7 +128,18 @@ submit your patch!
[arabic]
. Create a branch for your changes if you haven't done already. Many
contributors name their branches based on ticket number and Cassandra
-version, e.g. `git checkout -b 12345-3.0`
+version, e.g. `git checkout -b 12345-3.0` or
+`git checkout -b CASSANDRA-12345-3.0`.
+
+[TIP]
+.Hint
+====
+When working on multiple patches at the same time, instead of cloning
+the repository separately for each of them, set up multiple
+working trees for different Cassandra versions from the same repository
+using https://git-scm.com/docs/git-worktree[Git worktrees] feature.
+====
+
. Verify that you follow Cassandra's `code_style`
. Make sure all tests (including yours) pass using ant as described in
`testing`. If you suspect a test failure is unrelated to your change, it
diff --git a/site-content/source/modules/ROOT/pages/development/testing.adoc b/site-content/source/modules/ROOT/pages/development/testing.adoc
index 386422a..6e04d53 100644
--- a/site-content/source/modules/ROOT/pages/development/testing.adoc
+++ b/site-content/source/modules/ROOT/pages/development/testing.adoc
@@ -1,21 +1,60 @@
:page-layout: basic
-== Testing
+= Testing
Creating tests is one of the most important and also most difficult
parts of developing Cassandra. There are different ways to test your
code depending on what you're working on.
-=== Unit Testing
+Cassandra tests can be divided into three main categories, based on the
+way how they are executed:
-The simplest test to write for Cassandra code is a unit test.
-Cassandra uses JUnit as a testing framework and test cases
-can be found in the `test/unit` directory.
-Ideally, you’d be able to create a unit test for your implementation that would exclusively cover the class you created (the unit under test).
-Unfortunately, this is not always possible, because Cassandra doesn’t have a very mock friendly code base.
-Often you’ll find yourself in a situation where you have to use an embedded Cassandra instance to interact with your test.
-If you want to make use of CQL in your test, you can extend CQLTester and use
-some of the convenient helper methods, as shown here:
+* *<<java_tests>>* - tests implemented in Java and being a part of the
+Cassandra project. You can distinguish the following subcategories there:
+
+** *<<junit_tests>>* - consists of unit tests, single-node integration
+tests and some tool tests; those tests may run a server with limited
+functionality in the same JVM as the test code
+
+** *<<jvm_distributed_tests>>* - integrated tests against one or multiple
+nodes, each running in their own classloader; also contains upgrade
+tests
+
+** *<<microbenchmarks>>* - micro-benchmarks implemented with
+https://github.com/openjdk/jmh[JMH framework]
+
+* *<<cqlsh_tests>>* - CQLSH tests are Python tests written with the Nose
+test framework. They verify the CQLSH client that can be found in the
+bin directory. They aim at verifying CQLSH specific behavior like output
+formatting, autocompletion, parsing, etc).
+
+* *<<python_dtests>>* - Python distributed tests are
+implemented on top of the PyTest framework and located outside the main
+Cassandra project in the separate repository
+https://github.com/apache/cassandra-dtest[apache/cassandra-dtest]. They
+test Cassandra via https://github.com/riptano/ccm[CCM] verifying
+operation results, logs, and cluster state. Python Distributed tests are
+Cassandra version agnostic. They include upgrade tests.
+
+The recipes for running those tests can be found in the cassandra-builds repository https://github.com/apache/cassandra-builds/tree/trunk/build-scripts[here].
+
+Running full test suites locally takes hours, if not days. Beyond running specific tests you know are applicable, or are failing, to the work at hand, it is recommended to rely upon the project's https://cassandra.apache.org/_/development/ci.html[Continuous Integration systems]. If you are not a committer, and don't have access to a premium CircleCI plan, ask one of the committers to test your patch on the project's https://ci-cassandra.apache.org/[ci-cassandra.apache.org].
+
+[#java_tests]
+== Java tests
+
+The simplest test to write for Cassandra code is a unit test. Cassandra
+uses JUnit as a testing framework and test cases can be found in the
+`test/unit` directory. Ideally, you’ll create a unit test for
+your implementation that exclusively covers the class you created
+(the unit under test).
+
+Unfortunately, this is not always possible, because Cassandra doesn't
+have a very mock friendly code base. Often you’ll find yourself in a
+situation where you have to use the embedded Cassandra instance to
+interact with your test. If you want to use CQL in your test,
+you can extend CQLTester and use some convenient helper methods, as
+shown here:
[source,java]
----
@@ -34,28 +73,61 @@ public void testBatchAndList() throws Throwable
}
----
-Unit tests can be run using the command `ant test`. Both test suites and
-individual tests can be executed.
+[#junit_tests]
+=== JUnit tests
-Test suite:
-[source, plaintext]
+To run the unit tests:
+
+[source,none]
----
-ant test -Dtest.name=<simple_classname>
+ant test
----
-For example, replace `<simple_classname>` with `SimpleQueryTest` to test all the methods in `org.apache.cassandra.cql3.SimpleQueryTest`.
-Individual test:
-[source, plaintext]
+However, this is probably not what you want to do, since that
+command would run all the unit tests (those from `test/unit`). It would
+take about an hour or more to finish.
+
+To run the specific test class or even a method, use the following
+command:
+
+[source,none]
----
-ant testsome -Dtest.name=<FQCN> -Dtest.methods=<testmethod1>[,testmethod2]
+ant testsome -Dtest.name=<TestClassName> -Dtest.method=<testMethodName>
----
-For example, replace `<FQCN>` with `org.apache.cassandra.cql3.SimpleQueryTest`
-and `<testmethod1>` with `testStaticCompactTables` to test just the one method.
