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Contributing

We welcome bug fixes and patches from 3rd party contributors. Please see the Contributor Agreement for details.

Please follow these guidelines if you want to contribute to ArangoDB:

Reporting Bugs

When reporting bugs, please use our issue tracker on GitHub. Please make sure to include the version number of ArangoDB in your bug report, along with the platform you are using (e.g. Linux OpenSuSE x86_64). Please also include the ArangoDB startup mode (daemon, console, supervisor mode) plus any special configuration. This will help us reproducing and finding bugs.

Please also take the time to check there are no similar/identical issues open yet.

Contributing features, documentation, tests

  • Create a new branch in your fork, based on the devel branch

  • Develop and test your modifications there

  • Commit as you like, but preferably in logical chunks. Use meaningful commit messages and make sure you do not commit unnecessary files (e.g. object files). It is normally a good idea to reference the issue number from the commit message so the issues will get updated automatically with comments.

  • If the modifications change any documented behavior or add new features, document the changes. It should be written in American English. The documentation can be found in docs-hugo repository.

  • When done, run the complete test suite and make sure all tests pass.

  • When finished, push the changes to your GitHub repository and send a pull request from your fork to the ArangoDB repository. Please make sure to select the appropriate branches there. This will most likely be devel.

  • You must use the Apache License for your changes and have signed our CLA. We cannot accept pull requests from contributors who didn't sign the CLA.

  • Please let us know if you plan to work on a ticket. This way we can make sure redundant work is avoided.

Main sections

Source Code

Get the source code

Download the latest source code with Git, including submodules:

git clone --recurse-submodules --jobs 8 https://github.com/arangodb/arangodb

This automatically clones the devel branch.

If you only plan to compile a specific version of ArangoDB locally and do not want to commit changes, you can speed up cloning substantially by using the --depth and --shallow-submodules parameters and specifying a branch, tag, or commit hash using the --branch parameter for the clone command as follows:

git clone --depth 1 --recurse-submodules --shallow-submodules --jobs 8 --branch v3.12.0 https://github.com/arangodb/arangodb

On Windows, Git's automatic conversion to CRLF line endings needs to be disabled. Otherwise, compiling in the Linux build container fails. You can use git clone --config core.autocrlf=input ... so that it only affects this working copy.

Git Setup

Setting up git for automatically merging certain automatically generated files in the ArangoDB source tree:

git config --global merge.ours.driver true

Style Guide

We use clang-format to enforce consistent code formatting. Check STYLEGUIDE.md for a comprehensive description of ArangoDB's Coding Guidelines.

Compiler support policy

We support only officially released compiler versions which major version is at least 9 month old. ArangoDB does not guarantee successful compilation with arbitrary compilers, but uses a certain compiler make and version for building ArangoDB. Both the compiler make and version can change over time.

Unique Log Ids

We have unique log ids in order to allow for easy locating of code producing errors.

LOG_TOPIC("2dead", ....)

To ensure that the ids are unique we run the script ./utils/checkLogIds.py during CI runs. The script will fail with a non-zero status if id collisions are found. You can use openssl rand -hex 3 | sed 's/.//;s/\(.*\)/"\1"/' or anything that suits you to generate a 5 hex digit log id.

ESLint

Use:

./utils/giteslint.sh

to lint your modified files.

./utils/eslint.sh

to find out whether all of your files comply to eslint. This is required to make continuous integration work smoothly.

If you want to add new files / patterns to this make target, edit the respective shell scripts.

To be safe from committing non-linted stuff add .git/hooks/pre-commit with:

./utils/eslint.sh

Adding startup options

Startup option example with explanations:

options->
    addOption("--section.option-name",
              "A brief description of the startup option, maybe over multiple "
              "lines, with an upper-case first letter and ending with a .",
              // for numeric options, you may need to indicate the unit like "timeout (in seconds)"
                new XyzParameter(&_xyzVariable),
                arangodb::options::makeFlags(
                    arangodb::options::Flags::DefaultNoComponents,
                    arangodb::options::Flags::OnCoordinator, // in a cluster, it only has an effect on Coordinators
                    arangodb::options::Flags::OnSingle,      // supported in single server mode, too
                    arangodb::options::Flags::Enterprise,    // only available in the Enterprise Edition
                    arangodb::options::Flags::Uncommon))     // don't show with --help but only --help-all or --help-<section>
    .setIntroducedIn(30906) // format XYYZZ, X = major, YY = minor, ZZ = bugfix version
    .setIntroducedIn(31002) // list all versions the feature is added in but exclude versions that are implied, e.g. 31100
    .setLongDescription(R"(You can optionally add details here. They are only
shown in the online documentation (and --dump-options). 

The _text_ is interpreted as **Markdown**, allowing formatting like
`inline code`, fenced code blocks, and even tables.)");

See lib/ProgramOptions/Option.h for details.

For a feature that is added to v3.9.6, v3.10.2, and devel, you only need to set .setIntroducedIn() for 3.9 and 3.10 but not 3.11 (in devel) because all later versions (after v3.10.2) can reasonably be expected to include the feature, too. Leaving v3.10.2 out would be unclear, however, because users may assume to find the feature in v3.10.0 and v3.10.1 if it was added to v3.9.6.

In the 3.9 branch, you should only set the versions up to 3.9 but not 3.10, pretending no later version exists to avoid additional maintenance burdens.

In 3.9:

    .setIntroducedIn(30906)

In 3.10 and later:

    .setIntroducedIn(30906)
    .setIntroducedIn(31002)

These version remarks can be removed again when all of the listed versions for an option are obsolete (and removed from the online documentation).

