Open Distro for Elasticsearch asynchronous search

Asynchronous search makes it possible for users to run such queries without worrying about the query timing out. These queries run in the background, and users can track the progress, and retrieve partial results as they become available.

The asynchronous search plugin supports the below operations

1. Submit asynchronous search

POST /_opendistro/_asynchronous_search?wait_for_completion_timeout=500ms&keep_on_completion=true&keep_alive=3d
{  "aggs": {
    "city": {
      "terms": {
        "field": "city", "size": 50
      }
    }
  }
}

2. Retrieve asynchronous search results

GET /_opendistro/_asynchronous_search/FjdITFhYbC1zVFdHVVV1MUd3UkxkMFEFMjQ1MzYUWHRrZjhuWUJXdFhxMmlCSW5HTE8BMQ==?keep_alive=3d

3. Delete an asynchronous search

DELETE /_opendistro/_asynchronous_search/FjdITFhYbC1zVFdHVVV1MUd3UkxkMFEFMjQ1MzYUWHRrZjhuWUJXdFhxMmlCSW5HTE8BMQ==

4. Stats for asynchronous search

GET /_opendistro/_asynchronous_search/stats

Tunable Settings

1. opendistro.asynchronous_search.max_search_running_time : Maximum running time for the search beyond which the search would be terminated
2. opendistro.asynchronous_search.node_concurrent_running_searches : Concurrent searches running per coordinator node
3. opendistro.asynchronous_search.max_keep_alive : Maximum keep alive for search which dictates how long the search is allowed to be present in the cluster
4. opendistro.asynchronous_search.max_wait_for_completion_timeout : Maximum keep on completion to block for the search response
5. opendistro.asynchronous_search.persist_search_failures : Persist asynchronous search result ending with search failure in system index

Setup

1. Check out this package from version control.
2. Launch Intellij IDEA, choose Import Project, and select the settings.gradle file in the root of this package.
3. To build from the command line, set JAVA_HOME to point to a JDK >= 14 before running ./gradlew.

• Unix System

  1. export JAVA_HOME=jdk-install-dir: Replace jdk-install-dir with the JAVA_HOME directory of your system.
  2. export PATH=$JAVA_HOME/bin:$PATH

• Windows System

  1. Find My Computers from file directory, right click and select properties.
  2. Select the Advanced tab, select Environment variables.
  3. Edit JAVA_HOME to path of where JDK software is installed.

Build

The project in this package uses the Gradle build system. Gradle comes with excellent documentation that should be your first stop when trying to figure out how to operate or modify the build.

Building from the command line

1. ./gradlew build builds and tests project.
2. ./gradlew run launches a single node cluster with the asynchronous search plugin installed.
3. ./gradlew run -PnumNodes=3 launches a multi-node cluster with the asynchronous search plugin installed.
4. ./gradlew integTest launches a single node cluster with the asynchronous search plugin installed and runs all integ tests.
5. ./gradlew integTest -PnumNodes=3 launches a multi-node cluster with the asynchronous search plugin installed and runs all integ tests.
6. ./gradlew integTest -Dtests.class=*AsynchronousSearchRestIT runs a single integ class
7. ./gradlew integTest -Dtests.class=*AsynchronousSearchRestIT -Dtests.method="testSubmitWithRetainedResponse" runs a single integ test method (remember to quote the test method name if it contains spaces)

When launching a cluster using one of the above commands, logs are placed in build/testclusters/integTest-0/logs. Though the logs are teed to the console, in practices it's best to check the actual log file.

Debugging

Sometimes it is useful to attach a debugger to either the Elasticsearch cluster or the integ tests to see what's going on. When running unit tests, hit Debug from the IDE's gutter to debug the tests. For the Elasticsearch cluster or the integ tests, first, make sure start a debugger listening on port 5005.

To debug the server code, run:

./gradlew :integTest -Dcluster.debug # to start a cluster with debugger and run integ tests

OR

./gradlew run --debug-jvm # to just start a cluster that can be debugged

The Elasticsearch server JVM will connect to a debugger attached to localhost:5005.

The IDE needs to listen for the remote JVM. If using Intellij you must set your debug configuration to "Listen to remote JVM" and make sure "Auto Restart" is checked. You must start your debugger to listen for remote JVM before running the commands.

To debug code running in an integration test (which exercises the server from a separate JVM), first, setup a remote debugger listening on port 8000, and then run:

./gradlew :integTest -Dtest.debug

The test runner JVM will connect to a debugger attached to localhost:8000 before running the tests.

Additionally, it is possible to attach one debugger to the cluster JVM and another debugger to the test runner. First, make sure one debugger is listening on port 5005 and the other is listening on port 8000. Then, run:

./gradlew :integTest -Dtest.debug -Dcluster.debug

Security

See CONTRIBUTING for more information.

License

This project is licensed under the Apache-2.0 License.