+* `test.name` property is for either a simple or fully qualified class
+name
+* `test.method` property is optional; if not specified, all test cases
+from the specified class are executed. Though, you can also specify
+multiple methods separating them by comma
+You can also use the IDE to run the tests - when you generate IDE files and
+properly import the Cassandra project, you can run the
+tests by right-clicking on the test class or package name. Remember that
+it is not enough to compile with IDE for some tests, and you need to
+call `ant jar` to build the distribution artifacts. When
+the test runs some tool as an external process, the tool expects
+Cassandra artifacts to be in the build directory.
-If you get the following error for a unit test, install the `ant-optional` package
-because you need the `JUnitTask` class:
+Note that those commands apply to the tests in the `test/unit`
+directory. There are, however, some other test categories that have
+tests in individual directories:
+
+* `test/burn` - to run them, first build the uber jar with
+`ant burn-test-jar`, and then to run the tests call `ant test-burn` or
+`ant burn-testsome`
+* `test/long` - to run them, call `ant long-test` or `ant long-testsome`
+* `test/memory` - to run them, call `ant test-memory`
+* `test/microbench` discussed in <<microbenchmarks>>
+* `test/distributed` discussed in <<jvm_distributed_tests>>
+
+[TIP]
+.Hint
+====
+If you get the error similar to the one below, install the
+`ant-optional` package
+because you need the `JUnitTask` class
+(see xref:development/ide.adoc[prerequisites]).
[source,none]
----
@@ -63,27 +135,434 @@ Throws: cassandra-trunk/build.xml:1134: taskdef A class needed by class org.krum
org/apache/tools/ant/taskdefs/optional/junit/JUnitTask using the classloader
AntClassLoader[/.../cassandra-trunk/lib/jstackjunit-0.0.1.jar]
----
+====
+
+[#stress_and_fqltool_tests]
+=== Stress and FQLTool tests
+
+_Stress_ and _FQLTool_ are separate modules located under the `tools`
+directory in the Cassandra project. They have their own source code and
+unit tests. To run the tests for those tools, first, build jar artifacts
+for them but calling:
+
+[source,]
+----
+ant fqltool-build fqltool-build-test
+ant stress-build stress-build-test
+----
+
+Then you can execute the tests with either one of the commands:
+
+[source,plaintext]
+----
+ant fqltool-test
+ant stress-test
+and stress-test-some
+----
+
+or using your IDE.
+
+[#jvm_distributed_tests]
+=== JVM distributed tests
+
+JVM distributed tests can run a cluster of nodes inside a single JVM -
+they utilize a particular framework (that can be found at
+https://github.com/apache/cassandra-in-jvm-dtest-api[apache/cassandra-in-jvm-dtest-api])
+for that purpose. Those tests are intended to test features that require
+more started nodes or verify specific behaviors when the nodes get
+restarted, including upgrading them from one version to another. The
+tests are located at the `test/distributed` directory of the Cassandra
+project; however, only `org.apache.cassandra.distributed.test` and
+`org.apache.cassandra.upgrade` packages contain the actual tests. The
+rest of the files are various utilities related to the distributed test
+framework.
+
+The distributed tests can be run in few ways. `ant test-jvm-dtest`
+command runs all the distributed JVM tests. It is not very useful; thus,
+there is also `ant test-jvm-dtest-some`, which allows specifying test
+class and test name in the similar way as you could do that for the
+`ant testsome` command, for example:
+
+[source,plaintext]
+----
+ant test-jvm-dtest-some -Dtest.name=org.apache.cassandra.distributed.test.SchemaTest
+
+ant test-jvm-dtest-some -Dtest.name=org.apache.cassandra.distributed.test.SchemaTest -Dtest.methods=readRepair
+----
+
+[TIP]
+.Hint
+====
+Unlike for JUnit tests, for JVM distributed tests you need to provide
+fully qualified class name
+====
+
+Distributed tests can also be run using IDE (in fact, you can even debug
+them).
+
+==== Upgrade tests
+
+JVM upgrade tests can be run precisely in the same way as any other JVM
+distributed tests. However, running them requires some preparation -
+for example, if a test verifies the upgrade from Cassandra 3.0 and
+Cassandra 3.11 to the current version (say Cassandra 4.0), you need to
+have prepared dtest uber JARs for all involved versions. To do this:
+
+. Check out Cassandra 3.0 based branch you want to test the upgrade
+from into some other directory
+
+. Build dtest uber JAR with `ant dtest-jar` command
+
+. Copy the created `build/dtest-3.0.x.jar` to the build
+directory of your target Cassandra project
+
+. Repeat the procedure for Cassandra 3.11
+
+. Once you have dtest jars of all the involved versions for the upgrade
+test, you can finally execute the test using your favorite method, say:
+
+[source,plaintext]
+----
+ant test-jvm-dtest-some -Dtest.name=org.apache.cassandra.distributed.upgrade.MixedModeReadTest
+----
+
+[TIP]
+.Hint
+====
+You may pre-generate dtest uber JARs for certain past Cassandra
+releases, store is somewhere and reuse in you future work - no need to
+rebuild them all the time.
+====
+
+=== Running multiple tests
+
+It is possible to define a list of test classes to run with a single command.
+Define a text file, by default called `testlist.txt`, and put it into your project directory.