Note that .setDeprecatedIn() should not be removed until the startup option is obsoleted or fully removed.

Adding metrics

As of 3.8 we have enforced documentation for metrics. This works as follows. Every metric which is generated has a name. The metric must be declared by using one of the macros

  DECLARE_COUNTER(name, helpstring);
  DECLARE_GAUGE(name, type, helpstring);
  DECLARE_HISTOGRAM(name, scaletype, helpstring);

in some .cpp file (please put only one on a line). Then, when the metric is actually requested in the source code, it gets a template added to the metrics feature with the add method and its name. Labels can be added with the withLabel method. In this way, the compiler ensures that the metric declaration is actually there if the metric is used.

Then there is a helper script utils/generateAllMetricsDocumentation.py which needs python3 with the yaml module. It will check and do the following things:

  • Every declared metric in some .cpp file in the source has a corresponding documentation snippet in Documentation/Metrics under the name of the metric with .yaml appended
  • Each such file is a YAML file of a certain format (see template under Documentation/Metrics/template.yaml)
  • Many of the components are required, so please provide adequate information about your metric
  • Make sure to set introducedIn to the version the metric is added to the current branch's version (e.g. "3.9.6" in the 3.9 branch, "3.10.2" in the 3.10 and devel branches)
  • The script can also assemble all these YAML documentation snippets into a single file under Documentation/Metrics/allMetrics.yaml, the format is again a structured YAML file which can easily be processed by the documentation tools, this is only needed when we update the documentation web pages.

Please, if you have added or modified a metric, make sure to declare the metric as shown above and add a documentation YAML snippet in the correct format. Afterwards, run

utils/generateAllMetricsDocumentation.py

but do not include Documentation/Metrics/allMetrics.yaml in your PR (as was a previous policy). The file is only generated if you add -d as command line option to the script.


Building

Note: Make sure that your source path does not contain spaces. Otherwise, the build process will likely fail.

Building the binaries

To compile ArangoDB 3.12 or later, you can use a Docker build container that is based on Ubuntu and includes the necessary toolchain. You need Git on the host system to get the source code and mount it into the container, however.

Check the .circleci/base_config.yml file for the default build-docker-image value to ensure it's the matching image tag for the version you want to build.

You can start the build container as follows in a Bash-like terminal:

cd arangodb
docker run -it -v $(pwd):/root/project -p 3000:3000 arangodb/ubuntubuildarangodb-devel:3

In PowerShell, use ${pwd} instead of $(pwd).

The port mapping is for accessing the web interface in case you want to run a development server for working on the frontend.

In the fish shell of the container, run the following commands for a release-like build using the officially supported version of the Clang compiler (also see the VERSIONS):

cd /root/project
cmake --preset community -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld" -DCMAKE_LIBRARY_PATH=$OPENSSL_ROOT_DIR/lib -DOPENSSL_ROOT_DIR=/opt
cmake --build --preset community --parallel (nproc)

For a debug build, you can use the community-developer preset instead.

The default target CPU architecture is sandybridge for the x86-64 platform and graviton1 for 64-bit ARM chips. You can specify a different architecture to enable more optimizations or to limit the compiler to the available instructions for a particular architecture:

cmake --preset community -DTARGET_ARCHITECTURE=native ...

On ARM, disable the USE_LIBUNWIND option:

cmake --preset community -DUSE_LIBUNWIND=Off ...

To build specific targets instead of all, you can specify them like shown below:

cmake --build --preset community --target arangod arangosh arangodump arangorestore arangoimport arangoexport arangobench arangovpack frontend

You can find the output files at build-presets/<preset-name>/, with the compiled executables in the bin/ subfolder.

To collect all files for packaging, you can run the following command (with <preset-name> substituted, e.g. with community):

cmake --install ./build-presets/<preset-name> --prefix install/usr

It copies the needed files to a folder called install. It may fail if you only built a subset of the targets. The folder is organized following the Linux directory structure, with the server executable at usr/sbin/arangod, the tools in usr/bin/, the configuration files in usr/etc/arangodb3/, and so on.

For building the ArangoDB Starter (arangodb executable), see the ArangoDB Starter repository.

Building the Web Interface

The web interface is also known as the Web UI, frontend, or Aardvark. Building ArangoDB also builds the frontend unless -DUSE_FRONTEND=Off was specified when configuring CMake or if the frontend target was left out for the build.

To build the web interface via CMake, you can run the following commands:

cmake --preset community
cmake --build --preset community --target frontend

To remove all installed Node.js modules and start a clean installation, run:

cmake --build --preset community --target frontend_clean

You can also build the frontend manually without CMake. Node.js and Yarn need to be installed.

cd <SourceRoot>/js/apps/system/_admin/aardvark/APP/react
yarn install
yarn build

To run a development server, go to js/apps/system/_admin/aardvark/APP/react and run the following command:

yarn start

It should start your browser and open the web interface at http://localhost:3000. Changes to any frontend source files trigger an automatic re-build and reload the browser tab. If you use the build container, make sure to start it with a port mapping for the development server.

Cross Origin Policy (CORS) error

Our front-end development server currently runs on port:3000, while the backend runs on port:8529 respectively. This implies that when the front-end sends a request to the backend would result in Cross-Origin-Policy security checks which recently got enforced by some browsers for security reasons. Until recently, we never had reports of CORS errors when running both the backend and front-end dev servers independently, however, we recently confirmed that this error occurs in (Chrome version 98.0.4758.102 and Firefox version 96.0.1).