+Here is an example of that file:
+
+[source,none]
+----
+org/apache/cassandra/db/ReadCommandTest.java
+org/apache/cassandra/db/ReadCommandVerbHandlerTest.java
+----
+
+Essentially, you list the paths to the class files of the tests you want
+to run. Then you call `ant testclasslist`, which uses the text file
+to run the listed tests. Note that, by default, it applies to
+the tests under the `test/unit` directory and takes the `testlist.txt`
+file, but this behavior can be modified by providing additional
+parameters:
+
+[source,plaintext]
+----
+ant testclasslist -Dtest.classlistprefix=<category> -Dtest.classlistfile=<class list file>
+----
+
+For example, if you want to run the distributed tests this way, and say
+our tests were listed in the `distributed-tests-set.txt` file (paths to
+test classes relative to `test/distributed` directory), you can do that
+by calling:
+
+[source,plaintext]
+----
+ant testclasslist -Dtest.classlistprefix=distributed -Dtest.classlistfile=distributed-tests-set.txt
+----
+
+=== Running coverage analysis
+
+Coverage reports from the executed JVM tests can be obtained in two ways
+- through IDE - for example, IntelliJ supports running tests with
+coverage analysis (another run button next to the one for running in debug mode).
+
+The other way is to run Ant target `codecoverage`. Basically, it works
+for all the ways mentioned above of running JVM tests - the only
+difference is that instead of specifying the target directly, you pass it
+as a property called `taskname`. For example - given the original test
+command is:
+
+[source,plaintext]
+----
+ant testsome -Dtest.name=org.apache.cassandra.utils.concurrent.AccumulatorTest
+----
+
+to run it with coverage analysis, do:
+
+[source,plaintext]
+----
+ant codecoverage -Dtaskname=testsome -Dtest.name=org.apache.cassandra.utils.concurrent.AccumulatorTest
+----
+
+It applies to all the targets like `test`, `testsome`, `test-long`,
+etc., even `testclasslist`. You can find the coverage report in
+`build/jacoco` (`index.html` is the entry point for the HTML version,
+but there are also XML and CSV reports).
+
+Note that if you run various tests that way, the coverage information is
+added to the previously collected runs. That is, you get the cumulative
+coverage from all runs unless you clean up the project or at least clean
+up the recorded coverage information by executing the command
+`ant jacoco-cleanup`.
+
+[#microbenchmarks]
+=== Micro-benchmarks
+
+To run micro-benchmarks, first build the uber jar for the JMH framework.
+Use the following `ant` command:
-Tests that consume a significant amount of time during execution can be found
-in the `test/long` directory.
-They can be executed as a regular JUnit test or standalone program.
-Except for the execution time, there’s nothing
-really special about them, but `ant` will only execute these test with the
-`ant long-test` target.
+[source,plaintext]
+----
+ant build-jmh
+----
+
+Then, you can run either all benchmarks (from the `test/microbench`
+directory) or the tests matching the name specified by the
+`benchmark.name` property when executing the `ant microbench` command.
+Whether you run all benchmarks or just a selected one, only classes
+under the `microbench` package are selected. The class selection pattern
+is actually `.\*microbench.*${benchmark.name}`. For example,
+in order to run `org.apache.cassandra.test.microbench.ChecksumBench`,
+execute:
-=== DTests
+[source,plaintext]
+----
+ant microbench -Dbenchmark.name=ChecksumBench
+----
+
+The `ant microbench` command runs the benchmarks with default parameters
+as defined in the `build.xml` file (see the `microbench` target
+definition). If you want to run JMH with custom parameters,
+consider using the `test/bin/jmh` script. In addition to allowing you to
+customize JMH options, it also sets up the environment and JVM options
+by running Cassandra init script (`conf/cassandra-env.sh`). Therefore,
+it lets the environment for running the tests to be more similar to
+the production environment. For example:
+
+[source,plaintext]
+----
+test/bin/jmh -gc true org.apache.cassandra.test.microbench.CompactionBench.compactTest
+----
+
+You may also find it useful to run the command to list all the tests:
+`test/bin/jmh -l` or `test/bin/jmh -lp` (also showing the default
+parameters). The list of all options can be shown by running
+`test/bin/jmh -h`
+
+== Python tests
+
+=== Docker
+
+The Docker approach is recommended for running Python distributed tests.
+The behavior will be more repeatable, matching the same environment as
+the official testing on https://ci-cassandra.apache.org/[Cassandra CI].
+
+==== Setup Docker
+
+If you are on Linux, you need to install Docker using the system package
+manager.
+
+If you are on MacOS, you can use either
+https://www.docker.com/products/docker-desktop[Docker Desktop] or some
+https://runnable.com/docker/install-docker-on-macos[other approach].
+
+==== Pull the Docker image
+
+The Docker image used on the official Cassandra CI can be found in
+https://github.com/apache/cassandra-builds[this] repository.
+You can use either
+https://github.com/apache/cassandra-builds/blob/trunk/docker/testing/ubuntu2004_j11.docker[docker/testing/ubuntu2004_j11.docker]
+or
+https://github.com/apache/cassandra-builds/blob/trunk/docker/testing/ubuntu2004_j11_w_dependencies.docker[docker/testing/ubuntu2004_j11_w_dependencies.docker]
+The second choice has prefetched dependencies for building each main
+Cassandra branch. Those images can be either built
+locally (as per instructions in the GitHub repo) or pulled from the
+Docker Hub - see
+https://hub.docker.com/search?q=apache%2Fcassandra-testing&type=image[here].
+
+First, pull the image from Docker Hub (it will either fetch or
+update the image you previously fetched):
+
+[source,plaintext]
+----
+docker pull apache/cassandra-testing-ubuntu2004-java11-w-dependencies
+----
+
+==== Start the container
+
+[source,plaintext]
+----
+docker run -di -m 8G --cpus 4 \
+--mount type=bind,source=/path/to/cassandra/project,target=/home/cassandra/cassandra \
+--mount type=bind,source=/path/to/cassandra-dtest,target=/home/cassandra/cassandra-dtest \
+--name test \
+apache/cassandra-testing-ubuntu2004-java11-w-dependencies \
+dumb-init bash
+----
+
+[TIP]
+.Hint
+====
+Many distributed tests are not that demanding in terms of resources
+- 4G / 2 cores should be enough to start one node. However, some tests
+really run multiple nodes, and some of them are automatically skipped
+if the machine has less than 32G (there is a way to force running them
+though). Usually 8G / 4 cores is a convenient choice which is enough
+for most of the tests.