In case you run into CORS errors while running the development server, here is a quick fix:

Simply stop your already running backend process with the command below:

cmd + c

Then restart arangodb server with the command below:

./build-presets/<preset-name>/bin/arangod ../Arango --http.trusted-origin '*'

Note:

a: ./build-presets/<preset-name>/bin/arangod: represents the location of arangodb binaries in your machine.

b: ../Arango: is the database directory where the data will be stored.

c: --http.trusted-origin '*' the prefix that allows cross-origin requests.

NPM Dependencies

To add new NPM dependencies, switch into the js/node folder and install them with npm using the following options:

npm install [<@scope>/]<name> --global-style --save --save-exact

or simply

npm install [<@scope>/]<name> --global-style -s -E

The save and save-exact options are necessary to make sure the package.json file is updated correctly.

The global-style option prevents newer versions of npm from unrolling nested dependencies inside the node_modules folder. Omitting this option results in exposing all dependencies of all modules to ArangoDB users.

Finally add the module's licensing information to LICENSES-OTHER-COMPONENTS.md.

If you need to make adjustments/modifications to dependencies or replace transitive dependencies with mocks, make sure to run npx patch-package $dependencyName in the js/node folder and commit the resulting patch file in js/node/patches. This will ensure the changes are persisted if the dependency is overwritten by npm in the future.

For example to commit a patch for the transitive dependency is-wsl of the dependency node-netstat, make your changes in js/node/node_modules/node-netstat/node_modules/is-wsl and then run npx patch-package node-netstat/is-wsl in js/node and commit the resulting patch file in js/node/patches.

Build the HTTP API documentation for Swagger-UI

The REST HTTP API of the ArangoDB server is described using the OpenAPI specification (formerly Swagger). The source code is in documentation repository at https://github.com/arangodb/docs-hugo.

To build the api-docs.json file for viewing the API documentation in the Swagger-UI of the web interface (SUPPORT section, Rest API tab), run the following commands in a terminal:

  1. Get a working copy of the documentation content with Git:

    git clone https://github.com/arangodb/docs-hugo

  2. Enter the docs-hugo folder:

    cd docs-hugo

  3. Optional: Switch to a tag, branch, or commit if you want to build the API documentation for a specific version of the docs:

    git checkout <reference>

  4. Enter the folder of the Docker toolchain, amd64 on the x86-64 architecture and arm64 on ARM CPUs:

    cd toolchain/docker/amd64 # x86-64
    cd toolchain/docker/arm64 # ARM 64-bit
  5. Set the environment variable ENV to any value other than local to make the documentation tooling not start a live server in watch mode but rather create and static build and exit:

    export ENV=static  # Bash
    set -xg ENV static # Fish
    $Env:ENV='static'  # PowerShell
  6. Run Docker Compose using the plain build configuration for the documentation:

    docker compose -f docker-compose.plain-build.yml up --abort-on-container-exit

  7. When the docs building finishes successfully, you can find the api-docs.json files in site/data/<version>/.

  8. Copy the respective api-docs.json file into the ArangoDB working copy or installation folder under js/apps/system/_admin/aardvark/APP/api-docs.json and refresh the web interface.


Running

Temporary files and temp directories

ArangoDB tries to locate the temporary directory like this:

  • the environment variable TMPDIR is evaluated.
  • the startup option --temp.path overrules the above system provided settings.

Our testing framework uses this path in the cluster test cases to set an environment variable ARANGOTEST_ROOT_DIR which is global to the running cluster, but specific to the current test suite. You can access this as global.instanceManager.rootDir in Javascript client tests and via the environment variable on the C++ level.

Local Cluster Startup

The scripts scripts/startLocalCluster helps you to quickly fire up a testing cluster on your local machine. scripts/shutdownLocalCluster stops it again.

scripts/startLocalCluster [numDBServers numCoordinators [mode]]

Without arguments it starts 2 DB-Servers and 1 Coordinator in the background, running on ports 8629, 8630 and 8530 respectively. The Agency runs on port 4001.

Mode:

  • C: Starts the first Coordinator with --console in a separate window (using an xterm).
  • D: Starts all DB-Servers in the GNU debugger in separate windows (using xterms). Hit ENTER in the original terminal where the script runs to continue once all processes have been started up in the debugger.

Debugging

Runtime

  • start arangod with --console to get a debug console
  • Cheapen startup for valgrind: --server.rest-server false

Startup

Arangod has a startup rc file: ~/.arangod.rc. It's evaled as JavaScript. A sample version to help working with the arangod rescue console may look like that:

internal = require("internal");
fs = require("fs");
db = internal.db;
time = internal.time;
timed = function (cb) {
  let s = time();
  cb();
  return time() - s;
};
print = internal.print;

Hint: You shouldn't lean on these variables in your Foxx services.

Debugging AQL execution blocks

To debug AQL execution blocks, two steps are required:

  • turn on logging for queries using --extraArgs:log.level queries=info
  • divert this facilities log output into individual files: --extraArgs --log.output queries file://@ARANGODB_SERVER_DIR@/arangod_queries.log
  • send queries enabling block debugging: db._query('RETURN 1', {}, { profile: 4 })

You now will get log entries with the contents being passed between the blocks.

Crashes

The Linux builds of the arangod executable contain a built-in crash handler (introduced in v3.7.0). The crash handler is supposed to log basic crash information to the ArangoDB logfile in case the arangod process receives one of the signals SIGSEGV, SIGBUS, SIGILL, SIGFPE or SIGABRT. SIGKILL signals, which the operating system can send to a process in case of OOM (out of memory), are not interceptable and thus cannot be intercepted by the crash handler,

In case the crash handler receives one of the mentioned interceptable signals, it will write basic crash information to the logfile and a backtrace of the call site. The backtrace can be provided to the ArangoDB support for further inspection. Note that backtraces are only usable if debug symbols for ArangoDB have been installed as well.