+====
+
+To log into the container, use the following `docker exec` command:
+
+[source,plaintext]
+----
+docker exec -it `docker container ls -f name=test -q` bash
+----
+
+[#setup_python_env]
+==== Setup Python environment
+
+The tests are implemented in Python, so a Python virtual environment
+(see https://docs.python.org/3/tutorial/venv.html[here] for details)
+with all the required dependencies is good to be set up. If you are
+familiar with the Python ecosystem, you know what it is all about.
+Otherwise, follow the instructions; it should be enough to run the
+tests.
+
+For Python distributed tests do:
+
+[source,plaintext]
+----
+cd /home/cassandra/cassandra-dtest
+virtualenv --python=python3 --clear --always-copy ../dtest-venv
+source ../dtest-venv/bin/activate
+CASS_DRIVER_NO_CYTHON=1 pip install -r requirements.txt
+----
+
+For CQLSH tests, replace some paths:
+
+[source,plaintext]
+----
+cd /home/cassandra/cassandra/pylib
+virtualenv --python=python3 --clear --always-copy ../../cqlsh-venv
+source ../../cqlsh-venv/bin/activate
+CASS_DRIVER_NO_CYTHON=1 pip install -r requirements.txt
+----
+
+[TIP]
+.Hint
+====
+You may wonder why this weird environment variable `CASS_DRIVER_NO_CYTHON=1` was added - it is not required at all. Still, it allows avoiding the compilation of Cassandra driver with Cython, which is not needed unless you want to test that Cython compiled driver. In the end, it speeds up the installation of the requirements significantly from the order of minutes to the order of seconds.
+====
+
+The above commands are also helpful for importing those test projects
+into your IDE. In that case, you need to run them on your host
+system rather than in Docker container. For example, when you open the
+project in IntelliJ, the Python plugin may ask you to select the runtime
+environment. In this case, choose the existing _virtualenv_
+based environment and point to `bin/python` under the created
+`dtest-venv` directory (or `cqlsh-venv`, or whichever name you have
+chosen).
+
+Whether you want to play with Python distributed tests or CQLSH tests,
+you need to select the right virtual environment. Remember to switch to
+the one you want:
+
+[source,plaintext]
+----
+deactivate
+source /home/cassandra/dtest-venv/bin/activate
+----
+
+or
+
+[source,plaintext]
+----
+deactivate
+source /home/cassandra/cqlsh-venv/bin/activate
+----
+
+[#cqlsh_tests]
+=== CQLSH tests
+
+CQLSH tests are located in the `pylib/cqlshlib/test` directory. They are
+based on the Nose framework. They require a running Cassandra cluster
+(it can be one or more nodes cluster) as they start a CQL shell
+client which tries to connect to a live node. Each test case starts the
+CQLSH client as a subprocess, issues some commands, and verifies the
+outcome returned by CQLSH to the console.
+
+You need to set up and activate the `virtualenv` for CQLSH tests (see
+<<setup_python_env>> section for details).
+
+So let’s start the cluster first - you can use CCM for that (note that
+CCM gets automatically installed with the `virtualenv` and is
+immediately available once the `virtualenv` is activated):
+
+[source,plaintext]
+----
+ccm create test -n 1 --install-dir=/home/cassandra/cassandra
+ccm updateconf "enable_user_defined_functions: true"
+ccm updateconf "enable_scripted_user_defined_functions: true"
+ccm updateconf "cdc_enabled: true"
+ccm start --wait-for-binary-proto
+----
+
+When those commands complete successfully, there is a cluster up and
+running, and you can run the CQLSH tests. To do so, go to the
+`pylib/cqlshlib` directory (not to the test subdirectory) and call
+the `nosetests` command without any arguments. The tests take around
+5 minutes to complete.
+
+Finally, remember that since you manually started the cluster, you need
+to stop it manually - just call:
+
+[source,plaintext]
+----
+ccm remove test
+----
+
+There is a helper script that does all of those things for you. In
+particular, it builds the Cassandra project, creates a virtual
+environment, runs the CCM cluster, executes the tests, and eventually
+removes the cluster. You find the script in the `pylib` directory. The
+only argument it requires is the Cassandra project directory:
+
+[source,plaintext]
+----
+cassandra@b69a382da7cd:~/cassandra/pylib$ ./cassandra-cqlsh-tests.sh /home/cassandra/cassandra
+----
+
+As you noticed, if you have already built Cassandra, the previous method
+of running tests is much faster. Just remember that all the
+`ccm updateconf` calls must be aligned with the Cassandra version you
+are testing, with the supported features enabled.
+Otherwise, Cassandra won’t start.
+
+==== Running selected tests
+
+You may run all test tests from the selected file by passing that
+file as an argument:
+
+[source,plaintext]
+----
+~/cassandra/pylib/cqlshlib$ nosetests test/test_constants.py
+----
+
+To run a specific test case, you need to specify the module, class name,
+and the test name, for example:
+
+[source,plaintext]
+----
+~/cassandra/pylib/cqlshlib$ nosetests cqlshlib.test.test_cqlsh_output:TestCqlshOutput.test_boolean_output
+----
+
+For more information on selecting tests with the Nose framework, see
+https://nose.readthedocs.io/en/latest/usage.html[this] page.
+
+[#python_dtests]
+=== Python distributed tests
One way of doing integration or system testing at larger scale is
using https://github.com/apache/cassandra-dtest[dtest] (Cassandra distributed test).
These dtests automatically setup Cassandra clusters with certain configurations and simulate use cases you want to test.
-DTests are Python scripts that use `ccmlib` from the https://github.com/pcmanus/ccm[ccm] project.
-The clusters set up with dtests run like ad-hoc clusters executed with `ccm` on your local machine.
-
-Once a cluster is initialized, the http://datastax.github.io/python-driver/installation.html[Python driver] is used to interact with the nodes, manipulate the file system, analyze logs, or change individual nodes.
-
-The https://builds.apache.org/[CI server] uses dtests against new patches to prevent regression bugs.
-Committers can set up build branches and use the CI environment to run tests for your submitted patches.
-Read more on the motivation behind http://www.datastax.com/dev/blog/cassandra-testing-improvements-for-developer-convenience-and-confidence[continuous integration].
The best way to learn how to write dtests is probably by reading the
introduction "http://www.datastax.com/dev/blog/how-to-write-a-dtest[How
@@ -101,7 +580,563 @@ submitting patches!
Please ask in the corresponding JIRA ticket how to write a good dtest for the patch.
In most cases a reviewer or committer will able to support you, and in some cases they may offer to write a dtest for you.
-=== Performance Testing
+==== Run the tests - quick examples
+
+Note that you need to set up and activate the virtualenv for DTests
+(see <<setup_python_env>> section for details). Tests are implemented
+with the PyTest framework, so you use the pytest command to run them.
+Let’s run some tests:
+
+[source,plaintext]
+----
+pytest --cassandra-dir=/home/cassandra/cassandra schema_metadata_test.py::TestSchemaMetadata::test_clustering_order
+----
+
+That command runs the `test_clustering_order` test case from
+`TestSchemaMetadata` class, located in the `schema_metadata_test.py`
+file. You may also provide the file and class to run all test cases from
+that class:
+
+[source,plaintext]
+----
+pytest --cassandra-dir=/home/cassandra/cassandra schema_metadata_test.py::TestSchemaMetadata
+----
+
+or just the file name to run all test cases from all classes defined in that file.
+
+[source,plaintext]
+----
+pytest --cassandra-dir=/home/cassandra/cassandra schema_metadata_test.py
+----
+
+You may also specify more individual targets:
+
+[source,plaintext]
+----
+pytest --cassandra-dir=/home/cassandra/cassandra schema_metadata_test.py::TestSchemaMetadata::test_basic_table_datatype schema_metadata_test.py::TestSchemaMetadata::test_udf
+----
+
+If you run pytest without specifying any test, it considers running all
+the tests it can find. More on the test selection
+https://docs.pytest.org/en/6.2.x/usage.html#specifying-tests-selecting-tests[here]
+You probably noticed that `--cassandra-dir=/home/cassandra/cassandra`
+is constantly added to the command line. It is
+one of the `cassandra-dtest` custom arguments - the mandatory one -
+unless it is defined, you cannot run any Cassandra dtest.
+
+==== Setting up PyTest
+
+All the possible options can be listed by invoking pytest `--help`. You
+see tons of possible parameters - some of them are native PyTest
+options, and some come from Cassandra DTest. When you look carefully at
+the help note, you notice that some commonly used options, usually fixed
+for all the invocations, can be put into the `pytest.ini` file. In
+particular, it is quite practical to define the following:
+
+[source, none]
+----
+cassandra_dir = /home/cassandra/cassandra
+log_cli = True
+log_cli_level = DEBUG
+----
+
+so that you do not have to provide `--cassandra-dir` param each time you
+run a test. The other two options set up console logging - remove them
+if you want logs stored only in log files.
+
+==== Running tests with specific configuration
+
+There are a couple of options to enforce exact test configuration (their
+names are quite self-explanatory):
+
+* `--use-vnodes`
+* `--num-token=xxx` - enables the support of virtual nodes with a certain
+number of tokens
+* `--use-off-heap-memtables` - use off-heap memtables instead of the
+default heap-based
+* `--data-dir-count-per-instance=xxx - the number of data directories
+configured per each instance
+
+Note that the list can grow in the future as new predefined
+configurations can be added to dtests. It is also possible to pass extra
+Java properties to each Cassandra node started by the tests - define
+those options in the `JVM_EXTRA_OPTS` environment variable before
+running the test.
+
+==== Listing the tests
+
+You can do a dry run, so that the tests are only listed and not
+invoked. To do that, add `--collect-only` to the pytest command.
+That additional `-q` option will print the results in the same
+format as you would pass the test name to the pytest command:
+
+[source,plaintext]
+----
+pytest --collect-only -q
+----
+
+lists all the tests pytest would run if no particular test is specified.
+Similarly, to list test cases in some class, do:
+
+[source,plaintext]
+----
+$ pytest --collect-only -q schema_metadata_test.py::TestSchemaMetadata
+schema_metadata_test.py::TestSchemaMetadata::test_creating_and_dropping_keyspace
+schema_metadata_test.py::TestSchemaMetadata::test_creating_and_dropping_table
+schema_metadata_test.py::TestSchemaMetadata::test_creating_and_dropping_table_with_2ary_indexes
+schema_metadata_test.py::TestSchemaMetadata::test_creating_and_dropping_user_types
+schema_metadata_test.py::TestSchemaMetadata::test_creating_and_dropping_udf
+schema_metadata_test.py::TestSchemaMetadata::test_creating_and_dropping_uda
+schema_metadata_test.py::TestSchemaMetadata::test_basic_table_datatype
+schema_metadata_test.py::TestSchemaMetadata::test_collection_table_datatype
+schema_metadata_test.py::TestSchemaMetadata::test_clustering_order
+schema_metadata_test.py::TestSchemaMetadata::test_compact_storage
+schema_metadata_test.py::TestSchemaMetadata::test_compact_storage_composite
+schema_metadata_test.py::TestSchemaMetadata::test_nondefault_table_settings
+schema_metadata_test.py::TestSchemaMetadata::test_indexes
+schema_metadata_test.py::TestSchemaMetadata::test_durable_writes
+schema_metadata_test.py::TestSchemaMetadata::test_static_column
+schema_metadata_test.py::TestSchemaMetadata::test_udt_table
+schema_metadata_test.py::TestSchemaMetadata::test_udf
+schema_metadata_test.py::TestSchemaMetadata::test_uda
+----
+
+You can copy/paste the selected test case to the pytest command to
+run it.