After logging the crash information, the crash handler will execute the default action for the signal it has caught. If core dumps are enabled, the default action for these signals is to generate a core file. If core dumps are not enabled, the crash handler will simply terminate the program with a non-zero exit code.

The crash handler can be disabled at server start by setting the environment variable ARANGODB_OVERRIDE_CRASH_HANDLER to 0 or off.

An example log output from the crash handler looks like this:

2020-05-26T23:26:10Z [16657] FATAL [a7902] {crash} ArangoDB 3.7.1-devel enterprise [linux], thread 22 [Console] caught unexpected signal 11 (SIGSEGV) accessing address 0x0000000000000000: signal handler invoked
2020-05-26T23:26:10Z [16657] INFO [308c3] {crash} frame 1 [0x00007f9124e93ece]: _ZN12_GLOBAL__N_112crashHandlerEiP9siginfo_tPv (+0x000000000000002e)
2020-05-26T23:26:10Z [16657] INFO [308c3] {crash} frame 2 [0x00007f912687bfb2]: sigprocmask (+0x0000000000000021)
2020-05-26T23:26:10Z [16657] INFO [308c3] {crash} frame 3 [0x00007f9123e08024]: _ZN8arangodb3aql10Expression23executeSimpleExpressionEPKNS0_7AstNodeEPNS_11transaction7MethodsERbb (+0x00000000000001c4)
2020-05-26T23:26:10Z [16657] INFO [308c3] {crash} frame 4 [0x00007f9123e08314]: _ZN8arangodb3aql10Expression7executeEPNS0_17ExpressionContextERb (+0x0000000000000064)
2020-05-26T23:26:10Z [16657] INFO [308c3] {crash} frame 5 [0x00007f9123feaab2]: _ZN8arangodb3aql19CalculationExecutorILNS0_15CalculationTypeE0EE12doEvaluationERNS0_15InputAqlItemRowERNS0_16OutputAqlItemRowE (+0x0000000000000062)
2020-05-26T23:26:10Z [16657] INFO [308c3] {crash} frame 6 [0x00007f9123feae85]: _ZN8arangodb3aql19CalculationExecutorILNS0_15CalculationTypeE0EE11produceRowsERNS0_22AqlItemBlockInputRangeERNS0_16OutputAqlItemRowE (+0x00000000000000f5)
...
2020-05-26T23:26:10Z [16657] INFO [308c3] {crash} frame 31 [0x000018820ffc6d91]: *no symbol name available for this frame
2020-05-26T23:26:10Z [16657] INFO [ded81] {crash} available physical memory: 41721995264, rss usage: 294256640, vsz usage: 1217839104, threads: 46
Segmentation fault (core dumped)

The first line of the crash output will contain the cause of the crash (SIGSEGV in this case). The following lines contain information about the stack frames. The hexadecimal value presented for each frame is the instruction pointer, and if debug symbols are installed, there will be name information about the called procedures (in mangled format) plus the offsets into the procedures. If no debug symbols are installed, symbol names and offsets cannot be shown for the stack frames.

Memory profiling

Starting in 3.6 we have support for heap profiling when using jemalloc on Linux. Here is how it is used:

Use this cmake option in addition to the normal options:

-DUSE_JEMALLOC_PROF

when building. Make sure you are using the builtin jemalloc. You need debugging symbols to analyze the heap dumps later on, so compile with -DCMAKE_BUILD_TYPE=Debug or RelWithDebInfo. Debug is probably less confusing in the end.

Then set the environment variable for each instance you want to profile:

export MALLOC_CONF="prof:true"

When this is done, jemalloc internally does some profiling. You can then use this endpoint to get a heap dump:

curl "http://localhost:8529/_admin/status?memory=true" > heap.dump

You can analyze such a heap dump with the jeprof tool, either by inspecting a single dump like this:

jeprof build/bin/arangod heap.dump

or compare two dumps which were done on the same process to analyze the difference:

jeprof build/bin/arangod --base=heap.dump heap.dump2

So far, we have mostly used the web command to open a picture in a browser. It produces an svg file.

The tool isn't perfect, but can often point towards the place which produces for example a memory leak or a lot of memory usage.

This is known to work under Linux and the jeprof tool comes with the libjemalloc-dev package on Ubuntu.

Using it with the integration tests is possible; snapshots will be taken before the first and after each subsequent testcase executed.

Core Dumps

A core dump consists of the recorded state of the working memory of a process at a specific time. Such a file can be created on a program crash to analyze the cause of the unexpected termination in a debugger.

Linux Core Dumps

Linux Core Dump Generation

Generally core dumps have to be enabled using:

 ulimit -c unlimited

You should then see:

 ulimit -a
 core file size          (blocks, -c) unlimited

for each shell and its subsequent processes.

Hint: on Ubuntu the apport package may interfere with this; however you may use the systemd-coredump package which automates much of the following:

So that the unit testing framework can autorun gdb it needs to reliably find the corefiles. In Linux this is configured via the /proc filesystem, you can make this reboot permanent by creating the file /etc/sysctl.d/corepattern.conf (or add the following lines to /etc/sysctl.conf)

# We want core files to be located in a central location
# and know the PID plus the process name for later use.
kernel.core_uses_pid = 1
kernel.core_pattern =  /var/tmp/core-%e-%p-%t

to reload the above settings most systems support:

sudo sysctl -p

Note that the proc paths translate sub-directories to dots. The non permanent way of doing this in a running system is:

echo 1 > /proc/sys/kernel/core_uses_pid
echo '/var/tmp/core-%e-%p-%t' > /proc/sys/kernel/core_pattern

(you may also inspect these files to validate the current settings)

More modern systems facilitate systemd-coredump (via a similar named package) to control core dumps. On most systems it will put compressed core dumps to /var/lib/systemd/coredump.