+
+==== Filtering tests
+
+===== Based on configuration
+
+Most tests run with any configuration, but a subset of tests (test
+cases) only run if a specific configuration is used. In particular,
+there are tests annotated with:
+
+* `@pytest.mark.vnodes` - the test is only invoked when the support of
+virtual nodes is enabled
+* `@pytest.mark.no_vnodes` - the test is only invoked when the support
+of virtual nodes is disabled
+* `@pytest.mark.no_offheap_memtables` - the test is only invoked if
+off-heap memtables are not used
+
+Note that enabling or disabling _vnodes_ is obviously mutually
+exclusive. If a test is marked to run only with _vnodes_, it does not
+run when _vnodes_ is disabled; similarly, when a test is marked to run
+only without _vnodes_, it does not run when _vnodes_ is enabled -
+therefore, there are always some tests which would not run with a single
+configuration.
+
+===== Based on resource usage
+
+There are also tests marked with:
+
+`@pytest.mark.resource_intensive`
+
+which means that the test requires more resources than a regular test
+because it usually starts a cluster of several nodes. The meaning of
+resource-intensive is hardcoded to 32GB of available memory, and unless
+your machine or docker container has at least that amount of RAM, such
+test is skipped. There are a couple of arguments that allow for some
+control of that automatic exclusion:
+
+* `--force-resource-intensive-tests` - forces the execution of tests
+marked as `resource_intensive`, regardless of whether there is enough
+memory available or not
+* `--only-resource-intensive-tests` - only run tests marked as
+`resource_intensive` - it makes all the tests without
+`resource_intensive` annotation to be filtered out; technically, it is
+equivalent to passing native PyTest argument: `-m resource_intensive`
+* `--skip-resource-intensive-tests` - skip all tests marked as
+`resource_intensive` - it is the opposite argument to the previous one,
+and it is equivalent to the PyTest native argument: `-m 'not resource_intensive'`
+
+===== Based on the test type
+
+Upgrade tests are marked with:
+
+`@pytest.mark.upgrade_test`
+
+Those tests are not invoked by default at all (just like running
+PyTest with `-m 'not upgrade_test'`), and you have to add some extra
+options to run them:
+* `--execute-upgrade-tests` - enables execution of upgrade tests along
+with other tests - when this option is added, the upgrade tests are not
+filtered out
+* `--execute-upgrade-tests-only` - execute only upgrade tests and filter
+out all other tests which do not have `@pytest.mark.upgrade_test`
+annotation (just like running PyTest with `-m 'upgrade_test'`)
+
+===== Filtering examples
+
+It does not matter whether you want to invoke individual tests or all
+tests or whether you only want to list them; the above filtering rules
+apply. So by using `--collect-only` option, you can learn which tests
+would be invoked.
+
+To list all the applicable tests for the current configuration, use the
+following command:
+
+[source,plaintext]
+----
+pytest --collect-only -q --execute-upgrade-tests --force-resource-intensive-tests
+----
+
+List tests specific to vnodes (which would only run if vnodes are enabled):
+
+[source,plaintext]
+----
+pytest --collect-only -q --execute-upgrade-tests --force-resource-intensive-tests --use-vnodes -m vnodes
+----
+
+List tests that are not resource-intensive
+
+[source,plaintext]
+----
+pytest --collect-only -q --execute-upgrade-tests --skip-resource-intensive-tests
+----
+
+==== Upgrade tests
+
+Upgrade tests always involve more than one product version. There are
+two kinds of upgrade tests regarding the product versions they span -
+let’s call them fixed and generated.
+
+In case of fixed tests, the origin and target versions are hardcoded.
+They look pretty usual, for example:
+
+[source,plaintext]
+----
+pytest --collect-only -q --execute-upgrade-tests --execute-upgrade-tests-only upgrade_tests/upgrade_supercolumns_test.py
+----
+
+prints:
+
+[source,plaintext]
+----
+upgrade_tests/upgrade_supercolumns_test.py::TestSCUpgrade::test_upgrade_super_columns_through_all_versions
+upgrade_tests/upgrade_supercolumns_test.py::TestSCUpgrade::test_upgrade_super_columns_through_limited_versions
+----
+
+When you look into the code, you will see the fixed upgrade path:
+
+[source, python]
+----
+def test_upgrade_super_columns_through_all_versions(self):
+ self._upgrade_super_columns_through_versions_test(upgrade_path=[indev_2_2_x, indev_3_0_x, indev_3_11_x, indev_trunk])
+----
+
+The generated upgrade tests are listed several times - the first
+occurrence of the test case is a generic test definition, and then
+it is repeated many times in generated test classes. For example:
+
+[source,plaintext]
+----
+pytest --cassandra-dir=/home/cassandra/cassandra --collect-only -q --execute-upgrade-tests --execute-upgrade-tests-only upgrade_tests/cql_tests.py -k test_set
+----
+
+prints:
+
+[source,plaintext]
+----
+upgrade_tests/cql_tests.py::cls::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_current_2_2_x_To_indev_2_2_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_current_3_0_x_To_indev_3_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_current_3_11_x_To_indev_3_11_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_current_4_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_2_2_x_To_indev_3_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_2_2_x_To_indev_3_11_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_3_0_x_To_indev_3_11_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_3_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_3_11_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_4_0_x_To_indev_trunk::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_current_2_2_x_To_indev_2_2_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_current_3_0_x_To_indev_3_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_current_3_11_x_To_indev_3_11_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_current_4_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_2_2_x_To_indev_3_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_2_2_x_To_indev_3_11_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_3_0_x_To_indev_3_11_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_3_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_3_11_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_4_0_x_To_indev_trunk::test_set
+----
+
+In this example, the test case name is just `test_set`, and the class
+name is `TestCQL` - the suffix of the class name is automatically
+generated from the provided specification. The first component is the
+cluster specification - there are two variants: `Nodes2RF1` and `Nodes3RF3`
+- they denote that the upgrade is tested on 2 nodes cluster with a
+keyspace using replication factor = 1. Analogously the second variant
+uses 3 nodes cluster with RF = 3.