In order to use automatic core dump analysis with the unittests you need to configure /etc/systemd/coredump.conf and set Compress=no - so instant analysis may take place.

Please note that we can't support Ubuntu Apport. Please use apport-unpack to send us the bare core dumps.

In order to get core dumps from binaries changing their UID the system needs to be told that its allowed to write cores from them. Default ArangoDB installations will do exactly that, so the following is necessary to make the system produce core dumps from production ArangoDB instances:

Edit /etc/security/limits.conf to contain:

arangodb        -       core            infinity

Edit the systemd unit file /lib/systemd/system/arangodb3.service (USE infinity!!!):

## setting for core files
# Any dir that is writable by the user running arangod
WorkingDirectory=/var/lib/arangodb3
# core limit - set this to infinity to enable cores
LimitCORE=0

Enable new systemd settings:

systemctl daemon-reload && systemctl restart arangodb3.service

Enable suid process dumping:

echo 1 >/proc/sys/fs/suid_dumpable

Make the above change permanent:

echo "sys.fs.suid_dumpable = 1" >> /etc/sysctl.d/99-suid-coredump.conf

Please note that at least GDB 9 is required.

You can also generate core dumps from running processes without killing them by using gdb:

# sleep 100000 &
[2] 6942
# gdb /bin/sleep 6942
...
0x00007faaa7abd4e4 in __GI___nanosleep (requested_time=0x7ffd047c9940, remaining=0x0) at ../sysdeps/unix/sysv/linux/nanosleep.c:28
gdb> gcore
Saved corefile core.6942
gdb> quit
Detaching from program: /bin/sleep, process 6942
# ls -l core*
-rw-r--r--  1 me users  352664 Nov 27 10:48  core.6942
Installing GDB 8 on RedHat7 or Centos7

RedHat7 and Centos7 have a package called devtoolset-7 which contains a complete set of relative modern development tools. It can be installed by running

sudo yum install devtoolset-7

These will be installed under some path under /opt. To actually use these tools, run

scl enable devtoolset-7 bash

to start a shell in which these are used. For example, you can pull a core dump with gcore using this version, even for ArangoDB >= 3.4.

Analyzing Core Dumps on Linux

We offer debug packages containing the debug symbols for your binaries. Please install them if you didn't compile yourselves.

Given you saw in the log of the arangod with the PID 25216 that it died, you should then find /var/tmp/core-V8 WorkerThread-25216-1490887259 with this information. We may now start GDB and inspect whats going on:

gdb /usr/sbin/arangod /var/tmp/*25216*

These commands give useful information about the incident:

backtrace full
thread apply all bt

The first gives the full stacktrace including variables of the last active thread, the later one the stacktraces of all threads.

Unittests

Dependencies

  • Google Test (compile time, shipped in the 3rdParty directory)

Folder Locations

There are several major places where unittests live:

Path / File Description
tests/js/server/ JavaScript tests, runnable on the server
tests/js/common/ JavaScript tests, runnable on the server & via arangosh
tests/js/common/test-data/ Mock data used for the JavaScript tests
tests/js/client/ JavaScript tests, runnable via arangosh
tests/ (remaining) Google Test unittests
implementation specific files
scripts/unittest Entry wrapper script for UnitTests/unittest.js
                                      |

see [js/client/modules/@arangodb/README.md] about implementation details of the framework.

Filename conventions

Special patterns in the test filenames are used to select tests to be executed or skipped depending on parameters:

Substring Description
-cluster These tests will only run if clustering is tested (option 'cluster' needs to be true).
-noncluster These tests will only run if no cluster is used (option 'cluster' needs to be false)
-noinstr_or_noncluster These tests will not be ran if instrumented binaries are used and we are running in cluster mode
-noasan These tests will not be ran if *san instrumented binaries are used
-noinstr These tests will not be ran if instrumented binaries are used, be it *san or gcov
-nocov These tests will not be ran if gcov instrumented binaries are used.
-timecritical These tests are critical to execution time - and thus may fail if arangod is to slow. This may happen i.e. if you run the tests in valgrind, so you want to avoid them since they will fail anyways. To skip them, set the option skipTimeCritical to true.
-spec These tests are run using the mocha framework instead of jsunity.
-nightly These tests produce a certain thread on infrastructure or the test system, and therefore should only be executed once per day.
-grey These tests are currently listed as "grey", which means that they are known to be unstable or broken. These tests will not be executed by the testing framework if the option --skipGrey is given. If --onlyGrey option is given then non-"grey" tests are skipped. See tests/Greylist.txt for up-to-date information about greylisted tests. Please help to keep this file up to date.

JavaScript Framework

Since several testing technologies are utilized, and different ArangoDB startup options may be required (even different compilation options may be required) the framework is split into testsuites.