+
+Then, there is the upgrade specification - for example,
+`Upgrade_indev_3_11_x_To_indev_4_0_x` - which means that this test
+upgrades from the development version of Cassandra 3.11 to the
+development version of Cassandra 4.0 - the meaning of `indev/current`
+and where they are defined is explained later.
+
+When you look into the implementation, you notice that such upgrade test
+classes inherit from `UpgradeTester` class, and they have the
+specifications defined at the end of the file. In this particular case,
+it is something like:
+
+[source, python]
+----
+topology_specs = [
+ {'NODES': 3,
+ 'RF': 3,
+ 'CL': ConsistencyLevel.ALL},
+ {'NODES': 2,
+ 'RF': 1},
+]
+specs = [dict(s, UPGRADE_PATH=p, __test__=True)
+for s, p in itertools.product(topology_specs, build_upgrade_pairs())]
+----
+
+As you can see, there is a list of the cluster specifications and
+the cross product is calculated with upgrade paths returned by the
+`build_upgrade_pairs()` function. That list of specifications is used to
+dynamically generate upgrade tests.
+
+Suppose you need to test something specifically for your scenario. In
+that case, you can add more cluster specifications, like a test with 1
+node or a test with 5 nodes with some different replication factor or
+consistency level. The `build_upgrade_pairs()` returns the list of
+upgrade paths (actually just the origin and target version). That list
+is generated according to the upgrade manifest.
+
+===== Upgrade manifest
+
+The upgrade manifest is a file where all the upgrade paths are defined.
+It is a regular Python file located at
+`upgrade_tests/upgrade_manifest.py`.
+As you noticed, Cassandra origin and target version descriptions
+mentioned in the upgrade test consist of `indev` or `current` prefix
+followed by version string. The definitions of each such version
+description can be found in the manifest, for example:
+
+[source, python]
+----
+indev_3_11_x = VersionMeta(name='indev_3_11_x', family=CASSANDRA_3_11, variant='indev', version='github:apache/cassandra-3.11', min_proto_v=3, max_proto_v=4, java_versions=(8,))
+
+current_3_11_x = VersionMeta(name='current_3_11_x', family=CASSANDRA_3_11, variant='current', version='3.11.10', min_proto_v=3, max_proto_v=4, java_versions=(8,))
+----
+
+There are a couple of different properties which describe those two
+versions:
+
+* `name` - is a name as you can see in the names of the generated
+test classes
+* `family` - families is an enumeration defined in the beginning of
+the upgrade manifest - say family `CASSANDRA_3_11` is just a string
+`"3.11"`. Some major features were introduced or removed with new
+version families, and therefore some checks can be done or some features
+can be enabled/disabled according to that, for example:
+
+[source, python]
+----
+if self.cluster.version() < CASSANDRA_4_0:
+ node1.nodetool("enablethrift")
+----
+
+But it is also used to determine whether our checked-out version matches
+the target version in the upgrade pair (more on that later)
+
+* `variant` and `version` - there are `indev` or `current` variants:
+** `indev` variant means that the development version of Cassandra
+will be used. That is, that version is checked out from the Git
+repository and built before running the upgrade (CCM does it). In this
+case, the version string is specified as `github:apache/cassandra-3.11`,
+which means that it will checkout the `cassandra-3.11` branch from the
+GitHub repository whose alias is `apache`. Aliases are defined in CCM
+configuration file, usually located at `~/.ccm/config` - in this
+particular case, it could be something like:
+
+[source, none]
+----
+[aliases]
+apache:git@github.com:apache/cassandra.git
+----
+
+** `current` variant means that a released version of Cassandra will
+be used. It means that Cassandra distribution denoted by the specified
+version (3.11.10 in this case) is downloaded from the Apache
+repository/mirror - again, the repository can be defined in CCM
+configuration file, under repositories section, something like:
+
+[source,none]
+----
+[repositories]
+cassandra=https://archive.apache.org/dist/cassandra
+----
+
+* `min_proto_v`, `max_proto_v` - the range of usable Cassandra driver
+protocol versions
+* `java_versions` - supported Java versions
+
+The possible upgrade paths are defined later in the upgrade manifest -
+when you scroll the file, you will find the `MANIFEST` map which may
+look similar to:
+
+[source, python]
+----
+MANIFEST = {
+current_2_1_x: [indev_2_2_x, indev_3_0_x, indev_3_11_x],
+current_2_2_x: [indev_2_2_x, indev_3_0_x, indev_3_11_x],
+current_3_0_x: [indev_3_0_x, indev_3_11_x, indev_4_0_x],
+current_3_11_x: [indev_3_11_x, indev_4_0_x],
+current_4_0_x: [indev_4_0_x, indev_trunk],
+
+ indev_2_2_x: [indev_3_0_x, indev_3_11_x],
+ indev_3_0_x: [indev_3_11_x, indev_4_0_x],
+ indev_3_11_x: [indev_4_0_x],
+ indev_4_0_x: [indev_trunk]
+}
+----
+
+It is a simple map where for the origin version (as a key), there is
+a list of possible target versions (as a value). Say:
+
+[source, python]
+----
+current_4_0_x: [indev_4_0_x, indev_trunk]
+----
+
+means that upgrades from `current_4_0_x` to
+`indev_4_0_x` and from `current_4_0_x` to `indev_trunk` will be considered.