Get a list of the available testsuites and options by invoking:

./scripts/unittest

To locate the suite(s) associated with a specific test file use:

./scripts/unittest find --test tests/js/client/shell/api/aqlfunction.js

Run all suite(s) associated with a specific test file in single server mode:

./scripts/unittest auto --test tests/js/client/shell/api/aqlfunction.js

Run all suite(s) associated with a specific test file in cluster mode:

./scripts/unittest auto --cluster true --test tests/js/client/shell/api/aqlfunction.js

Run all C++ based Google Test (gtest) tests using the arangodbtests binary:

./scripts/unittest gtest

Run specific gtest tests:

./scripts/unittest gtest --testCase "IResearchDocumentTest.*:*ReturnExecutor*"
# equivalent to:
./build/bin/arangodbtests --gtest_filter="IResearchDocumentTest.*:*ReturnExecutor*"

Controlling the place where the test-data is stored:

TMPDIR=/some/other/path ./scripts/unittest shell_client_aql

Note that the arangodbtests executable is not compiled and shipped for production releases (-DUSE_GOOGLE_TESTS=off).

scripts/unittest is only a wrapper for the most part, the backend functionality lives in js/client/modules/@arangodb/testutils. The actual testsuites are located in the js/client/modules/@arangodb/testsuites folder.

Passing Options

The first parameter chooses the facility to execute. Available choices include:

  • shell_client
  • shell_api
  • shell_api_multi
  • shell_client_aql
  • shell_client_multi

Different facilities may take different options. The above mentioned usage output contains the full detail.

Instead of starting its own instance, unittest can also make use of a previously started arangod instance. You can launch the instance as you want including via a debugger or rr and prepare it for what you want to test with it. You then launch the test on it like this (assuming the default endpoint):

./scripts/unittest shell_client --server tcp://127.0.0.1:8529/

A commandline for running a single test (-> with the facility 'single_server') using valgrind could look like this. Options are passed as regular long values in the syntax --option value --sub:option value. Using Valgrind could look like this:

./scripts/unittest shell_client --test tests/js/server/aql/aql-escaping.js \
  --cluster true \
  --extraArgs:server.threads 1 \
  --extraArgs:scheduler.threads 1 \
  --extraArgs:javascript.gc-frequency 1000000 \
  --extraArgs:javascript.gc-interval 65536 \
  --extraArgs:agent.log.level trace \
  --extraArgs:log.level request=debug \
  --extraArgs:log.force-direct true \
  --javascript.v8-contexts 2 \
  --valgrind /usr/bin/valgrind \
  --valgrindargs:log-file /tmp/valgrindlog.%p
  • We specify the test to execute
  • We specify some arangod arguments via --extraArgs which increase the server performance
  • We specify to run using valgrind (this is supported by all facilities)
  • We specify some valgrind commandline arguments
  • We set the log levels for agents to trace (the Iinstance type can be specified by:
    • single
    • agent
    • dbserver
    • coordinator )
  • We set the requests log level to debug on all instances
  • We force the logging not to happen asynchronous
  • Eventually you may still add temporary console.log() statements to tests you debug.

Running a Single Unittest Suite

Testing a single test with the framework directly from the arangosh:

scripts/unittest shell_client --test tests/js/client/shell/shell-client.js

You can also only execute a filtered test case in a jsunity/mocha/gtest test suite (in this case testTokens):

scripts/unittest shell_client_aql --test tests/js/client/aql/aql-escaping.js --testCase testTokens

scripts/unittest shell_client --test shell-util-spec.js --testCase zip

scripts/unittest gtest --testCase "IResearchDocumentTest.*"

Running a test against a server you started (instead of letting the script start its own server):

scripts/unittest shell_client --test api-batch.js --server tcp://127.0.0.1:8529 --serverRoot /tmp/123

Re-running previously failed tests:

scripts/unittest <args> --failed

Specifying a --test filter containing -cluster will implicitly set --cluster true and launch a cluster test.

The <args> should be the same as in the previous run, only --test/--testCase can be omitted. The information which tests failed is taken from the UNITTEST_RESULT.json in your test output folder. This failed filter should work for all jsunity and mocha tests.

Running several Suites in one go

Several testsuites can be launched consequently in one run by specifying them as coma separated list. They all share the specified commandline arguments. Individual arguments can be passed as a JSON array. The JSON Array has to contain the same number of elements as testsuites specified. The specified individual parameters will overrule global and default values.

Running the same testsuite twice with different and shared parameters would look like this:

./scripts/unittest  shell_client_multi,shell_client_multi --test shell-admin-status.js  --optionsJson '[{"http2":true,"suffix":"http2"},{"http":true,"suffix":"http"}]'

Running Foxx Tests with a Fake Foxx Repo

Since downloading Foxx apps from GitHub can be cumbersome with shaky DSL and DoS'ed GitHub, we can fake it like this:

export FOXX_BASE_URL="http://germany/fakegit/"
./scripts/unittest single_server --test 'tests/js/server/shell/shell-foxx-manager-spec.js'

Running jsUnity Tests

Assume that you have a test file containing:

function exampleTestSuite () {
  return {
    testSizeOfTestCollection : function () {
    assertEqual(5, 5);
  };
}

jsUnity.run(aqlTestSuite);

return jsunity.done();

Then you can run the test suite using jsunity.runTest():

arangosh> require("jsunity").runTest("test.js");
2012-01-28T19:10:23Z [10671] INFO Running aqlTestSuite
2012-01-28T19:10:23Z [10671] INFO 1 test found
2012-01-28T19:10:23Z [10671] INFO [PASSED] testSizeOfTestCollection
2012-01-28T19:10:23Z [10671] INFO 1 test passed
2012-01-28T19:10:23Z [10671] INFO 0 tests failed
2012-01-28T19:10:23Z [10671] INFO 1 millisecond elapsed

Running jsUnity Tests with arangosh client

Run tests this way:

require("jsunity").runTest("tests/js/client/shell/shell-client.js");

You can only run tests which are intended to be ran via arangosh.

Mocha Tests

All tests with -spec in their names are using the mochajs.org framework. To run those tests, e.g. in the arangosh, use this:

require("@arangodb/mocha-runner").runTest('tests/js/client/endpoint-spec.js', true)

Release tests

RTA has some tests to verify production integration. To aid their development, they can also be used from the ArangoDB source tree.

MakeData / CheckData suite

The makedata framework as git submodule in 3rdParty/rta-makedata is implemented in arangosh javascript. It uses the respective interface to execute DDL and DML operations. It facilitates a per database approach, and can be run multiple times in loops. It has hooks, that are intended to create DDL/DML objects in a way their existence can be revalidated later on by other script hooks. The check hooks must respect a flag whether they can create resources or whether they're talking to a read-only source. Thus, the check-hooks may create data, but must remove it on success. The checks should be considered not as time intense as the creation of the data.

It is used by RTA to:

  • revalidate data can be created
  • data survives hot backup / restore
  • data makes it across the replication
  • data is accessible with clusters with one failing DB-Server
  • data makes it across DC2DC replication

With this integration additional DDL/DML checks can be more easily be developed without the rather time and resource consuming and complex RTA framework.

The rta_makedata testsuite can be invoked with:

  • --cluster false - to be ran on a single server setup.
  • --cluster true to be ran on a 3 db-server node cluster; one run will check resilience with 2 remaining dbservers.

These combinations are also engaged via test-definitions.txt.

Invoke it like this:

./scripts/unittest rta_makedata --cluster true

(you can override the 3rdParty/rta-makedata with --rtasource ../rta-makedata ,if you want to work with a full git clone of RTA-makedata)

Driver tests

Go driver

Pre-requisites:

  • have a go-driver checkout next to the ArangoDB source tree
  • have the go binary in the path

Once this is completed, you may run it like this:

./scripts/unittest go_driver --gosource ../go-driver/ --testCase View --goOptions:timeout 180m --cluster true

This will invoke the test with a filter to only execute tests that have View in their name. As an additional parameter we pass -timeout 100m to the driver test.

The driver integration also features JWT pass in. It will launch a cluster with 3 DB-Servers, as the tests expect to have at least 3 DB-Servers.

Java driver

Pre-requisites:

  • have a arangodb-java-driver checkout next to the ArangoDB source tree in the 'next' branch
  • have a maven binary in the path (mvn) configured to use JDK 11

You can check if maven is correctly configured to use JDK 11 executing: mvn -version. In case you have multiple JVMs in your machine and JDK 11 is not the default one, you can set the environment variable JAVA_HOME to the root path of JDK 11.

Once this is completed, you may run it like this:

./scripts/unittest java_driver --javasource ../arangodb-java-driver/ \
    --javaOptions:failIfNoTests false \
    --testCase com.arangodb.next.api.collection.CollectionApiTest#countAndDropCollection \
    --cluster true

For possible javaOptions see arangodb-java-driver/dev-README.md#test-provided-deployment in the java source, or the surefire documentation

ArangoJS

Pre-requisites:

  • have a arangojs checkout next to the ArangoDB source tree
  • have a nodejs and yarn binaries installed and in the path
  • ran yarn once in the arangojs source tree

Once this is completed, you may run it like this:

./scripts/unittest js_driver --jssource ../arangojs/ \
    --testCase 'kills the given query' \
    --cluster true

arangodb-php

Pre-requisites:

  • have a arangodb-php checkout next to the ArangoDB source tree
  • have php and phpunit binaries installed and in the path

At the time being phpunit version 6.5 is supported. Install it like this:

wget "https://phar.phpunit.de/phpunit-6.5.14.phar"
mv phpunit-6.5.14.phar /usr/bin/phpunit
chmod a+x /usr/bin/phpunit

Once this is completed, you may run it like this:

./scripts/unittest php_driver --phpsource ../arangodb-php/ \
    --testCase testSaveVerticesAndEdgeBetweenThemAndRemoveOneByOne \
    --cluster true \
    --phpkeepalive false

(without connection keepalive)

generic driver interface

The generic driver interface expects to find i.e. script inside the driver source, that does all the plumbing to run the respective tests against the provided arangodb instance. The invoked script is expected to exit non-zero on failure. All content of stdout will be forwarded to the testresults. All required data is passed as parameters:

  • driversource - the source directory with the workingcopy of the driver
  • driverScript - the script to be executed. defaults to run_tests.sh
  • driverScriptInterpreter - since currently there is no shebang support, this needs to be provided or defaults to /bin/bash.
  • driverOptions options to be passed on to the driver works in the form of --driverOptions.argname value evaluating to --argname value
  • --test testcase evaluates to --testsuite testcase
  • --testCase testcaseExp evaluates to --filter testcaseExp

Statically provided options (with sample values):

  • --instanceUrl http://127.0.0.1:7327
  • --instanceEndpoint tcp://127.0.0.1:7327
  • --port 7327
  • --host 127.0.0.1
  • --auth false
  • --username root
  • --password ''
  • --[no-]enterprise
  • --deployment-mode [SINGLE_SERVER|CLUSTER]

Debugging Tests

This is quick introduction only.