+You may make changes to that upgrade scenario in your development branch
+according to your needs.
+There is a command-line option that allows filtering across upgrade
+scenarios: `--upgrade-version-selection=xxx`. The possible values for
+that options are as follows:
+
+* `indev` - which is the default, only selects those upgrade scenarios
+where the target version is in `indev` variant
+* `both` - selects upgrade paths where either both origin and target
+versions are in the same variant or have the same version family
+* `releases` - selects upgrade paths between versions in current variant
+or from the `current` to `indev` variant if both have the same version
+family
+* `all` - no filtering at all - all variants are tested
+
+==== Running upgrades with local distribution
+
+The upgrade test can use your local Cassandra distribution, the one
+specified by the `cassandra_dir` property, as the target version if the
+following preconditions are satisfied:
+
+* the target version is in the `indev` variant,
+* the version family set in the version description matches the version
+family of your local distribution
+
+For example, your local distribution is branched off from the
+`cassandra-4.0` branch, likely matching `indev_4_0_x`. It means that the
+upgrade path with target version `indev_4_0_x` uses your local
+distribution.
+There is a handy command line option which will filter out all the
+upgrade tests which do not match the local distribution:
+`--upgrade-target-version-only`. Given you are on `cassandra-4.0` branch,
+when applied to the previous example, it will be something similar to:
+
+[source,plaintext]
+----
+pytest --cassandra-dir=/home/cassandra/cassandra --collect-only -q --execute-upgrade-tests --execute-upgrade-tests-only upgrade_tests/cql_tests.py -k test_set --upgrade-target-version-only
+----
+
+prints:
+
+[source,plaintext]
+----
+upgrade_tests/cql_tests.py::cls::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_current_4_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_3_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes3RF3_Upgrade_indev_3_11_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_current_4_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_3_0_x_To_indev_4_0_x::test_set
+upgrade_tests/cql_tests.py::TestCQLNodes2RF1_Upgrade_indev_3_11_x_To_indev_4_0_x::test_set
+----
+
+You can see that the upgrade tests were limited to the ones whose target
+version is `indev` and family matches 4.0.
+
+==== Logging
+
+A couple of common PyTest arguments control what is logged to the file
+and the console from the Python test code. Those arguments which start
+from `--log-xxx` are pretty well described in the help message
+(`pytest --help`) and in PyTest documentation, so it will not be discussed
+further. However, most of the tests start with the cluster of
+Cassandra nodes, and each node generates its own logging information and
+has its own data directories.
+
+By default the logs from the nodes are copied to the unique directory
+created under logs subdirectory under root of dtest project. For example:
+
+[source,plaintext]
+----
+(venv) cassandra@b69a382da7cd:~/cassandra-dtest$ ls logs/ -1
+1627455923457_test_set
+1627456019264_test_set
+1627456474949_test_set
+1627456527540_test_list
+last
+----
+
+The `last` item is a symbolic link to the directory containing the logs
+from the last executed test. Each such directory includes logs from each
+started node - system, debug, GC as well as standard streams registered
+upon each time the node was started:
+
+[source,plaintext]
+----
+(venv) cassandra@b69a382da7cd:~/cassandra-dtest$ ls logs/last -1
+node1.log
+node1_debug.log
+node1_gc.log
+node1_startup-1627456480.3398306-stderr.log
+node1_startup-1627456480.3398306-stdout.log
+node1_startup-1627456507.2186499-stderr.log
+node1_startup-1627456507.2186499-stdout.log
+node2.log
+node2_debug.log
+node2_gc.log
+node2_startup-1627456481.10463-stderr.log
+node2_startup-1627456481.10463-stdout.log
+----
+
+Those log files are not collected if `--delete-logs` command-line option
+is added to PyTest. The nodes also produce data files which may be
+sometimes useful to examine to resolve some failures. Those files are
+usually deleted when the test is completed, but there are some options
+to control that behavior:
+
+* `--keep-test-dir` - keep the whole CCM directory with data files and
+logs when the test completes
+* `--keep-failed-test-dir` – only keep that directory when the test has
+failed
+
+Now, how to find where is that directory for the certain test - you need
+to grab that information from the test logs - for example, you may add
+`-s` option to the command line and then look for `"dtest_setup INFO"`
+messages. For example:
+
+[source,plain]
+----
+05:56:06,383 dtest_setup INFO cluster ccm directory: /tmp/dtest-0onwvgkr
+----
+
+says that the cluster work directory is `/tmp/dtest-0onwvgkr`, and all
+node directories can be found under the `test` subdirectory:
+
+[source,plaintext]
+----
+(venv) cassandra@b69a382da7cd:~/cassandra-dtest$ ls /tmp/dtest-0onwvgkr/test -1
+cluster.conf
+node1
+node2
+----
+
+== Performance Testing
Performance tests for Cassandra are a special breed of tests that are
not part of the usual patch contribution process. In fact, many people
@@ -111,7 +1146,7 @@ improvements; such improvements must be measurable.
Several tools exist for running performance tests. Here are a few to investigate:
+* Described above <<microbenchmarks>>
* `cassandra-stress`: built-in Cassandra stress tool
* https://github.com/thelastpickle/tlp-stress[tlp-stress]
* https://github.com/nosqlbench/nosqlbench[NoSQLBench]
-* https://github.com/datastax/cstar_perf[cstar_perf]
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