Running a single arangosh client test:

./scripts/unittest shell_client --test api-import.js

Debugging arangosh with gdb:

server> ./scripts/unittest shell_client --test api-import.js --server tcp://127.0.0.1:7777

client> gdb --args ./build/bin/arangod --server.endpoint http+tcp://127.0.0.1:6666 \
                                       --server.authentication false \
                                       --log.level communication=trace \
                                       ../arangodb-data-test

Debugging a storage engine:

host> rm -fr ../arangodb-data-rocksdb/; \
   gdb --args ./build/bin/arangod \
       --console \
       --foxx.queues false \
       --server.statistics false \
       --server.endpoint http+tcp://0.0.0.0:7777 \
       ../arangodb-data-rocksdb
(gdb) catch throw
(gdb) r
arangod> require("jsunity").runTest("tests/js/client/shell/shell-client.js");

Forcing downgrade from VPack to JSON

While velocypack is better for the machine to machine communication, JSON does a better job if you want to observe the communication using tcpdump. Hence a downgrade of the communication to JSON can be made at start time:

arangosh --server.force-json true --server.endpoint ...

Running tcpdump / windump for the SUT

Don't want to miss a beat of your test? If you want to invoke tcpdump with sudo, make sure that your current shell has sudo enabled. Try like this:

sudo /bin/true; ./scripts/unittest http_server \
  --sniff sudo --cleanup false

The pcap file will end up in your tests temporary directory. You may need to press an additional ctrl+c to force stop the sudo'ed tcpdump.

Evaluating json test reports from previous testruns

All test results of testruns are dumped to a json file named UNITTEST_RESULT.json which can be used for later analyzing of timings etc.

Currently available Analyzers are:

  • unitTestPrettyPrintResults - Prints a pretty summary and writes an ASCII representation into out/testfailures.txt (if any errors)

  • saveToJunitXML - saves jUnit compatible XML files

  • locateLongRunning - searches the 10 longest running tests from a testsuite; may add comparison to --otherFile specified times

  • locateShortServerLife - whether the servers lifetime for the tests isn't at least 10 times as long as startup/shutdown

  • locateLongSetupTeardown - locate tests that may use a lot of time in setup/teardown

  • yaml - dumps the json file as a yaml file

  • unitTestTabularPrintResults - prints a table, add one (or more) of the following columns to print by adding it to --tableColumns:

    • duration - the time spent in the complete testfile
    • status - success/fail
    • failed - fail?
    • total - the time spent in the testcase
    • totalSetUp - the time spent in setup summarized
    • totalTearDown - the time spent in teardown summarized
    • processStats.sum_servers.minorPageFaults - Delta run values from /proc/<pid>/io summarized over all instances
    • processStats.sum_servers.majorPageFaults -
    • processStats.sum_servers.userTime -
    • processStats.sum_servers.systemTime -
    • processStats.sum_servers.numberOfThreads -
    • processStats.sum_servers.residentSize -
    • processStats.sum_servers.residentSizePercent -
    • processStats.sum_servers.virtualSize -
    • processStats.sum_servers.rchar -
    • processStats.sum_servers.wchar -
    • processStats.sum_servers.syscr -
    • processStats.sum_servers.syscw -
    • processStats.sum_servers.read_bytes -
    • processStats.sum_servers.write_bytes -
    • processStats.sum_servers.cancelled_write_bytes -
    • processStats.sum_servers.sockstat_sockets_used - Absolute values from /proc/<pid>/net/sockstat summarized over all instances
    • processStats.sum_servers.sockstat_TCP_inuse -
    • processStats.sum_servers.sockstat_TCP_orphan -
    • processStats.sum_servers.sockstat_TCP_tw -
    • processStats.sum_servers.sockstat_TCP_alloc -
    • processStats.sum_servers.sockstat_TCP_mem -
    • processStats.sum_servers.sockstat_UDP_inuse -
    • processStats.sum_servers.sockstat_UDP_mem -
    • processStats.sum_servers.sockstat_UDPLITE_inuse -
    • processStats.sum_servers.sockstat_RAW_inuse -
    • processStats.sum_servers.sockstat_FRAG_inuse -
    • processStats.sum_servers.sockstat_FRAG_memory -

    Process stats are kept by process. So if your DB-Server had the PID 1721882, you can dial its values by specifying processStats.1721882_dbserver.sockstat_TCP_tw into the generated table.

i.e.

./scripts/examine_results.js -- 'yaml,locateLongRunning' --readFile out/UNITTEST_RESULT.json

or:

./scripts/examine_results.js -- 'unitTestTabularPrintResults' \
   --readFile out/UNITTEST_RESULT.json \
   --tableColumns 'duration,processStats.sum_servers.sockstat_TCP_orphan,processStats.sum_servers.sockstat_TCP_tw

revalidating one testcase using jq:

jq '.shell_client."enterprise/tests/js/common/shell/smart-graph-enterprise-cluster.js"' < \
  out/UNITTEST_RESULT.json |grep sockstat_TCP_tw

getting the PIDs of the server in the testrun using jq:

jq '.shell_client."enterprise/tests/js/common/shell/smart-graph-enterprise-cluster.js"' < \
  out/UNITTEST_RESULT.json |grep '"[0-9]*_[agent|dbserver|coordinator]'
"1721674_agent": {
"1721675_agent": {
"1721676_agent": {
"1721882_dbserver": {
"1721883_dbserver": {
"1721884_dbserver": {
"1721885_coordinator": {

Installing bash completion for ./scripts/unittest

Calling

./scripts/buildUnittestBashCompletion.bash > ~/arango_unittest_comp.bash

generates a bash completion script for ./scripts/unittest which can be sourced in your ~/.bashrc or ~/.bash_profile:

. ~/arango_unittest_comp.bash

You can also install completions directly by running

  eval "$(./scripts/buildUnittestBashCompletion.bash)"

in your shell, or .bashrc etc., but note that it has to be executed in the arangodb directory.

Additional Resources